Lauren White - 18 Sep 2023 Form 4 Insider Report for ImmunoGen, Inc.

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	IMGN	Stock Option (Right to Buy)	Award	$0	+295,975		$0.000000	295,975	18 Sep 2023	Common Stock	295,975	$15.71	Direct	F1
transaction	IMGN	Restricted Stock Unit	Award	$0	+51,625		$0.000000	51,625	18 Sep 2023	Common Stock	51,625	$0.000000	Direct	F2, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Id	Content
F1	These options vest over a four-year period, with 25% of the shares vesting on the one-year anniversary of the date of grant, and thereafter an additional 6.25% of the shares vesting on each succeeding quarterly anniversary of the date of grant, subject to continued service through each vesting date.
F2	Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock.
F3	The RSUs vest over a four-year period, with 25% of the RSUs vesting on each of the first four anniversaries of the date of grant, subject to continued service through each vesting date.