Daiichi Sankyo has secured the US Food and Drug Administration (FDA) approval for its Turalio (pexidartinib) capsules to treat adult patients with symptomatic tenosynovial giant cell tumour (TGCT).

The rare, non-malignant tumour affects small and large joints and can cause debilitating symptoms.

Daiichi Sankyo oncology research and development executive vice-president and global head Antoine Yver said: “We are proud to be a part of today’s landmark approval and offer a much-needed treatment advancement for TGCT patients whose disease is not amenable to improvement with surgery, and who, until now, have had no approved systemic treatment options.

“With patients at the centre of everything we do, Daiichi Sankyo believes patient safety and providing effective medicines are our most important responsibilities.”

The FDA granted the approval to Turalio based on the results of the pivotal double-blind, randomised, placebo-controlled Phase III ENLIVEN study of systemic therapy in patients with TGCT.

As part of the ENLIVEN study, Turalio was evaluated in patients with symptomatic TGCT whose surgical removal of the tumour would be associated with potentially exacerbated functional limitation or severe morbidity.

The double-blind phase of the study enrolled 120 patients. Upon completion, patients randomised to either Turalio or placebo were eligible to enter the second part of ENLIVEN.

The trial’s primary efficacy endpoint was the overall response rate (ORR) analysed after 25 weeks of treatment.

It demonstrated a statistically significant improvement in ORR in patients who were given Turalio, with an ORR of 38%, compared to no responses in patients who received a placebo.

Turalio inhibits colony-stimulating factor-1 receptor (CSF1R), as well as KIT and FLT3-ITD. It was discovered by Daiichi Sankyo’s small molecule structure-guided R&D centre Plexxikon.