Onyx Pharmaceuticals announced this morning that it has completed submission of its application to the U.S. Food and Drug Administration (FDA) for the approval of carfilzomib (Kyprolis) as a treat­ment for re­lapsed and refractory multiple myeloma.

Onyx began submitting the application in January after the FDA granted car­filz­o­mib "Fast Track" status, which expedites the review process by allowing the submission of application materials on a rolling basis.  The com­pany has requested priority review of the car­filz­o­mib application, which, if granted by the FDA, could allow the drug to be launched in the United States as early as next spring.

The car­filz­o­mib application also was submitted through what is known as an "accelerated approval process," which allows Onyx to file for approval based on Phase 2 data from its "003-A1" study.  Normally, the FDA requires new drug applications to be based on data from more extensive Phase 3 clinical trials.

In Onyx's 003-A1 trial, 266 re­lapsed and refractory myeloma patients were treated with car­filz­o­mib.  Among these heavily pre-treated patients, 24 per­cent responded to car­filz­o­mib for a median duration of 7.8 months (see related Beacon news).

A number of addi­tional car­filz­o­mib studies are ongoing, and the FDA will later review the safety and efficacy results from those studies.  One Phase 3 study is investigating single-agent car­filz­o­mib in re­lapsed and refractory myeloma patients, while another is investigating car­filz­o­mib in com­bi­na­tion with Revlimid (lena­lido­mide) and dexamethasone (Decadron), also in re­lapsed and refractory myeloma patients.

A Phase 1/2 study is investigating the com­bi­na­tion of car­filz­o­mib, Revlimid, and dexa­meth­a­sone as a treat­ment for newly diagnosed myeloma patients.

Until car­filz­o­mib receives FDA approval, the drug is available through Onyx’s expanded access pro­gram for re­lapsed and refractory myeloma patients in the U.S. who do not have any other treat­ment options.

Carfilzomib works similarly to the existing multiple myeloma treat­ment Velcade (bor­tez­o­mib) by preventing the breakdown of protein in cancer cells, triggering their death.

Along with pomalidomide – a chemical relative of multiple myeloma drugs Revlimid and thalidomide (Thalomid) – car­filz­o­mib is considered one of the most promising myeloma treat­ments that could be approved by the FDA in the next few years.

For more in­­for­ma­tion, see the Onyx press release.