Elizabeth A. R. Garfinkle, Renzo Perales-Linares, Ryan C. Gimple, Alexandra J. Livingstone, Kaleigh F. Roberts, Omar H. Butt, S. Peter Goedegebuure, Michael D. McLellan, Gue Su Chang, Jasreet Hundal, Jian Yan, Jaye Navarro, Sophia A. Paxton, Srestha Chattopadhyay, Neil Cooch, Alfredo Perales-Puchalt, Konstantina Stavroulaki, Sarah Rochestie, Joann Peters, Beth Junker, Jian L. Campian, Milan G. Chheda, Michael R. Chicoine, Albert H. Kim, Jon T. Willie, Gregory J. Zipfel, Joshua L. Dowling, Christopher A. Miller, Obi L. Griffith, Malachi Griffith, William E. Gillanders, Katherine E. Miller, Elaine R. Mardis, Niranjan Y. Sardesai, Gavin P. Dunn, Tanner M. Johanns
Glioblastoma is a fatal disease with a median prognosis of 12-18 months. Recent studies have shown encouraging results using neoantigen-based vaccines to stimulate glioblastoma-directed immune responses, but overall immunogenicity has been low. Here, we report the results of an open-label, single-arm, phase 1 clinical trial (GT-20) to evaluate the safety and feasibility (primary endpoints) as well as immunogenicity and preliminary clinical activity (secondary endpoints) of GNOS-PV01 monotherapy, a DNA-based personalized therapeutic cancer vaccine administered following surgical resection and radiation for patients with MGMT unmethylated glioblastoma. The GT-20 study vaccinated nine patients, using up to 40 neoantigens per patient (range, 17-40) without causing any serious adverse events, unexpected toxicities or dose-limiting toxicities. The vaccine induced activation and expansion of circulating peripheral T cells in all evaluated patients, except one who was being treated with dexamethasone. The secondary endpoint was to evaluate 6 month progression-free survival and 12 month overall survival; each observed in 66.7% of patients. Median progression-free survival was 8.5 months, median overall survival was 16.3 months and survival at 24 months was 33%, including one long-term survivor still alive 4 years from the time of initial surgery. This study met the pre-specified endpoints and supports the use of GNOS-PV01 as a potentially impactful component of glioblastoma immunotherapy. ClinicalTrials.gov: NCT04015700 .