GSK, Genmab leukemia drug fails to meet main trial goal

June 27 (Reuters) - GlaxoSmithKline Plc and Genmab A/S said on Friday their cancer drug Arzerra failed to treat a type of leukemia more effectively than other drugs in a late-stage trial.

Arzerra, known chemically as ofatumumab, was being tested in patients with a type of blood cancer known as bulky fludarabine-refractory chronic lymphocytic leukemia, as required by European regulators for conditional approval of the medicine.

The companies said they were unlikely to apply for marketing of approval for the drug to treat such patients, based on the results of the study.

Arzerra is already approved for newly diagnosed chronic lymphocytic leukemia, or CLL, for which the chemotherapy fludarabine is considered inappropriate.

Patients in the study who received Arzerra on average went 5.4 months before their disease progressed compared with 3.6 months for the physician's choice of alternative treatment, but that difference is not statistically significant, the companies said.

(Reporting by Toni Clarke in Washington and Bill Berkrot in New York)