Bare Possibility, Not Actual Confusion: Phonetic Similarity and the Anti-Dissection Rule in Alkem Laboratories v. Numen Pharma

Introduction

Trademark conflict in the pharmaceutical sector is a unique situation in Indian trademark law. Medicinal products have the potential to cause actual harm to the patient receiving the product if there is any doubt about the correct product, rather than just commercial loss, due to the possibility of someone thinking that two competing marks are the same. This has led to a more demanding approach by courts to pharmaceutical marks, which now require a question to be asked as to whether there is any "bare" possibility of confusion.

The judicial interpretation that the Bombay High Court in Alkem Laboratories Ltd. v. Numen Pharma Private Limited^[1] gave to the term “highest standard” is applicable in the context where both the marks were used for pharmaceutical preparations. While the two products cure totally different conditions, they have an identical sound, and the Court found that an ad-interim injunction was appropriate, reiterating the anti-dissection rule and the bare possibility test for this type of case.

Facts of the Case

Alkem Laboratories Ltd, the Plaintiff, is the registered proprietor of the trade mark “ALCIPRO” which was adopted in 1990 and registered under the erstwhile Trade and Merchandise Marks Act, 1958 in class 5. The Plaintiff had then registered the same mark “ALCIPRO-TN” in 1998. The Plaintiff's product is used for bacterial infections of the urinary tract, nose, throat, skin, soft tissue and lungs and includes the active pharmaceutical ingredient Ciprofloxacin, which the Plaintiff obtained by attaching the prefix “AL” to a shortened version of the name of the molecule.

In December 2023, Plaintiff was notified of an application of Numen Pharma Private Limited (Defendant) for registration of the mark “ACIPROX” on a proposed-to-be-used basis dated 16th January 2023. The Defendant's product, which is known as ACIPROX, is an Aceclofenac product that is prescribed for the short term relief of pain, inflammation and swelling associated with musculoskeletal conditions. The Plaintiff had filed a notice of opposition, while the Defendant had filed an affidavit-in-reply, asserting its use of the impugned mark since 2023 and the claim that “ACECLOFENAC” and “PYREXIA” were the sources from which ACIPROX had derived its meaning.

The Defendant opposed the Plaintiff's application on a number of grounds: that the term ‘CIPRO' was descriptive of Ciprofloxacin and could not be monopolised; that there were at least 314 registered trade marks that included the term ‘CIPRO', including a similar mark ‘CALCIPRO' registered in 1986; that the term ‘CIPRO' did not have a similar sound to the Plaintiff's mark; that the ending ‘X' in ACIPROX was different; and that both products were ‘Schedule H' drugs and could only be sold by prescription from a medical professional, which meant there was no real possibility of consumer confusion. Mr. Kamod for the Plaintiff explained that the competing marks were similar in sound despite their different composition, and that even if there was any ‘likelihood of confusion', whether that was between two drugs for different indications or one drug for a disease and another for a different one, this could have devastating effects upon a patient.

Court's Decision and Analysis

The Court granted an ad-interim injunction which prohibited Defendant from manufacturing, marketing and selling its product under the trade mark “ACIPROX”, finding that a prima facia case of infringement and passing off had been made out in favour of the Plaintiff. The Court's reasoning was based on three main points: the anti-dissection rule, the bare possibility test for medicinal products, and the impact of registration under Section 31 of the Trade Marks Act, 1999.

Defendant had argued that the marks be compared syllable by syllable, arguing that the Defendant's mark is pronounced “A-SI-PROX” while the Plaintiff's mark is pronounced “AL-SI-PROX”. This approach was not followed by the Court, which had relied on the Division Bench's order in Sun Pharmaceutical Industries Ltd. v. Meghmani Lifesciences Ltd.^[2] which had disapproved of the syllable-wise dissection of the marks “RACIRAFT” and “ESIRAFT”. When comparing the two composite wholes of ACIPROX and ALCIPRO the Court determined that the marks were phonetically similar because each could be spoken with haste or neglect both of which might make the marks indistinguishable, and the “X” could be slurred over in speech.

The Court stressed upon the bare possibility test as explained in Cadila Health Care Ltd. v. Cadila Pharmaceuticals Ltd.^[3] and also reiterated in Milmet Oftho Industries v. Allergan Inc.^[4] and a mere possibility of confusion was enough to prevent the use of the impugned mark, as in India, people are multilingual and semi-literate and prescriptions are often dictated to the pharmacist or handwritten and not legible. The Court noted that the Defendant had "argued that the risk of confusion would be eliminated by the existence of a physician's prescription under Schedule H; however, physicians and pharmacists are not protected from mistake.

The Court also dismissed the Defendant's arguments that there were 314 identical registered marks and third-party usage printouts from the website that proved that the mark was common to the trade, finding that an extensive amount of actual use is necessary, and the Defendant had failed to show. Likewise, the Court concluded that the Defendant's explanation for the creation of the coined term ACIPROX, which it stated was based on the terms “Aceclofenac” and “Pyrexia”, was not convincing as no combination of those words was likely to lead to the creation of this coined term “ACIPROX”.

Registration, Anti-Dissection Rule and Prohibition on Monopolising an INN

A major component of the Defendant's defence was that the mark was not identical to nor deceptively similar to a World Health Organisation (WHO) declared International Non-Proprietary Name (INN). The Court found that this prohibition did not help the Defendant for two distinct reasons. First, the WHO notification which identified Ciprofloxacin as an INN occurred much later in 2012, following the earlier registration of the Plaintiff's mark under the Trade and Merchandise Marks Act, 1958 and the saving clause in the 1999 Act. Second, the Court decided that the Plaintiff's mark ALCIPRO was not deceptively similar to the INN Ciprofloxacin; the Plaintiff was not claiming a monopoly over the molecule itself but on the unique combination of the shortened word of the molecule and the prefix “AL”.

The Court found the facts in the case to differ from the ones in the cited precedents, both of which involved the adoption of a similar INN or active ingredient by both the litigants without any distinguishing prefix or suffix. The Court found that the Plaintiff's registered mark was sufficiently distinctive, and that the registration under Section 31 of the Trade Marks Act would be prima facie evidence of validity, which was not met by the Defendant.

In the absence of any irreparable harm to be done to the Defendant on the granting of an injunction pending trial, the Court concluded that the circumstances on which the Plaintiff relies, namely goodwill, misrepresentation and damage, were similar to the classical trinity as enunciated in Laxmikant V. Patel v. Chetanbhai Shah^[5] and Satyam Infoway Ltd. v. Siffynet Solutions (P) Ltd.^[6] gave a nod to the Plaintiff's substantial and long-standing sales turnover and the Defendant being a late entrant incorporated only in 2023.

Conclusion

In pharmaceutical trade mark disputes, the Indian courts will continue to apply an exacting test of scrutiny under the anti-dissection rule and the bare possibility test and will not be swayed by their chemical or therapeutic similarity to the competitor's product.The Indian courts will still apply an exacting test under the anti-dissection rule and the bare possibility test in cases involving pharmaceutical trade marks irrespective of whether the competitor's product is chemically or therapeutically related. In this area, the importance of the possibility of deception, as a whole rather than broken down into individual syllables, will remain the hallmark of the doctrine of deceptive similarity, and that the harm to the patient will generally outweigh any defence of an 'honest adoption' or 'prior registration search' or a 'widespread use of similar marks on the register'.

The judgment also provides much welcome clarity on the relationship between Section 13 of the Trade Marks Act, 1999 and pre-1998 registration, clarifying that pre-1998 registration is not automatically cancelled by the WHO's declaration of a particular INN, and that the relevant question is, not whether the registered mark is simply a copy of the INN, but whether it is deceptively similar.

^[1] Alkem Laboratories Ltd. v. Numen Pharma Private Limited, 2026 SCC OnLine Bom 4400 (Bombay High Court, Deshmukh, J., decided 8 June 2026).

^[2] Sun Pharmaceutical Laboratories Ltd. v. Hetero Healthcare Ltd. and Anr. 2022 SCC OnLine Del 2580

^[3] Cadila Health Care Ltd. v. Cadila Pharmaceuticals Ltd., (2001) 5 SCC 73.

^[4] Milmet Oftho Industries v. Allergan Inc., (2004) 12 SCC 624.

^[5] Laxmikant V. Patel v. Chetanbhai Shah, (2002) 3 SCC 65.

^[6] Satyam Infoway Ltd. v. Siffynet Solutions (P) Ltd., (2004) 6 SCC 145.

Medhavi Capoor

Associate

medhavi.capoor@iprattorneys.com