A late-stage trial of Servier and CTI BioPharma’s Pixuvri in combination with Roche's MabThera has failed to hit targets in B-cell non-Hodgkin lymphoma, putting its conditional approval in Europe in jeopardy.

In the trial, Pixuvri (pixantrone) plus MabThera (rituximab) did not show a statistically significant improvement in progression-free survival compared to gemcitabine plus rituximab.

Pixuvri won conditional approval in Europe back in 2012 for multiply relapsed or refractory aggressive non-Hodgkin B-cell lymphomas.

As per the requirements of conditional approval, CTI BioPharma said at the time that it would undertake a post-marketing study to “confirm the clinical benefit previously observed”.

The PIX306 trial enrolled 312 patients who had relapsed after therapy with CHOP-R or an equivalent regimen and were ineligible for stem cell transplant.

The primary endpoint was progression-free survival while overall survival, complete response rate, overall response rate and safety were secondary endpoints.

"We are disappointed with the outcome of the PIX306 trial and will proceed to conduct a thorough review of clinical data to assess the next steps for the Pixuvri programme," said Adam Craig, CTI’s chief executive, but failure to hit the primary endpoint throws a huge shadow of doubt over the drug’s future in Europe.

Pixuvri was never approved in the US, as the marketing application was voluntarily withdrawn in 2012 and has not been resubmitted since.