Study of STRO-002, an Anti-Folate Receptor Alpha (FolRα) Antibody Drug Conjugate in Ovarian & Endometrial Cancers

Inclusion Criteria:

1. Age ≥ 18 years

2. Measurable disease per RECIST 1.1

3. ECOG performance status (0-1)

4. Life expectancy > 3 months

5. Pathological confirmation of disease under study (historical information, diagnosis,pathology report, etc)

6. Expansion Cohorts A and C: High-grade serous EOC, fallopian tube cancer orprimary peritoneal cancer

7. Expansion Cohort B: Histologically diagnosed epithelial endometrial cancer (endometrioid and serous adenocarcinomas; undifferentiated carcinoma; mixedepithelial carcinoma; or adenocarcinoma NOS)

8. Relapsed and/or progressive disease

9. Dose Expansion Cohorts A and C (Ovarian Cancer):

• Platinum resistant and received 1-3 prior regimens or
• Platinum sensitive and either:
• Progressed after 2 prior lines of platinum therapy (regardless of platinumstatus)and received 2-3 prior regimens or
• Progressed after 1 line of platinum therapy and 1 line of non-platinumtherapy and received a total of 2-3 prior regimens if contraindicated toreceive second platinum regimen.

2. Dose Expansion Cohort B (Endometrial Cancer):

• Relapsed or progression after at least 1 platinum-based chemotherapyregimen or 1 immunotherapy-based regimen but not to exceed more than 3prior regimens.

7. Fresh or archival tumor tissue samples

Exclusion Criteria:

1. Low grade (grade 1) ovarian carcinoma, clear cell, mucinous and sarcomatous ovariancarcinomas (Cohort A).

2. Endometrial carcinosarcomas, leiomyosarcoma and stromal sarcomas (Cohort B).

3. Prior treatment with a FolRα-targeting ADCs or FolRα-targeting vaccines

4. Platinum-refractory during frontline treatment (Cohorts A and C)

5. Greater than 3 lines of prior treatment

6. History of severe allergic or anaphylactic reactions to monoclonal antibody therapyor to antibody-related fusion protein treatment

7. Preexisting clinically significant ocular disorders, clinically significantpre-exisiting ocular disorders, severe chronic obstructive pulmonary disease orasthma, clinically significant cardiac or cerebrovascular disease, or othersignificant concurrent, uncontrolled medical condition

8. Metastatic central nervous system or meningeal disease

9. Concurrent participation in another therapeutic treatment trial