Addex Therapeutics Ltd.

Exhibit 99.1

ADDEX THERAPEUTICS LTD

INDEX TO UNAUDITED INTERIM CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

Unaudited Interim Condensed Consolidated Financial Statements
Unaudited Interim Condensed Consolidated Balance Sheets as of June 30, 2026 and December 31, 2025	2
Unaudited Interim Condensed Consolidated Statements of Comprehensive Loss for the three-month and six-month periods ended June 30, 2026 and 2025	3
Unaudited Interim Condensed Consolidated Statements of Changes in Equity for the six-month periods ended June 30, 2026 and 2025	4
Unaudited Interim Condensed Consolidated Statements of Changes in Equity for the three-month periods ended June 30, 2025	5
Unaudited Interim Condensed Consolidated Statements of Changes in Equity for the three-month periods ended June 30, 2026	6
Unaudited Interim Condensed Consolidated Statements of Cash Flows for the six-month periods ended June 30, 2026 and 2025	7
Unaudited Notes to the Interim Condensed Consolidated Financial Statements for the six-month period ended June 30, 2026	8

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Balance Sheets

as of June 30, 2026, and December 31, 2025


		June 30,	December 31,
	Notes	2026	2025

		Amounts in Swiss francs
ASSETS

Current assets
Cash and cash equivalents	6	767,328	1,638,612
Other financial assets	7/13	3,984	5,130
Trade and other receivables	7	29,746	20,087
Prepayments	7	237,449	16,295
Total current assets		1,038,507	1,680,124

Non-current assets
Right-of-use assets	8	75,721	33,530
Intangible assets	10	—	—
Equipment	9	495	707
Non-current financial assets	11	54,543	7,086
Investment accounted for using the equity method	22	1,517,007	3,847,796
Financial assets at fair value through Other Comprehensive Income	23	285,962	285,962
Derivative financial instruments	24	509,067	509,067
Total non-current assets		2,442,795	4,684,148

Total assets		3,481,302	6,364,272

LIABILITIES AND EQUITY

Current liabilities
Current lease liabilities		54,472	7,680
Payables and accruals	12	1,262,941	1,191,284
Other current liabilities	12	47,461	—
Total current liabilities		1,364,874	1,198,964

Non-current liabilities
Non-current lease liabilities		23,023	27,008
Retirement benefits obligations	15	184,847	371,608
Total non-current liabilities		207,870	398,616

Equity
Share capital	13	2,186,545	2,186,545
Share premium	13	267,620,796	267,308,174
Other equity	13	64,620,223	64,620,223
Treasury shares reserve	13	(921,768)	(1,014,980)
Other reserves		31,949,881	31,757,431
Accumulated deficit		(363,547,119)	(360,090,701)
Total equity		1,908,558	4,766,692

Total liabilities and equity		3,481,302	6,364,272

The accompanying notes form an integral part of these consolidated financial statements.

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Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Statements of Comprehensive Loss

for the three-month and six-month periods ended June 30, 2026 and 2025


		For the three months ended		For the six months ended
		June 30,		June 30,
	Notes	2026	2025	2026	2025

		Amounts in Swiss Francs
Revenue from contract with customer	16	—	—	—	—
Other income	17	9,948	36,375	17,639	107,430

Operating costs
Research and development		(37,986)	(234,454)	(74,115)	(390,520)
General and administration		(617,314)	(534,819)	(1,068,703)	(1,056,070)
Total operating costs	18	(655,300)	(769,273)	(1,142,818)	(1,446,590)

Operating loss		(645,352)	(732,898)	(1,125,179)	(1,339,160)

Finance income		3,382	—	1,681	—
Finance expense		(1,175)	5,831	(2,131)	(13,319)
Finance result	20	2,207	5,831	(450)	(13,319)

Share of net loss of investments accounted for using the equity method	22	(1,101,534)	(1,231,845)	(2,330,789)	(2,079,296)
Net loss before tax from continuing operations		(1,744,679)	(1,958,912)	(3,456,418)	(3,431,775)

Income tax expense		—	—	—	—
Net loss from continuing operations		(1,744,679)	(1,958,912)	(3,456,418)	(3,431,775)

Net profit from discontinued operations (attributable to equity holders of the Group)	21	—	117,747	—	117,747
Net loss for the period		(1,744,679)	(1,841,165)	(3,456,418)	(3,314,028)

Basic and diluted loss per share for loss attributable to the ordinary equity holders of the Company	25	(0.01)	(0.02)	(0.03)	(0.03)
From continuing operations		(0.01)	(0.02)	(0.03)	(0.03)
From discontinued operations		—	—	—	—

Other comprehensive income / (loss)
Items that will never be reclassified to profit or loss :
Remeasurements of retirement benefits obligation related to continuing operations		36,918	(11,585)	178,060	54,307
Items that may be classified subsequently to profit or loss:
Exchange difference on translation of foreign operations		312	(1,218)	358	(1,088)
Other comprehensive income / (loss) for the period, net of tax		37,230	(12,803)	178,418	53,219

Total comprehensive loss for the period		(1,707,449)	(1,853,968)	(3,278,000)	(3,260,809)
From continuing operations		(1,707,449)	(1,971,715)	(3,278,000)	(3,378,556)
From discontinued operations		—	117,747	—	117,747

The accompanying notes form an integral part of these consolidated financial statements.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Statements of Changes in Equity

for the six-month periods ended June 30, 2026 and 2025


												Foreign
										Treasury		Currency
				Share		Share		Other		Shares		Translation		Other		Accumulated
		Notes		Capital		Premium		Equity		Reserve		Reserve		Reserves		Deficit		Total

				Amounts in Swiss francs
Balance as of January 1, 2025				1,843,545		266,382,670		64,620,223		(869,708)		(658,885)		31,721,881		(353,362,455)		9,677,271
Net loss for the period				—		—		—		—		—		—		(3,314,028)		(3,314,028)
Other comprehensive (loss) / Income for the period				—		—		—		—		(1,088)		54,307		—		53,219
Total comprehensive loss for the period				—		—		—		—		(1,088)		54,307		(3,314,028)		(3,260,809)
Value of share-based services		14		—		—		—		—		—		44,098		—		44,098
Movement in treasury shares:		13
Sale of Treasury shares				—		648,558		—		128,988		—		—		—		777,546
Value of Warrants granted				—		(65,609)		—		—		—		65,609		—		—
Costs related to the sale of treasury shares.				—		(25,897)		—		—		—		—		—		(25,897)
Net sale under liquidity agreement				—		(1,714)		—		2,231		—		—		—		517
Balance as of June 30, 2025				1,843,545		266,938,008		64,620,223		(738,489)		(659,973)		31,885,895		(356,676,483)		7,212,726


												Foreign
										Treasury		Currency
				Share		Share		Other		Shares		Translation		Other		Accumulated
		Notes		Capital		Premium		Equity		Reserve		Reserve		Reserves		Deficit		Total

				Amounts in Swiss francs
Balance as of January 1, 2026				2,186,545		267,308,174		64,620,223		(1,014,980)		(659,399)		32,416,830		(360,090,701)		4,766,692
Net loss for the period				—		—		—		—		—		—		(3,456,418)		(3,456,418)
Other comprehensive Income for the period.				—		—		—		—		358		178,060		—		178,418
Total comprehensive loss for the period				—		—		—		—		358		178,060		(3,456,418)		(3,278,000)
Value of share-based services		14		—		—		—		—		—		14,032		—		14,032
Movement in treasury shares:		13
Sale of treasury ADSs and shares				—		331,698		—		95,122		—		—		—		426,820
Costs related to the sale of treasury ADSs and shares				—		(19,729)		—		—		—		—		—		(19,729)
Net purchase under liquidity agreement				—		653		—		(1,910)		—		—		—		(1,257)
Balance as of June 30, 2026				2,186,545		267,620,796		64,620,223		(921,768)		(659,041)		32,608,922		(363,547,119)		1,908,558

The accompanying notes form an integral part of these consolidated financial statements.

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Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Statements of Changes in Equity

for the three-month period ended June 30, 2025


												Foreign
										Treasury		Currency
				Share		Share		Other		Shares		Translation		Other		Accumulated
		Notes		Capital		Premium		Equity		Reserve		Reserve		Reserves		Deficit		Total

				Amounts in Swiss francs
Balance as of January 1, 2025				1,843,545		266,382,670		64,620,223		(869,708)		(658,885)		31,721,881		(353,362,455)		9,677,271
Net loss for the period				—		—		—		—		—		—		(1,472,863)		(1,472,863)
Other comprehensive Income for the period.				—		—		—		—		130		65,892		—		66,022
Total comprehensive loss for the period				—		—		—		—		130		65,892		(1,472,863)		(1,406,841)
Value of share-based services		14		—		—		—		—		—		24,917		—		24,917
Net sale under liquidity agreement		13		—		(75)		—		406		—		—		—		331
Balance as of March 31, 2025				1,843,545		266,382,595		64,620,223		(869,302)		(658,755)		31,812,690		(354,835,318)		8,295,678
Net loss for the period				—		—		—		—		—		—		(1,841,165)		(1,841,165)
Other comprehensive loss for the period				—		—		—		—		(1,218)		(11,585)		—		(12,803)
Total comprehensive profit for the period				—		—		—		—		(1,218)		(11,585)		(1,841,165)		(1,853,968)
Value of share-based services				—		—		—		—		—		19,181		—		19,181
Movement in treasury shares:		13
Sale of treasury shares				—		648,558		—		128,988		—		—		—		777,546
Value of Warrants granted				—		(65,609)		—		—		—		65,609		—		—
Costs related to the sale of treasury shares.				—		(25,897)		—		—		—		—		—		(25,897)
Net sale under liquidity agreement				—		(1,639)		—		1,825		—		—		—		186
Balance as of June 30, 2025				1,843,545		266,938,008		64,620,223		(738,489)		(659,973)		31,885,895		(356,676,483)		7,212,726

The accompanying notes form an integral part of these consolidated financial statements.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Statements of Changes in Equity

for the three-month period ended June 30, 2026


												Foreign
										Treasury		Currency
				Share		Share		Other		Shares		Translation		Other		Accumulated
		Notes		Capital		Premium		Equity		Reserve		Reserve		Reserves		Deficit		Total

				Amounts in Swiss francs
Balance as of January 1, 2026				2,186,545		267,308,174		64,620,223		(1,014,980)		(659,399)		32,416,830		(360,090,701)		4,766,692
Net loss for the period				—		—		—		—		—		—		(1,711,739)		(1,711,739)
Other comprehensive Income for the period.				—		—		—		—		46		141,142		—		141,188
Total comprehensive loss for the period				—		—		—		—		46		141,142		(1,711,739)		(1,570,551)
Value of share-based services		14		—		—		—		—		—		22,907		—		22,907
Sale of treasury ADSs/shares		13		—		59,058		—		14,452		—		—		—		73,510
Cost related to the sale of treasury ADSs and shares				—		(3,181)		—		—		—		—		—		(3,181)
Net purchase under liquidity agreement				—		(925)		—		(1,790)		—		—		—		(2,715)
Balance as of March 31, 2026				2,186,545		267,363,126		64,620,223		(1,002,318)		(659,353)		32,580,879		(361,802,440)		3,286,662
Net loss for the period				—		—		—		—		—		—		(1,744,679)		(1,744,679)
Other comprehensive income for the period				—		—		—		—		312		36,918		—		37,230
Total comprehensive loss for the period				—		—		—		—		312		36,918		(1,744,679)		(1,707,449)
Value of share-based services				—		—		—		—		—		(8,875)		—		(8,875)
Sale of treasury ADSs and shares		13		—		272,640		—		80,670		—		—		—		353,310
Cost related to the sale of treasury ADSs and shares				—		(16,548)		—		—		—		—		—		(16,548)
Net purchase under liquidity agreement				—		1,578		—		(120)		—		—		—		1,458
Balance as of June 30, 2026				2,186,545		267,620,796		64,620,223		(921,768)		(659,041)		32,608,922		(363,547,119)		1,908,558

The accompanying notes form an integral part of these consolidated financial statements.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed Consolidated Financial Statements

Unaudited Interim Condensed Consolidated Statements of Cash Flows

for the six-month periods ended June 30, 2026 and 2025


		For the six months ended
		June 30,
	Notes	2026	2025

		Amounts in Swiss francs
Net loss for the period		(3,456,418)	(3,314,028)
Adjustments for:
Net gain on Neurosterix Transaction	21	—	(117,747)
Fair value of services received at zero cost recorded as income	10/17	(17,639)	(105,660)
Fair value of services received at zero cost recorded as other operating costs	10/18	17,639	105,660
Value of share-based services	14	14,032	44,098
Post-employment benefits	15	(8,701)	2,003
Share of the net loss of associates	22	2,330,789	2,079,296
Depreciation	8/9	35,046	4,236
Finance cost net		(5,555)	33,399
Decrease / (increase) in other financial assets	7	1,146	(498)
Decrease / (increase) in trade and other receivables	7	4,682	(22,926)
Increase in prepayments	7	(221,154)	(81,430)
Decrease in other current assets		—	7,967
Increase in payables and accruals	12	24,570	347,082
Increase in other liabilities	12	47,461	—
Net cash used in operating activities		(1,234,102)	(1,018,548)

Cash flows used in investing activities
Consideration from Neurosterix Transaction	21	—	57,673
Investment in Stalicla Ltd - preferred shares	23	—	(285,962)
Investment in Stalicla Ltd – derivative financial instruments	24	—	(509,067)
Net cash used in investing activities		—	(737,356)

Cash flows from financing activities
Sale of treasury ADSs and shares	13	411,588	777,546
Cost paid on sale of treasury ADSs and shares	13	(18,860)	(25,897)
Movements under liquidity agreement	13	(1,257)	517
Principal element of lease payment		(34,208)	(3,607)
Interest paid	20	(2,131)	(1,374)
Net cash from financing activities		355,132	747,185

Decrease in cash and cash equivalents		(878,970)	(1,008,719)

Cash and cash equivalents at the beginning of the period	6	1,638,612	3,341,738
Exchange difference on cash and cash equivalents		7,686	(32,025)

Cash and cash equivalents at the end of the period	6	767,328	2,300,994

During the six-month periods ended June 30, 2025 and 2026 the non-cash item transactions reported by the Group primarily related to the share of net loss of associates amounting to CHF 2.1 million and CHF 2.3 million, respectively.

The accompanying notes form an integral part of these consolidated financial statements.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

Unaudited Notes to the Interim Condensed Consolidated Financial Statements

for the six-month period ended June 30, 2026

(Amounts in Swiss francs)

1. General information

Addex Therapeutics Ltd (the “Company”) and its subsidiaries (together, the “Group”) are a clinical stage biopharmaceutical company focused on developing a portfolio of novel small molecule allosteric modulators for neurological disorders.

The Company is a Swiss stockholding corporation domiciled c/o Addex Pharma SA, Chemin des Aulx 12, CH 1228 Plan-les-Ouates, Geneva, Switzerland and the parent company of Addex Pharma SA, Addex Pharmaceuticals France SAS and Addex Pharmaceuticals Inc. Addex Therapeutics also owns a 20% equity interest in Neurosterix US Holdings LLC, USA. Neurosterix US Holdings LLC fully owns directly Neurosterix Swiss Holdings AG, Switzerland and indirectly Neurosterix Pharma Sàrl whose principal place of business is Chemin des Mines 9, CH 1202 Geneva, Switzerland.

The Group’s principal place of business is Chemin des Mines 9, CH 1202 Geneva, Switzerland. Its registered shares are traded at the SIX Swiss Exchange, under the ticker symbol ADXN and its American Depositary Shares (ADSs) on the Nasdaq Stock Market under the symbol “ADXN”. ADSs represents shares that continue to be admitted to trading on SIX Swiss Exchange.

These interim condensed consolidated financial statements have been approved for issuance by the Board of Directors on September 25, 2026.

2. Basis of preparation

These interim condensed consolidated financial statements for the six-month period ended June 30, 2026, have been prepared under the historic cost convention and in accordance with IAS 34 “Interim Financial Reporting” and are presented in a format consistent with the consolidated financial statements under IAS 1 “Presentation of Financial Statements”. However, they do not include all the notes that would be required in a complete set of financial statements. Thus, this interim financial report should be read in conjunction with the consolidated financial statements for the year ended December 31, 2025.

Interim financial results are not necessarily indicative of results anticipated for the full year. The preparation of these unaudited interim condensed consolidated financial statements made in accordance with IAS 34 requires the use of estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although these estimates are based on management’s best knowledge of current events and actions, actual results ultimately may differ from those estimates. The areas involving a higher degree of judgment which are significant to the interim condensed consolidated financial statements are disclosed in note 4 to the consolidated financial statements for the year ended December 31, 2025.

A number of new or amended standards and interpretations became applicable for financial reporting periods beginning on or after January 1, 2026. The Group noted that IFRS 18 -Presentation and Disclosure in Financial Statements-, will replace IAS 1 - Presentation of Financial Statements - from January 1, 2027. The Group concluded that no material impact is expected on its consolidated financial statements. Based on the initial assessment, the Group also expects that no Management defined Performance Measures or MPM’s will be required to be reported.

Due to rounding, numbers presented throughout these interim condensed consolidated financial statements may not add up precisely to the totals provided. All ratios and variances are calculated using the underlying amounts rather than the presented rounded amounts.

Where necessary, comparative figures have been revised to conform with the current presentation.

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Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

3. Material accounting estimates and judgments

The Group makes estimates and assumptions concerning the future. These estimates and judgments are continually evaluated and are based on historical experience and other factors, including expectations of future events that are believed to be reasonable under the circumstances.

The resulting accounting estimates will, by definition, seldom equal the related actual results. The estimates and assumptions that have a significant risk of causing a material adjustment to the carrying amounts of assets and liabilities or may have had a significant impact on the reported results are disclosed below:

Going concern

The Group’s accounts are prepared on a going concern basis. Since inception, the Group has financed its cash requirements primarily from share issuances, licensing certain of its research and development stage products and selling its allosteric modulator drug discovery technology platform with a portfolio of preclinical programs. The Group is a development-stage enterprise and is exposed to all the risks inherent in establishing a business. The Group expects that its existing cash and cash equivalents at the issuance date of these unaudited interim condensed consolidated financial statements will be sufficient to fund its operations and meet all of its obligations as they fall due through the fourth quarter of 2027. These factors individually and collectively indicate that a material uncertainty exists that raises substantial doubt about the Group’s ability to continue as a going concern for one year from the issuance date of these unaudited interim condensed consolidated financial statements. The future viability of the Group is dependent on its ability to raise additional capital through public or private financing or collaboration agreements to finance its future operations, which may be delayed due to reasons outside of the Group’s control including health pandemics and geopolitical risks. The sale of additional equity may dilute existing shareholders. The inability to obtain funding, as and when needed, would have a negative impact on the Group’s financial condition and ability to pursue its business strategies. If the Group is unable to obtain the required funding to run its operations and to develop and commercialize its product candidates, the Group could be forced to delay, reduce or stop some or all of its research and development programs to ensure it remains solvent. Management continues to explore options to obtain additional funding, including through collaborations with third parties related to the future potential development and/or commercialization of its product candidates, as well as through the monetization of the Group’s intellectual property portfolio or financial assets. However, there is no assurance that the Group will be successful in raising funds, closing collaboration agreements, obtaining sufficient funding on terms acceptable to the Group, or if at all, which could have a material adverse effect on the Group’s business, results of operations and financial condition.

The Business of the Group could be adversely affected by geopolitical risks

The business of the Group could be adversely affected by geopolitical risks in regions where the Group or partners have concentrations of business operations and could cause significant disruption in the operations of third-party manufacturers and CROs upon whom the Group or partners rely. Geopolitical risks such as Russia-Ukraine war or Middle East conflict may create global security concerns including the possibility of an expanded regional or global conflict and potential ramifications such as disruption of the supply chain including research and development activities being conducted by the Group and its strategic partners. Delays in research and development activities of the Group and its partners could increase associated costs and, depending upon the duration of any delays, require the Group and its partners to find alternative suppliers at additional expense. In addition, Russia-Ukraine war and Middle East conflict have had significant ramifications on global financial markets, which may adversely impact the ability of the Group to raise capital on favorable terms or at all.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

Discontinued operations related to the Neurosterix Transaction

On April 2, 2024, the Group sold a part of its business constituting its allosteric modulator drug discovery technology platform and a portfolio of preclinical programs (note 21). As a consequence, the Group recognized discontinued operations in the statements of profit or loss under “net profit or loss from discontinued operations” and identified cash flow from discontinued operations in accordance with IFRS 5. The Group has not identified any discontinued transactions for the six-month period ended June 30, 2026. The identification of discontinued operations may require some degree of judgement.

Fair value measurement of financial instruments

The Group measures its financial instruments at fair value at each reporting date. Fair value is the price that would be received to sell its financial asset in an orderly transaction between market participants at the measurement date, in the principal or most advantageous market, under current market conditions. Fair value measurements are categorized into three levels based on the degree to which inputs to the valuation techniques are observable:

●

Level 1: Quoted prices (unadjusted) in active markets for identical assets;

●

Level 2: Inputs other than quoted prices included within Level 1 that are all observable, either directly or indirectly used to measure the fair value;

●

Level 3: One or more of the significant inputs used to measure fair value is not based on observable market data. This is the case for unlisted equity securities or financial instruments where climate risk gives rise to a significant unobservable adjustment.

The Group uses appropriate valuation techniques in the circumstances and maximizes the use of relevant observable inputs. The transfers between levels are assessed at the end of each reporting period.

Investments accounted for using the equity method

The Group received an equity interest of 20% in Neurosterix US Holdings LLC as part of the Neurosterix Transaction. The initial recognition of the investment has been accounted at a fair value based on a financial valuation of Neurosterix’s Group. This carrying amount has been decreased to recognize the share of loss of Neurosterix’s Group.

Impairment of the investments accounted for using the equity method

The Group assesses its investment in Neurosterix US Holdings LLC, which is accounted for using the equity method whenever events, factors or changes in circumstances indicate that it may not be recoverable. An impairment loss is recognized for the amount by which the asset’s carrying amount exceeds its recoverable amount. The recoverable amount of the investment accounted for using the equity method is based on its fair value. No impairment loss was recognized in respect of the Group’s investment in Neurosterix US Holdings LLC for the three-month and six-month periods ended June 30, 2025 and 2026.

Financial assets at fair value through Other Comprehensive Income (OCI)

The financial assets at fair value through OCI relate to strategic investments made by the Group into early-stage R&D companies. The Group made the irrevocable election to classify these strategic investments, that are not held for trading, at fair value through OCI. The valuation at fair value is based on prices paid by investors during recent fundings (note 23). At each closing, the investments are tested by the Group to reflect any change in value due to events, factors or changes in circumstances.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

Derivative financial instruments

Derivative financial instruments relate to phantom shares and warrants received as part of the purchase of strategic investment. Derivative financial instruments are accounted at fair value through the statements of loss in accordance with IFRS 9, because they are considered as held for trading. The fair value is measured using the Black-Scholes and binomial valuation models (note 24). A number of assumptions related to the volatility of the underlying shares and to the risk-free rate are made in this model. Should the assumptions and estimates underlying the fair value of these instruments vary significantly from management’s estimates, then the fair value of the derivative financial instruments would be materially different from the amounts recognized. At each closing, the investments are tested by the Group to reflect any change in value due to events, factors or changes in circumstances.

Revenue recognition

Revenue is primarily from fees related to licenses, milestones and research services. Given the complexity of the relevant agreements, judgements are required to identify distinct performance obligations, allocate the transaction price to these performance obligations and determine when the performance obligations are met. In particular, the Group’s judgement over the estimated stand-alone selling price which is used to allocate the transaction price to the performance obligations is disclosed in note 16.

Accrued research and development costs

The Group records accrued expenses for estimated costs of research and development activities conducted by third party service providers. The Group records accrued expenses for estimated costs of research and development activities based upon the estimated amount of services provided, but not yet invoiced, and these costs are included in accrued expenses on the balance sheets and within research and development expenses in the statements of profit or loss. These costs are a significant component of research and development expenses. Accrued expenses for these costs are recorded based on the estimated amount of work completed in accordance with agreements established with these third parties. Due to the nature of estimates, the Group may be required to make changes to the estimates after a reporting period as it becomes aware of additional information about the status or conduct of its research activities.

Share-based compensation

The Group recognizes an expense for share-based compensation based on the valuation of equity incentive units using the Black-Scholes valuation model. A number of assumptions related to the volatility of the underlying shares and to the risk-free rate are made in this model. Should the assumptions and estimates underlying the fair value of these instruments vary significantly from management’s estimates, then the share-based compensation expense would be materially different from the amounts recognized.

Equity instruments

The Group records in equity the pre-funded warrants sold to investors and the warrants granted to investors at a fair value calculated using Black-Scholes model. A number of assumptions related to the volatility of the underlying shares and to the risk - free rate are made in this model. Should the assumptions and estimates underlying the fair value of these instruments vary significantly from management’s estimates, then the fair value of the equity instruments would be materially different from the amounts recorded in equity at the grant date.

Pension obligations

The present value of the pension obligations is calculated by an independent actuary and depends on a number of assumptions that are determined on an actuarial basis such as discount rates, future salary and pension increases, and mortality rates. Any changes in these assumptions will impact the carrying amount of pension obligations. The Group determines the appropriate discount rate at the end of each period. This is the interest rate that should be used to determine the present value of estimated future cash outflows expected to be required to settle the pension obligations. In determining the appropriate discount rate, the Group considers the interest rates of high-quality corporate bonds that are denominated in the currency in which the benefits will be paid, and that have terms to maturity approximating the terms of the related pension liability. Other key assumptions for pension obligations are based in part on current market conditions. Additional information is disclosed in note 15.

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4. Interim measurement note

Seasonality of the business: The business is not subject to any seasonality, but expenses and corresponding revenue are largely determined by the phase of the respective projects, particularly with regard to external research and development expenditures.

Costs: Costs that incur unevenly during the financial year are anticipated or deferred in the interim report only if it would also be appropriate to anticipate or defer such costs at the end of the financial year.

5. Segment reporting

Management has identified one single operating segment, related to the discovery, development and commercialization of small-molecule pharmaceutical products.

Information about products, services and major customers

External income of the Group is derived from the business of discovery, development and commercialization of pharmaceutical products. Income primarily relates to research services provided to a pharmaceutical company and the fair value of services received from Neurosterix’s Group at zero cost.

Information about geographical areas

External income is exclusively recorded in the Swiss operating company.

Analysis of revenue from contract with customer and other income by nature is detailed as follows:


		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Fair value of services received at zero cost from Neurosterix Group		9,948		34,505		17,639		105,560
Other service income		—		1,870		—		1,870
Total		9,948		36,375		17,639		107,430

Analysis of other income by major counterparties is detailed as follows:


		For the three months			For the six months
		ended June 30,			ended June 30,
		2026		2025	2026		2025
Neurosterix Group		9,948		34,505	17,639		105,560
Other counterparties		—		1,870	—		1,870
Total		9,948		36,375	17,639		107,430

For more detail, refer to note 17 “Other income”.

The geographical allocation of long-lived assets is detailed as follows:


		June 30,		December 31,
		2026		2025
Switzerland		2,442,463		4,683,813
France		332		335
Total		2,442,795		4,684,148

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The geographical analysis of operating costs is as follows:


		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Switzerland		650,988		765,310		1,135,332		1,439,158
United States of America		3,206		2,840		5,199		5,155
France		1,106		1,123		2,287		2,277
Total operating costs (note 18)		655,300		769,273		1,142,818		1,446,590

The capital expenditure during the three-month and six-month periods ended June 30, 2025 and 2026 is nil.

6. Cash and cash equivalents


		June 30,		December 31,
		2026		2025
Cash at bank and on hand		767,328		1,638,612
Total cash and cash equivalents		767,328		1,638,612

Split by currency:


		June 30,		December 31,
		2026		2025
CHF		23.05	%	88.80	%
USD		65.09	%	4.09	%
EUR		8.75	%	4.45	%
GBP		3.10	%	2.67	%
Total		100.00	%	100.00	%

The Group invests its cash balances into a variety of current accounts mainly with two Swiss banks whose external credit rating is P-1/A-1.

All cash and cash equivalents were held either at banks or on hand as of June 30, 2026 and December 31, 2025.

7. Other current assets


		June 30,		December 31,
		2026		2025
Other financial assets		3,984		5,130
Trade and other receivables		29,746		20,087
Prepayments		237,449		16,295
Total other current assets		271,179		41,512

Total other current assets increased by CHF 0.2 million as of June 30, 2026 compared to December 31, 2025, primarily due to increased prepayments driven by the retirement benefit contributions and D&O insurance paid annually at the beginning of the year. The Group applies the IFRS 9 simplified approach to measuring expected credit losses (“ECL”), which uses a lifetime expected loss allowance for all trade receivables and other receivables. The Group has considered that the trade receivables and other receivables have a low risk of default based on historic loss rates and forward-looking information on macroeconomic factors affecting the ability of the third parties to settle invoices. As a result, expected loss allowance has been deemed as nil as of June 30, 2026 and December 31, 2025.

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8. Right-of-use assets


Year ended December 31, 2025		Properties
Opening net book amount		41,578
Depreciation charge		(8,048)
Closing net book amount		33,530

As of December 31, 2025		Properties
Cost		111,642
Accumulated depreciation		(78,112)
Net book value		33,530


Period ended June 30, 2026		Properties
Opening net book amount		33,530
Additions		77,024
Depreciation charge		(34,833)
Closing net book amount		75,721

As of June 30, 2026		Properties
Cost		188,666
Accumulated depreciation		(112,945)
Net book value		75,721

9. Equipment


Year ended December 31, 2025		Equipment
Opening net book amount		1,131
Depreciation charge		(424)
Closing net book amount		707

As of December 31, 2025		Equipment
Cost		84,775
Accumulated depreciation		(84,068)
Net book value		707

Period ended June 30, 2026		Equipment
Opening net book amount		707
Depreciation charge		(212)
Closing net book amount		495

As of June 30, 2026		Equipment
Cost		84,775
Accumulated depreciation		(84,280)
Net book value		495

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10. Intangible assets


		Service
As of December 31, 2025 and June 30, 2026		agreement
Cost		182,348
Accumulated depreciation		(182,348)
Net book value		—

The service agreement relates to staff and infrastructure provided by Neurosterix Pharma Sàrl at zero cost in accordance with the Neurosterix Transaction and initially valued at CHF 182,348 (note 21). The depreciation charge was recognized at the rate at which these services were provided during the closing period ended December 31, 2024. As of January 1, 2025, the agreement was not formally renewed. However, Neurosterix agreed to provide the Group with access to certain employees and infrastructure at zero cost. The fair value of the services received at zero cost recognized as other income and other operating expenses for the three-month and six-month periods ended June 30, 2026, amounted to CHF 9,948 and 17,639 respectively (CHF 34,505 and CHF 105,560, respectively for the three-month and six-month periods ended June 30, 2025).

11. Non-current financial assets


		June 30,		December 31,
		2026		2025
Security rental deposits		54,543		7,086
Total non-current financial assets		54,543		7,086

Security rental deposits relate to office space. The applicable interest rate to such deposits is immaterial, and therefore, the value approximates amortized cost.

12. Payables, accruals and other current liabilities


		June 30,		December 31,
		2026		2025
Trade payables		776,028		602,901
Social security and other taxes		—		43,792
Accrued expenses		486,913		544,591
Other current liabilities		47,461		—
Total		1,310,402		1,191,284

All payables mature within 3 months. Accrued expenses and trade payables primarily relate to R&D services from contract research organizations, consultants and professional fees. The total amount of payables, accruals and other current liabilities increased by CHF 0.1 million as of June 30, 2026 compared to December 31, 2025, primarily due to increased trade payables. The carrying amounts of payables do not materially differ from their fair values, due to their short-term nature.

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13. Share capital


		Number of shares
		Common shares	Treasury shares	Total
Balance as of January 1, 2025		184,354,496	(56,061,527)	128,292,969
Sale of treasury shares		—	12,898,903	12,898,903
Movement of shares under liquidity agreement		—	6,268	6,268
Acquisition of shares forfeited from DSPPP		—	(5,848)	(5,848)
Balance as of June 30, 2025		184,354,496	(43,162,204)	141,192,292
Shares reclassed as treasury shares under IFRS 2		—	(29,944,420)	(29,944,420)
Balance as of June 30, 2025 IFRS 2		184,354,496	(73,106,624)	111,247,872


		Number of shares
		Common		Treasury
		shares		shares		Total
Balance as of January 1, 2026		218,654,496		(70,822,682)		147,831,814
Sale of treasury ADS’s and shares		—		9,512,234		9,512,234
Movement of shares under liquidity agreement		—		(28,524)		(28,524)
Balance as of June 30, 2026		218,654,496		(61,338,972)		157,315,524
Shares reclassed as treasury shares under IFRS 2		—		(29,904,690)		(29,904,690)
Balance as of June 30, 2026 IFRS 2		218,654,496		(91,243,662)		127,410,834

As of June 30, 2026, 157,315,524 shares were outstanding excluding 61,338,972 treasury shares directly held by Addex Pharma SA and including 29,904,690 outstanding shares benefiting from our DSPPP, considered as treasury shares under IFRS 2 (note 14). Of the treasury shares, 21,133,320 were held on the form of ADSs as of June 30, 2026.

As of June 30, 2025, 141,192,292 shares were outstanding excluding 43,162,204 treasury shares directly held by Addex Pharma SA and including 29,944,420 outstanding shares benefiting from our DSPPP, considered as treasury shares under IFRS 2 (note 14).

The Group maintains a liquidity agreement with Kepler Cheuvreux (“Kepler”). Under the agreement, the Group has provided Kepler with cash and shares to enable them to buy and sell the Company’s shares. As of June 30, 2026, 173,475 (December 31, 2025: 144,951) treasury shares are recorded under this agreement in the treasury share reserve and CHF 3,984 (December 31, 2025: CHF 5,130) is recorded in other financial assets.

During the six-month period ended June 30, 2026, the Group sold 9,512,234 treasury shares at an average price of CHF 0.045 per share for total gross proceeds of CHF 426,820 (during the six-month period ended June 30, 2025, the Group sold 12,898,903 treasury shares at an average price of CHF 0.06 per share for total gross proceeds of CHF 777,546). Of these treasury shares 8,866,680 were sold under the form of ADSs through the At The Market Agreement with H.C. Wainwright at an average price of USD 6.75 per ADS (equivalent to CHF 0.045 per share) for gross proceeds of USD 498,536 (CHF 394,148). The remaining 645,554 treasury shares have been sold under the sale agency agreement with Kepler Cheuvreux at an average price of CHF 0.051 per share for gross proceeds of CHF 32,672.

14. Share-based compensation

The total share-based compensation expense related to equity incentive units recognized in the statements of loss amounted to CHF 44,098 and CHF 14,032 for the six-month periods ended June 30, 2025 and 2026, respectively.

As of December 31, 2025 and June 30, 2026, 7,956,764 options and 29,904,690 shares benefiting from our Deferred Strike Price Payment Plan (DSPPP) were outstanding. All the shares benefiting from our DSPPP have been recorded as treasury shares in accordance with IFRS 2 (note 13).

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Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

15. Retirement benefits obligations

The amounts recognized in the statements of profit or loss are as follows:


	For the three months		For the six months
	ended June 30,		ended June 30,
	2026	2025	2026	2025
Current service cost	(17,268)	(7,521)	(34,536)	(15,043)
Interest cost	(16,659)	(5,399)	(33,319)	(10,799)
Interest income	15,452	4,861	30,904	9,721
Company pension amount (note 19)	(18,475)	(8,059)	(36,951)	(16,121)

The Group’s pension costs recognized in the statement of loss for the three-month and the six-month period ended June 30, 2026, amounted to CHF 18,475 and CHF 36,951, respectively (CHF 8,059 and CHF 16,121 for the three-month and the six-month period ended June 30, 2025).

The amounts recognized in the balance sheet are determined as follows:


		June 30, 2026		December 31, 2025
Defined benefit obligation		(5,096,588)		(5,126,017)
Fair value of plan assets		4,911,741		4,754,409
Retirement benefit obligation		(184,847)		(371,608)

Retirement benefit obligation decreased by CHF 0.2 million as of June 30, 2026 compared to December 31, 2025, primarily due to an actuarial gain arising from experience adjustments recorded in Other Comprehensive Income.

16. Revenue from contract with customer

License & research agreement with Indivior PLC

On January 2, 2018, the Group entered into an agreement with Indivior for the discovery, development and commercialization of novel GABAB PAM compounds for the treatment of addiction and other CNS diseases. On August 27, 2024, Indivior selected a compound for future development in substance use disorder and the Group also exercised its right to select a compound to advance its own independent GABAB PAM program for the treatment of chronic cough. On May 12, 2025, Indivior successfully completed IND enabling studies with their selected compound. On September 25, 2026, Indivior terminated our license agreement, following their announced merger with Supernus, returning to us the program including all related intellectual property.

No amount has been recognized by the Group under this agreement for the three-month and six-month periods ended June 30, 2025, and 2026.

Janssen Pharmaceuticals Inc. (formerly Ortho-McNeil-Janssen Pharmaceuticals Inc)

On December 31, 2004, the Group entered into a research collaboration and license agreement with Janssen Pharmaceuticals Inc. (JPI). In accordance with this agreement, JPI has acquired an exclusive worldwide license to develop mGlu2 PAM compounds for the treatment of human health.

In 2024, Janssen completed a Phase 2a proof of concept clinical trial of ADX71149 in epilepsy patients that did not achieve statistical significance for the primary endpoint of time for patients to reach baseline seizure count when ADX71149 was added to standard of care and decided to terminate the development of ADX71149. On April 17, 2025, the Group announced that the license agreement had been terminated and the program and all related intellectual property has been returned to the Group.

No amounts have been recognized under this agreement for the three-month and six – month periods ended June 30, 2026 and 2025.

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17. Other income

During the three-month and the six-month periods ended June 30, 2026, the Group recognized CHF 9,948 and CHF 17,639, respectively (CHF 34,505 and CHF 105,560 for the three-month and six-month periods ended June 30, 2025) related to the fair value of services received from Neurosterix’s Group at zero cost (note 10).

18. Operating costs


		For the three months			For the six months
		ended June 30,			ended June 30,
		2026	2025		2026	2025
Staff costs (note 19)		221,601	44,496		441,014	145,538
Depreciation (notes 8/9)		25,226	2,118		35,046	4,236
External research and development cost		11,587	68,492		20,981	101,075
Patent maintenance and registration costs		15,540	53,865		29,580	97,119
Professional fees		237,532	320,253		355,873	622,635
D&O insurance		37,027	47,207		74,056	91,857
Fair value services received at zero costs		9,948	34,505		17,639	105,560
Other operating costs		96,839	198,337		168,629	278,570
Total operating costs		655,300	769,273		1,142,818	1,446,590

The evolution of the total operating costs is mainly driven by staff costs and professional fees.

During the six-month period ended June 30, 2026, total operating costs decreased by CHF 0.3 million compared to the same period ended June 30, 2025, primarily due to lower professional fees of CHF 0.3 million, reduced external research and development and patent costs of CHF 0.2 million, decreased services received at zero costs valued at CHF 0.1 million, partially offset by higher staff costs of CHF 0.3 million.

During the three-month period ended June 30, 2026, total operating costs decreased by CHF 0.1 million compared to the same period ended June 30, 2025, primarily due to lower professional fees of CHF 0.1 million, reduced external research and development and patent costs of CHF 0.1 million, partially offset by higher staff costs of CHF 0.2 million.

19. Staff costs


		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Wages and salaries		188,848		28,811		373,300		113,580
Social charges and insurances		13,743		5,775		29,452		11,550
Value of share-based services		535		1,851		1,311		4,287
Retirement benefit (note 15)		18,475		8,059		36,951		16,121
Total staff costs		221,601		44,496		441,014		145,538

During the three-month and six-month periods ended June 30, 2026, total staff costs increased by CHF 0.2 million and CHF 0.3 million, respectively, compared to the same period ended June 30, 2025, primarily due to an increase in the number of full-time employees.

20. Finance result, net


		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Interest cost		—		(331)		(209)		(362)
Interest expense on leases		(1,175)		(495)		(1,922)		(1,012)
Foreign exchange gains /(losses)		3,382		6,657		1,681		(11,945)
Finance result, net		2,207		5,831		(450)		(13,319)

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21. Discontinued operations

On February 8, 2024, the Group signed a non-binding term sheet with Perceptive Advisors related to the divestment of part of its business. On April 2, 2024, the sale became effective. The allosteric modulator drug discovery technology platform and a portfolio of preclinical programs have been divested to a new Swiss company, Neurosterix Pharma Sàrl that has received a funding of USD 65 million from a syndicate of investors led by Perceptive Advisors (Perceptive Xontogeny Venture Fund II L.P, Perceptive Life Sciences Master Fund Ltd and Acorn Bioventures 2, L.P) (the “Neurosterix Transaction” or “Transaction”). The Group received gross proceeds of CHF 5.0 million in cash and an equity interest representing 20% of Neurosterix US Holdings LLC (note 1). The Group retained its partnerships with Janssen Pharmaceuticals, Inc. and Indivior PLC, as well as unpartnered clinical stage assets including dipraglurant for Parkinson’s disease and post-stroke/TBI recovery and its preclinical GABAB PAM program for chronic cough. The Transaction includes the transfer of the associated R&D staff and infrastructure. As part of the Transaction, the Group and Neurosterix Pharma Sàrl entered into a service agreement which provides the Group with access to certain staff and infrastructure at zero cost to ensure the operation of the Group retained business until December 31, 2024. As of January 1, 2025, the agreement was not formally renewed. However, Neurosterix agreed to provide the Group with access to certain employees and infrastructure at zero cost (note 10). Since November 1, 2025, the CEO, Tim Dyer, has been directly remunerated by the Group. On February 28, 2026, Neurosterix relocated its offices, and since that date we assumed responsibility for the rent of our administrative offices. As of the issuance date of these unaudited interim condensed consolidated financial statements, the Group continues to have access to research and development staff at zero cost.

As the allosteric modulator drug discovery technology platform and a portfolio of preclinical programs have been sold on April 2, 2024. The net gain of the sale of activities amounted to CHF 13,943,595 for the year ended December 31, 2024 including CHF 5.0 million in cash and CHF 9.4 million for the equity interest of 20% in Neurosterix US Holdings LLC, partially offset by costs related to the activities sold. During the six-month period ended June 30, 2025, the Group recognized an additional gain from discontinued operations of CHF 117,747 from the sale of activities, related to consideration receivable considered as contingent during previous periods. During the six-month periods ended June 30, 2026, the Group did not record any discontinued operations that impacted the statement of comprehensive loss or cash flow.

22. Interests in associates

On April 2, 2024, the Group received an equity interest of 20% in Neurosterix US Holdings LLC domiciliated in the US and parent company of Neurosterix Pharma Sàrl as part of Neurosterix transaction (note 21). Neurosterix’s Group primarily operates in Switzerland and uses Swiss franc as functional currency and US Dollars as presentation currency. The carrying amount of the equity-accounted investment in Neurosterix’s Group has changed as follow :


		For the three months			For the six months
		ended June 30,			ended June 30,
		2026		2025	2026		2025
Beginning of the period		2,618,541		6,239,691	3,847,796		7,087,142
Share of the net loss for the period of Neurosterix’s Group		(1,101,534)		(1,231,845)	(2,330,789)		(2,079,296)
End of period		1,517,007		5,007,846	1,517,007		5,007,846

The 20% equity interest in Neurosterix US Holdings LLC received by the Group on April 2, 2024 was initially valued at CHF 9.43 million using a financial valuation of the Neurosterix’s Group. From April 2, 2024 to June 30, 2026, the carrying amount of the equity-accounted investment in Neurosterix’s Group decreased by CHF 7.9 million primarily due to the share of net loss in accordance with IAS 28. The loss recognized primarily reflects expenditures related to research and development and general and administrative activities, which are incurred in the ordinary course of Neurosterix operations. As of June 30, 2026, the equity-accounted investment in Neurosterix’s Group is not impaired.

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23. Financial assets at fair value through other comprehensive income

In June 2025, the Group invested CHF 795,029 in Stalicla SA and received 23,342 preferred shares with attached derivative financial instruments (note 24). The purchase price allocation was performed on the basis of the fair value of the derivative financial instruments, with the residual amount allocated to the preferred shares, initially recognized at CHF 285,962. The Group has made the irrevocable election to classify the 23,342 preferred shares received at fair value through other comprehensive income rather than through the statements of profit or loss, as the shares are held for strategic purposes and not for trading.

As of December 31, 2025, and June 30, 2026, the fair value of the unlisted securities of Stalicla SA (level 3) remained unchanged:


		June 30, 2026		December 31, 2025
Stalicla SA		285,962		285,962
Total		285,962		285,962

24. Derivative financial instruments

As part of its investment in Stalicla SA (note 23), the Group was granted several related financial instruments. These comprised an anti-dilution protection through a contingent ratchet mechanism, 23,342 phantom shares entitling the Group to proceeds equivalent to those distributable to 23,342 ordinary shares, 23,342 warrants with a ten-year exercise period at a strike price of CHF 34.05 to purchase 23,342 ordinary shares and 3,591 warrants with a five-year exercise period, a strike price of CHF 0.10 to purchase 3,591 preferred shares. These financial instruments are classified as derivatives and valued at fair value (level 3) using Black-Scholes and binomial valuation models. On initial recognition, their aggregate fair value amounted to CHF 509,067. The fair value of phantom shares was capped at the fair value of the preferred shares, as management concluded that the two values should be deemed equivalent. As a result, the amount of CHF 111,552 was not recorded as phantom shares.

As of June 30, 2026, the fair value (level 3) of these derivative financial instruments, driven by the value of Stalicla SA shares (note 23), remained unchanged:


	June 30, 2026		December 31, 2025
Phantom shares	285,962		285,962
Anti-dilution protection	102,547		102,547
Warrants	120,558		120,558
Total	509,067		509,067

The following table presents the Group’s financial assets measured and recorded at fair value at June 30, 2026, and December 31, 2025:


		Levels 1 and 2				Level 3
		June 30,		December 31,		June 30,		December 31,
		2026		2025		2026		2025
Financial assets at fair value through profit and loss (FVPL)
Phantom shares (Stalicla SA)		—		—		285,962		285,962
Anti-dilution protection (Stalicla SA)		—		—		102,547		102,547
Warrants (Stalicla SA)		—		—		120,558		120,558
Financial assets at fair value through other comprehensive income (OCI)
Preferred shares (Stalicla SA) (note 23)		—		—		285,962		285,962
Total financial assets		—		—		795,029		795,029

Certain inputs used to measure the fair value of the financial instruments related to the investment in Stalicla SA (note 23) were not based on observable market data and have been classified at a level 3 in the fair value hierarchy.

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The following table summarizes the quantitative information about the significant unobservable inputs used in level 3 fair value measurement and how a reasonable possible change in the input would affect the fair values:

Fair value at

Range of inputs

June 30,

December 31,

June 30,

December 31,

Relation of unobservable inputs to

Description

 

2026

 

2025

 

Unobservable inputs

 

2026

 

2025

 

fair value

Preferred shares (Stalicla SA)

285,962

(1)

CHF17-CHF30

(2)

Phantom shares (Stalicla SA)

285,962

Stalicla share price used in Black-Scholes valuation model, determined by the price paid by external investors. The fair value of phantom shares is capped at the fair value of preferred shares

CHF17

A 10% increase or decrease in Stalicla’s share price would increase or decrease the fair value by CHF 39,682 and CHF 36,138, respectively. In both cases the fair value would remain capped at the fair value of preferred shares.

Anti-dilution protection (Stalicla SA)

102,547

Sale price of Stalicla shares used in the different scenarios in binomial valuation model

CHF17-CHF30

CHF17 -CHF30

A 10% increase or decrease in the sale price of Stalicla shares under the scenario used in the binomial valuation model, would increase or decrease the fair value by CHF 25,064 and CHF 18,949, respectively.

Warrants (Stalicla SA)

60,547

Stalicla share price used in Black-Scholes valuation model, determined by the price paid by external investors

CHF17

A 10% increase or decrease in Stalicla’s share price would increase or decrease the fair value by CHF 15,673 and CHF 12,791, respectively.

Warrants (Stalicla SA)

60,011

Stalicla share price used in Black-Scholes valuation model, determined by the price paid by external investors

CHF17

A 10% increase or decrease in Stalicla’s share price would increase or decrease the fair value by CHF 6,091 and CHF 5,538, respectively.

(1)The fair value of the preferred shares was determined as the residual amount between the subscription price of CHF 795,029 and the fair value of the derivative financial instruments measured using Black-Scholes and binomial valuation models. The fair value of the phantom shares was capped at the fair value of the preferred shares.

(2)An increase or decrease of 10% in Stalicla’s share price used to calculate the fair value of the anti-dilution protection through a ratchet mechanism and warrants would result in a decrease or increase in fair value by CHF 21,697 and CHF 20,357, respectively.

25. Loss per share

Basic profit or loss per share is calculated by dividing the profit or loss attributable to equity holders of the Company by the weighted average number of shares in issue during the period excluding treasury shares. Diluted loss per share and diluted profit per share including a loss from continuing operations are calculated excluding our options and warrants as they would be antidilutive and our treasury shares.


		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Net loss from continuing operations		(1,744,679)		(1,958,912)		(3,456,418)		(3,431,775)
Net profit from discontinued operations		—		117,747		—		117,747
Net loss attributable to equity holders of the company		(1,744,679)		(1,841,165)		(3,456,418)		(3,314,028)
Weighted average number of shares in issue		122,592,940		100,523,234		120,977,878		99,440,314
Basic and diluted loss per share		(0.01)		(0.02)		(0.03)		(0.03)
From continuing operations		(0.01)		(0.02)		(0.03)		(0.03)
From discontinued operations		—		—		—		—

The Company has three categories of dilutive potential shares: treasury shares, share options and warrants which have been ignored in the calculation of the loss per share for the three-month and six-month periods ended June 30, 2026, and 2025.

Table of Contents

Addex Therapeutics │ Unaudited Interim Condensed consolidated Financial statements │ Notes

26. Related party transactions

Related parties include members of the Board of Directors and the Executive Management of the Group. The following transactions were carried out with related parties:

Key management compensation


Key management compensation		For the three months				For the six months
		ended June 30,				ended June 30,
		2026		2025		2026		2025
Salaries, other short-term employee benefits and post-employment benefits		216,591		99,864		438,143		197,156
Share‑based compensation		5,654		18,910		13,980		43,428
Total		222,245		118,774		452,123		240,584

Salaries, other short-term employee benefits and post-employment benefits relate to members of the Board of Directors and Executive Management who are employed by the Group. The total compensation costs for key management increased by CHF 0.1 million and CHF 0.2 million during the three-month and six-month periods ended June 30, 2026, respectively, compared to the same periods ended June 30, 2025, primarily because our CEO has been directly remunerated by the Group since November 2025 (note 21). As of June 30, 2025 and 2026, the Group had a net payable of CHF 0.1 million to the Board of Directors and Executive Management. Share-based compensation relates to the fair value of equity incentive units recognized through profit and loss following their vesting plan.

Transactions with Neurosterix’s Group

On April 2, 2024, Addex Group divested a part of its business to Neurosterix Pharma Sàrl (note 22). As part of the transaction, Addex Group received gross proceeds of CHF 5.0 million in cash, an equity interest of 20% of Neurosterix US Holdings LLC whose fair value amounted to CHF 9.42 million and concluded a service agreement allowing Key Members of Addex staff transferred to Neurosterix Pharma Sàrl, including the Chief Executive Officer to support the activities of the Addex Group at zero cost until December 31, 2024. As of January 1, 2025, the agreement was not formally renewed. However, Neurosterix agreed to provide the Group with access to certain employees and infrastructure at zero cost (note 10). The fair value of the service agreement amounted to CHF 9,948 and CHF 17,639, respectively for the three-month and six-month periods ended June 30, 2026 (CHF 34,505 and CHF 105,560 for the three-month and the six-month periods ended June 30, 2025). As of June 30, 2026, the Group owed CHF 47,461 to Neurosterix Pharma Sàrl.

27. Events after the balance sheet date

From July 1, 2026, to August 25, 2026, the Group sold 52,970,533 shares at an average price of CHF 0.043 (USD 0.053) for total gross proceeds of CHF 2.3 million (USD 2.8 million). Of these shares, 52,762,680 have been sold in a form of ADSs for total gross proceeds of USD 2.8 million (CHF 2.3 million) at an average price of USD 6.37 per ADS (equivalent to CHF 0.043 per share), through the At the Market (ATM) offering agreement with H.C Wainwright & CO. The number of outstanding shares amounts to 203,532,333 shares at the issuance date of these unaudited interim condensed consolidated financial statements excluding 8,437,843 treasury shares directly held by Addex Pharma SA and including 29,904,690 outstanding shares benefiting from our DSPPP considered as treasury shares under IFRS 2.

On September 2, 2026, the strike price of 29,904,690 shares acquired under our Deferred Strike Price Payment Plan (DSPPP) and the strike price of 6,971,992 options were reduced to CHF 0.026. This modification to the equity incentive plans increased the fair value by CHF 0.16 million, which will be recognized as share-based compensation expense in the third quarter of 2026.

On September 25, 2026, we announced that our partner, Indivior, terminated our license agreement, following their announced merger with Supernus Pharmaceuticals, returning to us the program including all related intellectual property