FDA Tags Seattle Genetics’s Lymphoma Drug With Breakthrough Tag

-Designation Based on Positive Phase 3 ECHELON-1 Trial Evaluating ADCETRIS in Frontline Advanced Hodgkin Lymphoma; Data will be Presented at Upcoming American Society of Hematology Annual Meeting in December-

-Submission of Supplemental Biologics License Application for ADCETRIS in Frontline Advanced Hodgkin Lymphoma Planned Before the End of 2017-

BOTHELL, Wash.--(BUSINESS WIRE)--Seattle Genetics, Inc. (NASDAQ:SGEN) today announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to ADCETRIS (brentuximab vedotin) in combination with chemotherapy for the frontline treatment of patients with advanced classical Hodgkin lymphoma. The positive topline results of the phase 3 ECHELON-1 clinical trial were announced in June 2017 and full data will be presented at the upcoming American Society of Hematology (ASH) annual meeting, December 9-12, 2017 in Atlanta, Georgia. ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30, a defining marker of classical Hodgkin lymphoma. ADCETRIS is being evaluated globally as the foundation of care for CD30-expressing lymphomas in more than 70 corporate- and investigator-sponsored clinical trials. ADCETRIS is currently not approved as a frontline therapy for Hodgkin lymphoma.

“The phase 3 ECHELON-1 study that supports the Breakthrough Therapy Designation for ADCETRIS in combination with chemotherapy showed superior activity versus the standard of care chemotherapy regimen in the treatment of frontline advanced classical Hodgkin lymphoma patients”

The FDA’s Breakthrough Therapy Designation is intended to expedite the development and review of promising drug candidates for serious or life-threatening conditions. It is based upon clinical evidence of substantial improvement over existing therapies on one or more clinically significant endpoints.

“The phase 3 ECHELON-1 study that supports the Breakthrough Therapy Designation for ADCETRIS in combination with chemotherapy showed superior activity versus the standard of care chemotherapy regimen in the treatment of frontline advanced classical Hodgkin lymphoma patients,” said Clay Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. “The decision by the FDA to grant this designation recognizes the need for new options that can change the care of people with newly diagnosed advanced Hodgkin lymphoma. The designation supports our goal to make ADCETRIS available to patients in this setting as soon as possible. We look forward to presenting the data from our phase 3 ECHELON-1 trial at the upcoming ASH annual meeting and intend to submit a supplemental Biologics License Application to the FDA before the end of 2017.”

This Breakthrough Therapy Designation was based on data from the phase 3 ECHELON-1 clinical trial. The ECHELON-1 study evaluated a combination of ADCETRIS plus AVD (Adriamycin, vinblastine, dacarbazine) compared to a recognized standard of care chemotherapy regimen in previously untreated advanced classical Hodgkin lymphoma. The ECHELON-1 study met its primary endpoint of a statistically significant improvement in modified progression-free survival (PFS) of the ADCETRIS containing regimen versus the control arm as assessed by an Independent Review Facility (hazard ratio=0.770; p-value=0.035). The two-year modified PFS rate for patients in the ADCETRIS arm was 82.1 percent compared to 77.2 percent in the control arm. Interim analysis of overall survival, the key secondary endpoint, also trended in favor of the ADCETRIS plus AVD arm. The safety profile of ADCETRIS+AVD in the ECHELON-1 trial was consistent with that known for the single-agent components of the regimen.

ECHELON-1 Phase 3 Clinical Trial Design

The randomized, open-label, phase 3 trial is investigating ADCETRIS plus AVD versus ABVD (Adriamycin, bleomycin, vinblastine, dacarbazine) as frontline therapy in patients with advanced classical Hodgkin lymphoma. The primary endpoint is modified PFS per Independent Review Facility assessment using the Revised Response Criteria for Malignant Lymphoma. Modified PFS is defined as the time to progression, death or receipt of additional anticancer therapy for patients who are not in complete response after completion of frontline therapy per Independent Review Facility. This endpoint was chosen as it provides a clearer picture of the efficacy of frontline chemotherapy and eliminates the confounding impact of salvage and consolidation chemotherapies and radiotherapy. Secondary endpoints include overall survival, complete remission and safety. The multi-center trial was conducted in North America, Europe, South America, Australia, Asia and Africa. The study enrolled 1,334 patients who had a histologically-confirmed diagnosis of Stage III or IV classical Hodgkin lymphoma and had not been previously treated with systemic chemotherapy or radiotherapy. The ECHELON-1 trial is being conducted under a Special Protocol Assessment (SPA) agreement from the FDA and the trial also received European Medicines Agency (EMA) scientific advice.

Please see Important Safety Information at the end of this press release.

About Classical Hodgkin Lymphoma

Lymphoma is a general term for a group of cancers that originate in the lymphatic system. There are two major categories of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma. Classical Hodgkin lymphoma is distinguished from other types of lymphoma by the presence of one characteristic type of cell, known as the Reed-Sternberg cell. The Reed-Sternberg cell expresses CD30.

About ADCETRIS

ADCETRIS is being evaluated broadly in more than 70 clinical trials, including four phase 3 studies: the ECHELON-1 trial in frontline classical Hodgkin lymphoma from which positive topline results were recently reported, the ongoing ECHELON-2 trial in frontline mature T-cell lymphomas, the completed ALCANZA trial in cutaneous T-cell lymphoma that supported the supplemental BLA with a Prescription Drug User Fee Act (PDUFA) target action date of December 16, 2017, and the recently initiated CHECKMATE 812 trial of ADCETRIS in combination with Opdivo (nivolumab) for relapsed/refractory Hodgkin lymphoma.

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-positive 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 in 2013, and non-conditional approval for post-ASCT consolidation treatment of Hodgkin lymphoma patients at increased risk of relapse or progression.

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. The European Commission extended the current conditional marketing authorization 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.

ADCETRIS has received marketing authorization by regulatory authorities in 67 countries for relapsed or refractory Hodgkin lymphoma and sALCL. 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 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 and is commercially available globally in 67 countries for relapsed classical Hodgkin lymphoma (HL) and relapsed systemic anaplastic large cell lymphoma (sALCL). Seattle Genetics is also advancing enfortumab vedotin, an ADC in a planned pivotal trial for metastatic urothelial cancer, in collaboration with Astellas and tisotumab vedotin, an ADC in a phase 1/2 trial for solid tumors, in collaboration with Genmab. Headquartered in Bothell, Washington and with European and international operations in Zug, Switzerland, 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, Celldex, Genentech, GlaxoSmithKline and Pfizer. More information can be found at www.seattlegenetics.com.

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

BOXED WARNING

WARNING PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY (PML): JC virus infection resulting in PML and death can occur in ADCETRIS-treated patients.

Contraindication

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

Warnings and Precautions

• Peripheral neuropathy (PN): ADCETRIS causes PN that is predominantly sensory. Cases of motor PN have also been reported. ADCETRIS-induced PN is cumulative. Monitor for symptoms such as hypoesthesia, hyperesthesia, paresthesia, discomfort, a burning sensation, neuropathic pain or weakness. Institute dose modifications accordingly.
• Anaphylaxis and infusion reactions: Infusion-related reactions (IRR), including anaphylaxis, have occurred with ADCETRIS. Monitor patients during infusion. If an IRR occurs, interrupt the infusion and institute appropriate medical management. If anaphylaxis occurs, immediately and permanently discontinue the infusion and administer appropriate medical therapy. Premedicate patients with a prior IRR before 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 ADCETRIS dose. 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 ADCETRIS-treated patients. Closely monitor patients during treatment for 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 use 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 use in patients with moderate or severe hepatic impairment.
• Hepatotoxicity: Serious cases, including fatal outcomes, have occurred in ADCETRIS-treated patients. Cases were consistent with hepatocellular injury, including elevations of transaminases and/or bilirubin, and occurred after the first ADCETRIS dose or rechallenge. Preexisting liver disease, elevated baseline liver enzymes, and concomitant medications may increase the risk. Monitor liver enzymes and bilirubin. Patients with new, worsening, or recurrent hepatotoxicity may require a delay, change in dose, or discontinuation of ADCETRIS.
• 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. Other possible contributory factors other than ADCETRIS include prior therapies and underlying disease that may cause immunosuppression. Consider PML diagnosis in patients 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: Noninfectious pulmonary toxicity events including pneumonitis, interstitial lung disease, and acute respiratory distress syndrome, some with fatal outcomes, have been reported. Monitor patients for signs and symptoms, 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 animal studies, ADCETRIS can cause fetal harm. Advise females of reproductive potential of the potential risk to the fetus and to avoid pregnancy during ADCETRIS treatment and for at least 6 months after the final dose of ADCETRIS.

Most Common (=20%) Adverse Reactions

Relapsed classical HL and relapsed sALCL: neutropenia, peripheral sensory neuropathy, fatigue, nausea, anemia, upper respiratory tract infection, diarrhea, pyrexia, rash, thrombocytopenia, cough and vomiting.

Classical HL post-auto-HSCT Consolidation: 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

Moderate or severe hepatic impairment or severe renal impairment: MMAE exposure and adverse reactions are increased. Avoid use.

Advise males with female sexual partners of reproductive potential to use effective contraception during, 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.

Forward Looking Statements for Seattle Genetics

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the therapeutic potential of ADCETRIS (brentuximab vedotin) as the foundation of care for CD30-expressing lymphomas, anticipated publication of data from ECHELON-1 and plans for submission for supplemental regulatory approval to and obtaining regulatory approval from the FDA and other regulatory authorities for frontline Hodgkin lymphoma. 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 possibility that the safety and/or efficacy results of the ECHELON-1 trial in Hodgkin lymphoma will not be sufficient for publication or to gain marketing approval in the United States or any other country, that we will be required to amend our submission for marketing approval or that such submission will be refused or delayed. In addition, our regulatory plans may change as a result of consultation with the FDA or other regulatory authorities. 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 June 30, 2017 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.