Seattle Genetics Announces ASH 2016 Abstracts Highlighting Company’s Expanding Global Leadership in the Development of Innovative Antibody-Drug Conjugates

Oral Presentation on Phase 3 ALCANZA Trial in CD30-Expressing Cutaneous T-Cell Lymphoma

Breadth of Data on ADCETRIS® (Brentuximab Vedotin), Vadastuximab Talirine (SGN-CD33A) and Other Pipeline Programs Demonstrate Company’s Commitment to Improve Therapeutic Options in Oncology

BOTHELL, Wash.--()--Seattle Genetics, Inc. (Nasdaq:SGEN) today announced that 18 abstracts including eight oral presentations have been accepted for presentation at the 58th American Society of Hematology (ASH) Annual Meeting and Exposition taking place in San Diego, Calif. from December 3-6, 2016. Collectively, the abstracts highlight advancement of the ADCETRIS (brentuximab vedotin) and vadastuximab talirine (SGN-CD33A) development programs and the company’s expanding global leadership in antibody-drug conjugates (ADCs), as well as its commitment to developing investigational compounds that have the potential to improve therapeutic options for patients with blood-related cancers.

Data accepted for presentation at this year’s ASH Annual Meeting include the following:

  • An oral presentation of full results from the phase 3 ALCANZA clinical trial evaluating ADCETRIS in patients with CD30-expressing cutaneous T-cell lymphoma (CTCL)
  • Numerous oral and poster presentations highlighting additional progress within the ADCETRIS development program including:
    • Preliminary results from a phase 1/2 study of ADCETRIS in combination with Opdivo (nivolumab) among patients with relapsed or refractory Hodgkin lymphoma (HL)
    • Long-term (e.g., four-year) survival and durability results in patients with CD30-expressing peripheral T-cell lymphomas who received ADCETRIS with cyclophosphamide, hydroxydaunorubicin, and prednisone (CHP) as frontline therapy
    • Final five-year survival and durability results in relapsed systemic anaplastic large cell lymphoma (sALCL) patients who received ADCETRIS monotherapy
  • Four oral presentations featuring data from clinical studies exploring vadastuximab talirine in acute myeloid leukemia (AML), including newly diagnosed patients

“At this year’s ASH Annual Meeting, we will present data from 18 abstracts, highlighting ADCETRIS, vadastuximab talirine and multiple pipeline programs,” said Jonathan Drachman, M.D., Chief Medical Officer and Executive Vice President, Research and Development at Seattle Genetics. “The oral presentation of the complete results of the ALCANZA trial represents the fourth consecutive registrational trial for ADCETRIS with a positive outcome. Data across our pipeline programs continue to support the potential for antibody-drug conjugates to improve outcomes for patients with cancer.”

Seattle Genetics is the world leader in the development and commercialization of a new generation of ADCs. The company’s novel, proprietary technology is designed to harness the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. There are more than 20 ADCs in clinical development that utilize Seattle Genetics’ proprietary ADC technology. ADCETRIS is the first drug approved utilizing this technology. The company also has vadastuximab talirine in a global phase 3 clinical study (CASCADE) in newly diagnosed, older AML patients.

ADCETRIS is currently not approved for the treatment of CTCL frontline treatment of non-Hodgkin lymphoma or as a combination therapy for HL.

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

Saturday, December 3, 2016

  • Results of an Ongoing Phase 2 Study of Brentuximab Vedotin with RCHP as Frontline Therapy in Patients with High-Intermediate/High-Risk Diffuse Large B-Cell Lymphoma (Abstract #104, oral presentation at 9:45 a.m. PT)
  • Brentuximab Vedotin Demonstrates Significantly Superior Clinical Outcomes in Patients with CD30-Expressing Cutaneous T-Cell Lymphoma Versus Physician's Choice (Methotrexate or Bexarotene): the Phase 3 ALCANZA Study (Abstract #182, oral presentation at 2:15 p.m. PT)
  • A Phase 1b Study of Vadastuximab Talirine in Combination with 7+3 Induction Therapy for Patients with Newly Diagnosed Acute Myeloid Leukemia (Abstract #211, oral presentation at 4:00 p.m. PT)
  • Safety and Activity of Brentuximab Vedotin plus Ifosfamide, Carboplatin, and Etoposide (ICE) for Relapsed/Refractory Classical Hodgkin Lymphoma: Initial Results of a Phase I/II Trial (Abstract #1834, poster presentation)
  • Real World Clinical and Economic Burden of Hematopoietic Cell Transplantation Among a Large US Commercially Insured Population (Abstract #2368, poster presentation)

Sunday, December 4, 2016

  • The Use of a Novel CME Format to Elicit and Develop True Competence in Hematologist Ability to Risk Stratify Patients with Hodgkin Lymphoma (Abstract #3560, poster presentation)
  • A Phase 1b Study of Vadastuximab Talirine as Maintenance and in Combination with Standard Consolidation for Patients with Acute Myeloid Leukemia (Abstract #340, oral presentation at 10:15 a.m. PT)
  • Four-Year Survival and Durability Results of Brentuximab Vedotin in Combination with CHP in the Frontline Treatment of Patients with CD30-Expressing Peripheral T-cell Lymphomas (Abstract #2993, poster presentation)
  • Toxicity Burden of Bleomycin Treatment in Hodgkin Lymphoma: A Systematic Literature Review (Abstract #3566, poster presentation)

Monday, December 5, 2016

  • Vadastuximab Talirine Monotherapy in Older Patients with Treatment Naive CD33-Positive Acute Myeloid Leukemia (Abstract #590, oral presentation at 7:15 a.m. PT)
  • Vadastuximab Talirine Plus Hypomethylating Agents: A Well-Tolerated Regimen with High Remission Rate in Frontline Older Patients With Acute Myeloid Leukemia (Abstract #591, oral presentation at 7:30 a.m. PT)
  • Preliminary Results from a Phase 1/2 Study of Brentuximab Vedotin in Combination with Nivolumab in Patients with Relapsed or Refractory Hodgkin Lymphoma (Abstract #1105, oral presentation at 4:30 p.m. PT)
  • A Phase I Study with an Expansion Cohort of the Combination of Ipilimumab and Nivolumab and Brentuximab Vedotin in Patients with Relapsed/Refractory Hodgkin Lymphoma: A Trial of the ECOG-ACRIN Cancer Research Group (E4412 Arms D and E) (Abstract #1106 oral presentation at 4:45 p.m. PT)
  • Brentuximab Vedotin Plus ESHAP (BRESHAP) Is a Highly Effective Combination for Inducing Remission in Refractory and Relapsed Hodgkin Lymphoma Patients Prior to Autologous Stem Cell Transplant: A Trial of the Spanish Group of Lymphoma and Bone Marrow Transplantation (GELTAMO) (Abstract #1109, oral presentation at 5:30 p.m. PT)
  • Five-Year Survival Data from a Pivotal Phase 2 Study of Brentuximab Vedotin in Patients with Relapsed or Refractory Systemic Anaplastic Large Cell Lymphoma (Abstract #4144, poster presentation)
  • Denintuzumab Mafodotin Stimulates Immune Responses and Synergizes with CD20 Antibodies to Heighten Anti-tumor Activity in Preclinical Models of Non-Hodgkin Lymphoma (Abstract #4177, poster presentation)
  • SGN-CD48A: A Novel Humanized Anti-CD48 Antibody-Drug Conjugate for the Treatment of Multiple Myeloma (Abstract #4470, poster presentation)
  • A Phase 1/2 Clinical Trial of Brentuximab Vedotin and Bendamustine in Elderly Patients with Previously Untreated Advanced Hodgkin Lymphoma (Halo Study): Preliminary Report (Abstract #4154, poster presentation)

About ADCETRIS

ADCETRIS is being evaluated broadly in more than 70 ongoing clinical trials, including two phase 3 studies, ECHELON-1 in frontline classical Hodgkin lymphoma 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 Hodgkin lymphoma 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 Hodgkin lymphoma 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 Hodgkin lymphoma 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 Hodgkin lymphoma 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 65 countries.

In June 2016, the European Commission extended the current conditional approval of ADCETRIS and approved ADCETRIS for the treatment of adult patients with CD30-positive Hodgkin lymphoma at increased risk of relapse or progression following ASCT. 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 Vadastuximab Talirine (SGN-CD33A)

Vadastuximab talirine (SGN-CD33A) 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. More information about SGN-CD33A and ongoing clinical trials can be found at www.ADC-CD33.com.

About Denintuzumab Mafodotin (SGN-CD19A)

Denintuzumab mafodotin (SGN-CD19A) 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 an innovative biotechnology company that develops and commercializes novel antibody-based therapies for the treatment of cancer. The company’s industry-leading antibody-drug conjugate (ADC) technology harnesses the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. ADCETRIS® (brentuximab vedotin), the company’s lead product, in collaboration with Takeda Pharmaceutical Company Limited, is the first in a new class of ADCs commercially available globally in 65 countries for relapsed classical Hodgkin lymphoma and relapsed systemic anaplastic large cell lymphoma (sALCL). Seattle Genetics is also advancing vadastuximab talirine (SGN-CD33A; 33A), an ADC in a phase 3 trial for acute myeloid leukemia. Headquartered in Bothell, Washington, Seattle Genetics has a robust pipeline of innovative therapies for blood-related cancers and solid tumors designed to address significant unmet medical needs and improve treatment outcomes for patients. The company has collaborations for its proprietary ADC technology with a number of companies including AbbVie, 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.

Contraindication

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

Warnings and Precautions

  • Peripheral neuropathy (PN): ADCETRIS treatment causes a PN that is predominantly sensory. Cases of motor PN have also been reported. ADCETRIS-induced PN 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. Patients who experienced a prior infusion-related reaction should be premedicated for subsequent infusions. Premedication may include acetaminophen, an antihistamine, and a corticosteroid.
  • 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.
  • Gastrointestinal (GI) complications: Fatal and serious GI complications, including perforation, hemorrhage, erosion, ulcer, intestinal obstruction, enterocolitis, neutropenic colitis, and ileus have been reported in ADCETRIS-treated patients. Lymphoma with preexisting GI involvement may increase the risk of perforation. In the event of new or worsening GI symptoms, perform a prompt diagnostic evaluation and treat appropriately.
  • Embryo-fetal toxicity: Based on the mechanism of action and findings in animals, ADCETRIS can cause fetal harm when administered to a pregnant woman. Females of reproductive potential should avoid pregnancy during ADCETRIS treatment and for at least 6 months after the final dose of ADCETRIS.

Adverse Reactions

In two uncontrolled single-arm trials of ADCETRIS as monotherapy in 160 patients with relapsed classical HL and sALCL, 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.

In a placebo-controlled trial of ADCETRIS in 329 patients with classical HL at high risk of relapse or progression post-auto-HSCT, 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.

Advise females of reproductive potential to avoid pregnancy during ADCETRIS treatment and for at least 6 months after the final dose of ADCETRIS.

Advise males with female sexual partners of reproductive potential to use effective contraception during ADCETRIS treatment and for at least 6 months after the final dose of ADCETRIS.

Advise patients to report pregnancy immediately and avoid breastfeeding while receiving ADCETRIS.

For additional Important Safety Information, including Boxed WARNING, please see the full Prescribing Information for ADCETRIS at www.seattlegenetics.com or www.ADCETRIS.com.

For Seattle Genetics Forward-Looking Statement:

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the therapeutic and commercial potential of ADCETRIS, SGN-CD33A (vadastuximab talirine) and SGN-CD19A (denintuzumab mafodotin), potential development and regulatory activities including future clinical trials and regulatory submissions, upcoming presentations and publications, and potential uses of the product candidates, as well as other statements that are not historical facts. 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 the risk that we may also be delayed in our planned clinical trial initiations, the enrollment in and conduct of our clinical trials, and obtaining data from clinical trials, and planned regulatory submissions in each case for a variety of reasons, including the difficulty and uncertainty of pharmaceutical product development and unexpected adverse events or regulatory action. We may also be unable to expand ADCETRIS’ labeled indications due to unexpected data from our ongoing phase 3 trials or regulatory action or complete the development of, and obtain regulatory approval for, our product candidates, each of which are in relatively early stages of development. More information about the risks and uncertainties faced by Seattle Genetics is contained under the caption “Risk Factors” included in the company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2016 filed with the Securities and Exchange Commission. 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.

Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Brandi Robinson, 425-527-2910
brobinson@seagen.com

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Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Brandi Robinson, 425-527-2910
brobinson@seagen.com