Total compensation cost recognized for all stock‑based compensation awards in the condensed consolidated statements of operations and comprehensive loss was as follows:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2026		2025		2026		2025
	(in thousands)
Research and development	$	1,128	$	1,629	$	1,788	$	3,114
General and administrative		1,305		2,504		3,133		4,692
Total stock-based compensation expense	$	2,433	$	4,133	$	4,921	$	7,806

In October 2015, the Company’s board of directors (the “Board”) and stockholders approved the 2015 Employee Stock Purchase Plan (the “2015 ESPP”). Under the 2015 ESPP, all full-time employees of the Company are eligible to purchase common stock of the Company twice per year, at the end of each six-month payment period. During each payment period, eligible employees who so elect, may authorize payroll deductions in an amount of 1% to 10% (whole percentages only) of the employee’s base pay for each payroll period. At the end of each payment period, the accumulated deductions are used to purchase shares of common stock from the Company at a discount. A total of 262,362 shares of common stock were initially authorized for issuance under the 2015 ESPP.

On March 18, 2025, the Board adopted, and on June 3, 2025, the stockholders approved, the Amended and Restated 2015 Employee Stock Purchase Plan (together with the 2015 ESPP, the “ESPP”) to (i) eliminate the evergreen provision in the 2015 ESPP and (ii) expand the class of eligible employees by eliminating the requirement that participants must have completed six months of employment.

As of June 30, 2026, there were 1,736,020 shares available for future purchase under the ESPP.

On March 18, 2025, the Board adopted, and on June 3, 2025, the stockholders approved, the 2025 Stock Incentive Plan (the “2025 Plan”). Under the 2025 Plan, the Company may issue awards for up to a number of shares of common stock equal to the sum of: (i) 3,631,952 shares of common stock; and (ii) such additional number of shares of common stock (up to 14,190,976 shares) as is equal to the sum of (x) the number of shares of common stock reserved for issuance under the Company’s 2015 Stock Option and Incentive Plan (the “2015 Plan”) that remained available for grant thereunder immediately prior to the date that the 2025 Plan was approved by our stockholders and (y) the number of shares of common stock subject to awards granted under the 2015 Plan that were

outstanding as of the date that the 2025 Plan was approved by our stockholders and which awards expire, terminate or are otherwise surrendered, cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right (subject, however, in the case of incentive stock options, to any limitations under the Internal Revenue Code of 1986, as amended, and any regulations thereunder).

The Company intends to utilize the 2025 Plan to grant equity awards to the Company’s employees, non-employee directors, consultants, and advisors in order to recruit, incentivize, retain and reward those who are critical to the Company’s success. No new awards will be granted under the 2015 Plan.

A summary of the status of and changes in unvested restricted stock unit (“RSU”) activity and performance-based restricted stock unit (“PRSU”) activity under the Company’s equity award plans for the six months ended June 30, 2026, was as follows:


				Weighted Average Grant
	Units			Date Fair Value Per Unit
Unvested as of December 31, 2025		2,296,920		$	5.39
Granted		797,398			3.71
Vested		(600,929	)		6.18
Forfeited		(578,021	)		5.39
Outstanding as of June 30, 2026		1,915,368		$	4.44

All RSUs granted during the six months ended June 30, 2026, vest in equal amounts, annually over three years. Stock-based compensation for RSUs is based on the fair value of the Company’s common stock on the date of grant and is recognized over the vesting period.

As of June 30, 2026, the Company had unrecognized stock-based compensation expense related to its unvested RSUs (excluding PRSUs) of $5.0 million, which is expected to be recognized over the remaining average vesting period of 2.0 years.

During the first quarter of 2025, in connection with the Company’s annual compensation cycle, the Company granted PRSUs to members of the Company’s senior leadership team to more closely align with long-term performance incentives. The awards vest as to a certain number of PRSUs upon the achievement of specified clinical performance milestones over multiple years. Stock-based compensation for PRSUs is based on the fair value of the Company’s common stock on the date of grant and will be recognized at the time the achievement of the specified performance milestones becomes probable. The Company did not recognize any stock-based compensation expense in connection with the PRSUs during the six months ended June 30, 2026.

As of June 30, 2026, the Company had unrecognized stock-based compensation expense related to its unvested PRSUs of $2.0 million. The Company will recognize a cumulative catch-up adjustment in the period in which the specified performance condition is considered probable.

The following is a summary of stock option activity for the six months ended June 30, 2026:


				Weighted		Remaining		Aggregate
				Average		Contractual		Intrinsic Value
	Shares			Exercise Price		Life (in years)		(in thousands)
Outstanding as of December 31, 2025		9,613,881		$	7.26		6.8	$	1,251
Granted		2,650,700			3.69
Exercised		(192,931	)		3.13
Cancelled or forfeited		(1,981,796	)		7.25
Outstanding as of June 30, 2026		10,089,854		$	6.41		7.1	$	596
Exercisable as of June 30, 2026		6,268,111		$	7.52		6.0	$	534

As of June 30, 2026, the Company had unrecognized stock-based compensation expense related to its unvested stock options of $11.1 million, which is expected to be recognized over the remaining weighted-average vesting period of 2.5 years.