Bristol-Myers Squibb Co's eagerly anticipated experimental drug ipilimumab extended survival of previously untreated patients with advanced melanoma in a late stage study, the company said.
Details of how much longer patients who were suffering from the deadly skin cancer lived after taking the highly promising Bristol drug will be unveiled at a major medical meeting in June.
Extending overall survival — the primary goal of the study — is considered the gold standard for cancer drug trials.
U.S. health regulators are expected to approve ipilimumab this week based on results of a different study of patients who had received prior treatment for advanced melanoma.
In that study the Bristol-Myers drug extended survival by an average of four months, which was seen as a major advance for a disease littered with drug failures and for which there are really no effective treatment options.
The Food and Drug Administration in November delayed its approval decision to give it more time to review data on the medicine, setting a new action date of March 26.
"Ipilimumab is an exciting drug, especially given the dearth of effective therapies for this bad form of cancer," Sanford Bernstein analyst Tim Anderson said in a research note.
Advanced melanoma is one of the deadliest cancers and can quickly spread from the skin to internal organs, such as the brain. Once melanoma spreads to other organs the average survival is typically only six to nine months.
The Phase III study of previously untreated patients compared ipilimumab in combination with chemotherapy against chemotherapy alone.
Patients in the study had stage III or stage IV melanoma. Stage IV is the most advanced form of the disease.
"If prior results are any gauge, then the drug likely gives a meaningful two-year survival benefit compared with monotherapy treatment and will likely show again that a smaller proportion of patients (15 percent of so) have a near-cure like response, said Anderson, who forecast worldwide ipilimumab sales reaching $1.7 billion in 2015.
The promise of ipilimumab has created new hope for desperately ill patients, many of whom in the earlier study survived well beyond the four-month average. At the time those results were unveiled last June, more than 20 percent of those who took the drug were still alive after two years
A consensus forecast of four analysts compiled by Thomson Reuters calls for ipilimumab sales to reach about $820 million by 2015.