Celltrion's Omlyclo: Could U.S. Rival's Patent Suit Prolong Its Solo Run?

Amneal and Kashiv Sued for Patent Infringement
Omlyclo Could Extend Its Market Lead

Celltrion's Omlyclo, the only product currently marketed in the U.S. market for biosimilars of Xolair (ingredient: omalizumab), is expected to benefit from setbacks facing a competitor. The rival product, which had been leading the race to catch up, has been hit by delays in the U.S. Food and Drug Administration (FDA) approval process and now faces the risk of a lawsuit from the maker of the original drug.

Celltrion's Omlyclo product image. Celltrion

According to industry sources on Oct. 23, Genentech and Novartis, the makers of original Xolair, filed a patent infringement lawsuit on Oct. 16 (local time) against U.S. pharmaceutical company Amneal Pharmaceuticals and its subsidiary Kashiv BioSciences. They allege that Kashiv's Xolair biosimilar candidate, ADL-018, infringes nine patents related to the manufacture and use of Xolair.

ADL-018 had been seen as a strong "second-place contender" nearing launch in the U.S. market, where Omlyclo has been the only biosimilar and has led the field on its own. However, its timeline was pushed back after the FDA sent a "refusal to accept" notice in November for the application submitted in September last year. The additional patent lawsuit has made its launch date even more uncertain. Amneal addressed the FDA's concerns and resubmitted the application in January this year, and is now awaiting the FDA's decision.

While the lawsuit will not immediately halt a launch, industry observers say Omlyclo is now more likely to extend its period of market leadership in the U.S. by a considerable amount. In the United States, a biosimilar can still be launched while a patent lawsuit is ongoing unless a court issues an injunction barring its sale. However, because companies face the risk of substantial damages and a sales ban if patent infringement is subsequently established, many delay launches and seek settlements with the makers of original drugs.

A delay in later entrants' market entry could also be advantageous, as it would allow Omlyclo to secure formulary listing agreements with pharmacy benefit managers (PBMs) and insurers without facing price competition from other biosimilars. U.S. PBM formularies are typically set on an annual basis, so if key agreements are secured before a later product receives approval, that product may have to wait until the next negotiation cycle. The prescribing and supply experience gained by entering the market first could remain a competitive advantage even after later entrants launch.

Xolair, an allergy treatment jointly developed by Genentech and Novartis, saw its U.S. substance patent expire in June 2017 and its formulation patent expire in November 2025. According to U.S. publication Fierce Pharma, Xolair's U.S. sales last year were about $3.7 billion (approximately 5 trillion won), making it the highest-grossing drug among major medicines losing exclusivity this year. On Oct. 5, Celltrion officially launched Omlyclo at a wholesale acquisition cost (WAC) about 15% below that of the original drug.

“The situation could change depending on how quickly the lawsuit is resolved, but the increased uncertainty around a later entrant's launch timeline is itself a positive sign for the first mover,” an industry source said. “The key will be how effectively Omlyclo turns its head start into a stable prescribing base.”

This content was produced with the assistance of AI translation services.