India Patent law – Interpretation of section 3(d)

A high profile patent infringement case is pending before the Delhi High Court. The suit has gained much media attention because it could formulate new rules for the subject matter inquiry under the amended Section 3(d) of the Patents Act, 1970 (IPA). The battle between Roche, a Swiss pharmaceutical giant and one of India’s biggest pharma companies Cipla, is in respect to the patent of an anti lung-cancer drug.

The product is erlotinib – marketed in India by Switzerland’s F.Hoffmann-La Roche under the trademark Tarceva. Tarceva is believed to prolong the life of patients with advanced non-small cell lung cancer who have progressed after standard chemotherapy. It was jointly invented by Pfizer Inc. and OSI Pharmaceuticals Inc.; and licensed to F Hoffmann-La Roche Ltd, which launched Tarceva in India in 2006, after securing a product patent in India.

Mumbai based drug maker, Cipla, launched a generic version of Tarceva at a reduced cost, even with the knowledge that the original was patented in India.

Cipla was aware of the patent application for Tarceva by Roche in India, and despite this, did not oppose the application or the grant as provided under Section 25 of the IPA. Even after the patent grant to Roche, no revocation proceeding was initiated. A supposed reason for this being that a pre-grant opposition by another Indian pharma company, Natco was launched against the Roche application and failed. Instead, Cipla launched a generic version of Tarceva in the Indian market.

Roche sought an injunction against Cipla for the introduction of a copycat version of their lung cancer drug into the local market. Cipla, on the other hand asked the court to revoke the Tarceva patent, granted in February 2007. This is the first time such a request has been made on a patented drug.

Cipla argued the patent was invalid as it was not new, obvious and did not involve an inventive step; because it was an improved version of quinazoline, a pre-1995 drug, which is not eligible for a patent in India. The specifications in the application did not sufficiently describe the invention or its claim to improved efficacy and did not disclose that the drug was a mixture of two polymorphs, or drug derivatives; therefore qualifying it for rejection under Section 3(d) of the amended IPA. Roche counsel contended that they were not challenging Section 3(d) as it stands, but just its application in erlotinib’s case.

This case is keenly being watched by the drugs industry, patient groups and patent attorneys, as it may set the tone for future pharma cases in India. Cipla’s daring move has undoubtedly caused alarm among companies that hold patents or have applications pending. The pertinent question on everyone’s mind is if Cipla get its way, will it open the floodgates? As section 3(d) is a major bone of contention in this case, a decision may finally give some clue as to how section 3(d), India’s unique patent section, is to be interpreted.