- Merck & Co. can add another late-stage clinical success to the resume of its cancer immunotherapy Keytruda, reporting April 15 that treatment with the PD-1 blocker helped stave off recurrence of melanoma in a greater number of study participants than did placebo following surgical removal of patient tumors.
- In the study, called KEYNOTE-054, adjuvant treatment with Keytruda of Stage 3 melanoma reduced the risk of disease recurrence or death by 43% versus placebo. At one year, recurrence-free survival was reported in 75% of patients compared to 61% of those on placebo.
- In melanoma, Merck is playing catch-up to Bristol-Myers Squibb Co.'s Opdivo, which holds an edge in sales and recently secured an updated label that allows for a more convenient dosing option for patients.
For high-risk patients with Stage 3 melanoma who have already had surgery, the news Keytruda (pembrolizumab) outperformed placebo is welcome. But for Merck, Keytruda is arriving behind two rival therapies marketed by Bristol-Myers. Both of the New Jersey-based pharma's immunotherapies, Opdivo (nivolumab) and Yervoy (ipilimumab), carry approvals as an adjuvant treatment in the same population of melanoma patients.
Merck's results for Keytruda in melanoma were released Sunday during the annual meeting of the American Association for Cancer Research. The Phase 3 study is just one of the many studies evaluating Keytruda for melanoma — the company has enrolled approximately 4,500 patients across 10 clinical studies to look at the drug's efficacy as a monotherapy and as an adjuvant treatment.
Analysts from Cowen, an investment firm, were quick to compare Keytruda's data with results from Bristol-Myers' CheckMate-238 study, which pitted Opdivo against Yervoy in a similar setting.
Although cross-trial comparisons are always challenging, Opdivo appeared to show a broadly similar benefit, although it was compared to an active control. Merck, on the other hand, pitted Keytruda against placebo.
In Bristol-Myers' study, treatment with Opdivo led to a recurrence-free survival (RFS) in 66% of patients at 18 months, compared to only 53% of patients on Yervoy.
At a comparable time point in Merck's study, Keytruda showed a RFS rate of 71% versus 53% for the placebo arm.
Bristol-Myers currently earns between 14% and 20% of its U.S. sales of Opdivo from the drug's indication in melanoma, while roughly 15% of Keytruda sales come from that cancer type.
Both Merck and Bristol-Myers are searching for any possible competitive advantage to help secure broader share, including those related to dosing regimens.
In early March, Bristol-Myers announced it had won U.S.approval for an update to Opdivo’s label, allowing for flexible flat-dosing options every two weeks (240 mg) or every four weeks (480 mg). In addition, Opdivo was approved for a shorter 30-minute infusion across all approved indications.
This additional dosing schedule could prove to be preferable for patients. In melanoma, the second dosing schedule could mean that post-resection Stage 3 melanoma patients could get as few as 12 doses per year of Opdivo, compared with 18 doses per year with Keytruda.