Merck has secured approval from the US Food and Drug Administration (FDA) for KEYTRUDA (pembrolizumab) in combination with Padcev (enfortumab vedotin-ejfv) for first-line treatment of some adult patients with locally advanced or metastatic urothelial carcinoma (la/mUC).

KEYTRUDA is an anti-PD-1 therapy developed by Merck, while Padcev has been developed by Astellas and Seagen.

The combination therapy can be used to treat la/mUC patients who do not qualify for cisplatin-containing chemotherapy.

Merck stated that the regulatory approval represents the first of its kind received by an anti-PD-1 therapy in combination with an antibody-drug conjugate for use in targeted patients in the US.

It is supported by objective response rates (ORR) and median duration of response (DOR) in combined dose escalation/cohort A and cohort K of the Phase lb/ll KEYNOTE-869 study, also known as the EV-103 trial.

The trial was jointly conducted by Seagen and Astellas.

Results showed that patients treated with Padcev along with KEYTRUDA achieved a confirmed ORR of 68%. 12% experienced a complete response and 55% a partial response.

Merck Research Laboratories senior vice-president, global clinical development head and chief medical officer Dr Eliav Barr said: “This approval is a major milestone in the treatment of patients with locally advanced or metastatic urothelial carcinoma because it is the first approved combination of an immunotherapy and an antibody-drug conjugate for these patients.

“This expands the use of KEYTRUDA-based regimens to more patients with advanced urothelial carcinoma, and demonstrates the value of collaboration in creating new combination approaches for patients in need of more options.”