New details on Perjeta supply concerns

FDA provided new details Wednesday about the approval of Perjeta pertuzumab and revealed that the agency's manufacturing and product quality staff had recommended withholding approval of a BLA for the breast cancer drug until Genentech Inc. resolved manufacturing problems discovered in March. On Friday, FDA approved only Perjeta that contains drug substance produced during 2010 that was unaffected by the recent problems.

According to an agency review document released Wednesday, the staff had expressed concern that Genentech has yet to demonstrate a consistent process that would ensure continued supply of commercial material. FDA generally requires validation of a manufacturing process to be completed before approval. However, the agency said Perjeta's 6.1 month improvement in progression-free survival (PFS) in the CLEOPATRA study "suggests a meaningful clinical benefit" and outweighs the risk of a future disruption of drug supply. Details on the specific manufacturing issues and the amount of Perjeta produced in 2010 were redacted from the document. Genentech referred to the manufacturing issue as a "cell growth issue," but declined to elaborate. The company did say it expects to meet demand for the drug. ...