Seattle Genetics, Inc. (Nasdaq:SGEN) today announced that a record number of abstracts were accepted for presentation at the 57th American Society of Hematology (ASH) Annual Meeting and Exposition taking place in Orlando, Florida, December 5-8, 2015, including the following:

  • Several oral and poster data presentations on ADCETRIS (brentuximab vedotin) as both monotherapy and combination therapy in multiple Hodgkin lymphoma (HL) disease settings, supporting the company’s goal to establish ADCETRIS as the foundation of care for HL;
  • Data presentations on ADCETRIS in frontline non-Hodgkin lymphoma (NHL), including diffuse large B-cell lymphoma (DLBCL) and peripheral T-cell lymphomas (PTCL), to be presented in oral and poster sessions;
  • Phase 1 clinical data for SGN-CD33A (vadastuximab talirine) in acute myeloid leukemia (AML) as monotherapy and in combination with hypomethylating agents (HMAs) to be presented in two oral sessions; preclinical data supporting HMA combination strategy to be presented in poster session;
  • Updated phase 1 clinical data to be presented for SGN-CD19A (denintuzumab mafodotin) in acute lymphoblastic leukemia (ALL) and NHL in oral and poster sessions; and
  • Preclinical data from two new ADCs for hematologic malignancies, SGN-CD19B and SGN-CD123A, using the company’s proprietary pyrrolobenzodiazepine (PBD) technology to be presented in oral sessions.

“There will be more than 20 data presentations, including 13 orals, from corporate and investigator studies, representing the largest presence Seattle Genetics has ever had at ASH,” said Jonathan Drachman, M.D., Chief Medical Officer and Executive Vice President, Research and Development at Seattle Genetics. “Our broad ADCETRIS development program continues to generate data that support its potential as the foundation of care for Hodgkin lymphoma and other CD30-expressing lymphomas. We are also excited to share updates from our ongoing SGN-CD33A and SGN-CD19A programs and to present preclinical data from two new programs, SGN-CD19B and SGN-CD123A, which will advance into the clinic in 2016.”

With more than 15 years of experience and innovation, Seattle Genetics is the leader in developing ADCs, a technology designed to harness the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. More than 25 ADCs in clinical development utilize Seattle Genetics’ proprietary ADC technology. ADCETRIS is the first drug approved utilizing this technology.

ADCETRIS is currently not approved for the treatment of frontline HL, frontline NHL, salvage HL in patients eligible for autologous transplant, GVHD or as a combination therapy for HL or NHL.

Multiple corporate and investigator presentations will be featured at ASH. Abstracts can be found at www.hematology.org and include the following:

Saturday, December 5, 2015

  • Frontline Treatment of CD30+ Peripheral T-Cell Lymphomas with Brentuximab Vedotin in Combination with CHP: 3-Year Durability and Survival Follow-up (Abstract #1537, poster presentation)
  • A Phase 1 Study of Denintuzumab Mafodotin (SGN-CD19A) in Adults with Relapsed or Refractory B-Lineage Acute Leukemia (B-ALL) and Highly Aggressive Lymphoma (Abstract #1328, poster presentation)
  • AMC-085: A Pilot Trial of AVD and Brentuximab Vedotin in the Upfront Treatment of Stage II-IV HIV-Associated Hodgkin Lymphoma. A Trial of the AIDS Malignancy Consortium (Abstract #1526, poster presentation)
  • Risk Factors and a Prognostic Score in Patients with Relapsed or Refractory Hodgkin Lymphoma (rrHL) after Treatment with Autologous Stem Cell Transplantation (ASCT) (Abstract #1978, poster presentation)
  • Multicenter Phase I Trial of Brentuximab Vedotin for Steroid Refractory Acute Graft-vs.-Host Disease (GVHD) (Abstract #1930, poster presentation)

Sunday, December 6, 2015

  • A Phase 1 Study of Denintuzumab Mafodotin (SGN-CD19A) in Relapsed/Refractory B-Lineage Non-Hodgkin Lymphoma (Abstract #182, oral presentation at 7:45 a.m. ET)
  • TARC Predicts PET-Normalization and Event Free Survival in Relapsed/Refractory Hodgkin Lymphoma Patients Treated with Brentuximab Vedotin (Abstract #180, oral presentation at 8:45 a.m. ET)
  • A Phase 1 Trial of SGN-CD33A as Monotherapy in Patients with CD33-Positive Acute Myeloid Leukemia (AML) (Abstract #324, oral presentation at 5:45 p.m. ET)
  • SGN-CD123A, a Pyrrolobenzodiazepine Dimer Linked Anti-CD123 Antibody Drug Conjugate, Demonstrates Effective Anti-Leukemic Activity in Multiple Preclinical Models of AML (Abstract #330, oral presentation at 5:45 p.m. ET)
  • Five-Year Survival Data Demonstrating Durable Responses from a Pivotal Phase 2 Study of Brentuximab Vedotin in Patients with Relapsed or Refractory Hodgkin Lymphoma (Abstract #2736, poster presentation)
  • Updated Efficacy and Safety Data from the AETHERA Trial of Consolidation with Brentuximab Vedotin after Autologous Stem Cell Transplant (ASCT) in Hodgkin Lymphoma Patients at High Risk of Relapse (Abstract #3172, poster presentation)
  • Brentuximab Vedotin in Combination with Multi-Agent Chemotherapy is Well Tolerated and Effective as Frontline Treatment for Primary Mediastinal B-Cell Lymphoma (Abstract #2694, poster presentation)

Monday, December 7, 2015

  • Post Transplant Outcome of a Multicenter Phase II Study of Brentuximab Vedotin As First Line Salvage in Relapsed/Refractory HL Prior to AHCT (Abstract #519, oral presentation at 7:30 a.m. ET)
  • SGN-CD33A Plus Hypomethylating Agents: A Novel, Well-Tolerated Regimen with High Remission Rate in Frontline Unfit AML (Abstract #454, oral presentation at 7:45 a.m. ET)
  • Preliminary Safety and Efficacy of the Combination of Brentuximab Vedotin and Ipilimumab in Relapsed/Refractory Hodgkin Lymphoma: A Trial of the ECOG-ACRIN Cancer Research Group (E4412) (Abstract #585, oral presentation at 11:00 a.m. ET)
  • Targeted BEACOPP Variants in Patients with Newly Diagnosed Advanced Stage Classical Hodgkin Lymphoma: Final Analysis of a Randomized Phase II Study (Abstract #580, oral presentation at 11:15 a.m. ET)
  • The Combination of Brentuximab Vedotin (Bv) and Bendamustine (B) Demonstrates Marked Activity in Heavily Treated Patients with Relapsed or Refractory Hodgkin Lymphoma (HL) and Anaplastic Large T-Cell Lymphoma (ALCL): Results of an International Multicenter Phase I/II Experience (Abstract #586, oral presentation at 11:15 a.m. ET)
  • Brentuximab Vedotin in Combination with Dacarbazine or Bendamustine for Frontline Treatment of Hodgkin Lymphoma in Patients Aged 60 Years and Above: Interim Results of a Multi-Cohort Phase 2 Study (Abstract #587, oral presentation at 11:30 a.m. ET)
  • Evaluation of the Regimen Brentuximab Vedotin Plus ESHAP (BRESHAP) in Refractory or Relapsed Hodgkin Lymphoma Patients: Preliminary Results of a Phase I-II Trial from the Spanish Group of Lymphoma and Bone Marrow Transplantation (GELTAMO) (Abstract #582, oral presentation at 11:45 a.m. ET)
  • SGN-CD19B, a Pyrrolobenzodiazepine (PBD)-Based Anti-CD19 Drug Conjugate, Demonstrates Potent Preclinical Activity Against B-Cell Malignancies (Abstract #594, oral presentation at 11:45 a.m. ET)
  • Brentuximab Vedotin with RCHOP As Frontline Therapy in Patients with High-Intermediate/High-Risk Diffuse Large B-cell Lymphoma (DLBCL): Results from an Ongoing Phase 2 Study (Abstract #814, oral presentation at 5:15 p.m. ET)
  • SGN-CD33A in Combination with Hypomethylating Agents Is Highly Efficacious in Preclinical Models of AML (Abstract #3785, poster presentation)
  • Brentuximab Vedotin Plus Bendamustine: A Highly Active Salvage Treatment Regimen for Patients with Relapsed or Refractory Hodgkin Lymphoma (Abstract #3982, poster presentation)
  • A Phase I Trial of Brentuximab Vedotin in Combination with Lenalidomide in Relapsed or Refractory Diffuse Large B-cell Lymphoma (Abstract #3988, poster presentation)

About ADCETRIS

ADCETRIS is being evaluated broadly in more than 30 ongoing clinical trials, including the phase 3 ALCANZA trial and two additional phase 3 studies, ECHELON-1 in frontline classical HL and ECHELON-2 in frontline mature T-cell lymphomas, as well as trials in many additional types of CD30-expressing malignancies, including B-cell lymphomas.

ADCETRIS is an ADC comprising an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a microtubule disrupting agent, monomethyl auristatin E (MMAE), utilizing Seattle Genetics’ proprietary technology. The ADC employs a linker system that is designed to be stable in the bloodstream but to release MMAE upon internalization into CD30-expressing tumor cells.

ADCETRIS for intravenous injection has received approval from the FDA for three indications: (1) regular approval for the treatment of patients with classical HL after failure of autologous hematopoietic stem cell transplantation (auto-HSCT) or after failure of at least two prior multi-agent chemotherapy regimens in patients who are not auto-HSCT candidates, (2) regular approval for the treatment of classical HL patients at high risk of relapse or progression as post-auto-HSCT consolidation, and (3) accelerated approval for the treatment of patients with systemic anaplastic large cell lymphoma (sALCL) after failure of at least one prior multi-agent chemotherapy regimen. The sALCL indication is approved under accelerated approval based on overall response rate. Continued approval for the sALCL indication may be contingent upon verification and description of clinical benefit in confirmatory trials. Health Canada granted ADCETRIS approval with conditions for relapsed or refractory HL and sALCL.

ADCETRIS was granted conditional marketing authorization by the European Commission in October 2012 for two indications: (1) for the treatment of adult patients with relapsed or refractory CD30-positive HL following autologous stem cell transplant (ASCT), or following at least two prior therapies when ASCT or multi-agent chemotherapy is not a treatment option, and (2) the treatment of adult patients with relapsed or refractory sALCL. ADCETRIS has received marketing authorization by regulatory authorities in more than 55 countries. See important safety information below.

Seattle Genetics and Takeda are jointly developing ADCETRIS. Under the terms of the collaboration agreement, Seattle Genetics has U.S. and Canadian commercialization rights and Takeda has rights to commercialize ADCETRIS in the rest of the world. Seattle Genetics and Takeda are funding joint development costs for ADCETRIS on a 50:50 basis, except in Japan where Takeda is solely responsible for development costs.

About SGN-CD33A (Vadastuximab Talirine)

SGN-CD33A (vadastuximab talirine) is a novel ADC targeted to CD33 utilizing Seattle Genetics’ newest ADC technology. CD33 is expressed on most AML cells. The CD33 antibody is attached to a highly potent DNA binding agent, a pyrrolobenzodiazepine (PBD) dimer, via a proprietary site-specific conjugation technology to a monoclonal antibody with engineered cysteines (EC-mAb). PBD dimers are significantly more potent than systemic chemotherapeutic drugs and the site-specific conjugation technology (EC-mAb) allows uniform drug-loading of the cell-killing PBD agent to the anti-CD33 antibody. The ADC is designed to be stable in the bloodstream and to release its potent DNA binding agent upon internalization into CD33-expressing cells. SGN-CD33A is being evaluated in ongoing phase 1 clinical trials for patients with AML.

About SGN-CD19A (Denintuzumab Mafodotin)

SGN-CD19A (denintuzumab mafodotin) is an ADC targeting CD19, a protein expressed broadly on B-cell malignancies. Denintuzumab mafodotin is comprised of an anti-CD19 monoclonal antibody linked to a synthetic cytotoxic cell-killing agent, monomethyl auristatin F (MMAF). The ADC is designed to be stable in the bloodstream, and to release its cytotoxic agent upon internalization into CD19-expressing tumor cells. This approach is intended to spare non-targeted cells and thus reduce many of the toxic effects of traditional chemotherapy while enhancing the antitumor activity. SGN-CD19A is being evaluated in two ongoing phase 1 clinical trials for patients with B-cell ALL and aggressive NHL as well as a phase 2 clinical trial in relapsed or refractory DLBCL.

About Seattle Genetics

Seattle Genetics is a biotechnology company focused on the development and commercialization of innovative antibody-based therapies for the treatment of cancer. Seattle Genetics is leading the field in developing antibody-drug conjugates (ADCs), a technology designed to harness the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. The company’s lead product, ADCETRIS® (brentuximab vedotin) is a CD30-targeted ADC that, in collaboration with Takeda Pharmaceutical Company Limited, is commercially available in more than 55 countries, including the U.S., Canada, Japan and members of the European Union. Additionally, ADCETRIS is being evaluated broadly in more than 30 ongoing clinical trials in CD30-expressing malignancies. Seattle Genetics is also advancing a robust pipeline of clinical-stage programs, including SGN-CD33A (vadastuximab talirine), SGN-CD19A (denintuzumab mafodotin), SGN-LIV1A, SGN-CD70A, ASG-22ME, ASG-15ME and SEA-CD40. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including AbbVie, Agensys (an affiliate of Astellas), Bayer, Genentech, GlaxoSmithKline and Pfizer. More information can be found at www.seattlegenetics.com.

ADCETRIS (brentuximab vedotin) U.S. Important Safety Information

BOXED WARNING

Progressive multifocal leukoencephalopathy (PML): JC virus infection resulting in PML and death can occur in patients receiving ADCETRIS® (brentuximab vedotin).

Contraindication

ADCETRIS is contraindicated with concomitant bleomycin due to pulmonary toxicity (e.g., interstitial infiltration and/or inflammation).

Warnings and Precautions

  • Peripheral neuropathy: ADCETRIS treatment causes a peripheral neuropathy that is predominantly sensory. Cases of peripheral motor neuropathy have also been reported. ADCETRIS-induced peripheral neuropathy is cumulative. Monitor patients for symptoms of neuropathy, such as hypoesthesia, hyperesthesia, paresthesia, discomfort, a burning sensation, neuropathic pain or weakness and institute dose modifications accordingly.
  • Anaphylaxis and infusion reactions: Infusion-related reactions, including anaphylaxis, have occurred with ADCETRIS. Monitor patients during infusion. If an infusion-related reaction occurs, interrupt the infusion and institute appropriate medical management. If anaphylaxis occurs, immediately and permanently discontinue the infusion and administer appropriate medical therapy.
  • Hematologic toxicities: Prolonged (≥1 week) severe neutropenia and Grade 3 or 4 thrombocytopenia or anemia can occur with ADCETRIS. Febrile neutropenia has been reported with ADCETRIS. Monitor complete blood counts prior to each dose of ADCETRIS and consider more frequent monitoring for patients with Grade 3 or 4 neutropenia. Monitor patients for fever. If Grade 3 or 4 neutropenia develops, consider dose delays, reductions, discontinuation, or G-CSF prophylaxis with subsequent doses.
  • Serious infections and opportunistic infections: Infections such as pneumonia, bacteremia, and sepsis or septic shock (including fatal outcomes) have been reported in patients treated with ADCETRIS. Closely monitor patients during treatment for the emergence of possible bacterial, fungal or viral infections.
  • Tumor lysis syndrome: Closely monitor patients with rapidly proliferating tumor and high tumor burden.
  • Increased toxicity in the presence of severe renal impairment: The frequency of ≥Grade 3 adverse reactions and deaths was greater in patients with severe renal impairment compared to patients with normal renal function. Avoid the use of ADCETRIS in patients with severe renal impairment.
  • Increased toxicity in the presence of moderate or severe hepatic impairment: The frequency of ≥Grade 3 adverse reactions and deaths was greater in patients with moderate or severe hepatic impairment compared to patients with normal hepatic function. Avoid the use of ADCETRIS in patients with moderate or severe hepatic impairment.
  • Hepatotoxicity: Serious cases of hepatotoxicity, including fatal outcomes, have occurred with ADCETRIS. Cases were consistent with hepatocellular injury, including elevations of transaminases and/or bilirubin, and occurred after the first dose of ADCETRIS or rechallenge. Preexisting liver disease, elevated baseline liver enzymes, and concomitant medications may also increase the risk. Monitor liver enzymes and bilirubin. Patients experiencing new, worsening, or recurrent hepatotoxicity may require a delay, change in dose, or discontinuation of ADCETRIS.
  • Progressive multifocal leukoencephalopathy (PML): JC virus infection resulting in PML and death has been reported in ADCETRIS-treated patients. First onset of symptoms occurred at various times from initiation of ADCETRIS therapy, with some cases occurring within 3 months of initial exposure. In addition to ADCETRIS therapy, other possible contributory factors include prior therapies and underlying disease that may cause immunosuppression. Consider the diagnosis of PML in any patient presenting with new-onset signs and symptoms of central nervous system abnormalities. Hold ADCETRIS if PML is suspected and discontinue ADCETRIS if PML is confirmed.
  • Pulmonary Toxicity: Events of noninfectious pulmonary toxicity including pneumonitis, interstitial lung disease, and acute respiratory distress syndrome, some with fatal outcomes, have been reported. Monitor patients for signs and symptoms of pulmonary toxicity, including cough and dyspnea. In the event of new or worsening pulmonary symptoms, hold ADCETRIS dosing during evaluation and until symptomatic improvement.
  • Serious dermatologic reactions: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), including fatal outcomes, have been reported with ADCETRIS. If SJS or TEN occurs, discontinue ADCETRIS and administer appropriate medical therapy.
  • Embryo-fetal toxicity: Fetal harm can occur. Advise pregnant women of the potential hazard to the fetus.

Most Common Adverse Reactions:

ADCETRIS was studied as monotherapy in 160 patients with relapsed classical HL and sALCL in two uncontrolled single-arm trials. Across both trials, the most common adverse reactions (≥20%), regardless of causality, were neutropenia, peripheral sensory neuropathy, fatigue, nausea, anemia, upper respiratory tract infection, diarrhea, pyrexia, rash, thrombocytopenia, cough and vomiting.

ADCETRIS was studied in 329 patients with classical HL at high risk of relapse or progression post-auto-HSCT in a placebo-controlled randomized trial. The most common adverse reactions (≥20%) in the ADCETRIS-treatment arm (167 patients), regardless of causality, were neutropenia, peripheral sensory neuropathy, thrombocytopenia, anemia, upper respiratory tract infection, fatigue, peripheral motor neuropathy, nausea, cough, and diarrhea.

Drug Interactions:

Concomitant use of strong CYP3A4 inhibitors or inducers, or P-gp inhibitors, has the potential to affect the exposure to monomethyl auristatin E (MMAE).

Use in Specific Populations:

MMAE exposure and adverse reactions are increased in patients with moderate or severe hepatic impairment or severe renal impairment. Avoid use.

For additional Important Safety Information, including Boxed WARNING, please see the full Prescribing Information for ADCETRIS at http://www.seattlegenetics.com/pdf/adcetris_USPI.pdf.

Certain of the statements made in this press release are forward-looking, such as those, among others, relating to our goal to establish ADCETRIS as the foundation of therapy for a broad array of CD30-expressing malignancies including HL. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include risks that data resulting from additional trials with ADCETRIS will not support approvals in any of the studied indications. In addition, as our other drug candidates or those of our collaborators advance in clinical trials, adverse events and or regulatory actions may occur which affect the future development of those drug candidates and possibly other compounds using similar technology. More information about the risks and uncertainties faced by Seattle Genetics is contained under the caption “Risk Factors” included in Exhibit 99.1 to the company’s Current Report on Form 8-K filed with the Securities and Exchange Commission on September 9, 2015. Seattle Genetics disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.