All patients on this study will receive Pegylated Liposomal Doxorubicin (PLD) as standard of care combined with pembrolizumab and ALX148 iv every 21 days. Treatment of 45 mg/kg Q3W ALX148 in combination with pembrolizumab + chemotherapy will continue until disease progression or unacceptable grade 3/4 toxicities. For patients with a complete response to therapy, maintenance therapy with pembrolizumab and ALX148 will be continued for 12 months. Patients will have up to 4 weeks of screening, and will be treated until disease progression, patient withdraws consent, unacceptable toxicity occurs, complete response or the study is terminated. Patients may continue treatment after radiographic progression if, in the judgment of the treating investigator the patient is deriving clinical benefit from study treatment by demonstrating an absence of clinical symptoms or signs indicating clinically significant disease progression; no decline in performance status; absence of rapid disease progression or threat to vital organs or critical anatomical sites. A follow-up visit will occur within between 28 days and 35 days after the last treatment.
Immunotherapy with immune checkpoint inhibitors, including pembrolizumab, have emerged as a promising option in several solid cancers with durable effect and low toxicity profile. However, the benefit is limited to smaller subset of solid tumors. This trial involves the enhancement of current immune checkpoint-based immunotherapy with ALX148, an agent that inhibits CD47 (a trans-membrane protein that is highly expressed on the surface of many solid tumors as compared to normal cells).