During its May 3 meeting, the FDA Oncologic Drugs Advisory Committee reviewed data on efaproxiral (RSR13), a “radiation sensitizer” intended to be used as an adjunct to radiation therapy to make it more effective, and oblim- ersen (Genasense), part of a new class of “antisense” drugs thought to inhibit the production of proteins that protect cancer cells from treatments like ra- diotherapy and chemotherapy.Efaproxiral was being considered as an adjunct to whole brain radiation therapy (WBRT) for brain metastases in patients with breast cancer. Ap- proximately 20-30 percent of breast cancer patients develop brain metas- tases. In a 538-patient, randomized, open-label trial, the combination of WBRT and efaproxiral failed to im- prove overall survival compared to WBRT alone. A subgroup analysis not called for in the original trial de- sign, however, found that the WBRT/ efaproxiral combination nearly