(ChemotherapyAdvisor) – Adding algenpantucel-L immunotherapy to standard adjuvant treatment may improve survival in patients undergoing R0/R1 resection for pancreatic cancer, results of a Phase 2 study presented at the Society for Surgery of the Alimentary Tract, part of Digestive Disease Week, in San Diego May 22 has found.
The open-label, dose-finding, multi-institutional study enrolled 70 patients; median age was 62 years and 47% were female. A total of 81% were lymph node positive. Median tumor size was 3.2cm (range, 2–15cm; 25% >4cm) and 17% had a postoperative CA19-9 ≥180U/mL. Patients received algenpantucel-L 100million or 300million cells/dose and gemcitabine + 5-fluourouacil chemoradiation.
Algenpantucel-L comprises irradiated, live, allogenic human pancreatic cells expressing the enzyme α1,3 galactosyl transferase (α-CT), the major barrier to xenotransplantation from lower mammals to humans, the study investigators noted. “Up to 2% of circulating human antibodies are directed against the α-CT epitope of algenpantucel-L and are the proposed mechanism of initiating the anti-tumor immune response.”
At a median follow-up of 21 months, patients had received a mean of 12 doses (range, 1–14 doses) of algenpantucel-L immunotherapy plus standard adjuvant therapy. The primary endpoint of disease-free survival was a median of 14.3 months in 63% of patients.
Subgroup analysis showed that patients receiving 300million cells/dose had a longer 12-month disease-free survival than those receiving 100million cells/dose, 81% vs 52%, respectively (P=0.02). Overall survival, a secondary end point, was 86% at 1 year for the entire cohort. The subgroup receiving 300million cells/dose tended toward a longer overall survival, 96%, than the subgroup receiving 100million cells/dose (80%; P=0.053).
Algenpantucel-L was well tolerated; there were no grade 4 or 5 adverse events and 9 grade 3 adverse events directly or possibly related to immunotherapy. The most common adverse events were injection-site pain and induration.
A randomized Phase 3 trial of up to 18 immunizations of 300 million immunotherapy cells of algenpantucel-L plus standard gemcitabine and 5-FU chemoradiation vs. gemcitabine and 5-FU chemoradiation alone is currently enrolling; anticipated enrollment is 700 patients.
Algenpantucel-L, developed by NewLink Genetics Corporation, Ames, IA, is also known as HyperAcute Pancreas Immunotherapy and HAPa-1 and HAPa-2 immunotherapy components. The product candidate has received Fast Track and Orphan Drug designations from the U.S. Food and Drug Administration.