Approval for MS Pill: Merck Serono Takes a Shocking Tumble

The US FDA has refused to file Merck Serono's application for oral cladribine as a treatment for relapsing-remitting multiple sclerosis (RRMS). News of the agency's surprising decision was provided yesterday in a company press release.

Merck Serono submitted its NDA for the fast-track approval of oral cladribine at the end of September. According to yesterday's press release, the FDA acted within its allotted 60-day time frame to determine whether the company's NDA permits a "substantive review"; the agency evidently determined that the application was not "sufficiently complete."

Merck Serono states that it will request a meeting with FDA officials to understand and remedy any deficiencies of its NDA for oral cladribine. (The FDA's possible reasons for refusing to file an NDA can be found here.)

Data to support the review and approval of oral cladribine as a treatment for RRMS include the CLARITY and ORACLE MS studies, both of which are 2-year, placebo-controlled, phase 3 trials of monotherapy. A phase 2 study of oral cladribine as add-on therapy to interferon beta, the ONWARD study, was also used to support the NDA. Although publicly presented, none of these studies (to the best of my knowledge) has been printed in a peer-reviewed journal.

Another oral MS therapy, Novartis's fingolimod, is also in late-stage clinical development for RRMS. The company has indicated that it will submit an NDA for approval in the United States and Europe at the end of this calendar year...which is nigh approaching.

CLARITY = Cladribine Tablets Treatment MS Orally; ORACLE MS = Oral Cladribine in Early MS; ONWARD = Oral Cladribine Added on to Interferon Beta-1a in Patients With Active Relapsing Disease.