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Market Leading Anti-Malaria Drug Patent Invalid

In a ruling which will send shock waves through the pharmaceutical industry, a judge has decided that the European patent protecting the UK’s most successful anti-malarial prophylactic is invalid. In upholding arguments put forward by generic drug manufacturers, the court ruled that the particular combination of ingredients that makes up the market-leading preparation, marketed as Malarone, is ‘obvious’ in the light of research that pre-dated the patent application.

The patent protecting Malarone – which comprises a combination of atovaquone and proquanil at a ratio of 5:2 – has been in place since 1992 and has provided the foundation stone for the drug’s considerable commercial success. The registered proprietor of the patent, The Wellcome Foundation Limited, and its beneficial owner, Glaxo Group Limited, had argued, inter alia, that if the preparation was obvious ‘why had it not been done before?’

Wellcome and Glaxo conceded that there was no particular technical significance in the 5:2 ratio of ingredients and that the particular combination of the two drugs did not itself involve an inventive step. However, it was submitted that this did not mean that the decision to test and seek market approval for the formulation was obvious.

However, generic manufacturers, Glenmark Generics (Europe) Limited and Generics (UK) Limited, argued that an expert team with clinical experience of treating malaria would have viewed the formulation as obvious in the light of a research paper published nine months before the patent’s priority date.

The court acknowledged that, in considering the validity of the patent, it was important to avoid hindsight. However, it concluded that claims contained within the patent were obvious and it followed that the patent stood to be revoked. The generic manufacturers can now implement plans to market their own versions of Malarone which had been stayed pending the outcome of the expedited hearing.