Roche’s streamlining of its R&D portfolio continues apace and the latest firm to see its collaborator back out is Seattle Genetics.

The Swiss major’s Genentech unit has told Seattle Genetics 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. The decision has been taken a result of the ongoing portfolio review process going on at Genentech since Roche’s $46.8 billion buyout earlier this year.

The termination date is June 8 next year and all rights to the drug will be returned to Seattle Genetics, and Genentech, will remain responsible for costs tied to the completion of ongoing studies. Dacetuzumab is currently being evaluated in four ongoing Phase Ib clinical trials.

Just last week at the American Society of Hematology meeting in New Orleans, Seattle Genetics reported data from two of those trials of dacetuzumab, one in combination with Rituxan (rituximab) and Gemzar (gemcitabine) for diffuse large B-cell lymphoma and the other with Revlimid (lenalidomide) for multiple myeloma. The results from both demonstrate that the drug is well tolerated and “provide rationale to further assess the contribution of dacetuzumab to these combination therapies”, said chief medical officer Thomas Reynolds.

Genentech pulling out just a few days later after that announcement is a disappointment and the US firm said it will consider “possible next steps for the dacetuzumab programme”. However, Seattle Genetics noted that its antibody-drug conjugate collaboration with the Roche unit is unaffected by the termination and chief executive Clay Siegall said it will now concentrate on its lead product candidate, the NHL drug brentuximab vedotin, “which we are positioning for a potential New Drug Application in 2011”.

In the past week,Roche has terminated a cancer collaboration with Genmab and pulled out of a pact with Actelion to develop the latter’s selective sphingosine 1-phosphate receptor 1 (S1P1) agonist for psoriasis and multiple sclerosis.