Zydus and MSN Launch First Generic Riociguat in the U.S. to Challenge Bayer’s Adempas

Zydus Lifesciences Limited, through a partnership with MSN Laboratories Private Limited, has launched the first generic version of Bayer’s Adempas (riociguat) in the United States. Developed and manufactured by MSN Laboratories, the generic riociguat is FDA-approved and available across all five standard dosage strengths, providing a lower-cost alternative to the previously sole-branded medication.

Key Product & Clinical Details

Dosage Strengths: The generic riociguat is available in 0.5 mg, 1 mg, 1.5 mg, 2 mg, and 2.5 mg tablet strengths.
Mechanism of Action: Riociguat functions as a soluble guanylate cyclase (sGC) stimulator.
Approved Indications: The drug is indicated for adult patients with specific, rare, and progressive forms of pulmonary hypertension, including:
- CTEPH (WHO Group 4): Persistent or recurrent chronic thromboembolic pulmonary hypertension following surgical treatment or in inoperable cases, aimed at improving exercise capacity and WHO functional class.
- PAH (WHO Group 1): Pulmonary arterial hypertension to improve exercise capacity, enhance WHO functional class, and delay clinical worsening.

Strategic & Market Impact

Leadership Commentary: Dr. Sharvil Patel, Managing Director of Zydus Lifesciences, noted that this first-to-market launch represents a major milestone for their U.S. business, showcasing expertise in complex generics. Dr. MSN Reddy, Founder and CMD of MSN Laboratories, emphasized that riociguat is a technically demanding molecule, reflecting the company’s robust API and formulation capabilities.
Market Opportunity: While IQVIA does not separately report riociguat sales, Bayer’s 2025 Annual Report recorded global Adempas sales of approximately €745 million (roughly US$850 million).
Commercial Positioning: Combining Zydus’s U.S. commercial platform with MSN’s manufacturing strength, the partnership enters a specialized space with no prior generic competition, providing physicians and pharmacies flexible alternatives for patient transitions.