Millennium and Seattle Genetics have commenced an international pivotal Phase 3 clinical trial, evaluating Adcetris (brentuximab vedotin) in patients with CD30-expressing cutaneous T-cell lymphoma (CTCL).

Adcetris is an antibody-drug conjugate (ADC) comprising an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a microtubule disrupting agent and monomethyl auristatin E (MMAE), leveraging Seattle Genetics’s proprietary technology.

The randomised open-label Phase 3 trial will be conducted in around 124 patients with CTCL, including those with primary cutaneous anaplastic large cell lymphoma (pcALCL) or mycosis fungoides (MF), under a Special Protocol Assessment (SPA) agreement from the US Food and Drug Administration (FDA) regarding the trial design.

The study’s primary endpoint is overall response rate (ORR), lasting at least four months, with Adcetris in patients with CD30-positive MF or pcALCL, compared to that achieved with therapy in the control arm, and the secondary endpoints are complete response (CR), progression-free survival (PFS) and burden of symptoms.

Millennium chief medical officer Karen Ferrante said the study is expected to support the potential to supplement therapeutic options for patients, from traditional systemic chemotherapy to Adcetris, a targeted therapy.

Seattle Genetics chief medical officer Thomas Reynolds said data from patients with cutaneous lesions observed in the pivotal trial in systemic anaplastic large cell lymphoma (sALCL) and interim data from investigator-sponsored trials in CTCL with Adcetris, provide a strong rationale for initiating the Phase 3 trial.

“This trial complements many other ongoing and planned trials for patients in need, including two additional Phase 3 trials for front-line Hodgkin lymphoma (HL) and front-line mature T-cell lymphomas, expected to start by late 2012 or early 2013,” Reynolds added.

Both companies are jointly developing Adcetris and under the terms of the collaboration agreement, Seattle Genetics has US and Canadian commercialisation rights and Millennium has rights to commercialise Adcetris in the rest of the world.