The purpose of this study is to learn about the safety and what the body does to the medicine (Maplirpacept) when taken for the treatment of non-Hodgkin lymphoma or multiple myeloma.

Non-Hodgkin lymphoma is any of a large group of cancers of lymphocytes (white blood cells). Multiple myeloma is a type of cancer that begins in plasma cells (white blood cells that produce antibodies).

This study is seeking participants who:

• have non-Hodgkin lymphoma or multiple myeloma.
• have worsened with (or lack of improvement to) a standard treatment taken before.
• have relatively normal functioning organs.

All participants in this study will receive Maplirpacept as an intravenous (IV) infusion (given directly into a vein) at the study clinic every week.

Participants will continue to receive Maplirpacept until:

• the cancer worsens.
• some serious side effects show up.
• the participants do not wish to take the study medicine any more.

The experiences of the people receiving the study medicine will be collected. This will help to understand if the study medicine Maplirpacept, is safe and can be given to Chinese people.

The study is composed of 2 parts. In Part A, approximately 3-6 participants are expected to be enrolled to confirm the tolerability in Chinese participants. If deemed safe, the enrollment of Part B will proceed to include a total of approximately 9 participants in the study to continue to evaluate the pharmacokinetics, safety and preliminary efficacy of single agent PF-07901801 (Maplirpacept).

Key Inclusion Criteria:

• Histologically confirmed relapsed/refractory non-Hodgkin lymphoma without other effective therapeutic option. Or relapsed/refractory multiple myeloma exposed to therapies including PI, IMiD and anti-CD38 antibody.
• With measurable disease
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0, 1, or 2.
• Adequate organ functions (including hematologic status, coagulation, hepatic, and renal)

Key Exclusion Criteria:

• Active plasma cell leukemia, or POEMS syndrome.
• Known, current central nervous system disease involvement.
• Significant cardiovascular disease.
• Chronic use of systemic corticosteroids of more than 20 mg/day of prednisone or equivalent.
• Radiation therapy within 14 days of study treatment administration.
• Hematopoietic stem cell transplant within 90 days before the planned start of study treatment or participants with active GVHD disease.
• Use of any anticancer drug within 14 days before planned start of study treatment.
• Prior anti-CD47 or anti-SIRP alpha therapy.
• Participation in other studies involving investigational drug(s) or vaccines within 4 weeks from the last dose
• Known active, uncontrolled bacterial, fungal, or viral infection.

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.