CHICAGO ( TheStreet) -- Patients with advanced melanoma, a deadly form of skin cancer, are living longer following treatment with two new drugs developed separately by Roche ( RHHBY) and Bristol-Myers Squibb ( BMY), researchers reported Sunday at the American Society of Clinical Oncology annual meeting. While neither drug provides melanoma patients with a cure, the results from phase III studies of Roche's vemurafenib and Bristol's Yervoy are being heralded at this year's ASCO meeting as a triumph of science over a deadly cancer that has long alluded the best efforts of researchers. "The studies presented today highlight tremendous advances in the treatment of metastatic melanoma, said Dr. Lynn Schuchter, a University of Pennsylvania cancer expert. "Until recently, we've had limited options for our patients, and little hope for long-term survival. In the past two years, we've seen remarkable progress with immunotherapy, and now, a promising targeted therapy." Bristol's Yervoy was approved earlier this year and Roche's vemurafenib is still under regulatory review, but both drugs could generate $1 billion or more in sales, analysts say. Roche's vemurafenib is noteworthy in that it is the first drug developed specifically to target and block a mutation known as V600E in the BRAF gene. This mutation is found in approximately half of all melanoma tumors. The phase III study compared the efficacy of vemurafenib to the chemotherapy drug dacarbazine in 675 patients with previously untreated advanced, metastatic melanoma. All patients in the study had the defective mutation in the BRAF gene. At a planned interim analysis, vemurafenib-treated patients had a 63% reduction in risk of death compared to those receiving dacarbazine. Patients who received vemurafenib also had a 74% reduction in the risk of tumor progression or death compared to dacarbazine. All results were statistically significant in favor of vemurafenib. Extending survival is the gold standard for cancer drug clinical trials but in this study, vemurafenib also shrank more tumors than dacarbazine -- with response rates of 48.4% compared to 5.5%. "This is really a huge step toward personalized care in melanoma," said Dr. Paul Chapman, a melanoma expert at Memorial Sloan-Kettering Cancer Center in New York and the lead investigator in the vemurafenib study.