A Clinical Trial to Learn About the Study Medicine Called Maplirpacept (PF-07901801), Alone and When Used in Combination With Other Medicines to Treat Participants With Advanced Hematological Malignancies, Including Lymphoma, Leukemia and Multiple Myeloma

The purpose of this clinical trial is to learn how the experimental medicine maplirpacept (PF-07901801) affects people with various types of blood cancers:

* relapsed or refractory (R/R) lymphoma
* multiple myeloma
* newly diagnosed acute myeloid leukemia (AML).

This trial will be conducted in the outpatient setting in 2 parts, phase 1a and phase 1b. You may only participate in one part of the study.

During phase 1a of this study, we will explore how much maplirpacept (PF-07901801), when used by itself, can be safely used.

If you have lymphoma, the study medicine maplirpacept (PF-07901801) will be given by infusion through a vein once a week or once every 2 weeks or every 3 weeks as determined by your doctor. Following your first dose, you will be expected to come back twice more the first week. From week 2, you will have weekly visits for blood tests, questions about your medications, any side effects, or illnesses you may have experienced and your cancer response. After you have completed 21 days (for every week dosing) or 42 days (for every 2- or 3-weeks dosing), your doctor will discuss whether you should stop study treatment or continue.

If you continue, you will be expected to come back weekly for blood tests, vital signs, a brief physical exam, asked about any side effects or illnesses you may have experienced and medications you may be taking. The dosing schedule you are assigned to will continue until your disease has worsened, significant side effects occur or other reasons that lead you and your doctor to decide treatment may be stopped.

To be eligible for the first part of the study you must be 18 years or older, your disease has worsened after receiving other medicines approved for blood cancer, no other treatment options exist for you, a sample of your tissue for exploratory research which can be taken from tissue already obtained or if necessary, a new sample of your tissue will be taken so your disease may be seen and measured on routine tests/scans. If you have had radiation therapy or received any anticancer medication within 14 days before the planned start of study treatment your doctor will let you know if you are eligible to participate in the study. If you have had major surgery within 30 days before the planned start of study treatment you may not be eligible to participate.

The phase 1a part of the study may last up to 51/2 years. How long you participate in this study depends on side effects you may have to the study drug. It also depends on how your cancer responds to the study drug. Therefore, you may remain in the study as long as you and your study doctor think you may benefit. However, you are free to stop taking part in this study at any time and for any reason.

During phase 1b part of this study, we will explore how much maplirpacept (PF-07901801), when used with other anticancer medicine(s), can be safe and reduce cancer growth. In the phase 1b part of this study, you will receive maplirpacept (PF-07901801) and other anticancer medicine(s). Which medicine combination you will receive depends on the types of cancer under treatment. Your treatment experiences will be examined to determine if maplirpacept (PF-07901801) when given with other anticancer medicine(s), is safe and can reduce cancer growth.

To be eligible for the second part of the study you may have newly diagnosed Acute Myelocytic Leukemia with or without a genetic mutation or you have Multiple Myeloma or Diffuse Large B Cell Lymphoma, and your disease has worsened.

The Phase 1b part of this study may last as long as you and your study doctor think you may benefit which could be up to approximately 31/2 years. How long you participate in this study depends on side effects you may have to the study drug. It also depends on how your cancer responds to the study drug. Therefore, you may remain in the study as long as you and your study doctor think you may benefit. However, you are free to stop taking part in this study at any time and for any reason.

This is a trial of maplirpacept (PF-07901801) in subjects with relapsed or refractory lymphoma or multiple myeloma (MM) and subjects with newly diagnosed acute myeloid leukemia (AML).

This trial will be conducted in 2 phases: Phase 1a (Dose-Escalation Phase for Single-Agent maplirpacept (PF-07901801) and Phase 1b maplirpacept (PF-07901801) Combinations and Single-Agent.

In the Dose-Escalation Phase for Single-Agent maplirpacept (PF-07901801), subjects with relapsed or refractory lymphoma will be enrolled in sequential dose cohorts.

In the Combination and Single-Agent Treatment part, subjects will be included in 1 of 14 cohorts: (Cohort A1 and A2) subjects with newly diagnosed TP53-mutated AML will be treated with maplirpacept (PF-07901801) + azacitidine; (Cohort B1 and B2) elderly subjects or subjects unfit for intensive induction chemotherapies with newly diagnosed TP53-wildtype AML will be treated with maplirpacept (PF-07901801) + azacitidine and venetoclax; (Cohort C1, C2, and C3) subjects with relapsed or refractory MM will be treated with maplirpacept (PF-07901801) + carfilzomib and dexamethasone;(Cohort D1 and D2) subjects in relapsed or refractory CD20+ diffuse large B-cell lymphoma will be treated with maplirpacept (PF-07901801) + an anti-CD20 targeting agent; (Cohort E1 and E2) subjects with relapsed refractory MM will be treated with single-agent maplirpacept (PF-07901801); and (Cohorts F1, F2 and F3) with relapsing or refractory MM will be treated with increasing doses of maplirpacept (PF-07901801) + isatuximab, carfilzomib and dexamethasone.

Eligibility Criteria:
Key Inclusion Criteria (Phase 1a and Phase 1b, all Cohorts):

1. Available fresh or archived tumor tissue.
2. Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1, or 2.
3. Adequate coagulation function.
4. Adequate hepatic function.
5. Adequate hematologic status.
6. Adequate renal function.
7. Recovery from non-hematopoietic toxicities of previous anticancer drugs or radiotherapy or previous surgeries to ≤Grade 1 (or to baseline grade if condition was pre-existing).

Key Inclusion Criteria (Phase 1a): Histologically confirmed relapsed/refractory, transfusion- independent lymphoma (Hodgkin or non-Hodgkin) per the 2014 Lugano classification.

Key Inclusion Criteria (Phase 1b Cohort A1 and A2): Histologically confirmed, newly diagnosed TP53-mutated Acute Myeloid Leukemia (AML).

Key Inclusion Criteria (Phase 1b Cohort B1 and B2): Histologically confirmed, newly diagnosed TP53-wildtype AML, elderly or unfit for more aggressive treatment.

Key Inclusion Criteria (Phase 1b Cohorts C1, C2, C3 and E1, E2, F1, F2, F3): Histologically documented relapsed/refractory Multiple Myeloma (MM).

Key Inclusion Criteria (Phase 1b Cohort D1 and D2): Pathologically confirmed relapsed/refractory diffuse large B-cell lymphoma (DLBCL)

Key Exclusion Criteria (Phase 1a and Phase 1b, all Cohorts):

1. Known, current central nervous system disease involvement.
2. Use of any investigational agent or any anticancer drug within 14 days before planned start of study treatment (within 4 weeks for antibody-based therapies and within 8 weeks for cell-based therapies).
3. Subjects who have undergone radiation therapy within 14 days of study treatment administration.
4. Hematopoietic stem cell transplant within 90 days before the planned start of study treatment or subjects with active graft-vs-host disease, with the exception of Grade 1 skin involvement.
5. Major surgery within 30 days before planned start of study treatment.