Researchers from OSI Pharmaceuticals, Inc found that the appearance of a rash in cancer patients treated with erlotinib (Tarceva) is strongly associated with longer survival.

This is not the first time that rash has been associated with a survival advantage with EGFR inhibitors - a class of drugs which includes erlotinib, cetuximab, panitumumab and others designed to block overproduction of the epidermal growth factor receptor - but it is the most detailed analysis to date.

The study, published in the July 1 issue of Clinical Cancer Research, a journal of the American Association for Cancer Research, reports that for patients taking Tarceva who developed a moderate to severe rash, survival without progression of disease was 245 percent longer than in patients who had a mild rash or none at all. In fact, in the majority of cases, the more severe the rash, the longer a patient's cancer was held in check, researchers found.

This rash, which often looks like acne, can be unpleasant enough for some people to consider discontinuing treatment, but "it is important for physicians and patients to understand that this a positive event because it means there is likely to be a better clinical outcome," said the lead author, Bret Wacker, MS Director of Biostatistics at OSI Pharmaceuticals, Inc.

"Further studies are needed to both identify patients most likely to develop rash and to determine if dose escalation to induce rash can improve efficacy."