We use equity-based compensation programs to provide long-term performance incentives for our employees. These incentives consist primarily of stock options and RSUs. In December 2008, we adopted the MEI Pharma, Inc. 2008 Stock Omnibus Equity Compensation Plan (the Omnibus Plan), as amended and restated from time to time, under which 1,850,739 shares of common stock are authorized for issuance. The Omnibus Plan provides for the grant of options and/or other stock-based or stock-denominated awards to our non-employee directors, officers, employees and advisors. As of June 30, 2024, there were 465,633 shares available for future grant under the Omnibus Plan.

In May 2021, we adopted the 2021 Inducement Plan (Inducement Plan), under which 125,000 shares of common stock were authorized for issuance. On June 9, 2023 our Board approved an amendment and restatement of the Inducement Plan to increase the aggregate number of shares of common stock authorized for issuance by 92,000 shares. The Inducement Plan is intended to assist us in attracting and retaining selected individuals to serve as employees who are expected to contribute to our success, by providing an inducement for such individuals to enter into employment with us, and to achieve long-term objectives that will benefit our stockholders. As of June 30, 2024, there were 130,737 shares available for future grant under the Inducement Plan.

Total share-based compensation expense for all stock awards consists of the following, in thousands:


	For the Fiscal Year Ended June 30,
	2024		2023
Research and development	$	349	$	724
General and administrative		1,929		2,865
Total share-based compensation	$	2,278	$	3,589

Stock options granted to employees vest 25% one year from the date of grant and ratably each month thereafter for a period of 36 months and expire ten years from the date of grant. Stock options granted to directors vest ratably each month for a period of 12 months from the date of grant and expire ten years from the date of grant. As of June 30, 2024, there were a total of 1,357,213 options outstanding of which 1,270,950 were granted under the Omnibus Plan and 86,263 were granted under the Inducement Plan.

A summary of our stock option activity and related data follows:


	Number of Options			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value
Outstanding at June 30, 2023		1,284,907		$	38.32
Granted		290,437		$	6.92
Forfeited		(218,131	)	$	38.34
Outstanding at June 30, 2024		1,357,213		$	31.60		7.1	$	—
Vested and expected to vest at June 30, 2024		1,357,213		$	31.60		7.1	$	—

As of June 30, 2024, the aggregate intrinsic value of outstanding options is calculated as the difference between the exercise price of the underlying options and the closing price of our common stock of $2.91 on that date.

Unrecognized compensation expense related to non-vested stock options totaled $1.3 million as of June 30, 2024. Such compensation expense is expected to be recognized over a weighted-average period of 1.57 years. As of June 30, 2024, we expect all outstanding options to vest.

We use a Black-Scholes valuation model to estimate the grant date fair value of stock options. To calculate these fair values, the following weighted-average assumptions were used:


	For the Fiscal Year Ended June 30,
	2024			2023
Risk-free interest rate		4.5	%		3.2	%
Expected life (years)		5.7			6.0
Volatility		89.8	%		85.5	%
Dividend yield		—	%		—	%
Weighted-average grant date fair value	$	5.20		$	7.04

Each RSU represents the contingent right to receive one share of our common stock. Under the terms of the Omnibus Plan, each of the RSUs is calculated as 1.25 shares of common stock for purposes of determining the number of shares available for future grant. As of June 30, 2024 and 2023, we had no unvested RSUs.