Malignant melanoma has resisted virtually all treatment approaches once it’s metastasized. It’s wonderful that there’s been progress at least for one subset of these patients. Abstract LBA4 ASCO 2011 also.
Early results in a study using the drug vermurafenib in melanoma patients with a specific tumor mutation (GRAF V600E) showed strong evidence of the drug’s efficacy. This mutation is found in 40-60% of patients with cutaneous melanoma. Whether this will result in prolonged remissions and significant life extension remains uncertain.
A previous phase 2 trial with this drug showed a rated of response of 57% with a duration of 6.7 months. A previously unheard of response rate in melanoma. This phase 3 trial compared the drug with dacarbazine alone which has response rates of 7-12% and an overall survival of 5-8 months.
This phase 3 trial found:
A total of 672 patients were evaluated for overall survival. The hazard ratio for death in the vemurafenib group was 0.37 (95% confidence interval [CI], 0.26 to 0.55; P<0.001)The survival benefit in the vemurafenib group was observed in each prespecified subgroup, according to age, sex, ECOG performance status, tumor stage, lactate dehydrogenase level, and geographic region (Figure 1B). At the time of the interim analysis, there were an inadequate number of patients in follow-up beyond 7 months in either study group to provide reliable Kaplan–Meier estimates of the survival curves.17 At 6 months, overall survival was 84% (95% CI, 78 to 89) in the vemurafenib group and 64% (95% CI, 56 to 73) in the dacarbazine group. Further follow-up is required.
Very hopeful, but very preliminary, results.
Medicynical notes: The discussion of the results in the NEJM article reported a relative reduction of 63% in the risk of death and 74% a tumor progression compared with dacarbazine. Dacarbazine is a poor comparator as it probably is not much better than placebo in this very resistant to treatment tumor.
I don’t argue that the new drug is not an advance but touting the improvements in outcome as a percentage rather than actual numbers overstates the benefit–not surprising that this is done in a drug company study.
You might want to look at the Kaplan-Meier survival curve in the article which shows the percent surviving (40%) in the two groups apparently merging at 9 months. The drug offers some benefit but it not a panacea.
Wonder what Roche will charge?