“This study shows a potential new treatment paradigm in oncology and is the first active immunotherapy to demonstrate improvement in overall survival (OS) for metastatic CRPC (castrate-resistant prostate cancer),” said Shore
Shore said the effect was upheld with longer follow-up and that the majority of the most common adverse events occurred within one day of infusion, were mild and moderate in severity ( < Grade 2) and resolved within one to two days.
“Response rate and time to progression may not be appropriate endpoints in therapeutic vaccine trials,” Shore said, adding that the use of immune therapy earlier in the natural history of the disease requires further study.
Sipuleucel-T is an investigational autologous active cellular immunotherapy for treatment of prostate cancer. The randomised, double-blind, placebo controlled phase III trial in CRPC showed a significant increase in OS. Adverse events reported more commonly in the sipuleucel-T than the placebo arm included chills, pyrexia, headache, influenza- like illness, myalgia, hypertension, hyperhidrosis and groin pain.
Other findings indicate that prognostic factors were well-balanced with the median predicted OS of patients in the sipuleucel-T and placebo arms were 20.3 and 21.2 months, respectively, using the Halabi model (2003).