Amgen's closely watched melanoma prospect misses PhIII survival endpoint

Amgen's ($AMGN) cancer-fighting viral vaccine has been rolling through Phase III, producing a series of positive results. But after missing a secondary endpoint in overall survival, the California-based biotech's hot prospect now has a big blot on its resume.

Friday, Amgen announced that while its talimogene laherparepvec (T-Vec) vaccine--designed to infect tumor cells and spur an immune system attack--hit its first goal of durable response in patients with metastatic melanoma, it missed statistical significance on its second objective of boosting overall survival. But the jab wasn't far off, the company pointed out, highlighting a statistical significance trend in its favor with a p value of 0.051.

That trend, according to Amgen R&D Chief Sean Harper, "supports further research of talimogene laherparepvec to better understand its role in melanoma, both as a single-agent and in combination with other therapies." And the company is already testing such combos, examining its shot's results as part of a pair containing Merck's ($MRK) PD-1 checkpoint inhibitor MK-3475, for one.

"The combination of T-Vec with immunotherapy, a drug to boost the immune response, is clearly a logical one," ISI Group analyst Mark Schoenebaum wrote in a note to investors.

As far as using T-Vec on its own, while the company didn't present any subgroup analyses Friday, back in November it disclosed that the virus worked particularly well in patients with stage IIIB, IIIC or IV melanoma and in those taking T-Vec as a first-line treatment.

Friday's results represent a disappointment for a closely watched program that has so far impressed its way through the clinic, shrinking tumors, preventing regrowth and, as reported in November, improving median survival. Before Amgen announced the latest results, Schoenebaum forecast the drug's 2019 sales at around $240 million--a consensus that's now subject to change.

Cancer vaccine development has so far proved a tricky business, and Amgen's candidate is not the only melanoma treatment that has stumbled in trials as of late. Last September, GlaxoSmithKline's ($GSK) MAGE-A3--another high-risk, high-reward vax--sank analysts' hopes by failing to outperform a placebo in a Phase III trial; the British pharma giant is still testing that prospect in melanoma subpopulations.

- read the release
- see FierceBiotech's take

Special Report: Top 10 experimental cancer drugs - 2013 - T-Vec

Suggested Articles

Merck has a big target in mind for its pneumococcal vaccine V114: Prevnar 13, the world's best-selling shot—and its phase 3 program shows it.

A Lancet Infectious Diseases study shows antibody response persists for two years or more after a single shot of Merck’s rVSV-ZEBOV vaccine.

Behind the under-pressure blockbuster Prevnar 13 are several pipeline vaccines Pfizer hopes will propel future growth.