India’s Patent Office revokes Sutent cancer drug patent

India’s Patent Office has revoked pharmaceutical company Sugen and licensee Pfizer’s patent for the cancer drug Sutent, agreeing with Indian drugs maker Cipla that it lacks inventive step.

An injunction preventing Cipla from launching a generic version of the drug, Sunitinib, has also been lifted.

Sugen was granted a patent for Sutent in 2007. Cipla filed a post-grant opposition in 2008, arguing that the invention of the active compound in Sutent would have been obvious to anyone skilled in medicinal chemistry, based on prior art published on previous compounds used in anti-cancer treatments. Cipla also argued that Sugen had failed to disclose information required under section 8 of India’s Patent Act.

In its counterargument, Sugen attributed Cipla’s lack of inventive step claim to hindsight bias, but the claim was upheld and the patent revoked in September 2012.

Sugen appealed against this decision at Delhi’s High Court, and was granted an injunction preventing Cipla from launching Sunitinib. Cipla appealed against the injunction at India’s Supreme Court and in November, the case was referred to the assistant controller of patents.

The decision to revoke Pfizer’s patent was published by the controller on Monday. Cipla is now free to produce Sunitinib unless Sugan and Pfizer can have it reinstated.

A spokesperson for Pfizer said on Tuesday that the company is disappointed with the Indian Patent Office’s decision and plans to appeal against it.

“This ruling may further deter innovative companies from engaging in local partnerships and investing in the healthcare industry in India.

"While Pfizer understands the Indian Government’s intent to improve affordability and access to medicines, these concerns need to be addressed holistically to ensure both the quality and availability of innovative medicines,” they said.

Ranjna Dutt, a partner at Remfry & Sagar, said it would be a wise decision to appeal against the Patent Office's finding, given how important Sutent is to Sugen.

Dutt welcomed the controller’s decision to reject the Cipla’s claim of non-disclosure, adding that the controller did not observe the information disclosure requirement under Indian law very strictly, but said:

“It was a little surprising that the controller accepted Cipla’s claim that Sugen’s application lacks inventive step – this decision is not well-reasoned."