'Cannot Launch Drug Without Basic Trademark Search': Delhi High Court Bars 'CLAVIX' As Similar To 'PLAVIX'

The Delhi High Court has granted a permanent injunction restraining Intas Pharmaceuticals Ltd. from using the mark “CLAVIX” for its medicinal products, holding it deceptively similar to Sanofi's registered mark “PLAVIX” and finding the adoption to be dishonest and infringing.

In a judgment pronounced on April 28, 2026, Justice Amit Bansal held that the competing marks differ only by a single letter and are used for identical pharmaceutical products, making confusion highly likely.

“In the present case, the products of the plaintiff and the defendant are medicinal products having an identical active ingredient and are used for treatment of the same disease. Viewed in this light, the likelihood of confusion on the part of the public, who could be patients, would be very high as the only difference between the competing marks is of a single letter,” the court observed.

Sanofi filed the present suit in 2008 after becoming aware around 2005 that Intas was marketing a competing drug under the phonetically similar mark “CLAVIX”.

While Intas claimed prior use since 2001, the Court noted that Sanofi's trademark rights traced back to applications filed in 1995 and 1998, with global use of the “PLAVIX” mark commencing in 1998. The Court held that these prior rights defeated the defendant's claim of protection.

The suit, which was initially filed as a passing off action, was amended in 2009 to include claims of trademark infringement. Over the course of the proceedings, evidence was recorded before a Local Commissioner, and the plaint was amended in 2016 to revise the damages claim.

On the issue of infringement, the Court held that “CLAVIX” is structurally, visually, and phonetically similar to “PLAVIX”, merely substituting the letter “P” with “C”. It further found that both products contain the same active ingredient and are used to treat the same condition, heightening the risk of confusion, especially in the context of medicinal products.

The court rejected Intas' defence under Section 34 of the Trade Marks Act, holding that such protection is not available where adoption of the mark is dishonest. It noted that the defendant failed to conduct even a basic trademark search or market inquiry prior to adopting the mark.

“A reputed pharmaceutical company cannot be expected to launch a new drug in the market under a mark without conducting even a basic search about competing drugs with identical or similar trade marks that are already available in the market,” the court remarked.

The court also took note of evidence showing that Intas had marketed the same drug under other marks such as “PREVA” and “PRASUGEL”, undermining its claim of bona fide adoption of “CLAVIX”.

However, on the issue of passing off, the Court ruled against Sanofi, holding that it failed to establish goodwill and reputation in the Indian market as of 2001.

While acknowledging the drug's global reputation, the court clarified that trans-border reputation alone is insufficient without evidence of substantial goodwill in India at the relevant time.

Accordingly, the court decreed a permanent injunction restraining the defendants from using the mark “CLAVIX” or any deceptively similar mark in relation to medicinal products, along with consequential relief, including costs.