GlaxoSmithKline has linked up with privately-held Concert Pharmaceuticals of the USA to develop medicines containing deuterium, which may “substantially improve” the metabolic properties of drugs.

As part of the deal, GSK gets access to three R&D programmes – CTP-518, a protease inhibitor for HIV due to start Phase I trials this year, a preclinical drug for chronic renal disease and an undisclosed product in Concert’s pipeline. It will also provide GSK with deuterium-modified versions of three of its own pipeline compounds.

Cashwise, Concert will receive $35 million upfront, including a $16.7 million equity investment from GSK. It is also eligible for milestones and tiered, double-digit percentage royalties based on how successful the drugs are and the total value of the deal could exceed $1 billion.

Patrick Vallance, senior vice president of drug discovery at GSK, said the agreement marks the firm’s “continued efforts to access the best science and technology platforms worldwide”. He added that Concert’s approach to deuterium modification of medicines “has broad potential to enhance certain drug properties and result in innovative new medicines”.

Deuterium is an isotope of hydrogen, but is heavier and “therefore forms a stronger chemical bond to a carbon atom of a molecule”, says GSK. This may “substantially improve the drug’s metabolic properties, potentially resulting in better safety, tolerability and/or efficacy”, the firm added.

Lamictal XR approved by FDA
Meantime, the US Food and Drug Administration has approved GSK’s Lamictal XR (lamotrigine) as a once-daily add-on therapy for patients with epilepsy aged 13 or older who experience partial onset seizures.

The approval was based on results from the ARMOR study involving 236 patients which showed that Lamictal XR reduced partial seizures by 47%, compared to 25% with placebo over 19 weeks of treatment. The drug is an extended-release formulation of Lamictal, which has lost patent protection and first-quarter sales of Lamictal sank 61% to £144 million.