Citius Pharmaceuticals scored an approval from the FDA on Thursday for its treatment for a rare form of non-Hodgkin lymphoma, bringing to the market a reformulation of a cancer immunotherapy that was previously approved but later withdrawn.
The company’s initial application for approval in relapsed or refractory cutaneous T cell lymphoma (CTCL) was struck down by the FDA in 2023. But it said the FDA’s complete response letter took no issue with the treatment’s safety, efficacy or prescribing information.
Leonard MazurIn a Thursday interview, Citius CEO Leonard Mazur told Endpoints News it was a delay in a manufacturing test that caused the CRL: The company passed the test, but the validation procedure was going to run past the PDUFA date last year.
The approval is based on a Phase 3 trial that showed a 36% overall response rate, a reduction in skin disease in 84% of patients, and pruritus improvement in 31.7% of patients. The approval also comes with a boxed warning for capillary leak syndrome, including life-threatening or fatal reactions.
The company now plans to launch the drug, to be sold as Lymphir, within the next five months. It is the first new targeted systemic therapy approved by the FDA for relapsed or refractory CTCL since 2018, and has a potential market estimated around $300 million to $400 million, according to Mazur.
“We’ve been doing a lot of analysis and we’ve identified where all the treaters are and so forth,” Mazur added. “So with that, we’ll have a sales force that will be a mix of both sales force and medical service liaisons.”
Earlier this month, Citius also announced that the company’s cancer subsidiary, Citius Oncology, will combine with TenX Keane Acquisition in order to support the launch Lymphir.
“The reason we’re doing it — we’ve done it this way is primarily because we didn’t want to dilute Citius Pharmaceutical shareholders anywhere with the raise that’s going to be required for the launch of the drug,” Mazur added. “The funding for all that will take place within Citius Oncology and ultimately the shareholders will benefit from that.”
Citius first licensed the drug from Dr. Reddy’s Laboratories in 2021 with a $40 million upfront payment and the promise of another $110 million more in milestone payments. Dr. Reddy’s had previously licensed it from Eisai, which has steered the drug to approvals in Japan. Eisai will also be in on the deal — it’s set to receive a $6 million development milestone payment now that the drug is approved, on top of additional commercial milestone payments based on net product sales.
The drug, an IL-2-diphtheria toxin fusion protein, is a reformulation of a previously-approved drug called Ontak which left the market voluntarily in 2014 following manufacturing issues.
Citius said that its new formulation has higher purity and 15.2 times greater specific bioactivity, which could overcome the shortfalls of Ontak.