Pre-treatment factors affect response to vemurafenib treatment in melanoma

The authors aimed to determine the effect of pre-treatment factors in melanoma patient response and survival when treated with vemurafenib.

Vemurafenib (Zelboraf) is a drug treatment used in advanced melanoma. It targets and kills melanoma cancer cells in patients that have BRAF V600 melanoma mutations.

The aim of this study was to consider pre-treatment factors in regards to patient response and survival when treated with vemurafenib.

300 patients were used in this study with a follow-up time of 13 months. 65% of patients had the BRAF V600 mutation.

All patients were given the same initial dose of vemurafenib. 12.7% needed a reduced dose due to side effects. 57.7% of patients experienced a complete response (disappearance of all cancer signs as a result of treatment) or partial response (cancer responded to treatment but did not go away) to treatment. 22.3% showed stable disease (cancer is neither increasing or decreasing in size) and 15.7% experienced cancer progression despite treatment. The average progression-free survival (time after treatment that the patient lives with the cancer without getting worse) was 5.1 months and the overall survival (time from treatment that patients diagnosed with melanoma are still alive) was 7.6 months.

Patients who were older (over 55 years) had a better survival rate than younger patients. Patients with a V600E mutation had a better response to vemurafenib treatment than patients with other mutations and had a higher progression-free survival of 6.7 months compared to V600K patients at 4.9 months. These patients also had a higher overall survival rate of 12.4 months compared to 10.7 months.

Patients previously treated with immunotherapy had favorable progression-free survival and overall survival rates compared to patients who had received chemotherapy or kinase inhibitors.

The authors concluded that pre-treatment factors affect the the outcome of vemurafenib treatment.

Future research needs to be done in this area so that results can be applied across a large population without bias.

If you are considering vemurafenib as a treatment option and would like more information on the effect of previous treatments on vemurafenib success, please consult your doctor.