The tweaking and transformation of GlaxoSmithKline continues apace, with the announcement today that the UK company would be selling the US and Canadian rights to Wellbutrin XL, a treatment for major depressive disorder and seasonal affective disorder, back to Biovail, the Canadian specialty group which has co-promoted the drug in the US since 2003, for the tidy sum of $510m. 

While the deal appears to be win-win for Glaxo, it is a little bit harder to see the benefits for Biovail, which developed the controlled-release once-a-day drug and then licensed it to Glaxo in 2001 for $62m and is thought to be raking in about 30% of US sales in the form of royalties. The latest sales figures for the drug released by Glaxo show that in the first quarter sales of Wellbutrin XL were only $45m, a 70% year-on-year reduction.