18. Pregnancy Test or FSH Level (Serum): For female particip ants of childbearing potential, a serum or urine pregnancy test, with sensitivity of at least 25 mIU/mL and assayed in a certified laboratory, will be performed on 2 occasions prior to starting study therapy, once at the start of screening and once at the baseline visit immediately before investigational product administration. Pregnancy tests will also be routinely repeated at Day 1 of every treatment cycle during the active treatment period, at the End of Treatment visit, at the 28 -day Follow -Up Visit, a nd additionally whenever one menstrual cycle is missed or when potential pregnancy is otherwise suspected. Additional pregnancy tests may also be undertaken if requested by institutional review board/ethics committee (IRB/ECs) or if required b y local regu lations. Participants with confrmed positive pregnanct test(s) should not be dosed. For female participants who achieved postmenopausal status and have not experienced their menses for at least 12 consecutive months, a serum FSH test must be conducted at screening only to confirm a FSH level within the laboratory’s reference ranges. 19. Contraception Check : The contraception check is to confirm that contraception, if assigned, is used consistently and correctly. Male participan ts who are able to father child ren and female participants who are of childbearing potential will need to affirm that they meet the criteria for correct use of 2of the selected methods of contraception. The investigator or his or her designee will discuss with the participant the need to use 2 highly effective contraception methods consistently and correctly and document such conversation in the participant’s chart. In addition, the investigator or his or her designee will instruct the participant to call immediately if one or both selected contraception methods are discontinued, or if pregnancy is known or suspected in the participant or the participant’s partner. 20. 12 leads ECGs : A single ECG will be performed at Screening. At all other time points, three consecutive 12 -lead ECGs will be performed approximately 2 minutes apart to determine mean QTcF interval. If the mean QTcF is prolonged (>500 msec), the ECGs should be re-evaluated by a qualified person at the institution for confirmation. Following the end of Cycle 2, triplicate EC Gs will be performed at Month 12 Day 1, Month 18 Day 1, and may be performed as clinically indicated. 21. Registration : Participant number and dose level allocation operated by Pfizer Inc. 22. Investigational Product Administration: Treatment to be administered after all other assessments required on that day have been performed. PF-06936308 C3621001Final Protocol Amendment 2, 22 Dec 2020 PFIZER CONFIDENTIAL Page 20Protocol Activity Screen 1 (£28 days)Treatment Period Post Treatment Cycle 1 Cycle 2 End of Treatment 33Follow- Up (Months after EOT visit)Survival Follow-up35 Study Day Day 1Day 8Day 15Day 22Day 29Day 43Day 57Day 71Day 85Day 113Month 134Month 2 Month 4 Month 6 Post 6-Month Follow-up Cycle Day Day 1Da y 29Day 57Da y 85Day 9928 to 35 daysEvery 3 Months Visit Window (Days) *±1 ±2 ±2 ±2 ±4 ±2 ±4 ±2 ±2 ±2 ±2 ±2 ±4 ±4 ±4 ±4 ±10 23. Tumor Assessments: Tumor assessments will include all known or suspected disease sites.