Zydus Lifesciences and its manufacturing partner, MSN Laboratories, began selling the first FDA-approved generic version of riociguat in the United States on 5 October 2026, the companies say — taking aim at Bayer's Adempas, a pulmonary-hypertension drug with roughly $850 million in worldwide sales in 2025. The generic launches across all five of Adempas's approved strengths at once, from 0.5 milligrams to 2.5 milligrams.
The riociguat launch, in four figures
Figures from the companies' 5 October 2026 launch announcement and Bayer's reported 2025 Adempas sales.
One molecule, two companies, five strengths
Zydus Lifesciences, in partnership with MSN Laboratories Private Limited, announced the US launch of Riociguat Tablets on 5 October 2026 — FDA-approved as a generic equivalent of Bayer's Adempas across all five strengths the brand sells, 0.5mg, 1mg, 1.5mg, 2mg and 2.5mg. MSN, a privately held Hyderabad generics manufacturer, developed and manufactures the tablets; Zydus, a publicly traded Indian pharmaceutical major, is bringing them to the US market. The companies describe themselves as the first to reach the US market with a generic version of the drug.
“Being first to market with generic riociguat is a milestone for our U.S. business and for patients with pulmonary hypertension.” Dr. Sharvil Patel, Managing Director, Zydus Lifesciences — 5 October 2026 announcement
A pill that relaxes blood vessels by a different route
Riociguat is a soluble guanylate cyclase (sGC) stimulator, a drug class that works somewhat differently from the better-known endothelin-receptor antagonists and prostacyclin-pathway drugs also used for pulmonary hypertension: it sensitizes sGC to the body's own nitric oxide and stimulates the enzyme directly, widening narrowed pulmonary blood vessels and easing the heart's workload. FDA first approved it as Adempas in 2013 for two related but distinct uses: chronic thromboembolic pulmonary hypertension (CTEPH), both inoperable disease and cases that persist or recur after surgery, and pulmonary arterial hypertension (PAH) in adults. Generic riociguat carries the same approved indications and dosing as the brand it copies.
Three things make this launch stand out
All five strengths, day one
Rather than launching a single strength and adding others later, Zydus and MSN brought all five FDA-approved riociguat doses to market simultaneously, letting physicians and pharmacies switch existing Adempas patients without a dose-matching gap.
A technically demanding molecule
Riociguat's manufacturing has long been considered complex for generic-makers to replicate at scale; MSN's ability to develop and manufacture all five strengths reflects a complex-generics capability the two companies' announcement specifically highlighted.
First mover against an $850M brand
As the first generic to reach the US market, Zydus and MSN get a period of competing against Adempas with fewer or no generic rivals, before other ANDA holders can follow with their own riociguat versions.
The $850 million the brand still earns
Adempas remained a meaningful earner for Bayer through 2025, even heading into generic competition — a reminder that a first-generic launch does not erase a branded drug's sales overnight. CTEPH is itself a rare, often underdiagnosed condition, while PAH is more widely treated and served by a broader shelf of branded competitors; riociguat's generic entry changes the cost calculus for payers and patients on this specific drug without altering the wider pulmonary-hypertension treatment landscape.
What the pulmonary arterial hypertension drug category is worth
$10.9B → $11.9B
Global pulmonary arterial hypertension drugs market forecasts for 2030, as estimated by Vision Research Reports and NovaOne Advisor respectively; Grand View Research's more recent estimate puts the 2030 figure around $11.02B, with most published forecasts clustering in the same $11B-$12B range.
Sources: BioSpace, citing Vision Research Reports, “Pulmonary Arterial Hypertension Market Size Worth Around USD 10.9 BN by 2030” · BioSpace, citing NovaOne Advisor, “Pulmonary Arterial Hypertension Market to Reach USD 11.9 Bn by 2030”
Regulatory News outlook
Riociguat's generic entry affects pricing within the PAH and CTEPH drug category rather than its overall size: published forecasts above model the branded and generic market together, growing in the mid-single-digit percentages annually as diagnosis rates improve, regardless of which company sells a given prescription.
How we got here: We average the three cited 2030 PAH-market forecasts ($10.9B, $11.9B and $11.02B) to note they cluster closely around $11B-$12B despite coming from different publishers, without adjusting any of them for riociguat's specific generic entry, since none of the three publishers breaks out a riociguat- or CTEPH-specific sub-forecast.
Riociguat against other pulmonary-hypertension drug classes
| Product | Drug class | Route | US status |
|---|---|---|---|
| Riociguat Tablets (Zydus/MSN) | sGC stimulator | Oral | FDA-approved generic, launched Oct 2026 |
| Adempas / riociguat (Bayer) | sGC stimulator | Oral | FDA approved, 2013; branded original |
| Tracleer / bosentan (Janssen) | Endothelin-receptor antagonist | Oral | FDA approved (established drug) |
| Uptravi / selexipag (Johnson & Johnson) | Prostacyclin-receptor agonist | Oral | FDA approved (established drug) |
From each company's own labelling and FDA approval records; not a clinical comparison.
From a 1952 Ahmedabad pharmacy to a US generics first
Zydus's road to a first-to-market US generic
- 1952
Zydus founded
Founded in Ahmedabad, India, as Cadila Healthcare; later renamed Zydus Lifesciences in February 2022.
- 2003
MSN Laboratories founded
MSN Laboratories founded in Hyderabad, India, focused on complex generic active pharmaceutical ingredients and finished dosage forms.
- 2013
Adempas approved
FDA approves Bayer's Adempas (riociguat), the branded drug this generic will eventually challenge.
- 5 October 2026
First generic riociguat launches
Zydus and MSN launch the first FDA-approved generic riociguat in the US, across all five approved strengths.
- Ahead
Other generics may follow
As the first generic entrant, Zydus and MSN compete against Adempas largely alone for a period before other ANDA holders can bring their own riociguat versions to market.
What the launch announcement leaves out
Neither company's announcement discloses wholesale or launch pricing for the generic, the length of any marketing exclusivity Zydus and MSN may hold as first filer, or how many other ANDA applicants are waiting behind them for their own riociguat approvals — all facts that would let a reader judge how long this first-mover position lasts and how much patients and payers will actually save.
- What launched: the first FDA-approved generic riociguat in the US, across all five Adempas strengths, on 5 October 2026.
- Who makes it: MSN Laboratories develops and manufactures the product; Zydus Lifesciences markets it in the US.
- What it targets: Bayer's Adempas, which the companies say recorded roughly $850 million in worldwide sales in 2025.
- Not yet public: launch pricing, the length of any first-filer exclusivity, and the number of competing ANDA applicants still awaiting their own FDA approval.
Sources & further reading
- Free Press Journal, “Zydus Lifesciences, MSN Launch First Generic Adempas® (Riociguat Tablets) In US,” 5 October 2026. freepressjournal.in
- Indian Pharma Post, “Zydus and MSN launch first generic version of Adempas in US,” October 2026. indianpharmapost.com
- Medical Dialogues, “Zydus, MSN launch first generic of Adempas (riociguat) in US across 5 strengths,” October 2026. medicaldialogues.in
- HDFC Sky, “Zydus Lifesciences, MSN Laboratories launch first generic of Adempas in US,” October 2026. hdfcsky.com
- SAHI, “Zydus Lifesciences Launches First Generic Adempas Tablets In US With MSN Labs,” October 2026. sahi.com
Regulatory News reports on public regulatory documents. It is not legal advice, and the primary sources above govern. If we have made an error, we will say so in public: see corrections.
Frequently asked questions
What did Zydus and MSN actually launch?
The first FDA-approved generic equivalent of Bayer's Adempas (riociguat) tablets in the United States, across all five approved strengths (0.5mg, 1mg, 1.5mg, 2mg and 2.5mg), launched 5 October 2026. MSN Laboratories developed and manufactures the product; Zydus Lifesciences markets it.
What is riociguat used for?
It is a soluble guanylate cyclase (sGC) stimulator approved to treat chronic thromboembolic pulmonary hypertension (CTEPH), both inoperable cases and persistent or recurrent disease after surgery, and pulmonary arterial hypertension (PAH) in adults.
Is this a new drug approval?
No. Riociguat itself has been FDA-approved as Adempas since 2013. This is FDA's approval and launch of the first generic competitor, not a new molecule or a new indication.
Who is MSN Laboratories?
A privately held, Hyderabad, India-based generics manufacturer founded in 2003, with API and finished-dose manufacturing facilities across India and the US. MSN developed and manufactures the riociguat tablets that Zydus is launching in the US market.
