Genmab is a giant leap closer to getting its cancer drug Arzerra on the market for maintenance treatment of chronic lymphocytic leukaemia, after US regulators said they would review the application in a speedy six-month timeframe.

The human monoclonal antibody targets the CD20 molecule found on the surface of CLL cells and normal B lymphocytes, and is already approved in the US for use in combination with chlorambucil for previously untreated patients with the disease who can’t take fludarabine-based therapy.

The application to broaden the drug’s label is based on data from the PROLONG trial, which showed that patients who received Arzerra (ofatumumab) maintenance treatment lived 13.4 months longer without their disease worsening than those receiving no further treatment, with median progression free survival 28.6 months versus 15.2 months, respectively. 

CLL is the most commonly diagnosed adult leukaemia in western countries and accounts for around one-third of all cases. In the US, more than 105,000 people currently live with or have been previously treated for CLL and an estimated 15,680 new cases were diagnosed in the past year.

Arzerra was co-developed with GlaxoSmithKline but Novartis now owns its rights to the drug, with cancer indications picked up through the firms mega asset swap and a subsequent $1-billion deal giving the Swiss drug giant ownership for other disease areas, including multiple sclerosis.

European regulators are also currently reviewing Arzerra as a maintenance therapy for relapsed CLL.