Celltrion has launched the intravenous formulation of its ustekinumab biosimilar Steqeyma in Japan, expanding an autoimmune disease portfolio that already includes market-leading biosimilars Remsima and Yuflyma.

The launch represents more than the addition of another product to Celltrion's Japanese lineup. The South Korean biopharmaceutical company is increasingly leveraging the commercial infrastructure and physician networks established through its existing autoimmune therapies to introduce new products and build a broader portfolio in one of Asia's largest pharmaceutical markets.

Celltrion said on Aug. 21 that its Japanese subsidiary launched Steqeyma IV about four months after receiving approval from Japan's Ministry of Health, Labour and Welfare in April.

The IV formulation adds Crohn's disease to Steqeyma's treatment scope, alongside existing indications for plaque psoriasis and psoriatic arthritis.

Celltrion's advantage in Japan begins with an established commercial base.

As of May, Remsima, its infliximab biosimilar, held a 46.9% share of Japan's infliximab biosimilar market, while Yuflyma, its adalimumab biosimilar, had a 19.5% share of the corresponding biosimilar market. Both ranked first in their respective segments.

Those positions provide Celltrion with an existing network of gastroenterologists, pharmacists and other healthcare professionals that can also be used to support Steqeyma.

For biosimilar companies, such commercial infrastructure is increasingly important. Entering a new market requires not only regulatory approval but also relationships with hospitals and physicians who ultimately determine whether a new therapy gains traction.

Steqeyma does not have to build those relationships entirely from scratch.

Celltrion plans to use the sales experience and medical networks accumulated through Remsima and Yuflyma to accelerate adoption of the new product.

Another differentiating factor is the availability of two formulations.

With the Japanese launch of Steqeyma IV, Celltrion now offers both intravenous and subcutaneous formulations of its ustekinumab biosimilar. According to the company, Steqeyma is currently the only ustekinumab biosimilar available in Japan with both IV and SC formulations.

That gives physicians greater flexibility across different stages of treatment.

For Crohn's disease, for example, the IV formulation can be used for induction therapy at the beginning of treatment, followed by the SC formulation for longer-term maintenance therapy.

Offering both formulations under the same product family could strengthen Steqeyma's position as biosimilar competition increases.

The Japanese launch also fits into a broader portfolio strategy.

Rather than building separate commercial operations around individual biosimilars, Celltrion is developing a group of autoimmune products that can be marketed through overlapping medical specialties and hospital networks.

Remsima and Yuflyma established the initial commercial footprint. Steqeyma adds another biologic target and additional indications. Remsima SC, meanwhile, is scheduled to enter the Japanese market next year.

That sequence could allow each new product to benefit from the commercial infrastructure created by its predecessors.

Celltrion plans to participate in major Japanese medical conferences during the second half of the year, including Japan Digestive Disease Week and the Japanese Society for Inflammatory Bowel Disease meeting.

The company intends to use those events to increase awareness of Steqeyma's dual-formulation offering while strengthening relationships with gastroenterologists and pharmacists.

Those relationships could also provide a commercial foundation for Remsima SC when it enters the market next year.

This is particularly relevant in inflammatory bowel disease, where Celltrion's products increasingly overlap across the treatment pathway.

The strategy reflects a broader shift in biosimilar competition.

In the early years of the market, competition largely centered on launching lower-cost alternatives to individual reference biologics. As more biosimilars become available, however, price and a single product are becoming less effective as standalone differentiators.

Companies with multiple products can potentially gain an advantage by serving the same hospitals and medical specialties with a broader portfolio, improving sales efficiency while deepening relationships with healthcare providers.

Japan provides Celltrion with an important test of that model.

The country is one of the world's major pharmaceutical markets and continues to seek ways to control healthcare expenditure as its population ages. Wider biosimilar adoption represents one avenue for reducing the cost of biologic treatments.

Celltrion has spent years building a direct commercial presence in the country, and the market shares of Remsima and Yuflyma indicate that the strategy has already produced a meaningful prescription base.

The next question is whether that base can shorten the time required for Steqeyma to gain market share.

A roughly four-month period between regulatory approval and commercial launch suggests that Celltrion is seeking to move quickly.

The company said the combination of IV and SC formulations should differentiate Steqeyma from competing ustekinumab biosimilars and that it will use its existing commercial network to accelerate adoption.

For Celltrion, the significance of Steqeyma therefore extends beyond the performance of a single biosimilar.

With Remsima holding a 46.9% share, Yuflyma at 19.5%, Steqeyma now available in both IV and SC formulations, and Remsima SC scheduled for launch next year, the company's Japanese business is evolving from a series of individual product launches into a portfolio-based autoimmune strategy.

How quickly Steqeyma can convert Celltrion's existing physician relationships into prescriptions will be an important measure of whether that strategy can deliver the next stage of growth in Japan.

Jung So-yeon More by this reporter