Coined, Not Derived: Dr. Reddy’s Laboratories v. Razenta Pharmaceuticals and the Limits of the “Named After the Molecule” Defence

By Lucy Rana

The decision at a glance

• The Delhi High Court (Justice Jyoti Singh) allowed a cancellation petition under Section 57 and struck DAPLOGIN (Class 5) from the Register, finding it deceptively similar to Dr. Reddy’s earlier coined mark DAPLO for a diabetes drug with the same active ingredient, dapagliflozin.
• The respondent’s central defence — that DAPLOGIN was legitimately derived from the molecule (DAP + LOZIN, with the suffix GIN) — failed, because DAPLO is a coined whole, not a recognisable short-form of the active ingredient.
• The “crowded field” defence failed too: citing four registered but unused lookalike marks proved “common to the register,” not “common to the trade.”
• Because DAPLOGIN subsumed all five letters of DAPLO, and pharmaceutical recall is largely phonetic, the suffix GIN did not dispel confusion.
• The Court applied the lower threshold for medicinal marks from Cadila Healthcare — given the public-health stakes, even the slightest possibility of confusion tells against registration, and prescription status is no shield.
• Notably, Dr. Reddy’s had missed the opposition window when DAPLOGIN was advertised; cancellation under Section 57 was the backstop that a trademark watch would have made unnecessary.

Nearly every pharmaceutical brand borrows something from the chemistry behind it. Companies coin names from the molecule or salt so that prescribers and pharmacists can recall them, and the law has long tolerated a degree of this. The difficult question is where tolerance ends: at what point does a name stop being an honest nod to the active ingredient and become a vehicle for sailing close to a competitor’s established mark? This case answers that question with unusual clarity, and the answer turns on a single distinction — between a mark derived from the molecule and a mark that simply absorbs a rival’s coined word.

DAPLO, DAPLOGIN, and a missed opposition window

Dr. Reddy’s had used the coined mark DAPLO since 2020 for a drug treating Type-2 Diabetes Mellitus, with the active ingredient dapagliflozin, and held a registration in Class 5 (as well as registrations in several other jurisdictions). Razenta obtained registration of DAPLOGIN in Class 5 for medicinal preparations, on a “proposed to be used” basis, in 2021.

The sequence that followed is instructive. DAPLOGIN was advertised in the Trade Marks Journal in June 2024. The publication escaped Dr. Reddy’s attention, no opposition was filed, and the mark proceeded to registration in November 2024. Dr. Reddy’s came across DAPLOGIN only in March 2025, when it appeared on an online pharmacy listing, and a Registry search revealed the registration. With the opposition window gone, the company moved to cancel the registration under Section 57.

Even a company of Dr. Reddy’s scale missed a journal advertisement, and the mark registered by default. The opposition stage is the cheap stop; cancellation is the expensive backstop.

“We derived it from the molecule”

Razenta’s defence was the one most commonly raised in pharmaceutical trademark disputes. It argued that DAPLOGIN was coined honestly and in line with industry practice, by taking the first three letters (DAP) and the last five (LOZIN) from dapagliflozin, substituting the Z with a G, and adding GIN to make the mark distinctive. On that account, DAPLO too was merely derived from the molecule, and no one could claim exclusivity over letters drawn from an international non-proprietary name.

To support the point, Razenta invoked the line of authority in which courts have declined to protect names that are simply short forms of the active ingredient — LETROZ from Letrozole, NIMULID from Nimesulide, TEMODAL and TEMODAR from Temozolomide. In each of those cases, the mark was found to be publici juris or descriptive of the compound, and the addition of distinct suffixes was enough to avoid confusion.

Coined vs derived: which side of the line a pharma name falls

The Court accepted that principle but held it did not help Razenta, and the reason repays attention. DAPLO, the Court found, is not a short name, prefix, suffix or abbreviation of dapagliflozin. It is a coined whole, conceived by combining DAP and LO, that does not by itself identify the salt. That places it on the opposite side of the line from LETROZ or NIMULID, which readers would recognise as truncations of their molecules.

DAPLOGIN, by contrast, subsumed the entirety of DAPLO. When two pharmaceutical marks are compared as wholes — the anti-dissection rule, tempered by the recognition that a dominant element may carry more weight — the dominant part of DAPLOGIN was DAPLO itself, identical to the petitioner’s mark. And because recall in this field is largely phonetic, with the opening syllables doing most of the identifying work, DAP-LO-GIN would be heard as carrying DAP-LO prominently within it. The suffix GIN did not dispel that; it decorated it.

The dividing line is simple to state and decisive in practice: a name that is a recognisable short-form of the molecule may be defensible; a name that swallows a competitor’s coined mark whole is not.

“Common to the register” is not “common to the trade”

Razenta’s second defence was that DAPLO sits in a crowded field, and it cited four other marks beginning with DAPLO to prove it. The Court rejected the argument on an evidentiary ground that is easy to overlook and important to remember: the four marks were registered, but there was no evidence that any of them was actually used in the market. Under the statute, a mark or part of a mark must be shown to be common to the trade — that is, in the actual flow of goods — not merely common to the register.

A register can be populated with marks that never reach a shelf, or reach it only sporadically. Citing such registrations, without proof of substantial use, does nothing to erode the distinctiveness of the mark being asserted. For anyone running or defending a “crowded field” argument, the lesson is concrete: a trade-mark search report is not evidence of use, and the burden of showing genuine market presence sits on the party asserting commonality.

You cannot call a mark generic while using it yourself

There was a further, neat turn. Razenta repeatedly argued that DAPLO was generic because DAP is drawn from dapagliflozin — yet it had itself adopted DAP, indeed DAPLO in full, as the leading element of its own mark. Having built its brand on the very element it now called generic, Razenta could not credibly ask the Court to treat that element as free for all. The Court also read the adoption of a mark that carried a competitor’s coined word as its dominant part, for the same drug, as an attempt to sail close and take advantage of the goodwill DR had built.

Why pharmaceutical marks get a lower confusion threshold

Underlying the whole analysis is the special standard that applies to medicines. Since Cadila Healthcare, Indian courts have required exacting scrutiny of pharmaceutical marks, because confusion between drugs is not merely an economic inconvenience but a potential danger to health. The threshold is correspondingly lower: the slightest possibility of confusion can be enough to refuse or cancel a registration. The Court reaffirmed, too, that the prescription-only status of a drug is not a reliable safeguard — prescriptions are misheard, mis-written and mis-filled, and the infrastructure of supervision varies widely across the country.

Applied to DAPLO and DAPLOGIN — identical goods, the same active ingredient, the same disease, and common trade channels — the marks were held deceptively similar, offending the absolute grounds in Section 9 and the relative grounds in Section 11 of the Trade Marks Act, 1999.

The strategic route: cancellation under Section 57 (and the watch that would have been cheaper)

With the opposition window missed, Dr. Reddy’s used the remedy that remained: rectification of the Register under Section 57, which allows a person aggrieved to have a wrongly entered mark removed so that the purity of the Register is maintained. It is a powerful backstop — but it is a backstop. Opposition at the advertisement stage would have stopped DAPLOGIN before it ever registered, at a fraction of the cost and delay.

The practical moral is one we return to often: a registration does not monitor the Register on its owner’s behalf. A systematic watch of the Trade Marks Journal is what converts an advertisement into an opposition rather than a later, harder cancellation. Notably, the Court left the petitioner’s separate claim that DAPLO is a well-known mark undecided — it did not need to reach that question to grant relief, which is itself a reminder that ordinary deceptive-similarity principles, strictly applied in the pharmaceutical context, were sufficient.

Pharmaceutical brand owners issues

The comfortable takeaway — that a distinctive pharma mark is protectable — is true but thin. The lessons that actually change decisions are these:

• Derive from the molecule, but coin a genuine whole. A name that a reader would recognise as a short-form of the active ingredient may be defensible; a name that absorbs a competitor’s coined mark is not. The safe question at the naming stage is whether your mark reads as the molecule or as the rival.
• The “crowded field” defence needs evidence of use. Registered-but-unused lookalikes are “common to the register,” not “common to the trade,” and do not dilute distinctiveness. Plaintiffs can take comfort in this; defendants must prove substantial market use, not merely produce a search report.
• Do not argue a mark is generic while using it. A defendant who builds its brand on an element it calls publici juris undermines its own case.
• Watch the journal — opposition is cheaper than cancellation. Even large companies miss advertisements. A trademark watch turns a journal entry into a timely opposition rather than a later Section 57 petition.
• Keep your evidence of use and goodwill current. Continuous use since a documented date, revenue supported by a chartered accountant’s certificate, and promotional records anchored the distinctiveness finding here.
• Prescription status is not a shield. For medicines, the confusion threshold is lower, not higher, and the fact that a drug is dispensed on prescription will not, by itself, defeat a claim.

In our experience, the pharmaceutical naming decision is where most of these disputes are won or lost. A name that reads as an honest reference to the molecule, and that does not carry a competitor’s coined mark as its dominant part, is far less likely to end in a cancellation petition — and a disciplined journal watch ensures that, if a conflicting mark is advertised, it is met at the opposition stage rather than years later.

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