GlaxoSmithKline's Arzerra flunks lymphoma trial, dashing plans for expanded use

GlaxoSmithKline ($GSK) has missed out on a big new market for its blood cancer drug Arzerra. Approved to treat chronic lymphocytic leukemia (CLL), Arzerra (ofatumumab) failed to pass the test in a B-cell lymphoma trial. And now, Glaxo officials say they're giving up on the indication.

"Based on today's results, we are unlikely to move forward with a regulatory filing," said Jan Van De Winkel, CEO of Glaxo's Arzerra partner, Genmab.

In the lymphoma trial, Arzerra was pitted against Roche's ($RHHBY) Rituxan (rituximab) in 447 patients with B-cell lymphoma, the most common form of non-Hodgkin lymphoma, who had relapsed or failed on another treatment. The Arzerra-plus-chemo combination didn't beat the Rituxan-plus-chemo combo on progression-free survival, Glaxo said in a statement Monday.

"We are disappointed that the ORCHARRD study did not meet its primary endpoint," Glaxo's oncology R&D chief Rafael Amado said in the statement. Detailed data will be released later this year, "which we hope will provide further clarity," Amado said.

And though Arzerra patients fared about as well as Rituxan patients in terms of serious side effects, the Arzerra group did suffer more dose interruptions and delays because of infusion reactions and elevated creatinine levels. Those reactions "require further analysis," GSK said.

It's a setback for Glaxo's oncology business, which the company recently agreed to sell to Novartis ($NVS) for up to $16 billion. In announcing that deal, Glaxo CEO Andrew Witty said that he believed the company's cancer portfolio would be in better hands at Novartis, which has greater depth in cancer research and a broader range of drugs. Novartis is adept at developing new indications for existing drugs, and Arzerra is currently under study for other indications, including follicular lymphoma.

As far as CLL goes, Glaxo has had some recent success with Arzerra. Approved in 2009 for relapsed CLL, the drug nabbed FDA approval last month as a first-line treatment. The first-line approval applies to patients who can't take a common chemo treatment, fludarabine. But earlier this year, Johnson & Johnson's ($JNJ) new blood cancer treatment Imbruvica beat Arzerra at second-line treatment for CLL.

- read the GSK release

Special Report: Top 10 pharma companies by 2013 revenue - GSK