Niall O'Donnell, Ph.D.

Insider Activist

First SEC filing: April 8, 2021 · Latest: Jan. 21, 2025

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Insider at Companies where this person is a reporting insider.
Insider transactions Every share this person bought or sold, from Form 4 filings.
Derivatives Options and other derivative holdings reported by this person.
Initial holdings The stakes this person held when they first started reporting.

Insider at

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 17 non-open-market transactions below last 12 months, based on the transactions shown below

Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted

17 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
June 6, 2023	OKUR	A	17,500	—	—	17,500 Direct	—	Acquired	(price as of 2026-08-21)
May 25, 2023	SPRB	A	30,000	—	—	30,000 Direct	—	Acquired	(price as of 2026-08-21)
May 8, 2023	OKUR	P	125,000	$8.00	$1,000,000	2,188,713 Indirect	+6.06%	Acquired	-95.0% (price as of 2026-08-21)
Feb. 16, 2023	SPRB	P	472,800	—	—	472,800 Indirect	—	Acquired	(price as of 2026-08-21)
Feb. 16, 2023	SPRB	P	630,400	$3.17	$1,998,368	1,326,305 Indirect	+90.59%	Acquired	-99.7% (price as of 2026-08-21)
Nov. 15, 2022	MIRM	S	93,770	$19.69	$1,846,331	1,621,118 Indirect	-5.47%	Disposed	394.7% (price as of 2026-08-21)
Nov. 14, 2022	MIRM	S	32,109	$19.60	$629,336	1,714,888 Indirect	-1.84%	Disposed	396.9% (price as of 2026-08-21)
Nov. 11, 2022	MIRM	S	174,121	$19.99	$3,480,679	1,746,997 Indirect	-9.06%	Disposed	387.2% (price as of 2026-08-21)
June 2, 2022	MIRM	A	17,000	—	—	17,000 Direct	—	Acquired	(price as of 2026-08-21)
June 1, 2022	OKUR	A	17,500	—	—	17,500 Direct	—	Acquired	(price as of 2026-08-21)
May 25, 2022	SPRB	A	22,500	—	—	22,500 Direct	—	Acquired	(price as of 2026-08-21)
June 4, 2021	MIRM	A	17,000	—	—	17,000 Direct	—	Acquired	(price as of 2026-08-21)
May 20, 2021	SPRB	A	10,000	—	—	10,000 Direct	—	Acquired	(price as of 2026-08-21)
April 13, 2021	OKUR	C	3,710,116	—	—	0 Indirect	-100.00%	Disposed	(price as of 2026-08-21)
April 13, 2021	OKUR	C	4,629,630	—	—	0 Indirect	-100.00%	Disposed	(price as of 2026-08-21)
April 13, 2021	OKUR	P	200,000	$15.00	$3,000,000	2,063,713 Indirect	+10.73%	Acquired	-97.4% (price as of 2026-08-21)
April 13, 2021	OKUR	C	829,113	—	—	1,863,713 Indirect	+80.14%	Acquired	(price as of 2026-08-21)
April 13, 2021	OKUR	C	1,034,600	—	—	1,034,600 Indirect	—	Acquired	(price as of 2026-08-21)
April 8, 2021	OKUR	A	14,000	—	—	14,000 Direct	—	Acquired	(price as of 2026-08-21)
Oct. 14, 2020	SPRB	C	2,916,664	—	—	0 Indirect	-100.00%	Disposed	(price as of 2026-08-21)
Oct. 14, 2020	SPRB	P	250,000	$15.00	$3,750,000	695,905 Indirect	+56.07%	Acquired	-99.9% (price as of 2026-08-21)
Oct. 14, 2020	SPRB	C	445,905	—	—	445,905 Indirect	—	Acquired	(price as of 2026-08-21)
June 11, 2020	MIRM	A	17,000	—	—	17,000 Direct	—	Acquired	(price as of 2026-08-21)
July 22, 2019	MIRM	C	11,968,944	—	—	0 Indirect	-100.00%	Disposed	(price as of 2026-08-21)
July 22, 2019	MIRM	P	300,000	$15.00	$4,500,000	1,921,118 Indirect	+18.51%	Acquired	549.3% (price as of 2026-08-21)
July 22, 2019	MIRM	C	1,496,118	—	—	1,621,118 Indirect	+1196.89%	Acquired	(price as of 2026-08-21)

P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding

Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.

Derivative holdings (Form 4 Table II)

Options, RSUs and convertible securities reported on Form 4 Table II.

Date	Ticker	Security	Underlying	Exercise price	Expiration	Shares	A/D
June 6, 2023	OKUR	Stock Option (right to buy)	Common Stock (17,500)	$9.01	June 5, 2033	17,500	Acquired
May 25, 2023	SPRB	Stock Option (Right to Buy)	Common Stock (30,000)	$2.26	May 24, 2033	30,000	Acquired
Feb. 16, 2023	SPRB	Common Stock Warrant (Right to Buy)	Common Stock (472,800)	$3.96	Feb. 16, 2028	472,800	Acquired
June 2, 2022	MIRM	Stock Option (right to buy)	Common Stock (17,000)	$23.51	June 1, 2032	17,000	Acquired
June 1, 2022	OKUR	Stock Option (right to buy)	Common Stock (17,500)	$2.09	May 31, 2032	17,500	Acquired
May 25, 2022	SPRB	Stock Option (Right to Buy)	Common Stock (22,500)	$1.32	May 24, 2032	22,500	Acquired
June 4, 2021	MIRM	Stock Option (right to buy)	Common Stock (17,000)	$16.88	June 3, 2031	17,000	Acquired
May 20, 2021	SPRB	Stock Option (Right to Buy)	Common Stock (10,000)	$15.24	May 19, 2031	10,000	Acquired
April 13, 2021	OKUR	Series B Preferred Stock	Common Stock (829,113)	—	—	3,710,116	Disposed
April 13, 2021	OKUR	Series A Preferred Stock	Common Stock (1,034,600)	—	—	4,629,630	Disposed
April 8, 2021	OKUR	Stock Option (right to buy)	Common Stock (14,000)	$15.00	April 7, 2031	14,000	Acquired
Oct. 14, 2020	SPRB	Series B Preferred Stock	Common Stock	—	—	2,916,664	Disposed
June 11, 2020	MIRM	Stock Option (right to buy)	Common Stock (17,000)	$16.71	June 10, 2030	17,000	Acquired
July 22, 2019	MIRM	Series A Preferred Stock	Common Stock	—	—	11,968,944	Disposed

Exercise/conversion price is blank when not applicable (e.g. RSUs).

Initial ownership (Form 3) 7 holdings

Securities held when first becoming an insider, per SEC Form 3.

Date	Ticker	Security	Shares	Ownership
April 8, 2021	OKUR	Series A Preferred Stock→ Common Stock (1,034,600)	1,034,600	Indirect
April 8, 2021	OKUR	Series B Preferred Stock→ Common Stock (829,113)	829,113	Indirect
April 8, 2021	OKUR	Stock option (right to buy)→ Common Stock (84,568)	84,568	Direct
April 8, 2021	OKUR	Stock option (right to buy)→ Common Stock (32,403)	32,403	Direct
Oct. 8, 2020	SPRB	Series B Preferred Stock→ Common Stock	—	Indirect
July 17, 2019	MIRM	Common Stock	125,000	Indirect
July 17, 2019	MIRM	Series A Preferred Stock→ Common Stock	—	Indirect