FDA Accepts BLA for Denileukin Diftitox for Those With Cutaneous T-Cell Lymphoma

The FDA has accepted a biologics license application for denileukin diftitox (I/Ontak, E7777; Citius Pharmaceuticals Inc) for the treatment of individuals with persistent or recurrent cutaneous T-cell lymphoma (CTCL).¹

E7777 is an engineered interleukin-2-diphtheria toxin fusion protein. It is a purified and more bioactive formulation of Ontak, which the FDA previously approved.¹

“The acceptance of the previously announced biologics license application submission for [E7777] is another important regulatory milestone for our oncology program,” Leonard Mazur, chairman and CEO of Citius, said in a statement. “We look forward to the potential approval of this therapeutic for patients with persistent or recurrent cutaneous T-cell lymphoma, a rare disease for which patients with advanced disease have limited treatment options.”¹

The Prescription Drug User Fee Act target action date is September 28, 2023. The biologics license application is based on results from a pivotal phase 3 study (NCT01871727).¹

The multicenter study of E7777 was an open-label trial for individuals with persistent or recurrent CTCL, consisting of a lead-in portion to select the recommended dose of the drug during the main parts of the study. The main part of the study was used to evaluate the efficacy of E7777.²

The trial consisted of 3 phases: pretreatment, treatment, and an extension and follow-up period.²

There were 112 individuals included in the study, with a start date was May 30, 2013, a primary completion date of December 6, 2021, and a study completion date of December 14, 2021.²

Investigators administered E7777 9 mcg/kg intravenously over 60 minutes on 5 consecutive days during every cycle of 21 days.²

The primary outcomes of the study were dose-limiting toxicities in the lead-in part of the study during the first 21 days, maximum tolerated dose in the lead-in part of the study for up to 12 months, and overall response rate in the main study from day 1 until disease progression or recurrence, or up to 30 months.²

References

1. Citius Pharmaceuticals Inc announces US Food and Drug Administration acceptance of biologics license application of denileukin diftitox for the treatment of patients with persistent or recurrent cutaneous t-cell lymphoma. Yahoo! Finance. News release. December 1, 2022. Accessed December 2, 2022. https://finance.yahoo.com/news/citius-pharmaceuticals-inc-announces-u-123000919.html

2. A trial of E7777 in persistent and recurrent cutaneous T-cell lymphoma. ClinicalTrials.gov. Updated December 5, 2022. Accessed December 12, 2022. https://beta.clinicaltrials.gov/study/NCT05074472