Genmab A/S announced that it has amended the design of an ongoing pivotal study of ofatumumab (HuMax-CD20) in rituximab refractory follicular non-Hodgkin's lymphoma (NHL) to a single arm trial that will now include approximately 81 patients. All patients will receive one infusion of 300 mg of ofatumumab followed by 7 weekly infusions of 1000 mg of ofatumumab, the company stated in a recent press release.

The original study design included 162 patients, who would have received one infusion of 300 mg of ofatumumab followed by 7 weekly infusions of either 500 or 1000 mg of ofatumumab. This is the first study of ofatumumab dedicated to patients with rituximab-refractory follicular lymphoma.

In order to establish that ofatumumab is efficacious in this refractory setting, reducing the number of patients in the trial will help to expedite a result. The lower dose (500 mg) was dropped to reduce the total number of patients to be accrued and ensure that these very sick patients receive the maximum dose. Data from patients who were already treated in the 500 mg dose group will be analyzed for safety and included in the secondary efficacy analysis, but will not be included in the primary efficacy analysis, the company said.

"This change to the pivotal study design will allow us to treat all the refractory patients with a higher dose level of ofatumumab, allowing the maximum opportunity for response and longer lasting effects in this patient population," said, Lisa N. Drakeman, Ph.D., chief executive officer, Genmab.

Ofatumumab is an investigational drug being developed under a co-development and commercialization agreement between Genmab and GlaxoSmithKline. It is not yet approved in any market.