Synthon B.V. v Teva Pharmaceutical Industries Ltd

Novelty requires both disclosure and enablement. The prior art must disclose subject matter which would necessarily infringe the claim. A possibility or choice left to the skilled person is insufficient. Evidence that the skilled person would choose the patented course may support obviousness, but not anticipation.

Obviousness is assessed on all the facts, including the motivation to solve the problem, the number and extent of possible research avenues, the effort involved and the expectation of success. A process improvement involving purer reagents may be patentable where it provides a technical advance. Added matter is prohibited where the amended claim conveys new information, and a clear and unambiguous disclosure is required.

Synthon sought revocation of two Teva patents concerning processes for preparing glatiramer acetate using purified hydrobromic acid in acetic acid. The challenged claims concerned limits on free bromine and metal-ion impurities, use of a bromine scavenger, solution colour, product composition and testing for bromotyrosine.

The issues were novelty over prior sales of Copaxone and the Lemmon process, inventive step over Lemmon, insufficiency, and added matter in the 924 patent. The court also considered the effect of the skilled person’s common general knowledge concerning bromine, tyrosine, metal impurities and analytical methods.

1. The court rejected the attacks on novelty and inventive step. Pre-priority sales of Copaxone did not establish the metal-ion levels required by the product claims. Lemmon did not disclose, expressly or inevitably, the claimed bromine or metal-ion limitations, the use of a bromine scavenger, or the avoidance of metal contamination. The skilled person retained choices, which was fatal to the novelty case.

2. For obviousness, the relevant skilled person was a synthetic chemist with practical experience of peptide synthesis. The court applied the structured approach in Pozzoli v BDMO and the factors approved in Conor v Angiotech. The common general knowledge did not include a concern that free bromine in HBr/AcOH would brominate tyrosine during liquid-phase deprotection. Nor would routine analysis necessarily alert the skilled person to bromotyrosine. The cause of red colouration from metal ions was sufficiently difficult to identify that simply eliminating metal equipment was not obvious.

3. The court rejected the insufficiency squeeze. Although the patent’s teaching did not make the claimed metal-ion levels inevitable, the skilled person reading the patent would know that metal ions were a problem and could investigate other sources or removal measures. Synthon had adduced no evidence establishing undue burden.

4. Claims 20, 27 and 28 of the 924 patent added matter. The application did not clearly and unambiguously disclose glatiramer acetate with the claimed metal-ion levels or APHA colour values. The distinction between “desired molecular weight” and “desired average molecular weight” did not itself add matter.

5. Claim 13 of the 528 patent was amended by deletion. Subject to further submissions, claim 20 was to be deleted and the dependencies of claims 21–28 and 32 amended accordingly. All other validity attacks failed.