The DiaMedica Therapeutics Inc. Omnibus Incentive Plan ( Plan) was adopted by the Board ofDirectors (Board) in and approved by our shareholders at our annual general and special meeting of shareholders held on The Plan permits the Board, or a committee or subcommittee thereof, to grant to the Company's eligible employees, non-employee directors and consultants non-statutory and incentive stock options, stock appreciation rights, restricted stock awards, restricted stock units, deferred stock units, performance awards, non-employee director awards and other stock-based awards. We grant options to purchase common shares under the Plan at less than the fair market value of the underlying common shares as of the date of grant. Options granted to employees and non-employee directors have a maximum term of years and generally vest in approximately equal quarterly installments over to years. Options granted to non-employees have a maximum term of years and generally vest in approximately equal quarterly installments over year. Subject to adjustment as provided in the Plan, the maximum number of the Company's common shares authorized for issuance under the Plan is shares. As of there were options to purchase common shares were outstanding and common shares were reserved for issuance upon settlement of deferred share units (DSUs) under the Plan.

 

 

The DiaMedica Therapeutics Inc. Stock Option Plan, Amended and Restated Prior Plan), was terminated by the Board in conjunction with the shareholder approval of the Plan. Awards outstanding under the Prior Plan remain outstanding in accordance with and pursuant to the terms thereof. Options granted under the Prior Plan have terms similar to those used under the Plan. As of options to purchase common shares were outstanding under the Prior Plan.

 

 

The DiaMedica Therapeutics Inc. Amended and Restated Deferred Share Unit Plan (Prior DSU Plan) was terminated by the Board in conjunction with the shareholder approval of the Plan. Awards outstanding under the DSU Plan remain outstanding in accordance with and pursuant to the terms thereof. As of there were common shares reserved for issuance upon settlement of DSUs outstanding.

 

The aggregate number of common shares reserved for issuance for awards granted under the Plan, the Prior Plan and the Prior DSU Plan as of was

 

Prior to all options granted under the Prior Plan were priced in Canadian dollars. Options granted after under the Plan and the Prior Plan have been priced in United States dollars.

 

Share-based compensation expense for each of the periods presented is as follows (in thousands):

 

		December 31, 2020				December 31, 2019
Research and development		$	534			$	370
General and administrative			1,309				794
Total share-based compensation		$	1,843			$	1,164

 

We recognize share-based compensation based on the fair value of each award as estimated using the Black-Scholes option valuation model. Ultimately, the actual expense recognized over the vesting period will only be for those shares that actually vest.

 

A summary of option activity is as follows (in thousands except share and per share amounts):

 

		Shares Underlying Options				Weighted Average Exercise Price Per Share				Aggregate Intrinsic Value
Balances at December 31, 2018			639,359			$	6.07			$	—
Granted			725,825				4.52
Exercised			(50,000	)			1.50
Expired/cancelled			(7,353	)			5.49
Forfeited			(87,472	)			5.22
Balances at December 31, 2019			1,220,359			$	5.33			$	678
Granted			302,332				4.73
Exercised			(14,283	)			3.21
Expired/cancelled			(78,147	)			5.29
Forfeited			(40,697	)			4.86
Balances at December 31, 2020			1,389,564			$	5.24			$	7,109

 

A summary of the status of our unvested shares underlying options during the year ended and as of is as follows:

 

		Shares Underlying Options				Weighted Grant Date Fair Value Per Share
Unvested at December 31, 2019			578,747			$	3.73
Granted			302,332				4.73
Vested			(449,556	)			5.09
Forfeited			(40,697	)			4.86
Unvested at December 31, 2020			390,826			$	4.83

 

Information about stock options outstanding, vested and expected to vest as of is as follows:

 

		Outstanding, Vested and Expected to Vest												Options Vested and Exercisable
Per Share Exercise Price		Shares				Weighted Average Remaining Contractual Life (Years)				Weighted Average Exercise Price				Options Exercisable				Weighted Average Remaining Contractual Life (Years)
$2.00 - $2.99			125,700				5.0			$	2.29				125,700				5.0
$3.00 - $3.99			15,000				6.2				3.90				15,000				6.2
$4.00 - $4.99			950,546				8.4				4.55				596,401				8.1
$5.00 - $10.00			248,168				6.7				8.33				211,487				6.7
$10.01 - $34.00			50,150				1.9				18.22				50,150				1.9
			1,389,564				7.5			$	5.33				998,738				7.1

 

The cumulative grant date fair value of employee options vested during the years ended and was million and respectively. Total proceeds received for options exercised during the years ended and were and respectively.

 

As of total compensation expense related to unvested employee stock options yet recognized was million, which is expected to be allocated to expenses over a weighted-average period of years.

 

The aggregate intrinsic value of stock options exercised during the years ended and was and respectively.

 

The assumptions used in calculating the fair value under the Black-Scholes option valuation model are set forth in the following table for options issued by the Company for the years ended and

 

		2020				2019
Common share fair value		$4.08	–	$6.91		$2.07	–	$4.60
Risk-free interest rate		0.3	–	1.3%		1.5	–	2.4%
Expected dividend yield			0%				0%
Expected option life (years)		5.0	–	5.2		4.2	–	5.1
Expected stock price volatility		94.4	–	102.2%		88.7	–	103.5%