GlaxoSmithKline is teaming up with Seattle Genetics to get access to the latter’s antibody-drug conjugate technology in a deal valued at potentially over $400 million.

Under the terms of the agreement, GSK will make an upfront fee of $12 million and potential milestone payments of up to $390 million. The ADC technology will be used with multiple antigens to be named by GSK and Seattle Genetics will also receive mid-single digit royalties on sales of any resulting ADC products.

The deal comes in what has been a busy fortnight for Seattle Genetics. First up, Roche’s Genentech unit said it is terminating the companies’ collaboration agreement for SGN-40 (dacetuzumab), a monoclonal antibody targeting the CD40 protein that has been investigated in trials for non-Hodgkin lymphoma and multiple myeloma. However the US firm then sealed a pact with Takeda to develop the former’s lymphoma drug SGN-35 (brentuximab vedotin).

Elsewhere, GSK’s partner Actelion suffered a significant share decline after it unveiled mixed data, including safety concerns, from a late-stage trial of its investigational insomnia drug, almorexant.

The Swiss firm said that a two-week Phase III study with almorexant has met its primary endpoint, namely superiority of the drug, a dual orexin receptor antagonist, compared to placebo. Actelion's vice president of sleep development, Jed Black, added that the drug has “demonstrated clinically meaningful effects on both sleep induction and sleep maintenance”, while chief executive Jean-Paul Clozel,said the initial data has provided “a first promising insight of the impact” of almorexant compared to the impact of a traditional GABA-agonist”, namely zolpidem, sold by Sanofi-Aventis as Ambien.

However, while almorexant was well-tolerated, Actelion noted that in this study “as well as in the ongoing non-pivotal programme, certain safety observations were made that will require further evaluation and assessment in longer-term Phase III studies”. The late-stage studies are currently in preparation in both adults and elderly patients suffering from primary insomnia, the Allschwil-based firm said.

Actelion signed a potentially lucrative deal for almorexant with GSK in July last year.