NEW GENE THERAPY FOR SYNOVIAL SARCOMA AND MELANOMA

NEW YORK (Reuters Health) Jan 31 - For the first time, scientists have been able to use cell transfer gene therapy to treat a common cancer other than melanoma, in a study reported online today in the Journal of Clinical Oncology.
"This provides a basis for extending this gene therapy to patients with common cancers," Dr. Steven A. Rosenberg from the National Cancer Institute, Bethesda, Maryland told Reuters Health in an email.
In the study by Dr. Rosenberg and colleagues, autologous lymphocytes genetically engineered to be reactive with the NY-ESO-1 cancer/testis antigen cause tumor regression in patients with metastatic synovial cell sarcoma and melanoma.
There were 17 patients altogether: six with metastatic synovial cell sarcoma and 11 with metastatic melanoma, all bearing tumors expressing NY-ESO-1.
"The patients described in this paper have had all available standard treatment and thus this experimental therapy was their last hope," Dr. Rosenberg said.
Four of the six patients with synovial cell sarcoma showed objective partial responses, with one lasting 18 months. Five of the 11 patients with metastatic melanoma experienced objective responses, including two complete responses (ongoing at 22 and 20 months) and 1 partial response (ongoing at 9 months).
One of six patients with synovial cell sarcoma and six of the 11 patients with melanoma showed significant anti-NY-ESO-1 antibody titers in pretreatment serum samples, but there was no association between pretreatment titers and response.
No toxicities associated with cell transfer were observed. The researchers note that this "contrasts with our previous observation of vigorous on-target toxicity in patients with melanoma treated with T cells engineered to express MART-1- and gp-100-reactive T-cell receptors."
"The antigen that we target (NY-ESO-1) is present on about one-third of common cancers," Dr. Rosenberg said. "Since patients with sarcoma and melanoma respond to this cell transfer gene therapy, we are now treating patients with common cancers that express NY-ESO-1, such as cancers of the breast, colon, and esophagus."
"As we treat more patients we hope to apply to the FDA to receive approval to more widely apply this treatment," Dr. Rosenberg added.
J Clin Oncol. Posted online January 31, 2011. Abstract