Private CalciMedica adopted an equity incentive plan in 2006 (“2006 Plan”) that provides for the issuance of common stock to employees, non-employee directors and consultants. Recipients of incentive stock options are eligible to purchase common stock at an exercise price equal to no less than the estimated fair market value of such stock on the date of grant. The 2006 Plan provides for the grant of incentive stock options, non-statutory stock options and stock purchase rights. The maximum contractual term of options granted under the 2006 Plan is ten years. The options generally vest 25% on the first anniversary of the grant date, with the balance vesting ratably over the following 36 months. Pursuant to the Merger Agreement, the Company assumed the 2006 Plan and all stock options issued and outstanding under the 2006 Plan.

The Company adopted 2023 Equity Incentive Plan (the “2023 Plan”), which became effective at the closing of the Merger and replaced our 2020 Equity Incentive Plan (“2020 Plan”) on the effective date of the Merger. As of the effective date of the Merger, there were 1,000,000 shares of the Company’s common stock available for grant under the 2023 Plan. In addition, the share reserve is subject to annual increases each January 1 for the first ten years following approval of the 2023 Plan of up to 5% of shares of the Company’s common stock outstanding (or a lesser number determined by the Company’s board of directors). As of June 30, 2024, 228,475 options have been returned of which 223,108 (granted under the 2020 Plan) are unavailable for future grant. Effective January 1, 2024, the shares reserved for issuance under the 2023 Plan was increased by 287,725. As of June 30, 2024, 55,060 shares were available for grant under the 2023 Plan.

The Company adopted the 2023 Employee Stock Purchase Plan (the “2023 ESPP”) which became effective at the closing of the Merger. As of the effective time of the Merger, there were 65,000 shares of the Company’s common stock reserved for issuance under the 2023 ESPP. In addition, the share reserve is subject to annual increases each January 1 for the first ten years following approval of the 2023 ESPP of the lesser of (i) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (ii) 195,000 shares of the Company’s common stock, or (iii) such lesser number of shares of the Company’s common stock as determined by the Company’s board of directors. An annual increase of 57,545 shares of the Company’s common stock was automatically added to the share reserve under the 2023 ESPP on January 1, 2024.

The following table summarizes the stock option transactions for the 2023 Plan:



	Total Options				Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)			Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2023		1,739,270		$		15.71		6.99	$		76
Granted		631,250				4.17		9.74			—
Exercised		(1,091	)			3.25		—			—
Cancelled		(228,475	)			75.27		—			—
Outstanding at June 30, 2024		2,140,954		$		5.95		8.12	$		644
Vested and exercisable at June 30, 2024		1,001,228		$		6.92		6.83	$		338

There were 1,091 options exercised during the six months ended June 30, 2024. The weighted-average fair value of options granted during the six months ended June 30, 2024 and 2023 was $4.17 and $4.47 per share, respectively. The total fair value of shares vested was $0.8 million for the six months ended June 30, 2024. The total fair value of shares vested as of June 30, 2023 was $11.6 million (includes $10.5 million related to the acceleration of vesting of the Graybug stock awards at the date of the Merger).

As of June 30, 2024, stock-based compensation not yet recognized is $3.6 million, which the Company expects to recognize over an estimated weighted-average term of 2.8 years.

The following are the underlying assumptions in Black-Scholes to determine the fair value of the stock option grants for the six months ended June 30, 2024 and 2023:


	Six Months Ended June 30,
	2024	2023
Risk free interest rate	2.96%	3.50%-3.56%
Expected volatility	89%	75%-76%
Expected term (years)	6.08	6.25
Expected dividend yield	0%	0%

Stock-based compensation expense recognized for options and restricted stock units granted was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Research and development	$	190	$	161	$	361	$	2,242
General and administrative		296		302		539		9,347
Total stock-based compensation expense	$	486	$	463	$	900	$	11,589

The stock-based compensation expense for the six months ended June 30, 2023, includes one-time charges for the acceleration of vesting of the Graybug stock options at the date of the Merger of $1.9 million and $8.6 million in research and development and general and administrative expenses, respectively.

Common stock reserved for future issuance consists of the following at June 30, 2024:


	June 30,
	2024
Common stock warrants		6,036,552
Stock options issued and outstanding		2,140,954
Shares available for issuance under the 2023 Plan		55,060
Shares available under the 2023 ESPP		122,545
Total		8,355,111