GlaxoSmithKline and Genmab announce results from a study of Arzerra in rituximab refractory follicular NHL

Issued:  17 August 2009, London, UK and Copenhagen, Denmark

GlaxoSmithKline (GSK) and Genmab A/S (OMX: GEN) announced today top-line results from an international multi-center study of Arzerra™ (ofatumumab) in rituximab refractory follicular non-Hodgkin’s lymphoma (NHL).

A total of 116 patients were treated in the study, including 30 patients treated with 500 mg ofatumumab and 86 patients treated with 1000 mg of ofatumumab.  The patients in the study were highly refractory.  Forty-nine percent of patients were refractory to their last chemotherapy treatment. Patients in the study had previously received a median of 4 prior treatment regimens. The primary endpoint was objective response (International Working Group Criteria) over six months from the start of treatment in the 1000 mg dose population.  

The overall response rate (ORR) in the 1000 mg treatment arm was 10%, including one complete response and 8 partial responses. In addition, 50% (43) of patients in the 1000 mg treatment arm had stable disease.  The overall response rate in the total population was 11%.

The ORR among patients who were refractory to prior rituximab monotherapy (n=27) was 22%.  For patients considered refractory to rituximab in combination with chemotherapy the response rate was 7% and among patients considered refractory to rituximab maintenance the response rate was 9%.  The median duration of response in the 1000 mg treatment arm was 6 months and the progression free survival was 6 months.

There were no unexpected safety findings reported during treatment and within 30 days after last infusion. The most common adverse events (greater than 10%) were rash, urticaria, pruritus, fatigue, nausea, pyrexia and cough. 

“The results of this study demonstrate the activity of ofatumumab in patients who had not responded to prior treatment with a CD20 antibody. The response rate in patients refractory to rituximab monotherapy is of interest and warrants further study. We are committed to the further development of ofatumumab in NHL,” said Lisa N. Drakeman, Ph.D., Chief Executive Officer of Genmab.

“Clearly, this is a challenging patient population to treat with a single agent CD 20 antibody. We are committed to evaluating ofatumumab in combination with other agents in this patient population to develop new treatment options for these difficult to treat patients,” said Kathy Rouan, Ph.D., Vice President and Medicines Development Leader at GSK.

GSK and Genmab continue to review the study results and discuss the development strategy for ofatumumab in NHL.

About the study
Patients in this study failed to achieve at least a partial response to rituximab in combination with chemotherapy, had disease progression while on rituximab or had disease progression following a response within 6 months of the last dose of rituximab.  Patients received one infusion of 300 mg of ofatumumab followed by 7 weekly infusions of 500 mg or 1000 mg of ofatumumab.  Disease status was assessed every 3 months until month 12, then every 6 months until month 24.  Patients will be followed every 6 months thereafter until month 60. The protocol was amended in 2007 to discontinue enrollment in the 500 mg dosing allowing full recruitment at 1000 mg.

The objective of the study was to determine the efficacy and safety of ofatumumab in rituximab refractory follicular NHL. The primary endpoint of the study was objective response as measured over a 6 month period from start of treatment and assessed by an Independent endpoints Review Committee according to the standardized criteria for NHL.  Secondary endpoints include duration of response and safety.

About ofatumumab
Ofatumumab is an investigational, fully human monoclonal antibody that binds specifically to the small and large extracellular loops of the CD20 molecule proximal to the cell membrane. The CD20 molecule is a key target in B-cell malignancy therapy because it is expressed on most B-cells.

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

About GlaxoSmithKline (GSK)

GlaxoSmithKline – one of the world's leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better, and live longer. For company information, visit GlaxoSmithKline at www.gsk.com.

GSK Oncology is dedicated to producing innovations in cancer that will make profound differences in the lives of patients. Through GSK’s revolutionary ‘bench to bedside’ approach, we are transforming the way treatments are discovered and developed, resulting in one of the most robust pipelines in the oncology sector.

GSK’s BioPharm R&D division has a rich early pipeline based on cutting edge molecular biology and genetics technology and a mature late-stage portfolio that will provide important medicines to oncology.

Cautionary statement regarding forward-looking statements
Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK' s operations are described under 'Risk Factors' in the 'Business Review' in the company' s Annual Report on Form 20-F for 2008.