The US Food and Drug Administration has approved GlaxoSmithKline’s Arranon (nelarabine) injection, a chemotherapy agent, for the treatment of patients with T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL) whose disease has not responded to or has relapsed following treatment with at least two chemotherapy regimens. This use is based on the induction of complete responses. Randomised trials demonstrating increased survival or other clinical benefit have not been conducted.

According to a GSK release, approximately 1,600 adults and children are diagnosed with T-ALL or T-LBL in the US each year. A subset of these patients will relapse or develop disease that is refractory to treatment. There is no standard of treatment for these patients and their prognosis is particularly poor. To facilitate the development of Arranon for this relatively small group of patients, GSK worked closely with the National Cancer Institute (NCI) of the National Institutes of Health (NIH), the Children’s Oncology Group (COG) and the Cancer and Leukemia Group B (CALGB), in conjunction with the Southwest Oncology Group (SWOG).

Arranon received accelerated approval, granted by the FDA to medicines for treating serious or life-threatening illnesses that address an unmet medical need, based on complete response rates demonstrated in two Phase II trials in patients who had exhausted standard treatment options. Post-marketing evaluation to verify and describe the product’s clinical benefit will be pursued through a randomised, multi-center Phase III trial that will be conducted by COG and sponsored by the NCI under a Clinical Trials Agreement with GSK. The Phase III study will assess both event-free survivals at four years and minimal residual disease in the post-consolidation phase for patients receiving standard therapy with or without nelarabine.

“Arranon represents new hope for adults and children suffering from these rare and deadly cancers. As the first in a series of innovative medicines set to emerge from GSK’s robust oncology pipeline over the next few years, Arranon is an important milestone for our oncology business and provides a glimpse of our promise for the future,” said Kevin Lokay, vice president of oncology and acute care at GSK.

The release further adds that in clinical studies of Arranon, hematologic toxicity was the most common grade 3 (moderate) or 4 (severe) adverse event. Consistent with various other cytotoxic agents, Arranon is associated with neurological events, some considered severe. Close monitoring for neurologic events is strongly recommended and dosing of Arranon should be discontinued for neurologic events of grade 2 or greater.

Discovered by GSK scientists, led by Gertrude Elion, Nobel Laureate for Medicine in 1988, Arranon is a water-soluble prodruct of ara-G, a T-cell selective nucleoside analog.