The US Food and Drug Administration (FDA) approved two new drug entities for treating, respectively, certain forms of breast cancer and multiple myeloma on Friday, 20 July. The approvals capped off a busy week for the agency, marking the fourth approval and second new molecular entity in the five-day period.

Afinitor (everolimus), manufactured by Novartis Pharmaceuticals, was approved for the treatment of postmenopausal women with advanced formone-receptor positive, HER2-negative breast cancer. The drug was first approved in 2009 for the treatment of advanced renal cell carcinoma after failure of treatment with sunitinib or sorefenib.

FDA's 20 July approval of the drug for a new indication highlights the drug's status as a first-in-class drug for breast cancer. "This is the first approval from the class of drugs known as mTOR inhibitors for the treatment of postmenopausal women with advanced hormone-receptor positive breast cancer," said Richard Pazdur, director of the Office of Hematology and Oncology Products in FDA's Center for Drug Evaluation and Research (CDER).

Pazdur added that the drug's approval is "another example of the value of continuing to study drugs in additional types of cancer after their initial approval."

Kyprolis for Multiple Myeloma

The agency's second approval was for Onyx Pharmaceuticals' Kyprolis (carfilzomib), indicated for the treatment of multiple myeloma. The new molecular entity is intended for use in patients with particularly aggressive forms of myeloma who have already received Velcade (bortezomib) and immunomodulatory therapy yet continue to see disease progression.

The drug received approval under FDA's accelerated approval regulations, and Onyx will be required to complete its clinical trial comparing the safety and efficacy of Kyprolis with lenalidomide dexamethasone by December 2013. Interim results of the trial formed the basis of approval, and complete results of the trial are due to FDA by June 2014.

Onyx will also be required to conduct six additional postmarketing studies for the drug to assess its potential for cardiac toxicities, pulmonary toxicities, and the general safety of Kyprolis when patients receive a standard, 30-minute intravenous infusion. A final trial will assess whether the drug is suitable for use in patients with "varying degrees of renal impairments and those on chronic dialysis," wrote FDA in its approval letter.

The approvals were FDA's third and fourth of the week, coming days after the agency approved Vivus Inc's Qsymia (phentermine and topiramate) for the treatment of obesity and Ferring Pharmaceuticals' Prepopik (sodium picosulfate, magnesium oxide and citric acid) for use in colonoscopy preparation.

Read more:

FDA approves Afinitor for advanced breast cancer

FDA approves Kyprolis for some patients with multiple myeloma