We use share-based compensation programs to provide long-term performance incentives for our employees. These incentives consist primarily of stock options and restricted stock units (RSU). In December 2008, we adopted the MEI Pharma, Inc. 2008 Stock Omnibus Equity Compensation Plan (Omnibus Plan), as amended and restated from time to time, under which 1,850,739 shares of common stock are currently 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, and employees. As of March 31, 2024, there were 451,768 shares available for future grant under the Omnibus Plan.

In May 2021, we adopted the 2021 Inducement Plan (Inducement Plan), under which 217,000 shares of common stock are authorized for issuance. 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 March 31, 2024, there were 128,348 shares available for future grant under the Inducement Plan.

Total share-based compensation expense for all stock awards consisted of the following for the periods presented (in thousands):


	For the Three Months Ended March 31,				For the Nine Months Ended March 31,
	2024		2023		2024		2023
Research and development	$	194	$	374	$	254	$	1,224
General and administrative		474		544		1,627		2,066
Total share-based compensation	$	668	$	918	$	1,881	$	3,290

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. Of the total options outstanding of 1,373,467 as of March 31, 2024, 1,284,815 were granted under the Omnibus Plan and 88,652 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		(201,877	)	$	40.28
Outstanding at March 31, 2024		1,373,467		$	31.39		7.3	$	—
Vested and expected to vest at March 31, 2024		1,373,467		$	31.39		7.3	$	—

As of March 31, 2024, the aggregate intrinsic value of outstanding options was calculated as the difference between the exercise price of the underlying options and the closing price of our common stock of $4.00 on that date.

Unrecognized compensation expense related to non-vested stock options totaled $1.8 million as of March 31, 2024. Such compensation expense is expected to be recognized over a weighted-average period of 1.55 years. As of March 31, 2024, we expect all options to vest.

The weighted-average assumptions used in the Black-Scholes option pricing model to determine the fair value of option grants were as follows:


	For the Nine Months Ended March 31,
	2024			2023
Risk-free interest rate		4.5	%		2.9	%
Expected life (years)		5.7			6.0
Volatility		89.8	%		84.1	%
Dividend yield		—	%		—	%
Weighted-average grant date fair value	$	5.20		$	7.71