2026 Public Offering

On February 6, 2026, the Company entered into a placement agency agreement (the “Placement Agency Agreement”) with Brookline Capital Markets, a division of Arcadia Securities, LLC (“Brookline” or the “Placement Agent”), pursuant to which the Company engaged the Placement Agent for the 2026 Offering, which included the public offering of (i) 0.8 million shares of the Company’s common stock (or pre-funded warrants in lieu of common stock) and accompanying Milestone Warrants to purchase 0.8 million shares of common stock, at a combined offering price of $12.50 per share of common stock and accompanying Milestone Warrant (or $12.25 per pre-funded warrant and accompanying Milestone Warrant). In connection with the Public Offering, the Company also entered into a securities purchase agreement (each, a “Purchase Agreement”) with certain investors who purchased common stock and Milestone Warrants in the Public Offering.

The pre-funded warrants were immediately exercisable (subject to certain ownership limitations) had an exercise price of $0.25 per share and did not expire until exercised in full. On February 11, 2026 and February 18, 2026, the Company issued approximately 53,000 and 27,000 shares of common stock, respectively, in connection with the exercise of the pre-funded warrants, for a total exercise price of approximately $20,000. There are no remaining pre-funded warrants outstanding related to the Public Offering.

The Milestone Warrants are tradeable on The Nasdaq Capital Market under the symbol “ERNAW.” The Milestone Warrants are immediately exercisable (subject to certain ownership limitations), have an exercise price of $17.00 per share, and expire on the earlier of (i) the five-year anniversary of the original issuance date or (ii) the 180^th calendar day following the public release by the Company of clinical trial data from the first cohort of the Phase 1 study of ERNA-101.

Pursuant to the Placement Agency Agreement, the Company paid the Placement Agent an aggregate cash fee of approximately $0.5 million, which was equal to 6.5% of the aggregate purchase price paid by investors in the Offering (or 1.5% with respect to certain existing investors). The Company will also pay the Placement Agent a cash fee as compensation for gross proceeds the Company receives from any exercise of any Milestone Warrants sold in connection with the Public Offering, payable quarterly on each January 1, April 1, July 1 and October 1 following the closing of the Public Offering (or the following business day if such day is not a business day), at the same percentage and as calculated in the manner as set forth above. The Company also issued approximately 9,000 shares of Common Stock to the Placement Agent (the “Agent’s Shares”), which was equal to 1.5% of the aggregate number of Shares and pre-funded warrants sold in the Public Offering (or 0.5% with respect to sales to certain existing investors). In addition, the Company reimbursed the Placement Agent for its accountable offering-related legal expenses in an amount of $125,000.

The Public Offering closed on February 10, 2026, for aggregate gross proceeds of approximately $10.5 million before deducting Placement Agent fees and other offering expenses payable by the Company. The Company is using the net proceeds from the Public Offering to support the advancement of its development programs and for working capital and general corporate purposes.

The Placement Agency Agreement and the Purchase Agreements contain customary representations, warranties and agreements by the Company, customary conditions to closing, indemnification obligations of the Company, the Placement Agent, or the investors, as the case may be, and other obligations of the parties.

Pursuant to the terms of the Purchase Agreements and the Placement Agency Agreement, the Company has agreed that for a period of ninety (90) days from the closing of the Public Offering, that neither the Company nor any subsidiary may (i) issue, enter into any agreement to issue or announce the issuance or proposed issuance of any shares of common stock or common stock equivalents or (ii) file any registration statement or prospectus, or any amendment or supplement thereto, in each case, subject to certain exceptions, unless waived by the Placement Agent. The Company has also agreed not to effect or enter into an agreement to effect any issuance of common stock or common stock equivalents involving a Variable Rate Transaction, as defined in the Purchase Agreements, for a period of ninety (90) days following the closing of the Public Offering, subject to certain exceptions, unless waived by the Placement Agent. In addition, as part of the Purchase Agreement, subject to certain exceptions, the Company’s officers and directors entered into lock-up agreements, pursuant to which they agreed not to sell or otherwise dispose of any of the Common Stock for a period of ninety (90) days following the date of closing of the Public Offering.

Universal Shelf and ATM

On March 13, 2026, the Company filed the Universal Shelf to offer and sell up to $50.0 million of its common stock from time to time in one or more offerings, which became effective on March 30, 2026. The Universal Shelf includes a prospectus supplement providing for sales of up to $9.2 million of common stock pursuant to an ATM program under a sales agent agreement the Company entered into with Brookline.

The Company is subject to the “baby shelf” rules, which limits the aggregate market value of securities the Company may sell under the Universal Shelf to no more than one-third of its public float in any 12-month period while its public float remains below $75.0 million. As of the filing of the Universal Shelf, one-third of the Company’s public float was approximately $9.2 million, representing the maximum amount to be sold under the ATM. As of March 31, 2026, the Company has not sold any securities under the ATM.

2025 Private Placement

On March 31, 2025, the Company entered into a securities purchase agreement (the “2025 SPA”) with certain accredited investors to sell in a private placement an aggregate of approximately 185,000 shares of common stock at a purchase price of $39.23 per share, or pre-funded warrants in lieu of common stock at a purchase price of $37.35 per pre-funded warrant (the “2025 Private Placement”). The pre-funded warrants will be exercisable until exercised in full at a nominal exercise of $1.88 per share of the Company’s outstanding common stock, subject to certain ownership limitations.

The 2025 SPA represented a forward sale contract obligating the Company to sell a fixed number of shares of its common stock at a fixed price per share and contained an adjustment to the settlement amount based on shareholder approval, which is not an input into the pricing of a fixed-for-fixed forward on equity shares. The Company measured the fair value of the forward sale contract as the difference between (i) the fair value of the expected shares to be purchased by the investors as of the date the Company entered into the 2025 SPA and (ii) the discounted purchase price of the shares and recorded a liability of approximately $5.3 million at the contract inception date. The Company also recognized a corresponding $5.3 million charge to expense on the contract inception date because the fair value of the expected shares to be purchased by the investors exceeded the expected proceeds under the 2025 SPA. There were no shares sold and issued under the 2025 SPA during the three months ended March 31, 2025, and the 2025 Private Placement closed during the second quarter of 2025.

Warrants

As of March 31, 2026, the Company had the following warrants outstanding:

Schedule of Warrants Outstanding 

As of March 31, 2026, the weighted average remaining contractual life of expiring warrants outstanding was 4.86 years and the weighted average exercise price for the expiring warrants was $32.78.

The following table shows the warrant activity from January 1, 2026 through March 31, 2026:

Schedule of Warrants Activity

On February 11, 2026 and February 18, 2026, the Company issued approximately 53,000 and 27,000 shares of common stock, respectively, in connection with the exercise of the pre-funded warrants from the Public Offering, for a total exercise price of approximately $20,000. There are no remaining pre-funded warrants outstanding related to the Public Offering.

Stock Repurchase Program

In November 2024, the Company’s Board of Directors authorized a stock repurchase program (the “Repurchase Program”) of up to $1.0 million of the Company’s outstanding common stock. Under the Repurchase Program, the repurchases may be made by the Company from time to time through open-market purchases, privately negotiated transactions or other means in accordance with applicable securities laws. The timing and amount of repurchases will be determined by the Company, taking into consideration market conditions, stock price, and other factors. The Repurchase Program does not have a set expiration date and may be suspended, modified or discontinued at any time without prior notice. The Company did not repurchase any of its shares under the Repurchase Program during the three months ended March 31, 2026 and 2025.