Shares in Pozen were on a slippery slope after US regulators failed to grant its migraine drug Pozen peadiatric exlusivity, leaving the drug open to generic competition.

The drugmaker said it has been informed by US partner GlaxoSmithKline that the Food and Drug Administration has not accepted its submission of clinical study data to support the use of Treximet (sumatriptan succinate/naproxen sodium) in a pediatric population.

The decision means that the drug's regulatory exclusivity will expire on April 15 this year, paving the way for cheaper copycat drugs to enter the market.

Treximet is protected by three patents in the US patents, two of which expire in August 2017 and the other October 2025. These have been challenged by four generic makers who filed Abbreviated New Drug Applications with the FDA to sell their own versions of the drug. 

Pozen has filed a suit against Par Pharmaceuticals, Alphapharm and Dr Reddy’s Laboratories as well as Teva Pharmaceuticals USA, having reached a settlement with the latter. A ruling in its case against the others - which was heard in October 2010 - is still pending, the firm said. If a decision is not reached before April 15 then Par, which has 180 days of exclusivity for its generic product, could proceed with a launch.

There is, however, still a chance for GSK to obtain paediatric exclusivity - and an extra six months' protection for the drug - as the FDA has agreed to accept a resubmission of the data once additional information is available. If this happens and Par has already rolled out its version, then the firm could be forced to withdraw its generic from the market and pay damages.

NICE OKs Votrient

Elsewhere for GSK, news was much more positive, as the cost watchdog for the NHS in England and Wales has agreed to fund its kidney cancer drug Votrient (pazopanib).

The National Institute for Health and Clinical Excellence has recommended that Votrient be considered as a first-line treatment option for patients with advanced renal cell carcinoma who have not previously received cytokine therapy, ruling that the drug represents value for money when taking into account a patient access scheme proposed by GSK. 

The access scheme offers a straight discount at the point of invoice, but also makes provision for a possible partial rebate to the NHS in the future, depending on the outcome of an ongoing head-to-head trial (COMPARZ) pitting the drug against Pfizer's Sutent (sunitinib), the current standard-of-care and only other targeted therapy currently available for the condition.

GSK said it is confident that the trial will demonstrate the clinical value of Votrient, and so has proposed a risk-sharing type scheme so that patients can get quicker access to its innovative cancer medicines.