Agenus (AGEN) reported on Tuesday updated results from an open-label, single-arm phase 2 study of Prophage, the company’s cancer vaccine, in glioblastoma multiforme. Patients treated with Prophage plus standard of care lived nearly twice as long as expected, says Agenus, with a median overall survival of 23.8 months. 33% of patients were alive at 2 years and continue to be followed for survival. Prophage-treated patients had a median progression-free survival (PFS) of 17.8 months. AGEN is up 22% in early trading on Tuesday.
The study did not include a control arm, thus the company compares survival and PFS in this trial to Stupp et al’s analysis of radiotherapy plus temozolomide, which produced a 14.6-month median overall survival in 2005.
This was a final analysis of Agenus’ phase 2 study, though it’s worth noting that Agenus reported median overall survival (OS) of 23.3 months and median PFS of 17.8 months last September. The company also presented preliminary results from this study at the American Association of Neurological Surgeons (AANS) Annual Meeting in May of 2013: at the time, data collected showed a median OS of 23.3 months and a PFS of 17 months. Considering that these encouraging results (compared to historical controls) were largely factored into the stock last Summer, we would not be surprised to see AGEN fade Tuesday’s rally; neither of the preceding spikes lasted.
