UPDATED: Amgen scores PhIII success with BioVex virus against melanoma

Roger Perlmutter--Courtesy of Amgen

Amgen ($AMGN) touted top-line results from a Phase III trial of an anti-cancer virus as a treatment for a deadly form of skin cancer, showing that talimogene laherparepvec met the primary goal for shrinking tumors in patients with late stages of the disease. The data indicate that the biotech giant and ex-R&D chief Roger Perlmutter, the new research czar of Merck ($MRK), may have gambled wisely in acquiring the program and developer BioVex two years ago for up to $1 billion.

Last month Amgen highlighted the engineered cold sore virus as one of the most important advanced therapies in its pipeline, which is expected to yield late-stage data for 8 new treatments between this year and 2016. While Amgen R&D boss Sean Harper aims to pick winners based on matching drugs with genetically validated targets, he inherited talimogene laherparepvec and other late-stage candidates from his predecessor Perlmutter, who Merck announced would take over for Peter Kim as its top research exec earlier this month.

R&D chief Sean Harper--Courtesy of Amgen

Talimogene laherparepvec (formerly OncoVex) could offer a new weapon against melanoma, which accounts for only 5% of skin cancers yet 75% of skin cancer deaths, according to figures cited by Amgen. Hitting its primary endpoint, the study showed that 16% of trial patients on the engineered virus had a durable response compared with 2% of those on the control therapy GM-CSF. Amgen also revealed a trend toward overall survival in favor of its virus compared with GM-CSF.

In the study of more than 400 patients, the most common serious adverse events included disease worsening, cellulitis and pyrexia. Chills and fatigue were among the frequent adverse events. Amgen plans to report more safety and efficacy data at the major annual ASCO meeting, which kicks off May 31. Overall survival data are expected in late 2013.

"These are the first Phase 3 results of this novel approach to cancer therapy," Amgen's Harper said in a statement. "A high unmet need exists in melanoma and we believe the innovative mechanism of action of talimogene laherparepvec may offer a promising approach for these patients."

Until Amgen produces some solid OS rates, though, a number of analysts will remain on the sidelines as to whether the biotech giant has a shot at market success. Amgen likely will have to wait until the arrival of OS data later this year before it can file for an approval, said ISI's Mark Schoenebaum in a note to investors. "In our view, OS is the single most important data point to track for this trial (both from regulatory and commercial perspective)."

Amgen executives weren't available for interviews about the program on Tuesday evening.

Thousand Oaks, CA-based Amgen scooped up the program via its March 2011 buyout of Woburn, MA-based BioVex (a 2009 Fierce 15 company) for $425 million upfront and up to $575 million milestones. Featuring a multi-pronged attack on tumors, talimogene laherparepvec is designed to replicate inside tumor cells until they burst as well as trigger immune responses against malignancies.

- here's Amgen's release
- see Forbes' article

Special Report: Talimogene laherparepvec (OncoVex) – Top 10 Late-Stage Cancer Drugs – 2012