Bristol-Myers (BMY 0.43%) updated investors on its prolific research program for the cancer drug nivolumab this week. The news came in a flurry Wednesday, beginning with a new combination study planned with Celldex, and culminating with updated data for nivolumab in lung and kidney cancer.
Out of all the news, investors seemed to focus on disappointing results from a study combining nivolumab with Bristol's Yervoy, a drug already approved as a treatment for melanoma.
However, that focus may be misplaced given that Bristol continues to push nivolumab forward across a slate of big-market indications.
The lung cancer stumble
Patients in the mid-stage study who received both nivolumab and Yervoy saw tumors shrink; however, adverse events occurred in almost half of the patients, causing some to discontinue treatment.
While the data didn't blow analysts away, Bristol remains confident that the combination regimen has merit. Bristol plans to advance the therapy into phase 3 trials later this year.
Growing book of evidence
So far, nivolumab has been highly successful in treating melanoma patients. Updated results in March show that median overall survival was 16.8 months for patients receiving nivolumab, and data released this week shows patients had a 48% survival rate at two years, and 41% survival rate at three years. Those results are pretty impressive considering thatmost patients in the trial had seen cancer progression despite two to five prior treatments.
Nivolumab also has some potential as a third-line non-small cell lung cancer treatment. Previously treated patients receiving nivolumab saw survival rates of 42% at one year, and 24% at two years. That success in tough-to-treat patients has sparked Bristol's plans to file nivolumab for a rolling approval with the FDA by year end.
While results from the nivolumab and Yervoy lung cancer study may not have impressed investors, results from a kidney cancer trial combining the two were solid. Patients' overall response rate to the regimen was between 43% and 48%, and progression-free survival rates ranged between 64% and 65% at 24 weeks.
Nivolumab may also benefit kidney cancer patients when used without Yervoy. In phase 2 trials, overall survival was between 63% and 72% at one year.
Racing to market
Bristol's nivolumab isn't the only promising PD-1 drug currently under development. Merck (MRK 0.92%) is also advancing MK-3475 through the clinic, and will likely beat Bristol to filing for conditional approval in advanced melanoma. During trials, 81% of advanced melanoma patients treated with MK-3475 were alive following 12 months of therapy.
Overall, Merck is studying MK-3475 across eight trials and 3,000 patients as a potential treatment for skin cancer and non-small-cell lung cancer. Those are huge markets that could make MK-3475 a blockbuster, and the FDA's recent granting of priority review for the drug could mean an approval by October.
Roche(RHHBY 1.64%) is also working on a PD-L1 therapy, MPDL3280A, which is matching up with its Zelboraf in a phase 1 trial treating advanced melanoma. Zeboraf won FDA approval for advanced melanoma back in 2011 and, if the combination results are strong, Roche thinks sales could head significantly higher than the $400 million Zelboraf registered last year.
In addition to melanoma, Roche is also studying its PD-L1 therapy in bladder cancer, and plans to update investors with data from its early-stage study. Among 20 people treated, half responded to Roche's drug, with average tumor size shrinking by 30%.
Fool-worthy final thoughts
Developing new drugs isn't easy, and developing new cancer drugs is especially difficult. Just 7% of all cancer drugs entering phase 1 ever make it to market. That suggests investors shouldn't be too surprised to see nivolumab come up short somewhere.
A lot of attention will focus on Bristol and Merck's competing PD-1 drugs at ASCO in a few weeks, so investors should stay tuned in to see if more complete data sways opinions. However, given the growing need and significant spending associated with oncology treatment, selling Bristol's shares may not be the right decision for long-term investors.
