Insiders / Dere Willard H

Dere Willard H

CIK 1311569personinsider

Companies

3

First seen

Jan 6, 2026

Last activity

Jun 11, 2026

Companies

Company	Role	Shares held	Peak held	Trades	Latest
BioMarin Pharmaceutical Inc · BMRN	Director	46,440	46,440	1	—
Mersana Therapeutics, Inc. · MRSN	Director	0	0	13	—
Metagenomi Therapeutics, Inc. · MGX	Director	—	21,000	1	—

All securities held

2 positions · latest reported per filing

Company	Security	Shares	As of
BioMarin Pharmaceutical Inc	Common Stock	46,440	Jun 2, 2026
Metagenomi Therapeutics, Inc.	Stock Option (Right to Buy)Derivative	21,000	Jun 9, 2026

Activity

InsidersInstitutions

This person's insider trades (Form 4), across every company.

Date	Action	Company	Value	Shares Δ	Position after	Impact
Jun 2, 2026	Grant	BMRN BioMarin Pharmaceutical Inc Common Stock	$0	+7K +19.23%	46,440 0.02% of shares	low
Jun 9, 2026	Grant	MGX Metagenomi Therapeutics, Inc. Stock Option (Right to Buy)	—	+21K	21,000 0.06% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-2K -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-734 -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-2K -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-513 -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-1K -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-125 -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-368 -100.00%	0 0.00% of shares	low
Jan 6, 2026	Other	MRSN Mersana Therapeutics, Inc. Stock Option (right to buy)	—	-450 -100.00%	0 0.00% of shares	low