The panel will review a 417-woman study comparing Perjeta in different combinations against older breast cancer treatments. When Perjeta was combined with Herceptin, another Genentech drug, and standard chemotherapy, 39 percent of women saw their cancer reach undetectable levels.
Only 21 percent of women experienced the same results from taking Herceptin and chemotherapy alone. After drug treatment all the women received standard breast surgery to remove any cancerous tumors. Genentech says this surgery allowed researchers to confirm the presence or absence of cancer.
Last year the FDA released guidelines for studying breast cancer drugs in the pre-surgical setting, with the aim of accelerating approval of promising therapies. Perjeta is the first drug to undergo FDA review since those recommendations were released. If approved, it could encourage more drugmakers to study cancer drugs for early-stage use.
“Despite advances in systemic therapy of breast cancer, there remains a need to expedite drug development and approval of highly effective therapies for patients with high-risk early-stage breast cancer,” the FDA states in its review.
Like Herceptin, Perjeta only works in a subset of about 20 percent of breast cancer patients who have tumors that overproduce a protein known as HER-2, which makes cancer cells rapidly divide and grow.
Breast cancer is the second most deadly form of cancer in U.S. women, and is expected to kill more than 39,000 Americans this year, according to the National Cancer Institute. About 6,000 to 8,000 deaths per year are attributed to the HER-2 form of the disease.
FDA scientists stress in their review that Genentech’s results are preliminary and will have to be confirmed in future trials. The company only measured the patients’ immediate response to the drug, and did not submit follow-up data showing whether the cancer returned or whether women ultimately lived longer.
But agency scientists said the company’s approach “is reasonably likely to predict clinical benefit,” and noted that Genentech is already enrolling patients in a late-stage trial that could confirm the results.