Delhi High Court Clarifies Trademark Protection for Pharmaceutical Brands: Intas Pharmaceuticals Ltd. v. Sun Pharma Laboratories Ltd.

Delhi High Court Clarifies Trademark Protection for Pharmaceutical Brands: Intas Pharmaceuticals Ltd. v. Sun Pharma Laboratories Ltd.

Introduction

In a significant judgment concerning pharmaceutical trademarks, the Delhi High Court in Intas Pharmaceuticals Limited v. Sun Pharma Laboratories Limited, RFA(OS)(COMM) 10/2026, set aside a permanent injunction granted against Intas Pharmaceuticals and held that its mark 'BEVATAS' did not infringe Sun Pharma's registered trademark 'BEVETEX.'

The Division Bench Comprising Justice V. Kameswar Rao and Justice Manmeet Pritam Singh Arora emphasized that a final finding of trademark infringement after trial must be supported by evidence establishing likelihood of confusion and cannot be based merely on a visual comparison of competing marks. The decision provides important guidance on the treatment of pharmaceutical trademarks derived from International Non-Proprietary Names (INNs), the doctrine of publici juris, and the evidentiary burden required to establish confusion in infringement actions.

Background of the Dispute

The dispute arose from competing anti-cancer pharmaceutical products marketed under the trademarks 'BEVATAS' and 'BEVETEX.'

Sun Pharma Laboratories Limited claimed rights in the registered trademark 'BEVETEX,' which was used in relation to a Paclitaxel-based anti-cancer drug. In December 2017, Sun Pharma instituted a trademark infringement suit against Intas Pharmaceuticals, alleging that Intas' use of the mark 'BEVATAS' for a Bevacizumab-based anti-cancer drug was deceptively similar to its registered mark.

Sun Pharma sought:

• Permanent injunction;
• Damages;
• Rendition of accounts;
• Relief for passing off; and
• Relief for unfair competition.

Intas defended the suit by asserting that the mark 'BEVATAS' was independently coined by combining 'BEVA,' derived from the active pharmaceutical ingredient Bevacizumab, and 'TAS,' taken from the corporate name Intas.

Earlier Proceedings

At the interim stage, the Single Judge refused to grant an injunction in September 2018. The Court found that the rival marks were visually, structurally and phonetically distinguishable.

Sun Pharma challenged this finding before a Division Bench of the Delhi High Court. The appeal was dismissed in January 2020, and the Supreme Court subsequently declined to interfere by dismissing Sun Pharma's Special Leave Petition in February 2020.

However, following a full trial, a Single Judge revisited the issue and in March 2026 granted a permanent injunction against Intas, holding that the marks were deceptively similar and likely to confuse consumers.

Intas appealed this decision before the Division Bench.

Core Legal Issues

The Division Bench was required to determine:

1. Whether 'BEVATAS' was deceptively similar to 'BEVETEX';
2. Whether the likelihood of confusion had been established through evidence at trial;
3. Whether portions of the marks derived from the pharmaceutical molecule Bevacizumab could enjoy exclusive trademark protection;
4. Whether the competing pharmaceutical products were sufficiently related to create confusion among consumers and healthcare professionals.

Requirement of Evidence After Trial

One of the most significant aspects of the judgment concerns the distinction between interim findings and final adjudication.

The Court observed that while courts may form prima facie opinions by visually comparing marks at the interlocutory stage, a final decree after trial requires evidence establishing actual or probable confusion.

The Division Bench held that the Single Judge's conclusion rested substantially on comparison of the rival marks without adequate evidentiary support demonstrating market confusion.

According to the Court, a finding of deceptive similarity after a full trial must be based on evidence led by the plaintiff and cannot merely replicate the reasoning ordinarily employed while deciding interim injunction applications.

The judgment thus reinforces the principle that evidentiary standards become significantly higher once a matter proceeds to trial.

Publici Juris and INN-Derived Pharmaceutical Marks

A central issue before the Court was the significance of the prefixes 'BEV' and 'BEVA.'

The Court noted that these elements are derived from 'Bevacizumab,' the International Non-Proprietary Name (INN) of a pharmaceutical molecule widely used in oncology treatments.

The Bench observed that several pharmaceutical manufacturers employ prefixes drawn from the names of active ingredients. Such descriptive or generic elements are commonly available to all traders in the industry and cannot ordinarily be monopolized by a single proprietor.

Consequently, the Court held that the prefixes 'BEV' and 'BEVA' are publici juris that is, they belong to the public domain and are available for common use in the pharmaceutical trade.

Because these portions lacked distinctiveness, the assessment of similarity had to focus on the remaining distinctive components of the marks.

Distinguishing Features: 'TAS' versus 'TEX'

Having excluded the common and descriptive prefixes from consideration, the Court turned to the suffixes.

The Bench found that:

• 'TAS' and 'TEX' are visually different;
• They are phonetically distinct;
• They create different auditory impressions when spoken.

The Court concluded that an average consumer, healthcare professional, pharmacist, or medical practitioner would perceive the marks as distinct rather than confusingly similar.

Accordingly, the essential distinguishing features of the competing marks weighed strongly against a finding of infringement.

Importance of Therapeutic Differences

The Court also examined the nature of the pharmaceutical products themselves.

Although both products fell within Class 5 pharmaceutical preparations and were used in oncology, they were found to be fundamentally different medicines.

The Court observed:

• BEVATAS contained Bevacizumab;
• BEVETEX contained Paclitaxel;
• The drugs possessed different compositions;
• They had different therapeutic indications;
• They were not therapeutic substitutes.

The Bench emphasized that pharmaceutical products cannot be regarded as similar merely because they belong to the broad category of anti-cancer drugs.

The Court stated that drugs which are not interchangeable and do not serve the same therapeutic purpose are, for practical purposes, dissimilar products.

This finding significantly weakened Sun Pharma's claim of likely confusion.

Rejection of the Chemist Substitution Argument

Sun Pharma argued that confusion could arise if a chemist dispensed one medicine when the prescribed medicine was unavailable.

The Court firmly rejected this submission.

According to the Bench, the argument assumed a level of professional negligence that the law cannot ordinarily presume. Trademark infringement must be assessed on realistic probabilities rather than hypothetical situations involving gross departures from accepted pharmaceutical practice.

The Court therefore held that speculative possibilities of negligent substitution could not satisfy the legal threshold for establishing likelihood of confusion.

Decision

The Division Bench concluded that:

1. The common prefixes 'BEV' and 'BEVA' are derived from the INN 'Bevacizumab' and are publici juris.
2. The distinguishing portions 'TAS' and 'TEX' are phonetically and visually different.
3. The competing products are based on different molecules and are not therapeutic substitutes.
4. Sun Pharma failed to establish a legally sustainable likelihood of confusion.
5. The Single Judge's decree granting a permanent injunction could not be sustained.

The appeal was accordingly allowed, the permanent injunction was set aside, and Sun Pharma's suit was dismissed.

Significance of the Judgment

The decision is likely to have substantial implications for pharmaceutical trademark litigation in India.

First, it reinforces the principle that portions of trademarks derived from drug molecules or INNs generally remain available for common use and cannot be exclusively appropriated.

Second, the judgment emphasizes the distinction between interim and final findings in trademark litigation. A plaintiff who succeeds at the interlocutory stage-or relies solely on visual comparison-must still produce evidence supporting confusion at trial.

Third, the Court adopted a nuanced approach by examining not only the marks themselves but also the underlying pharmaceutical products, their composition, therapeutic purpose, and interchangeability.

Finally, the ruling limits attempts to establish infringement based on speculative scenarios involving professional negligence by pharmacists or healthcare providers.

Conclusion

The Delhi High Court's decision in Intas Pharmaceuticals Limited v. Sun Pharma Laboratories Limited represents an important development in pharmaceutical trademark jurisprudence. By recognizing the public-domain character of INN-derived prefixes and insisting upon concrete evidence of confusion at the trial stage, the Court has reaffirmed the balance between trademark protection and fair competition within the pharmaceutical industry. The judgment underscores that trademark law protects distinctive source identifiers, not descriptive elements derived from the names of active pharmaceutical ingredients, and that infringement findings must rest on evidence rather than mere visual resemblance.

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