Talimogene laherparepvec showed favorable results in patients with metastatic melanoma

Patients with metastatic melanoma treated with talimogene laherparepvec experienced longer overall survival than those treated with granulocyte-macrophage colony-stimulating factor in a phase 3 study, according to results released by Amgen.

Researchers conducted an open-label trial of more than 400 patients with unresected stage IIIB, IIIC or IV melanoma who were randomly assigned talimogene laherparepvec intralesionally biweekly or control therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF) subcutaneously for the first 14 days of each 28-day cycle, according to a press release. Study results were to be presented at the Society for Melanoma Research Congress in Philadelphia.

Talimogene laherparepvec, an investigational immunotherapy designed to selectively replicate tumor tissue and initiate a systemic antitumor immune response, is injected directly into tissue. It is intended to cause lytic cell death and release tumor-specific antigens.

Patients treated with talimogene laherparepvec had a median overall survival of 23.3 months, compared with 19 months for the GM-CSF treatment cohort (HR=0.79; 95% CI, 0.61-1.02). There were pronounced survival rate differences in a subset of patients with stage IIIB, IIIC or IV M1a disease (HR=0.56; 95% CI, 0.38-0.81) or who received first-line treatment with talimogene laherparepvec (HR=0.49; 95% CI, 0.33-0.74), with each cohort comprising about 50% of the patient population, according to the release.

“The interim overall survival subset results complement the durable response data we reported earlier this year and these endpoints appear to correlate with each other in terms of where the most benefit is being seen in this trial,” Sean E. Harper, MD, executive vice president of research and development at Amgen, said in the release. “We look forward to the mature overall survival data expected in the first half of next year.”

Adverse events included fatigue, chills and pyrexia. Serious adverse events (SAEs) included disease progression in both treatment groups and cellulitis and pyrexia in the talimogene laherparepvec cohort. SAEs were experienced by 26% of patients treated with talimogene laherparepvec and 13% of patients treated with GM-CSF.