German drug manufacturer Bayer has received priority review designation for the new drug application (NDA) for copanlisib from the US Food and Drug Administration (FDA).

The experimental drug is indicated to treat patients affected with relapsed or refractory follicular lymphoma (FL) and have received at least two prior therapies.

Bayer Pharmaceuticals America region head Carsten Brunn said: “With this milestone, we are one step closer to making copanlisib available in the US to the community of doctors and patients facing a very difficult-to-treat disease.

“We look forward to continuing to work with the FDA throughout the review process.”

Copanlisibis is a pan-Class I phosphatidylinositol-3-kinase (PI3K) inhibitor with predominant inhibitory activity against PI3K-α and PI3K-δ.

The regulatory submission for copanlisib is based on Phase II, open-label, single arm CHRONOS-1 study data that assessed patients with relapsed or refractory indolent non-Hodgkin's lymphoma (iNHL).

The study included 142 patients, 141 of which had iNHL.

CHRONOS-1 was designed to evaluate the efficacy and safety of copanlisib in the patients.

The primary endpoint of CHRONOS-1 is to assess the objective tumour response rate, while the secondary endpoints include the duration of response, overall survival, progression-free survival, quality of life and safety.

The collected data from this CHRONOS-1 trial will be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting, to be held next month.

Non-Hodgkin's lymphoma is regarded as the seventh most common cancer in the US and estimated to affect nearly 73,000 more people this year.