Keytruda hits primary endpoint in confirmatory lymphoma trial

Merck & Co/MSD’s Keytruda has hit the primary endpoint in a confirmatory phase 3 trial in classical Hodgkin lymphoma (cHL), three years after scoring approval for the treatment of this type of cancer.

In March 2017, Keytruda (pembrolizumab) picked up a conditional approval for the treatment of adult and paediatric patients with refractory cHL, or who have relapsed after three or more prior lines fo therapy.

It was the first green light for the drug in a haematological cancer, and Keytruda has since gone on to receive approval in primary mediastinal B-cell lymphoma, a rare form of B-cell non-Hodgkin lymphoma.

Merck scored the cHL approval on the back of the phase 2 KEYNOTE-087 trial, with this most recent phase 3 trial – KEYNOTE-204 – providing more detailed results that demonstrate the checkpoint inhibitor has a solid effect in the blood cancer.

The trial compared Keytruda to Seattle Genetic’s antibody-drug conjugate Adcetris – a standard treatment for relapsed and refractory lymphoma.

Merck’s drug beat Adcetris in terms of progression-free survival (PFS), according to an interim review by an independent data monitoring committee.

As this is just an interim analysis, the detailed results of just how much Keytruda topped its rival are not yet available, but PFS is a primary endpoint of the study, so its a success all the same for Merck.

“Patients with classical Hodgkin lymphoma are generally young and when they do not achieve remission following standard treatment, their cancer is challenging to treat,” said Jonathan Cheng, vice president, oncology clinical research, Merck Research Laboratories.

“These pivotal phase 3 data indicate a statistically significant and clinically meaningful improvement in progression-free survival with Keytruda compared, in head to head fashion, with the currently approved therapy of Adcetris,” he added.

The other dual primary endpoint of the study – the more robust overall survival rate – was not tested at the interim analysis.

Keytruda’s main growth indication is undoubtedly non-small cell lung cancer, a therapy area which will likely help the PD-1 inhibitor to win $22.5bn in sales by 2025, as predicted by GlobalData.

CHL is, in comparison to Keytruda’s other indications, not quite as important. Still, this trial works to confirm the drug’s efficacy in the blood cancer, and the results are an encouraging sign for Merck, which has two other cHL trials for Keytruda currently underway.

That includes evaluating Keytruda in combination with chemotherapy in children and young adults in first-line cHL and in the post-Adcetris treatment setting.