Mersana’s innovative platforms are a highly efficient product engine that is building a robust discovery pipeline for us and our partners. Our ADCs in preclinical and clinical trials are first-in-class molecules that target multiple tumor types with high unmet medical need and have exhibited improved safety and efficacy compared to ADCs developed using first-generation technology. Our lead asset, XMT-1536, is a first-in-class Dolaflexin ADC in a Phase 1 proof-of-concept clinical trial in patients with tumors likely to express NaPi2b, including ovarian cancer and NSCLC adenocarcinoma. Our next clinical stage ADC, XMT-1592, a Dolasynthen ADC-targeting NaPi2b expressing tumors entered the clinic in May 2020.

ADC Program	Target	Indication	Platform	Discovery	Preclinical	P1	P1	P2/Pivotal Study
Clinical
XMT-1536*	NaPi2b	Ovarian Cancer NSCLC Adenocarcinoma	Dolaflexin
Preclinical
XMT-1592*	NaPi2b	NSCLC Adenocarcinoma Ovarian Cancer	Dolasynthen
Discovery
To Be Named	B7-H4	Multiple Solid Tumors	Dolaflexin or Dolasynthen
To Be Named	Multiple	Multiple Solid Tumors	Immunosynthen
To Be Named	Multiple	Undisclosed	Dolasynthen
To Be Named	Multiple	Undisclosed	Dolaflexin
Platform Collaborations
Multiple	Multiple	Undisclosed	Dolaflexin
ASN004	5T4	Undisclosed	Dolaflexin

Drug	Indication	Stage
Clinical
XMT-1536*	NaPi2b	Ovarian Cancer NSCLC Adenocarcinoma	Dolaflexin	Preclinical
Preclinical
XMT-1592*	NaPi2b	NSCLC Adenocarcinoma Ovarian Cancer	Dolasynthen	Discovery
Discovery
To Be Named	B7-H4	Multiple Solid Tumors	Dolaflexin or Dolasynthen	Discovery
To Be Named	Multiple	Multiple Solid Tumors	Immunosynthen	Discovery
To Be Named	Multiple	Undisclosed	Dolasynthen
To Be Named	Multiple	Undisclosed	Dolaflexin
Platform Collaborations
Multiple	Multiple	Undisclosed	Dolaflexin	Discovery
ASN004	5T4	Undisclosed	Dolaflexin	Discovery

*NaPi2b antibody used in XMT-1536 and XMT-1592 is in-licensed from Recepta Biopharma. Recepta has rights to commercialize XMT-1536 and XMT-1592 in Brazil.