AMGEN (NASDAQ: AMGN) today announced additional results from a pivotal Phase 3 trial evaluating talimogene laherparepvec in patients with unresected stage IIIB, IIIC or IV melanoma compared to granulocyte-macrophage colony-stimulating factor (GM-CSF). Results of the study's key secondary endpoints will be presented during a poster session at the 17th ECCO – 38th ESMO – 32nd ESTRO European Cancer Congress in Amsterdam (Abstract No. 3733 / P479).
New data presented include investigator assessments of response: the durable response rate (DRR) was 19 percent with talimogene laherparepvec as compared with one percent for the GM-CSF arm, and the objective response rate was 31 percent versus six percent in the GM-CSF arm. Overall there was a high degree of correlation between the independent and investigator assessments. Key secondary endpoints include time to response and duration of response by independent assessment. The median time to response was 4.1 months (range 1.2 months – 16.7 months). The duration of response was longer in the talimogene laherparepvec arm, with an estimated 68 percent of talimogene laherparepvec responders achieving responses lasting at least nine months compared to 47 percent among the GM-CSF responders.
“These results further support the primary analysis reported at ASCO which demonstrated a statistically significant durable response rate,” said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. “We look forward to the mature overall survival data expected next year.”
“This is the first successful Phase 3 study of a novel oncolytic immunotherapy,” said Howard Kaufman, M.D., professor and director of the section of surgical oncology in the Department of General Surgery, Rush University Medical Center in Chicago. “The fact that this study met the primary endpoint shows the value of continuing to explore the potential of talimogene laherparepvec in regional and distant metastatic melanoma.”
The most frequently observed adverse events were fatigue, chills and pyrexia. The most common serious adverse events include disease progression, cellulitis and pyrexia. Serious adverse events occurred in 26 percent of talimogene laherparepvec patients and 13 percent of GM-CSF patients.
This trial was a global, randomized, open-label, Phase 3 trial to evaluate the safety and efficacy of talimogene laherparepvec compared to a control therapy with GM-CSF in over 400 patients with unresected stage IIIB, IIIC or IV melanoma.
Patients were randomized 2:1 to receive either talimogene laherparepvec intralesionally every two weeks or GM-CSF subcutaneously for the first 14 days of each 28 day cycle. Treatment could last for up to 18 months. Where appropriate, stable or responding patients could receive additional treatment on an extension protocol.