Entering the U.S. market through a generic partnership

Zydus Pharmaceuticals USA Inc., the U.S. subsidiary of Indian pharmaceutical company Zydus Lifesciences Ltd., has begun full-scale distribution of Riociguat, a pulmonary hypertension treatment, in the United States in collaboration with MSN Laboratories Private Ltd. The product being distributed is a generic drug (ANDA 211135) developed by MSN Laboratories and granted final approval by the U.S. Food and Drug Administration (FDA) on September 1, 2022. Zydus, as a supply partner, is responsible for packaging and selling the finished product through its own distribution network in the U.S., aiming to capture the market. This collaboration between the two companies is the result of a strategic alliance to maximize the speed of commercialization in the specialized generic drug market, which requires highly complex manufacturing processes.

Market dominance and mechanism of action of the original Adempas

Riociguat is a generic version of Adempas, an original drug developed by Bayer AG, and it acts as a soluble guanylate cyclase (sGC) stimulator. This drug increases the efficiency of nitric oxide (NO) in the body, dilating pulmonary blood vessels and reducing the burden on the heart in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and pulmonary arterial hypertension (PAH). The original Adempas is sold through a global alliance between Bayer and Merck & Co., and in 2024, it generated $287 million in sales in Merck's sales region, making it a blockbuster drug. Due to the limited treatment options available for this rare disease, patients have high drug loyalty, and the drug is priced very high.

Resolution of long-term patent disputes and economic significance of final approval

MSN has undergone a long regulatory process in the U.S. FDA by submitting a patent challenge (Paragraph IV Certification) to overcome the patent barriers of Adempas. After securing tentative approval on April 23, 2019, it resolved the patent dispute and received final approval in September 2022, removing the legal obstacles to market entry. By launching the generic drug in a timely manner after the expiration of the original drug's patent, it has created an opportunity to reduce the burden of drug costs on patients and improve the financial health of the healthcare system. Zydus is launching the product early, targeting the time when the remaining patents of the original drug expire, in order to gain an early market share.

Changes and prospects in the $8 billion pulmonary hypertension market

The global market for pulmonary arterial hypertension (PAH) treatments is estimated at approximately $8.1 billion in 2025 and is growing annually due to the aging population and advances in diagnostic technology. With Zydus entering the market with a competitive generic price, the monopoly of brand-name drugs that have been providing standard treatments is expected to be broken. In the future, whether or not it is listed in the preferred drug list through negotiations with major U.S. pharmacy benefit managers (PBMs) will be the biggest factor in determining the initial prescription market share. With this launch, Zydus aims to diversify its chronic rare disease portfolio in the U.S. and create sustainable growth momentum.