A patent claim spanning sixteen years of prosecution, two rounds of amended claims, and objections spread across three separate statutory provisions collapsed on a single ground: obviousness.<\/p>\n
Esteve Pharmaceuticals S.A. (\u201cEsteve\u201d), a Spanish pharmaceutical company, filed a national phase patent application in India on February 15, 2012, claiming priority from an earlier European filing of October 16, 2009. The application, titled \u201cCo-Crystals of Tramadol and Coxibs,\u201d sought a co-crystal patent for a combination of tramadol, an opioid analgesic, with celecoxib, a coxib-class non-steroidal anti-inflammatory drug (NSAID) used to relieve pain while limiting the side effects associated with opioids alone. Esteve’s case rested on data showing that the co-crystal produced better pain relief than either drug administered individually, evidence it argued established the synergistic effect and enhanced efficacy needed to justify a fresh monopoly over an already-known combination.<\/p>\n
The Indian Patent Office raised objections after the First Examination Report was issued in October 2017, citing lack of novelty and inventive step under Section 2(1)(ja) of the Patents Act, 1970 (\u201cPatents Act\u201d), alongside separate objections under Section 3(d) and Section 3(e) of the Act. Esteve amended its claims twice, narrowing them from a broad class of coxibs to the specific tramadol-celecoxib combination. Despite the amendments, the Assistant Controller of Patents rejected the application on February 12, 2020, holding that the claimed co-crystal lacked inventive step and did not qualify as a patentable invention. Esteve appealed the rejection to the Delhi High Court under Section 117A of the Patents Act.<\/p>\n
The court noted that D5 disclosed a tramadol-NSAID combination and expressly listed celecoxib among the NSAIDs suitable for use in place of naproxen, the illustrative example used in that document. The court observed that D5 stated a person skilled in the art would know how the disclosed combination could be modified using other listed NSAIDs, including celecoxib, and that the same document acknowledged some combination products could produce a synergistic analgesic effect. Turning to D7, the court found that this document disclosed a general framework for preparing co-crystals from pairs of active pharmaceutical ingredients and that its Table IV expressly listed both tramadol and celecoxib as candidate APIs. The court held that D7’s claimed improvements, including increased bioavailability, dose response, and stability compared to the API alone, mirrored the very advantages Esteve claimed for its co-crystal patent, and that D7’s disclosed crystallisation methods, including dissolving components in a solvent and allowing the co-crystal to precipitate, overlapped substantially with the process Esteve had claimed.<\/p>\n
The court reasoned that D5 supplied the motivation to combine tramadol with an NSAID such as celecoxib for improved pain treatment, while D7 supplied the technique by which such a combination could be reduced to a co-crystal. The court observed that Esteve’s argument regarding the scale of possible combinations in D7’s Table IV did not displace the more targeted disclosure in D5, which had already narrowed the field to a specific combination of tramadol with NSAIDs including celecoxib. The court further observed that the efficacy data relied upon by Esteve, while showing some improvement in ED50 values for the co-crystal compared to tramadol and celecoxib individually, did not establish a synergistic effect materially beyond what D5 already anticipated as a general possibility for such combinations. The court found that novelty and inventive step remained separate inquiries under the Patents Act, and that the absence of a sustained novelty objection did not immunise the claims from a fresh assessment of obviousness. Given this finding on the co-crystal patent’s lack of inventive step, the court declined to examine the separate objections under Section 3(d) and Section 3(e), relying on the principle in Kroll Information Assurance, LLC v. Controller General of Patents<\/em> (C.A.(COMM.IPD-PAT) 439\/2022) that a sustained objection under Section 2(1)(ja) renders further examination of alternative grounds unnecessary.<\/p>\n In view of the observations and the arguments presented by both the parties, the Delhi High Court held that:<\/p>\nFindings<\/h2>\n
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