Zelboraf (vemurafenib) was found to double the survival times of patients with BRAF V600-Mutant Advanced Melanoma, researchers from UCLA’s Jonsson Comprehensive Cancer Center, and 12 other sites reported in NEJM (New England Journal of Medicine. The authors added that the findings of their study will alter how this deadly skin cancer is treated.

The Zelboraf Phase II study involved 132 patients who were treated with vemurafenib and followed for at least 12 months.

The average survival time for patients with with BRAF V600-Mutant Advanced Melanoma is approximately nine months. The researchers report that survival times lengthened to 15.9 months (average) in patients given Zelboraf. Zelboraf blocks a mutated BRAF protein. Senior author, Dr. Antoni Ribas, a professor of hematology/oncology and a researcher at UCLA’s Jonsson Cancer Center, said:

“This study shows that Zelboraf changes the natural history of this disease. This data is beyond what I would have expected. We’re seeing a significant number of patients with durable responses to the drug, and that the whole group of treated patients is living longer. These results tell us that this drug is having a very big impact, and this changes the way we treat metastatic melanoma.”

Dr. Ribas explained that about 4,000 people each year are diagnosed with the BRAF mutation form of melanoma, approximately half of all metastatic melanomas. 53% of them have an objective response to Zelboraf – this means their tumors shrink by over 30%. Another 30% of patients respond to the drug, but to a lesser degree. 14% have no response at all.

The authors describe vemurafenib as a “breakthrough” in metastatic melanoma treatment. Before, up to just 10% of all patients with BRAF V600-Mutant Advanced Melanoma responded to any kind of treatment.

Dr. Ribas said:

“We knew this drug would make the melanomas shrink in a large proportion of patients and that it worked better than chemotherapy. We did not know that patients taking Zelboraf were living longer until now.”

However, even with Zebloraf, the tumors eventually build up resistance. Even so, the scientists believe they may be able to seek out agents that target the mechanisms which get around Zelboraf.

Jonsson researchers mentioned a patient, Louise Belley, aged 60, who says Zelboraf extended her life long enough for her to be able to be there when her daughter graduated from college. Belley was first diagnosed with metastatic melanoma in November, 2007. She received Zelboraf in June 2009 during a Phase I study.

A CT scan performed in September 2009 showed she was clear of cancer, and she is still cancer-free today.

Belley said:

“At first I was devastated by my diagnosis, because I realized I was in a really bad place. But now I feel strongly that the chances are good that I will continue to be cancer free, and I plan to live every day to the fullest.”

In August, 2011, the US FDA (Food and Drug Administration) approved Zelboraf for the treatment of metastatic melanoma. Of the 70,000 new melanoma diagnoses each year in the USA, 8,000 are fatal.

Vemurafenib’s molecular formula is C23H18ClF2N3O3S.

The authors wrote:

“This trial shows a high rate of response to (Zelboraf) in patients with metastatic melanoma and activating BRAF mutations. These results independently confirm the high response rate and response duration shown in a Phase I trial.”

Written by Christian Nordqvist