FDA approval of Arzerra triggers $23 million milestone for Genmab from GSK

The US Food and Drug Administration has approved Arzerra (ofatumumab) for patients with chronic lymphocytic leukemia (CLL), a slowly progressing cancer of the blood and bone marrow. As a result, Denmark's biotechnology firm Genmab will receive a milestone payment of 116 million Danish kroner ($23 million) from partner UK drug giant GlaxoSmithKline.

Genmab licensed exclusive worldwide rights to co-develop and commercialize ofatumumab to GSK in December 2006. It received a license fee of 582.0 million kroner and GSK invested 2.03 billion kroner in the Danish firm's shares.

Arzerra is approved for patients with CLL whose cancer is no longer being controlled by other forms of chemotherapy. CLL primarily affects people older than 50 and arises from a group of white blood cells known as B-cells that are part of the body's immune system. Each year, about 16,000 people are diagnosed with CLL and about 4,400 people die from the disease.

The product was cleared under the FDA's accelerated approval process, which allows earlier approval of drugs that meet unmet medical needs. Products may receive accelerated approval based on a surrogate endpoint, such as a reduction in the size of the tumor or decrease in the number of cancerous white cells or in an enlarged spleen or lymph nodes. These indirect measures for clinical outcomes are considered reasonably likely to predict that the drug will allow patients to live longer or with fewer side effects of a disease

US launch shortly

Arzerra is anticipated to be available for prescription use in the coming weeks. GSK has added Arzerra to its patient assistance program, Commitment to Access, and has expanded the program. This program assists eligible patients, with or without insurance, with paying for cancer medicines.

The product's safety was evaluated in 181 patients in two studies in patients with cancer. Common side effects included a decrease in normal white blood cells, pneumonia, fever, cough, diarrhea, lower red blood cell counts, fatigue, shortness of breath, rash, nausea, bronchitis and upper respiratory tract infections, the FDA noted.

The most serious side effects of Arzerra are increased chance of infections, including progressive multifocal leukoencephalopathy (PML), a brain infection that is generally fatal. Patients at high risk for Hepatitis B should be screened before being treated with Arzerra. Patients with evidence of inactive hepatitis should be monitored for re-activation of the infection during and after completing treatment, the agency stated.