European regulators have expanded the reach of MSD’s Keytruda to include some patients with classical Hodgkin lymphoma (cHL), a type of lymphoma that develops in white blood cells.

The decision means that doctors will be able to prescribe the anti-PD-1 therapy to treat adults with relapsed or refractory cHL who have failed autologous stem cell transplant (ASCT) and brentuximab vedotin (BV), or who are transplant-ineligible and have failed BV.

“For patients with classical Hodgkin lymphoma who have not been successfully treated with prior therapies – many of whom are young and have a poor prognosis - there are limited options and treating the disease poses significant challenges,” said Pier Luigi Zinzani, associate professor of haematology, Institute of Haematology, University of Bologna. “With this approval, we will now be able to provide these patients with a much-needed new treatment option.”

Clearance in this setting was based on data from the KEYNOTE-087 and KEYNOTE-013 trials, which included patients regardless of the PD-L1 expression. KEYNOTE-087 showed an objective response rate (ORR) of 69 percent in the Keytruda (pembrolizumab) arm with a complete response rate (CRR) of 22 percent and a partial remission rate (PRR) of 47 percent. KEYNOTE-013 showed an ORR of 58 percent, CRR of 19 percent and a PRR of 39 percent.

On the safety side, the most common adverse reactions (greater than 10 percent) observed in patients taking Keytruda were fatigue (22 percent), pruritus (15 percent), rash (13 percent), diarrhoea (12 percent) and nausea (10 percent). The majority of adverse reactions reported were of Grade one or two severity, the firm noted.

The drug - a humanised monoclonal antibody that blocks the interaction between PD-1 and its ligands, thereby activating T lymphocytes which may affect both tumour cells and healthy cells - is already approved in Europe across lung cancer and melanoma indications.