FDA Files Application to Convert Denileukin Diftitox to Full Approval for Use in CTCL

Eisai Corporation of North America announced today that the US Food and Drug Administration (FDA) has accepted for priority review a supplemental biologics license application (sBLA) for denileukin diftitox (Ontak). The sBLA seeks to convert an accelerated approval indication into full approval. It is based on a placebo-controlled phase III clinical trial to confirm the clinical effectiveness of the drug in certain patients with cutaneous T-cell lymphoma (CTCL).

Denileukin diftitox is indicated for the treatment of patients with persistent or recurrent CTCL whose malignant cells express the CD25 component of the interleukin (IL)-2 receptor. The safety and efficacy of the agent in patients with CTCL whose malignant cells do not express the CD25 component of the IL-2 receptor have not been examined. Denileukin diftitox was granted accelerated approval under subpart E in February 1999.

Subpart E is an FDA regulation that allows the accelerated approval of a biologic agent based on a surrogate endpoint or an effect on a clinical endpoint other than survival and is most common in serious diseases or for medications that fill an unmet medical need. All subpart E approvals are contingent on the completion of postmarketing clinical trials that confirm a clinical benefit of the biologic agent.