US regulators have approved Eisai’s chemotherapy Halaven as a treatment for liposarcoma, offering patients access to the first therapy shown to offer a survival benefit.

Liposarcoma is a specific type of soft tissue sarcoma that occurs in fat cells, diagnosed in around 12,000 people in the US last year, according to National Cancer Institute data.

Clinical trials showed that the median overall survival for patients with liposarcoma receiving Halaven (eribulin mesylate) was 15.6 months compared to 8.4 months for those who received dacarbazine.

On the safety side, the most common side effects among participants given the drug were fatigue, nausea, hair loss, constipation, peripheral neuropathy, abdominal pain and fever, and it can also cause low levels of infection-fighting white blood cells or decreased levels of potassium or calcium.

Those of a more serious nature include a decrease in white blood cell count, which can increase the risk of serious infections that could lead to death; neuropathy; harm to a developing foetus; as well as changes in heartbeat (QTc prolongation), that may also lead to death, the FDA noted.

Halaven was given a priority review by the regulator and also carried orphan drug status, which provides incentives such as tax credits, user fee waivers, and eligibility for exclusivity to encourage the development of drugs for rare diseases.

The drug, which belongs to a class of antineoplastic agents, the halichondrins, that are derived from the marine sponge Halichondria okadai, was approved for breast cancer in the US in 2010 and in the EU in 2011.