Celltrion’s biosimilar cancer drug Vegzelma has cleared a major hurdle in the U.S. insurance market, gaining preferred status on the formularies of major pharmacy benefit managers, or PBMs.

The latest listings are expected to improve patient access to the bevacizumab biosimilar, which is used to treat metastatic colorectal cancer, breast cancer and other cancers. They also add a new growth engine in the insurance-covered prescription market to Vegzelma’s existing momentum in the U.S. open market.

Celltrion said Vegzelma has recently been listed as a preferred drug on both public and private insurance formularies managed by Express Scripts, one of the three largest PBMs in the United States, as well as on a public insurance formulary managed by Optum, another major PBM.

Reimbursement coverage through Express Scripts’ public insurance plan and Optum began this month, while coverage under Express Scripts’ private insurance plan is scheduled to take effect in January next year.

With the new listings, Vegzelma has secured reimbursement coverage for more than 35% of the U.S. insurance market, providing the drug with a broader and more stable prescription base.

PBMs play a central role in the U.S. pharmaceutical market by managing prescription drug benefits for health insurers and employers. Formulary placement can have a significant impact on patient access and prescribing decisions, making entry into major PBM networks a critical factor in expanding drug sales.

The development is particularly significant for Celltrion because Vegzelma has already demonstrated growth in the open market, where pharmaceutical companies compete more directly through sales capabilities, pricing and product competitiveness.

According to pharmaceutical market research firm IQVIA, Vegzelma captured a 10.6% share of the U.S. bevacizumab market in May, exceeding the 10% threshold for the first time since its launch.

The performance was largely driven by Celltrion’s U.S. subsidiary, which has pursued a direct sales strategy targeting hospitals and other healthcare providers.

The U.S. open market is regarded as particularly challenging for late-entering biosimilars because companies must compete directly on commercial execution and product value without relying primarily on broad insurance coverage. Vegzelma’s double-digit market share therefore provides an important foundation as Celltrion expands into the PBM-covered prescription market.

Celltrion plans to use the latest formulary listings to pursue growth in both channels. The company will continue strengthening sales in the open market while expanding insurance reimbursement coverage through negotiations with additional major PBMs.

Other Celltrion products are also gaining ground in the United States.

Steqeyma, Celltrion’s ustekinumab biosimilar, recorded a 13.3% market share in May. The product ranked second by prescription volume in a market where seven biosimilars are competing.

Yuflyma, the company’s adalimumab biosimilar, held an 8.1% share during the same period, maintaining a steady prescription trend.

Celltrion is also preparing to expand its U.S. portfolio in the second half of the year. The company plans to launch the subcutaneous formulation of autoimmune disease treatment Avtozma, a tocilizumab biosimilar, as well as Omlyclo, its omalizumab biosimilar for allergic diseases.

Omlyclo is expected to receive particular attention as a first mover in the omalizumab biosimilar market, potentially giving Celltrion an early advantage in building market share.

The latest PBM listings mark another step in Celltrion’s effort to evolve from a biosimilar supplier into a global pharmaceutical company with its own commercial capabilities in the world’s largest drug market.

For Vegzelma, the next phase of growth will depend not only on expanding open-market sales but also on converting broader insurance access into prescriptions. Its entry into major PBM formularies gives Celltrion a stronger platform to pursue both objectives simultaneously.