PD-1 checkpoint inhibition has revolutionized the care of cancer. A small portion of patients with stage IV cancer achieve durable control. But, early progression is common and dramatic control is achieved for only a minority. We hypothesized that ilixadencel, an allogeneic monocyte-derived dendritic cell product could be injected into tumor to potentiate PD-1 response and thus conducted a phase I study of pembrolizumab plus ilixadencel. Twenty-one patients were accrued. The most common treatment emergent adverse events were fatigue, injection site pain, anemia, weight decreased and hyponatremia, mostly grade 1-2. No dose limiting toxicities were observed and the recommended phase II dose was established at 10 million cells administered twice. Two unconfirmed responses were observed, with no confirmed responses.
Keywords: Ilixadencel; dendritic cells; head and neck cancer; immunotherapy; pembrolizumab.
Immunotherapy is an exciting new type of cancer medicine that uses the body’s own immune system to attack cancer. A small number of patients with stage IV cancers are even cured with immunotherapy. We tried to increase the number of patients with dramatic benefit by adding an experimental immunotherapy, called ilixadencel to approved immunotherapy. Ilixadencel is an immune cell type called “dendritic cells” which were injected directly into tumors. While we did show ilixadencil to be safe, efficacy was limitted.