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, Graybug assumed the 2006 Plan and all stock options issued and outstanding under the 2006 Plan.

On December 6, 2022, the Private CalciMedica board of directors approved an amendment to the 2006 Plan to increase the cumulative number of shares of common stock reserved for issuance thereunder by 180,245 shares.

The Company adopted 2023 Equity Incentive Plan (the “2023 Plan”), which became effective at the closing of the Merger. As of the effective time 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).

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 (1) 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year, (2) 195,000 shares of the Company’s common stock, or (3) such lesser number of shares of the Company’s common stock as determined by the Company’s board of directors.

The following table summarizes the stock option transactions for the 2006 Plan:



	Total Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (years)			Aggregate Intrinsic Value (in thousands)
Outstanding at December 31, 2022		739,511	$		6.94		7.36	$		8,903
Assumed in the Merger		310,431			76.72		—			—
Granted		180,231			17.34		—			—
Outstanding at March 31, 2023		1,230,173	$		26.14		5.82	$		371
Vested and exercisable at March 31, 2023		941,638	$		30.53		5.82	$		371

There were no options exercised during the three months ended March 31, 2023. The weighted-average fair value of options granted during the three months ended March 31, 2023 and 2022 was $11.94 and $6.60 per share, respectively. The total fair value of shares vested was $10.9 million (includes $10.5 million related to the acceleration of vesting of the Graybug stock awards at the date of the Merger) and $0.2 million for the three months ended March 31, 2023 and 2022, respectively.

As of March 31, 2023, stock-based compensation not yet recognized is $3.5 million, which the Company expects to recognize over an estimated weighted-average term of 2.7 years.

The following is the range of underlying assumptions in Black-Scholes to determine the fair value of the stock option grants for the three months ended March 31, 2023 and 2022:


	Three Months Ended March 31,
	2023		2022
Risk free interest rate	3.56%		1.62%-1.76%
Expected volatility	75%		88%
Expected term (years)		6.25	5.50-6.08
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 March 31,
	2023		2022
Research and development	$	2,080	$	224
General and administrative		9,046		111
Total stock-based compensation expense	$	11,126	$	335

The stock-based compensation expense 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 March 31, 2023:


	March 31,
	2023
Common stock warrants		276,437
Stock options issued and outstanding		1,230,173
Shares available for issuance under the 2023 Plan		1,000,000
Shares available under the 2023 ESPP		65,000
Total		2,571,610