Delhi High Court Awards ₹81 Lakh to Merck, Sun Pharma In Diabetes Drug Patent Infringement Case

In a judgment dated January 23, 2026, Justice Tushar Rao Gedela decreed the suit in favour of the pharmaceutical companies, holding that unauthorized manufacture and export of the patented drug stood established on the basis of unchallenged evidence. The Court also noted that the infringing conduct continued even after injunctive relief had been granted.

The court recorded that Merck is the owner of the suit patent and that Sun Pharma is the authorized licensee for marketing and distribution of Sitagliptin-based formulations in India. These formulations are sold under brands such as JANUVIA, JANUMET, ISTAVEL and ISTAMET.

According to the material placed on record, the pharmaceutical companies discovered rival Sitagliptin-based tablets branded as “SEPAMET-XR” in 2018 on online pharmacy platforms. The court observed that although the product was not sold in the domestic market, it was exported in commercial quantities, which constituted unauthorized use of the patented invention.

An ex parte ad interim injunction restraining the manufacture, sale, export, and distribution of the infringing drug was granted in August 2018. The court noted that while the rival manufacturers initially entered an appearance, they subsequently stopped participating in the proceedings and were eventually proceeded against ex parte. It was also recorded that the suit patent expired on July 5, 2022, after which the surviving relief was confined to damages and costs.

On the issue of compensatory damages, the Court referred to the ruling of Koninlijke Philips & Ors. vs. Amazestore and Rule 20(ii) of the Delhi High Court IPD Rules, 2022. Taking note of the export data placed on record showing shipments of the infringing product between September and November 2017, the Court assessed the compensatory damages at ₹49.44 lakh.

The Court further observed that online advertisements and listings of the infringing product continued even after the injunction order was passed, demonstrating wilful disregard of the Court's directions. In view of the continued infringing conduct, ₹10 lakh was awarded as exemplary damages.

In addition, the Court accepted the unrebutted evidence relating to court fees and legal expenses and awarded costs of ₹21.67 lakh.

Accordingly, the suit was decreed, directing payment of a total sum of ₹81.11 lakh towards compensatory damages, exemplary damages and legal costs in favour of the pharmaceutical companies.

For Plaintiffs: Advocates Pravin Anand, Tusha Malhotra and Sugandha Yadav