Genentech's application for Perjeta (pertuzumab ) won marketing approval from the US Food and Drug Administration (FDA) on 8 June, bringing to market a new-and expensive-biologic product for the treatment of advanced breast cancer.
Perjeta is a humanized monoclonal antibody, and works in conjunction with Herceptin (trastizumab) to further reduce the growth of HER2-positive cancerous cells in breast cancer patients. The HER2 gene is associated with approximately 20% of breast cancers. In a clinical trial of 808 subjects, patients treated with the combination therapy experienced a median progression-free survival of 18.5 months versus 12.4 months for those treated with a placebo.
In a press announcement, FDA said despite the product's approval, it was limiting its approval to limited lots of the drug as the result of production issues that could "potentially affect the long-term supply of the drug."
"Given the need for additional treatments for metastatic breast cancer, we made the decision to approve this drug today and not to delay its availability to patients pending resolution of the production issues relating to future supply," said Janet Woodcock, MD, director of FDA's Center for Drug Evaluation and Research. "Genentech is currently developing a plan to mitigate the effect on patients of any potential shortage of Perjeta."
The approval is the first since-though unlikely to be associated with-the release of new draft guidance from FDA that agency officials say has the potential to revolutionize the speed at which FDA reviews and potentially approves new breast cancer treatments.
The 29 May draft guidance, Pathologic Complete Response in neoadjuvant Treatment of High-Risk Early-Stage Breast Cancer: use as an Endpoint to Support Accelerated Approval, describes instances in which the agency will see fit to accept surrogate endpoints as proof of a product's effectiveness. Companies would still be required to conduct postmarket testing to assess their product's true measures of effectiveness.
In an interview with Reuters the week after the release of the guidance, FDA's Richard Pazdur, director of FDA's Office of Oncology Drug Products, said the goal of the guidance is to introduce potentially curative therapies to women who would otherwise require surgery to remove the cancer. "The aim of this therapy would be to cure the woman of breast cancer," Pazdur said. "It's moving a very promising drug into an early stage of the disease with a curative intent."
Regardless of Perjeta's effectiveness, patients and their insurers may find themselves experiencing sticker shock at the price of a course of treatment. The New York Times reports an 18-month treatment cycle involving both Perjeta and Herceptin is expected to cost $187,000, making the drug combo among the most expensive in the world.
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