Dr Reddy's Laboratories (UK) Ltd v Eli Lilly & Company Ltd

Factual and Procedural Background

This appeal arises from a judgment of Floyd J dated 13th October 2008, which dismissed an application by the Appellant to revoke a patent held by the Appellee. The patent in question, with a priority date of 25th April 1990, claims a single chemical compound used as an antipsychotic agent. The Appellant challenged the patent primarily on grounds of lack of novelty and obviousness based on prior disclosures, including a British Provisional Specification published in 1978 and a scientific paper published in 1980. The appeal concerns the validity of the patent in light of these prior disclosures and the relevant legal principles governing novelty, obviousness, and sufficiency of disclosure.

Legal Issues Presented

1. Whether the patent lacks novelty due to prior disclosure of a broad class of compounds that includes the patented compound.
2. Whether the patent is obvious in light of prior art, specifically the British Provisional Specification and the 1980 scientific paper, considering the concept of "selection patents".
3. Whether the patent disclosure is insufficient on the basis that it fails to demonstrate a unique advantage of the claimed compound over the prior art class.
4. What is the appropriate legal approach for assessing validity of a selection patent under the Patents Act 1977 and European Patent Convention jurisprudence.

Arguments of the Parties

Appellant's Arguments

• The Appellant contended that the patented compound lacked novelty because it was encompassed within a large class of compounds disclosed in the 1978 British Provisional Specification, which was said to have made the compound available to the public.
• The Appellant argued that the patent was obvious as the skilled person would have been led by the 1980 scientific paper to synthesize the claimed compound through a process of structure-activity relationship (SAR) optimization, making the selection arbitrary.
• The Appellant also raised insufficiency, arguing that the patent failed to disclose a substantial advantage of the claimed compound over the prior art class, thus rendering the disclosure inadequate.
• Reliance was placed on earlier English case law regarding selection patents, particularly the three-stage test requiring a substantial advantage, universal possession of that advantage by the selected class, and a peculiar quality inherent to the selected group.

Appellee's Arguments

• The Appellee submitted that the patent was novel because the prior disclosure did not provide an individualised description of the claimed compound, and that a general disclosure of a large class does not anticipate a specific member without such description.
• The Appellee argued that the patent was not obvious since the selection of the compound was not arbitrary but based on a credible technical advance supported by experimental and clinical data showing improved properties over related compounds in the prior art.
• The Appellee relied on the jurisprudence of the European Patent Office (EPO) Boards of Appeal, which require a technical contribution and non-arbitrary selection for patentability of selection patents.
• It was contended that the patent provided sufficient disclosure, including data from animal and early clinical tests, exceeding typical pharmaceutical patent standards.
• The Appellee rejected the applicability of the older English common law selection patent principles as superseded by the Patents Act 1977 and aligned with EPC jurisprudence.

Table of Precedents Cited

Court's Reasoning and Analysis

The court began by examining the state of the art at the priority date, noting the complexity and unpredictability in antipsychotic drug development. The prior art included a broad patent specification disclosing a vast class of compounds with no specific evidence supporting their claimed utility. The court rejected the Appellant's novelty argument that the broad class disclosure anticipated the specific compound, holding that a mere general disclosure of a class does not equate to an individualised description necessary to anticipate a specific member.

Regarding obviousness, the court applied the jurisprudence of the EPO Boards of Appeal, emphasizing that a selection patent must demonstrate a real technical advance and not be an arbitrary choice from a known class. The court found that the patent disclosed credible technical advantages of the claimed compound, supported by experimental and early clinical data, distinguishing it from the prior art class.

The court considered the Appellant's argument that the skilled person would have been led by the 1980 scientific paper to synthesize the claimed compound through SAR optimization. It rejected this, finding that the prior research suggested further development of the class but did not provide a reliable basis to expect the claimed compound to solve the specific problem of avoiding serious side effects.

In assessing sufficiency, the court noted that the patent's disclosure exceeded typical pharmaceutical patent standards by providing detailed experimental evidence and clinical observations. It held that the patent was sufficient even if it did not prove that no other compounds in the prior art class shared the same advantages.

The court also addressed the historical English common law approach to selection patents, concluding that it was superseded by the Patents Act 1977 and the EPC framework, which the court preferred for consistency and practicality.

Finally, the court took note of foreign decisions, particularly the German Supreme Court's validation of the patent, and found no reason to diverge from this consensus.

Holding and Implications

The court DISMISSED THE APPEAL, affirming the validity of the patent for the claimed compound.

The direct consequence is that the patent remains enforceable against the Appellant and others, preserving the Appellee's exclusive rights to the compound. The decision confirms the applicability and preference for the EPO's approach to assessing novelty and obviousness of selection patents under the Patents Act 1977 and the EPC. No new legal precedent was established beyond reinforcing existing principles and their consistent application in this jurisdiction.