Sanofi Vs. Intas Pharmaceuticals

Sanofi Vs. Intas Pharmaceuticals: 28.04.2026:CS(COMM) 120/2016:2026:DHC:3574:Amit Bansal 

Introduction:

The present suit before the Delhi High Court concerned an action for trademark infringement and passing off filed by Sanofi against Intas Pharmaceuticals in respect of the anti-thrombosis drug marketed under the mark PLAVIX. The defendant was using the mark CLAVIX for an identical pharmaceutical preparation containing the same active ingredient, Clopidogrel.

Factual Background:

Sanofi asserted statutory as well as common law rights in the mark PLAVIX, claiming prior adoption (1995), global reputation, and registration in India. It was contended that CLAVIX was deceptively similar, differing only by the substitution of the letter “P” with “C”, and was likely to cause confusion, particularly in the pharmaceutical sector where a stricter standard applies.The defendant, on the other hand, argued prior use since 2001, independent derivation of the mark, and dissimilarity based on the first letter and overall trade dress. It also invoked the defence under Section 34 of the Trade Marks Act, 1999.

Reasoning:

The marks PLAVIX and CLAVIX are phonetically, structurally, and visually similar, and the difference of a single letter is insufficient to obviate confusion, especially in medicinal products. Relying on established jurisprudence including Cadila Health Care Ltd. v. Cadila Pharmaceuticals Ltd., the Court emphasized that a stricter test applies in pharmaceutical trademark disputes due to potential public health consequences.

The Court further found that the defendant’s explanation for adoption of the mark CLAVIX was unconvincing and an afterthought, and that no due diligence or trademark search had been conducted prior to adoption. This led to a finding of dishonest adoption.

On the issue of prior use, the Court held that the defendant failed to satisfy the requirements of Section 34, as the plaintiff’s registration dated back to 1995/1998. Mere prior use since 2001 could not defeat statutory rights, particularly in the absence of bona fide adoption.

Accordingly, the Court concluded that the defendant’s use of CLAVIX amounted to trademark infringement under Section 29 , and granted relief in favour of the plaintiff.

Key Legal Principles

The judgment reiterates that:

In pharmaceutical trademarks, even minor similarities can lead to actionable confusion.

Registration confers strong statutory rights, and prior use defence must strictly satisfy Section 34.

Dishonest adoption disentitles a defendant from equitable defenses.

In infringement actions, similarity of marks alone may suffice, irrespective of differences in packaging or trade dress.

Disclaimer: Donot treat this as substitute for legal advise as it may contain subjective errors.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi

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Defense under Section 34 is not meant to shield acts tainted with bad faith

Introduction:

In the world of medicines, even a small similarity in brand names can create confusion that might affect patient safety. The Delhi High Court recently addressed this concern in a long-running dispute between two pharmaceutical companies. The case involved a well-known heart medicine sold under the name PLAVIX by the French company Sanofi and a similar product marketed as CLAVIX by Intas Pharmaceuticals. The court had to decide whether using a nearly identical name for the same type of drug amounted to trademark infringement and passing off. This judgment highlights how courts carefully examine brand names for medicines to protect both business rights and public health.

Factual Background:

Sanofi is a global pharmaceutical company known for developing and selling various medicines, including an important anti-thrombosis drug that helps prevent heart attacks and strokes. This drug is sold under the trademark PLAVIX, a specially created word that does not directly describe the medicine or its use. Sanofi had registered this mark in India and built significant reputation through sales and promotion over many years. The company launched the product in the Indian market in early 2003.

Intas Pharmaceuticals, an Indian company based in Ahmedabad, began selling a similar medicine containing the same active ingredient under the name CLAVIX. Intas claimed it had started using this name around 2001 and developed its own goodwill in the market. According to Intas, the name CLAVIX was derived from parts of the drug's scientific name and its medical purpose. The two products were identical in their therapeutic use and were sold through the same channels, mainly through prescriptions to doctors and pharmacies. Sanofi became aware of Intas's use of CLAVIX in the mid-2000s and eventually filed a lawsuit claiming that the similar name was likely to confuse doctors, pharmacists, and patients, leading them to mistake one product for the other.

Procedural Background:

The lawsuit began as a claim for passing off in 2008. Later, after Sanofi's word mark PLAVIX received formal registration, the company amended its pleadings to also include a claim for trademark infringement. The case went through several procedural steps, including applications for adding documents, recording evidence before a local commissioner, and addressing changes in the plaintiff's company name from Sanofi Aventis to Sanofi.

Both sides presented witnesses and evidence regarding their adoption of the marks, sales, advertising, and reasons for choosing the names. The matter was heard over multiple dates spanning several years, with arguments focusing on the similarity of the marks, the special rules that apply to pharmaceutical products, and whether Intas had honestly adopted its mark or was trying to ride on Sanofi's reputation. The evidence recording concluded in 2018, and final arguments were completed in March 2026 before the judgment was delivered.

Reasoning:

The court examined whether the marks PLAVIX and CLAVIX were deceptively similar. It noted that PLAVIX is a coined word with no direct meaning, making it highly distinctive and deserving of strong protection. The only difference between the two names was the first letter P versus C. When viewed as a whole, the names looked and sounded very much alike, especially to a person with average memory who might not recall the exact spelling.

The court emphasized that medicines require extra caution because any mix-up can harm health. It referred to the well-known principle that in pharmaceutical cases, courts must apply a stricter test for confusion. Even though both drugs required a doctor's prescription, the possibility of mistakes in reading handwriting, verbal communication, or dispensing errors could not be ignored, particularly in a country with diverse languages and literacy levels.

The judge also considered Intas's explanation for creating the name CLAVIX. The court found this reasoning unconvincing and appeared to be an afterthought rather than a genuine and honest choice made independently. Intas had not conducted proper searches before adopting the mark, and it was already selling the same drug under other names, which raised questions about the real motive behind choosing a name so close to PLAVIX.

Differences in packaging, colour, or price were noted but given limited weight in the infringement claim. Once the core names were found deceptively similar, added features in the overall get-up could not fully save the situation in an infringement action. The court clarified the legal position regarding device marks and word marks, holding that the prominent word element in a registered label mark deserves protection.

The Court also observed that the defendant cannot assert the benefit of prior user in terms of Section 34 of the Act, as such protection is available only to a bona fide adopter and user of the mark.  A party who has adopted a mark with knowledge of the plaintiff’s prior rights, or with an intention to ride upon the goodwill and reputation attached thereto, cannot seek refuge under the doctrine of prior use. The statutory defence under Section 34 is not meant to shield acts tainted with bad faith or to legitimise an attempt to cause confusion or deception in the market. Consequently, the defendant is disentitled from claiming any protection on the ground of prior user, and the said plea is liable to be rejected.

Judgements with Complete Citation and Their Context Discussed:

The court relied on several important precedents to guide its decision. A central reference was the Supreme Court case Cadila Health Care Ltd. Vs. Cadila Pharmaceuticals Ltd. (2001) 5 SCC OnLine SC 578. In that matter, the Supreme Court stressed that disputes involving medicinal products demand a stricter approach because confusion between drugs can have serious, even life-threatening, consequences. The judgment explained that unlike ordinary consumer goods, medicines are not everyday items, and factors like illiteracy, linguistic diversity, and pressure situations in hospitals make the risk of error higher. This principle was applied directly here to evaluate the likelihood of confusion between PLAVIX and CLAVIX.

Another key authority was Kaviraj Pandit Durga Dutt Sharma Vs. Navaratna Pharmaceutical Laboratories (1964) SCC OnLine SC 14 where the Supreme Court explained the difference between trademark infringement and passing off actions. It clarified that in infringement cases, if the essential features of the registered mark are copied, differences in get-up or packaging may not matter much, unlike in pure passing off claims.

The court also discussed Corn Products Refining Co. Vs. Shangrila Food Products Ltd. (1959) SCC OnLine SC 11, which laid down that marks must be compared as a whole from the perspective of an ordinary buyer with imperfect recollection. Other cases cited helped distinguish situations where common elements derived from generic or scientific names were involved, showing why those precedents did not help Intas in this instance.

Recent Delhi High Court decisions were referred to on issues such as the protection of essential word features in composite or device marks and the limited role of manufacturer names or additional elements when the marks themselves are confusingly similar.

Final Decision of the Court

After carefully weighing all arguments and evidence, the Delhi High Court decided the case in favour of Sanofi. It held that Intas's use of the mark CLAVIX constituted trademark infringement of Sanofi's PLAVIX mark. However relief of passing off was declined as Plaintiff failed to prove any goodwill and reputation in India . The court found the marks deceptively similar and likely to cause confusion among the trade and public, particularly in the sensitive field of pharmaceuticals. Consequently, the court granted a permanent injunction restraining Intas from manufacturing, selling, or offering for sale any medicinal preparations under the mark CLAVIX or any other deceptively similar mark. Other reliefs, including directions regarding delivery up of materials and consideration of damages or accounts of profits along with costs, followed in line with the findings on the issues framed.

Point of Law Settled in the Case:

This judgment reinforces that in trademark disputes involving pharmaceutical products, courts will apply a stricter standard while assessing deceptive similarity. Even a minor change, such as replacing one letter in a coined mark for identical drugs, can amount to infringement if it creates a likelihood of confusion. The decision also clarifies that packaging differences or the prescription-only nature of drugs do not automatically eliminate the risk of confusion in India’s context. It further settles that the essential word element in a registered device mark receives protection, and explanations for adopting similar names are scrutinized closely for honesty and independence. The defendant is not entitled to the benefit of prior user under Section 34 of the Act, as the adoption of the impugned mark is found to be dishonest and thus vitiates any claim of bona fide use. Overall, it strengthens the protection available to established pharma trademarks against close imitations that could endanger public health.

Case Title: Sanofi Vs. Intas Pharmaceuticals Ltd. & Anr.

Date of Order: 28th April, 2026

Case Number: CS(COMM) 120/2016

Neutral Citation: 2026:DHC:3574

Name of Court: High Court of Delhi

Name of Hon'ble Judge: Hon'ble Mr. Justice Amit Bansal

Disclaimer: Readers are advised not to treat this as substitute for legal advise as it may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor [Patent and Trademark Attorney], High Court of Delhi

Headnote of the Article

Delhi High Court grants permanent injunction in favour of Sanofi restraining Intas from using the deceptively similar trademark CLAVIX for anti-thrombotic medicine, reiterating stricter scrutiny for pharmaceutical trademarks to prevent public confusion and potential health risks.

Title Suggestions:

Delhi High Court Protects PLAVIX Trademark: Intas Restrained from Using Deceptively Similar CLAVIX Mark in Major Pharmaceutical Dispute

Single Letter Difference Proves Costly: Sanofi Wins Trademark Infringement Battle Against Intas Over Heart Drug Marks

Stricter Scrutiny for Pharma Trademarks: Delhi High Court Reiterates Cadila Principles in Sanofi vs Intas Judgment

PLAVIX vs CLAVIX: Delhi High Court Holds Close Similarity in Drug Names Amounts to Infringement and Passing Off

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