Study of Maplirpacept (PF-07901801) in Combination With PLD in Patients With Platinum-Resistant Ovarian Cancer

Pegylated liposomal doxorubicin (PLD), a type of chemotherapy, is a standard treatment option for patients with platinum-resistant ovarian cancer. However, despite being consider a standard treatment option, the clinical benefit of chemotherapy alone for these patients is small. Historically, response rates for PLD monotherapy have only ranged from 12 to 35% with a high likelihood of recurrence within months after treatment initiation. Although bevacizumab (BEV), an anti-new-vascular growth monoclonal antibody has been approved by FDA to combine with standard chemotherapy (e.g., PLD) for platinum-resistant recurrent ovarian cancer, there are still many restrictions or contraindications preventing certain women from receiving bevacizumab's combination treatment. The goal of this study is to improve upon the activity of PLD in a safe manner to provide a more effective therapeutic option for this group of patients.

The purpose of this study is to assess maplirpacept (PF-07901801) administered in combination with PLD in patients with platinum-resistant ovarian cancer and for whom PLD is a reasonable treatment option. The first portion of the study will evaluate the safety of increasing dose levels of maplirpacept (PF-07901801) in combination with PLD at 40 mg/m2 in patients with platinum-resistant EOC (epithelial ovarian cancer). This is a group of cancer, including ovarian, peritoneal, and fallopian tube malignancy. The aim of the first portion of the study is to establish a combination regimen for further assessment in a dose expansion cohort.

The study will consist of a 28-day screening period to ensure participants are qualified for the study treatment plan. During the treatment period, patients will receive maplirpacept (PF-07901801) in combination with PLD in 28-day cycles until their disease progresses or unacceptable toxicity develops. There will be a long-term follow-up period in this study to assess overall survival (length of time since start of treatment patients are alive).

Pegylated liposomal doxorubicin (PLD) is a standard treatment option for patients with platinum-resistant ovarian cancer who are not candidates for chemotherapy in combination with bevacizumab. However, despite being consider a standard treatment option, the clinical benefit of chemotherapy for this patient population is small. The goal of this clinical trial is to improve upon the activity of PLD in a safe manner to provide a more effective therapeutic option for this group of patients.

C4971002 (TTI-622-02) is a multi-center, open-label study designed to evaluate maplirpacept (PF-07901801) administered in combination with PLD in patients with platinum-resistant ovarian cancer and for whom PLD is a reasonable treatment option. The first portion of the study will evaluate the safety of increasing dose levels of maplirpacept (PF-07901801) in combination with PLD at 40 mg/m2 in patients with platinum-resistant EOC, including ovarian, peritoneal and fallopian tube malignancy, and establish a combination regimen for further evaluation in a dose expansion cohort. The study will consist of a 28-day screening period, a treatment period in which patients will receive maplirpacept (PF-07901801) in combination with PLD in 28-day cycles until documentation of objective disease progression or development of unacceptable toxicity, and a long-term follow-up period to assess overall survival.

Eligibility Criteria:
Key Inclusion Criteria:

* Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1
* Histologically-confirmed epithelial ovarian cancer (EOC), fallopian tube carcinoma (FTC) or primary peritoneal carcinomas (PPC).
* Platinum-resistant recurrent (disease progression ≤6 months after the most recent platinum-based treatment regimen (date calculated from the last administered dose of platinum) or the participant is no longer able to receive.

or declined treatment with platinum-based chemotherapy.

* Progression with standard of care therapies, including platinum-based therapies, poly ADP ribose polymerase (PARP) inhibitors or bevacizumab in the platinum-sensitive setting or intolerability to such therapies or patient refusal
* Measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
* Adequate organ and hematologic function
* No more than four prior treatment regimens for platinum-resistant disease
* All adverse events from prior treatment must be the Common Terminology Criteria for Adverse Events (NCI CTCAE) v5 Grade ≤ 1, except alopecia and stable neuropathy, which must have resolved to Grade ≤ 2 or baseline.

Key Exclusion Criteria:

* Platinum-refractory disease (defined as progression on or within 3 months of completing primary first-line platinum-based treatment)
* Non-epithelial histology, including malignant mixed Mullerian tumors
* Ovarian tumors with low malignant potential (i.e., borderline tumors), low grade serous ovarian cancer or carcinosarcoma
* History of acute coronary syndromes.
* History of or current Class II, III, or IV heart failure.
* History or evidence of known central nervous system (CNS) metastases or carcinomatous meningitis.
* Significant bleeding disorders, vasculitis or a significant bleeding episode from the Gastrointestinal (GI) tract.
* History of severe hypersensitivity reactions to antibodies.
* Systemic steroid therapy.
* History or autoimmune disease that has required systemic treatment with disease-modifying agents, corticosteroids, or immunosuppressive drugs.
* Prior organ transplantation including allogenic or autologous stem cell transplantation
* Prior treatment with anti-cluster of differentiation 47 (CD47) or anti-SIRPα therapy.