Amgen's cancer-fighting virus boosts melanoma survival in PhIII study

Amgen R&D Chief Sean Harper

In the latest trove of promising Phase III data for Amgen's ($AMGN) T-Vec, the cancer-fighting virus increased overall survival by four months compared to standard growth factor therapy, driving optimism that the drug can win approval and make some noise in the melanoma market.

In interim results, patients taking T-Vec, short for talimogene laherparepvec, posted a median overall survival rate of 23.3 months, besting the 19 months for those treated with the white blood cell-spurring GM-CSF. The virus, designed to infect tumor cells and lead an attack by the immune system, had a particularly strong effect on patients with stage IIIB, IIIC or IV melanoma and on those taking T-Vec as a first-line treatment, Amgen said.

"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," Amgen R&D Chief Sean Harper said in a statement. "We look forward to the mature overall survival data expected in the first half of next year."

As do many in the industry. The latest T-Vec data come on the heels of the drug's 16% durable response rate unveiled in June, and while the combined results suggest an efficacious therapy worthy of the FDA's blessing, analysts want to see some strong final OS numbers before backing T-Vec in the increasingly competitive melanoma space. Competitors like Merck ($MRK), Roche ($RHHBY) and Bristol-Myers Squibb ($BMY) are racking up promising results with PD-1-inhibiting immunotherapies, and it'll be up to Amgen to demonstrate that its virus can hang with a new class of melanoma treatments.

Amgen picked up T-Vec in its $1 billion deal for 2009 Fierce 15 luminary BioVex. The drug, a re-engineered herpes simplex virus, is designed to replicate itself within tumor cells until they burst, all the while stimulating an immune response against the cancer cells.

- read the results

Special Report: Top 10 experimental cancer drugs - 2013