Timothy B Lowinger

Date	Company	Security	Transaction	Code	Indirect	10b5-1	$Price	#Shares	$Value	#Remaining
16 Jan 25	MRSN Mersana Therapeutics	Common Stock	Sell	Dispose S	No	Yes	0.58	8,048	4.67 k	257,673
15 Jan 25	MRSN Mersana Therapeutics	Common Stock	Option exercise	Acquire M	No	No	0	12,500	0.00	265,721
15 Jan 25	MRSN Mersana Therapeutics	Common Stock	Option exercise	Acquire M	No	No	0	7,291	0.00	253,221
15 Jan 25	MRSN Mersana Therapeutics	RSU Common Stock	Grant	Acquire A	No	No	0	54,167	0.00	54,167
15 Jan 25	MRSN Mersana Therapeutics	Stock Option Common Stock	Grant	Acquire A	No	No	0.64	243,750	156.00 k	243,750
15 Jan 25	MRSN Mersana Therapeutics	RSU Common Stock	Option exercise	Dispose M	No	No	0	12,500	0.00	37,500
15 Jan 25	MRSN Mersana Therapeutics	RSU Common Stock	Option exercise	Dispose M	No	No	0	7,291	0.00	0
15 Jan 25	MRSN Mersana Therapeutics	Common Stock	Sell	Dispose S	No	Yes	0.63	1,794	1.13 k	245,930
14 Jan 25	MRSN Mersana Therapeutics	Common Stock	Option exercise	Acquire M	No	No	0	4,792	0.00	247,724
14 Jan 25	MRSN Mersana Therapeutics	RSU Common Stock	Option exercise	Dispose M	No	No	0	4,792	0.00	4,791

Data from 3, 4 and 5 filings. Values as filed, not updated for current price.