India's challenge to evergreening: 2026 may test drug patent regime

Experts say 2026 could be a crucial year for drug patents, with the likely emergence of fresh disputes over follow-on patents

The recent ruling by the Delhi High Court allowing Dr Reddy’s Laboratories to continue manufacturing diabetes and weight-management drug semaglutide in India opens up opportunities worth billion of dollars for domestic generic drugmakers. 

 

Sales and exports have, for now, been allowed only to those jurisdictions where Danish drugmaker Novo Nordisk, which holds the patent for semaglutide, does not have patent protection. 

 

In India and Canada, Novo Nordisk’s patent on semaglutide, the active ingredient in blockbuster brands such as Rybelsus, Ozempic, and Wegovy, expires on March 20. All of these brands are marketed as the next wonder in weight loss management.

 

The weight-loss market in India stands at around ₹1,446 crore on a moving annual turnover (MAT) basis, with semaglutide-based drugs accounting for ₹445 crore as of February 2026. Apart from semaglutide, several other blockbuster drugs are approaching patent expiry in India by 2026. These include sacubitril/valsartan (Vymada) and several biologic oncology drugs. India’s revocation of Novartis’ patent for its heart drug Vymada last year has already paved the way for generic competition.

 

Long-running battle

 

This and other similar rulings have also brought back into focus India’s long-running battle against “evergreening”, the practice by pharma companies to try and torpedo the expiry of a patent by claiming ‘improvements’ or changes to the original formulations.

 

At the heart of this debate is Section 3(d) of the Patents Act, a safeguard designed to prevent drugmakers from extending monopoly protection through trivial modifications to existing medicines. In the last few years, Indian courts have heard a series of cases involving blockbuster molecules such as semaglutide, risdiplam and nivolumab.

 

Most of the court’s decisions have either cleared the way for generics or challenged the validity of patents held by multinational (MNC) pharmaceutical companies.

 

In October 2025, the Delhi High Court allowed Hyderabad-based Natco Pharma to launch its version of Roche’s spinal muscular atrophy (SMA) therapy Risdiplam despite opposition from the latter.

 

Natco had then said that it would price its version at ₹15,900 per bottle, compared with ₹6.2 lakh per bottle charged by Roche under the brand Evrysdi. The Supreme Court also later dismissed Roche’s challenge, effectively clearing the way for the generic version to enter the market.

 

In another recent ruling, the Delhi High Court allowed Zydus to proceed with the manufacturing and sale of American multinational Bristol Myers Squibb (BMS)’s immunotherapy drug Nivolumab, marketed as Opdivo and as Opdyta in India.

 

Opdyta vials in the country can cost between ₹45,000 and around ₹1 lakh per vial, depending on the dosage strength (40 mg to 100 mg). Treatment costs, therefore, increase by ₹2-3.5 lakh per month. In its ruling, the court held that access to affordable treatment could not be denied to patients, while turning down BMS’ plea to block Indian companies from producing biosimilar versions of Nivolumab.

 

Following the ruling, Ahmedabad-based Zydus Lifesciences launched Tishtha, its version of Nivolumab, and priced it at ₹13,950 and ₹28,950 for the two dosage forms. 

 

Fresh wave

 

Legal and industry experts believe 2026 could be a crucial year, as a fresh wave of disputes over secondary patents covering formulations, dosages, and minor modifications could emerge. There could be intensified litigation as generic manufacturers challenge follow-on patents intended to prolong exclusivity, the experts said.

 

“Incremental pharmaceutical changes now need to show a substantial clinical benefit in order to get past the evergreening barrier. The decisions emerging from this phase will likely crystallise the evidentiary standards for therapeutic efficacy and shape enforcement strategies for the next decade,” said Ankit Rajgarhia, designate partner at Bahuguna Law Associates.

 

Most legal experts also believe that Indian courts have become increasingly exacting in applying Section 3(d). After testing for novelty and non-obviousness, judges apply the Section 3(d) filter to ensure incremental changes demonstrate enhanced therapeutic efficacy. Courts also weigh broader public-interest considerations when deciding interim relief in patent disputes, Rajgarhia said.

 

The test most courts apply to avoid patent evergreening is whether small changes in dosage, polymorph, or formulation demonstrate enhanced therapeutic efficacy, said Rahul Hingmire, managing partner at Vis Legis Law Practice. “In oppositions and revocation matters, judges now expect solid clinical data, not theoretical claims,” Hingmire said. Industry analysts say this combination of expiring patents and stricter scrutiny is likely to accelerate generic entry in India over the next two years.

 

While the legal framework is designed to curb evergreening, litigation tactics can still delay generic entry as even relatively weak secondary patents can temporarily block competition through interim injunctions, experts said.

 

“In infringement suits before the High Court, originators often seek ad-interim relief pending trial. Even a six-to-twelve-month delay can significantly affect market access,” Hingmire said.

 

‘Questionable patents’

 

Despite the risks and challenges, court rulings continue to strengthen generic companies to challenge questionable patents, the experts said.

 

A recent Delhi High Court ruling held that a revocation challenge under Section 64 of the Patents Act can continue even after the patent has expired, particularly where damages are claimed in an infringement suit.

 

A revocation challenge under patent law is a legal proceeding to challenge the validity of a granted patent, often initiated by third parties or the government for reasons such as lack of novelty, obviousness, or improper disclosure.

 

If the patent is eventually revoked by a court ruling, the invalidation operates retrospectively, treating the patent as void from the date of grant. 

 

Swati Sharma, partner and head of intellectual property at Cyril Amarchand Mangaldas, said the decision primarily clarifies procedural strategy rather than dramatically altering litigation risks for patent holders.

 

“Defendants would generally always defend any patent infringement claim by filing a revocation petition or counter-claim,” Sharma said. “The decision clarifies that such challenges can continue even after the patent expires.”

 

Despite periodic international pressure for stronger intellectual property protections through trade negotiations, experts say India’s anti-evergreening framework remains firmly entrenched.

 

Hingmire said Section 3(d) is now embedded in Indian patent jurisprudence and continues to shape how courts approach pharmaceutical innovation and access to medicines.

 

“In practice, India’s legal framework balances innovation and access,” he said. “It is unlikely to dilute core public health protections.”

 

As pharmaceutical companies prepare for a new cycle of patent expiries and follow-on filings, the outcomes of litigation in 2026 and in the coming years could determine how effectively India continues to police evergreening while still protecting genuine pharmaceutical innovation. 

Delhi High Court rulings 

Semaglutide (2026)

The court allowed Dr Reddy’s Laboratories to manufacture semaglutide in India but restricted sales and exports

  Risdiplam (2025)

It permitted Natco Pharma to launch a generic version of Roche’s spinal muscular atrophy drug

  Nivolumab (2025)

Zydus Lifesciences allowed to manufacture and sell biosimilar versions of Bristol Myers Squibb’s cancer immunotherapy drug