Seattle Genetics, Inc. (Nasdaq: SGEN) announced today that it has submitted a supplemental Biologics License Application (sBLA) to the U.S. Food and Drug Administration (FDA) supporting the use of ADCETRIS (brentuximab vedotin) for retreatment and extended duration beyond 16 cycles of therapy in relapsed Hodgkin lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL). ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30, a defining marker of HL and sALCL, that was granted accelerated approval by the FDA in August 2011 for relapsed HL and relapsed sALCL. “The sBLA submission includes data demonstrating ADCETRIS activity in managing HL and sALCL when used in the retreatment setting, as well as beyond the 16 cycles described in our current label, while retaining a manageable safety profile,” said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. “Our goal is to broaden the ADCETRIS U.S. labeling claims to provide both patients and physicians the opportunity to incorporate ADCETRIS into additional HL and sALCL treatment settings. The sBLA submission includes data that support these uses and we look forward to the regulatory outcome.” The sBLA is based on results from a phase II clinical trial with two treatment arms. One arm evaluated retreatment with ADCETRIS in patients who previously responded to treatment with ADCETRIS, then discontinued treatment and subsequently had disease progression or relapse. The other arm allowed treatment extension and evaluated prolonged treatment with ADCETRIS beyond 16 cycles of therapy. The sBLA submission includes updated data sets from this phase II trial. Preliminary data from this trial were previously reported at the 2011 American Society of Hematology (ASH) Annual Meeting and at the 2012 American Society of Clinical Oncology (ASCO) Annual meeting. At the 2012 ASCO Annual Meeting, retreatment data from the phase II trial were reported from 23 patients, including one patient who was treated twice. Patients had received a median of four prior systemic therapies, including ADCETRIS. Of 23 evaluable patients, 70 percent (16 of 23) achieved an objective response after retreatment with ADCETRIS, including nine complete remissions and seven partial remissions. Median duration of retreatment objective response was 8.8 months. Among retreated HL patients, nine of 16 (56 percent) achieved an objective response. Among retreated sALCL patients, seven of eight (88 percent) achieved an objective response. The most common adverse events were peripheral neuropathy (46 percent), nausea (42 percent), fatigue (38 percent), diarrhea (33 percent) and fever (29 percent).