Adcetris, which is being developed jointly Seattle Genetics and Takeda, showed a highly statistically significant improvement in the rate of objective response lasting at least four months (ORR4).
It is an antibody-drug conjugate (ADC) featuring an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a microtubule disrupting agent, monomethyl auristatin E (MMAE), utilizing Seattle Genetics' technology.
The phase 3 Alcanza randomized trial compared the use of single-agent Adcetris to a control arm of investigator's choice of standard therapies, methotrexate or bexarotene, in 131 patients with CD30-expressing CTCL who received prior systemic or radiation therapy.
Adcetris is directed to CD30 which is expressed on skin lesions in about 50% of patients with CTCL. It is currently not approved to treat CTCL.
The ORR4 was 56.3% in the Adcetris arm compared to 12.5% in the control arm.
Seattle Genetics said key secondary endpoints specified in the protocol, including complete response rate, progression-free survival and reduction in the burden of symptoms during treatment, were all highly statistically significant in favor of the Adcetris arm.
Seattle Genetics president and CEO Clay Siegall said: "Cutaneous T-cell lymphoma is a debilitating, disfiguring and painful disease, and there is a significant need for additional effective treatment options with meaningful durable responses.
“This is the first Phase 3 randomized trial in CTCL versus an active control to read out, and we are thrilled to have successfully demonstrated the positive impact of using Adcetris for patients enrolled in this study.”
The companies expect to report additional complete Alcanza data at the ASH annual meeting in December.
A supplemental Biologics License Application is planned to be submitted to the FDA in the first half of 2017 for approval in this setting.