Hyderabad-based Natco Pharma has once again moved the Delhi High Court against the Indian Patent Office's decision to grant a patent for the breast cancer drug ribociclib (Kisqali) to Swiss drugmaker Novartis AG and UK-based Astex Therapeutics.

Justice Anup Jairam Bhambhani briefly heard the matter on Wednesday, issued notice to all parties, and listed the case for further hearing on 16 September.

In a petition reviewed by Mint, Natco argued that the fresh patent would unfairly extend Novartis's monopoly over the medicine. The drugmaker challenged the patent office's order dated 10 July 2026, which rejected four pre-grant oppositions and directed the grant of the ribociclib patent with a single amended claim. The patent application was originally filed in 2011.

A pre-grant opposition is a process under the Patents Act that allows any person to challenge a patent application before it is granted.

Natco, one of the four companies that opposed the application, argued that the patent controller failed to recognise that ribociclib was already covered under Novartis's earlier patent and ignored previous court rulings while deciding to grant the new patent.

According to the petition, Novartis already owns Indian Patent No. 283133, which covers ribociclib and is valid until 24 May 2027. Natco said Novartis had earlier relied on this patent to stop the company from making or selling ribociclib. It argued that Novartis shouldn’t now be allowed to obtain another patent for the same drug that could extend its market exclusivity beyond 2027.

"The controller perpetuates an unlawful monopoly," Natco said in its petition. It alleged that Novartis cannot claim ribociclib is already protected under its existing patent while also obtaining a fresh patent that could keep generic competitors out of the market until 2029. The petition also said the patent controller “gravely errs by failing to appreciate that the applicants, by securing two patents for the same invention, are unlawfully extending the term of protection of the genus patent through the impugned patent application”.

A Novartis spokesperson said in response to Mint's queries, "Novartis remains committed to improving patient outcomes by providing quality innovative medicines such as Ribociclib to patients in India. At this point, we are unable to provide any further comment since the matter is sub judice.”

Queries emailed to Nacto and Astex remained unanswered at the time of publishing.

Case history

The dispute dates back to February 2011, when Novartis and Astex filed a patent application titled ‘Pyrrolopyrimidine Compounds as CDK Inhibitors’, covering ribociclib. The application was published later that year and a request for examination was filed in 2012. Natco filed its pre-grant opposition in November 2018, while three other parties also opposed the application in the subsequent years. After several rounds of hearings, expert opinions and written submissions, the patent office rejected all four oppositions in July this year and directed that the patent be granted.

Natco had also referred to a 7 September 2022 Delhi High Court order in an earlier patent dispute, under which it agreed not to launch ribociclib until the earlier patent expired in 2027. Having already secured protection under that patent, Novartis cannot now seek another patent over the same drug, Natco argued.

According to the petition, the controller wrongly concluded that the new patent was sufficiently different from the earlier one and failed to properly consider whether the existing patent already covered ribociclib. It also alleged that the patent office applied earlier Delhi High Court rulings inconsistently, making the decision arbitrary.

This follows Natco’s aggressive strategy of challenging innovator patents in courts abroad and in India. The drugmaker had previously settled a patent infringement suit by Novartis and Astex over Kisqali in a US court in 2025, as both parties stipulated to a dismissal with prejudice, meaning Novartis and Astex cannot refile the same specific infringement claims on those actions. Last year, the company won a landmark suit in the Delhi High Court against Roche over risdiplam, a drug used to treat spinal muscular atrophy.

Hyderabad-based Natco Pharma has once again moved the Delhi High Court against the Indian Patent Office's decision to grant a patent for the breast cancer drug ribociclib (Kisqali) to Swiss drugmaker Novartis AG and UK-based Astex Therapeutics.

Justice Anup Jairam Bhambhani briefly heard the matter on Wednesday, issued notice to all parties, and listed the case for further hearing on 16 September.

In a petition reviewed by Mint, Natco argued that the fresh patent would unfairly extend Novartis's monopoly over the medicine. The drugmaker challenged the patent office's order dated 10 July 2026, which rejected four pre-grant oppositions and directed the grant of the ribociclib patent with a single amended claim. The patent application was originally filed in 2011.

A pre-grant opposition is a process under the Patents Act that allows any person to challenge a patent application before it is granted.

Natco, one of the four companies that opposed the application, argued that the patent controller failed to recognise that ribociclib was already covered under Novartis's earlier patent and ignored previous court rulings while deciding to grant the new patent.

According to the petition, Novartis already owns Indian Patent No. 283133, which covers ribociclib and is valid until 24 May 2027. Natco said Novartis had earlier relied on this patent to stop the company from making or selling ribociclib. It argued that Novartis shouldn’t now be allowed to obtain another patent for the same drug that could extend its market exclusivity beyond 2027.

"The controller perpetuates an unlawful monopoly," Natco said in its petition. It alleged that Novartis cannot claim ribociclib is already protected under its existing patent while also obtaining a fresh patent that could keep generic competitors out of the market until 2029. The petition also said the patent controller “gravely errs by failing to appreciate that the applicants, by securing two patents for the same invention, are unlawfully extending the term of protection of the genus patent through the impugned patent application”.

A Novartis spokesperson said in response to Mint's queries, "Novartis remains committed to improving patient outcomes by providing quality innovative medicines such as Ribociclib to patients in India. At this point, we are unable to provide any further comment since the matter is sub judice.”

Queries emailed to Nacto and Astex remained unanswered at the time of publishing.

Case history

The dispute dates back to February 2011, when Novartis and Astex filed a patent application titled ‘Pyrrolopyrimidine Compounds as CDK Inhibitors’, covering ribociclib. The application was published later that year and a request for examination was filed in 2012. Natco filed its pre-grant opposition in November 2018, while three other parties also opposed the application in the subsequent years. After several rounds of hearings, expert opinions and written submissions, the patent office rejected all four oppositions in July this year and directed that the patent be granted.

Natco had also referred to a 7 September 2022 Delhi High Court order in an earlier patent dispute, under which it agreed not to launch ribociclib until the earlier patent expired in 2027. Having already secured protection under that patent, Novartis cannot now seek another patent over the same drug, Natco argued.

According to the petition, the controller wrongly concluded that the new patent was sufficiently different from the earlier one and failed to properly consider whether the existing patent already covered ribociclib. It also alleged that the patent office applied earlier Delhi High Court rulings inconsistently, making the decision arbitrary.

This follows Natco’s aggressive strategy of challenging innovator patents in courts abroad and in India. The drugmaker had previously settled a patent infringement suit by Novartis and Astex over Kisqali in a US court in 2025, as both parties stipulated to a dismissal with prejudice, meaning Novartis and Astex cannot refile the same specific infringement claims on those actions. Last year, the company won a landmark suit in the Delhi High Court against Roche over risdiplam, a drug used to treat spinal muscular atrophy.