Seattle Genetics Announces Multiple ADCETRIS® (Brentuximab Vedotin) Data Presentations at the International Conference on Malignant Lymphoma

Seattle Genetics, Inc.

today announced several ADCETRIS (brentuximab vedotin) data presentations at the 13th International Conference on Malignant Lymphoma (ICML) being held June 17 to 19, 2015, in Lugano, Switzerland. ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30, which is expressed in classical Hodgkin lymphoma (HL), systemic anaplastic large cell lymphoma (sALCL) and several other types of non-Hodgkin lymphoma (NHL). Seven oral presentations and one poster at ICML demonstrate the breadth of the clinical development program for ADCETRIS. Data include an additional analysis of the phase 3 AETHERA clinical trial showing that up to 16 cycles (approximately one year) of ADCETRIS consolidation therapy following autologous stem cell transplant (ASCT) significantly extended progression-free survival (PFS) versus placebo for those patients with primary-refractory HL. In addition, data from several corporate and investigator-sponsored trials with ADCETRIS showed activity in a variety of HL and NHL treatment settings. ADCETRIS is currently approved by the U.S. Food and Drug Administration (FDA) for relapsed HL and sALCL and was granted conditional marketing authorization by the European Commission for relapsed or refractory HL and sALCL. "Since the initial FDA approval of ADCETRIS in 2011 for the treatment of relapsed HL and sALCL, it has been approved in more than 55 countries, and our clinical development program has expanded to include more than 30 corporate and investigator-sponsored clinical trials in CD30-expressing malignancies," said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. "The ADCETRIS data presented at ICML support our broad development plans for ADCETRIS. In the near-term, we anticipate an FDA decision on its use in the AETHERA setting as a post-transplant consolidation therapy, and, ultimately, our goal is to move even earlier into the treatment paradigm and redefine frontline treatment of HL with the addition of ADCETRIS." Analysis of primary-refractory Hodgkin lymphoma patients in a randomized, placebo-controlled study of brentuximab vedotin consolidation after autologous stem cell transplant (Seattle Genetics and Takeda; Abstract #120, oral presentation Friday, June 19, 2015, at 11:50 a.m. CEST) Data were reported from an additional analysis of the phase 3 AETHERA clinical trial evaluating PFS by investigator in patients who were refractory to frontline treatment. Previously published data suggest primary-refractory HL patients have poor outcomes following ASCT, as demonstrated by the historical two-year PFS and three-year overall survival rates of less than 40 percent and 50 percent, respectively. Of the 329 patients enrolled in the AETHERA trial, 60 percent (196 patients) were primary-refractory to frontline treatment. Results of the analysis demonstrated: Two-year PFS rates per investigator among primary-refractory patients on the ADCETRIS and placebo arms were 60 percent and 42 percent, respectively, consistent with the primary analysis in the full intent-to-treat population. Subgroup analyses of patients by disease characteristics as well as number of risk factors showed that PFS was improved broadly across subgroups, including patients with B-symptoms, extranodal involvement and those who received more than two systemic anticancer treatments pre-ASCT. Adverse events in primary-refractory patients who received ADCETRIS were consistent with the known safety profile. Additional AETHERA data were included in a poster presentation reporting the frequency of healthcare resource utilization (HRU) among patients on the two treatment arms of the trial. Preliminary reports suggest a trend toward lower HRU in patients treated with ADCETRIS compared with placebo. ADCETRIS is currently not approved for use in the AETHERA treatment setting. Based on the positive results from the AETHERA trial, a supplemental Biologics License Application (BLA) for ADCETRIS in the post-ASCT consolidation treatment of HL patients at high risk of relapse or progression was accepted for filing by the FDA. The FDA granted Priority Review for the application and the Prescription Drug User Fee Act (PDUFA) target action date is August 18, 2015. Additional ADCETRIS corporate and investigator presentations are included below and full abstracts can be found in the ICML Educational and Abstract Book accessed on the ICML website at www.lymphcon.ch. Wednesday, June 17, 2015 Healthcare utilization in the AETHERA trial: phase 3 study of brentuximab vedotin in patients at increased risk of residual Hodgkin lymphoma post ASCT (Seattle Genetics and Takeda; Abstract #177, poster presentation) Thursday, June 18, 2015 Brentuximab vedotin plus AVD for non-bulky limited stage classical Hodgkin lymphoma: A phase 2 trial (Investigator-sponsored; Abstract #087, oral presentation at 5:15 p.m. CEST) Preliminary efficacy and safety of brentuximab vedotin and AVD chemotherapy followed by involved-site radiotherapy in early stage, unfavorable risk Hodgkin lymphoma (Investigator-sponsored; Abstract #088, oral presentation at 5:25 p.m. CEST) Sequential brentuximab vedotin and AVD for older Hodgkin lymphoma patients: Initial results from a phase 2 multicenter study (Investigator-sponsored; Abstract #089, oral presentation at 5:35 p.m. CEST) A phase 1 study of brentuximab vedotin (Bv) and bendamustine (B) in patients with relapsed or refractory Hodgkin lymphoma (HL) and anaplastic large T-Cell lymphoma (ALCL) (Investigator-sponsored; Abstract #090, oral presentation at 5:45 p.m. CEST) Brentuximab vedotin demonstrates antitumor activity in CD30+ DLBCL (Seattle Genetics; Abstract #091, oral presentation at 5:55 p.m. CEST) Updated results of a phase 2 trial of brentuximab vedotin combined with RCHOP in frontline treatment of pts with high-intermediate/high-risk DLBCL (Seattle Genetics; Abstract #092, oral presentation at 6:05 p.m. CEST) ADCETRIS is not currently approved for use in frontline HL, in combination with bendamustine for relapsed or refractory HL and sALCL, or in DLBCL.