Seattle Genetics Submits Supplemental Biologics License Application to FDA for ADCETRIS® (Brentuximab Vedotin) in Cutaneous T-Cell Lymphoma

BLA Based on Clinical Trial Results from the Phase 3 ALCANZA and Phase 2 Investigator-Sponsored Studies in Cutaneous T-Cell Lymphoma

BOTHELL, Wash.--()--Seattle Genetics, Inc. (Nasdaq: SGEN) announced today that it has submitted a supplemental Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) based on data from the phase 3 ALCANZA trial and two phase 2 investigator-sponsored trials of ADCETRIS (brentuximab vedotin) in patients with cutaneous T-cell lymphoma (CTCL). ADCETRIS is currently not approved for the treatment of CTCL.

“The submission of the supplemental BLA requesting label expansion for ADCETRIS as a treatment in CTCL patients who require systemic therapy is an important milestone. CTCL is an incurable and disfiguring disease in need of new therapeutic options, particularly those that achieve durable responses,” said Jonathan Drachman, M.D., Chief Medical Officer and Executive Vice President, Research and Development of Seattle Genetics. “Results from the phase 3 ALCANZA trial demonstrated that CTCL patients treated with ADCETRIS had superior outcomes across all primary and secondary endpoints compared to patients in the control arm who were treated with either methotrexate or bexarotene standard of care agents. In addition to the ALCANZA results, data from two investigator-sponsored trials also support ADCETRIS use in this disease setting. We believe these data are clinically meaningful and support a label expansion for ADCETRIS in CTCL, which would be the fourth indication for this program.”

In November 2016, based on preliminary analysis of ALCANZA, the FDA granted ADCETRIS Breakthrough Therapy Designation (BTD) for the treatment of patients with CD30-expressing mycosis fungoides and primary cutaneous anaplastic large cell lymphoma who require systemic therapy and have received one prior systemic therapy. These represent the most common subtypes of CTCL. Based on discussions with the FDA following the BTD, additional data from investigator-sponsored phase 2 trials have been incorporated into the supplemental BLA to support the potential for a broader label in CTCL.

The supplemental BLA is primarily based on positive results from a phase 3 trial called ALCANZA that were presented at the 58th American Society of Hematology (ASH) annual meeting in December 2016 and published in the Lancet in June 2017. Results from the ALCANZA trial in 128 CTCL patients requiring systemic therapy included:

  • The trial achieved its primary endpoint with the ADCETRIS treatment arm demonstrating a highly statistically significant improvement in the rate of objective response lasting at least four months (ORR4) versus the control arm as assessed by an independent review facility. ORR4, as assessed by Global Response Score, was 56.3 percent in the ADCETRIS arm compared to 12.5 percent in the control arm (p-value <0.0001).
  • Key secondary endpoints specified in the protocol, including complete response rate, progression-free survival and reduction in the burden of symptoms during treatment (Skindex-29), were all highly statistically significant in favor of the ADCETRIS arm.
  • The safety profile associated with ADCETRIS from the ALCANZA trial was generally consistent with the existing prescribing information. The most common adverse events of any grade include: peripheral neuropathy, nausea, diarrhea, fatigue, vomiting, alopecia, pruritis, pyrexia, decreased appetite and hypertriglyceridemia.

About CTCL

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. Cutaneous lymphomas are a category of non-Hodgkin lymphoma that primarily involve the skin. According to the Cutaneous Lymphoma Foundation, CTCL is the most common type of cutaneous lymphoma and typically presents with red, scaly patches or thickened plaques of skin that often mimic eczema or chronic dermatitis. Progression from limited skin involvement may be accompanied by skin tumor formation, ulceration and exfoliation, complicated by itching and infections. Advanced stages are defined by involvement of lymph nodes, peripheral blood and internal organs.

The standard treatment for systemically pretreated CTCL includes skin-directed therapies, radiation and systemic therapies. The systemic therapies currently approved for treatment have demonstrated 30 to 45 percent objective response rates, with low complete response rates.

About ADCETRIS

ADCETRIS is being evaluated broadly in more than 70 ongoing clinical trials, including three Phase 3 studies, the ongoing ECHELON-1 trial in frontline classical Hodgkin lymphoma and the ongoing ECHELON-2 trial in frontline mature T-cell lymphomas, as well as the completed ALCANZA trial in cutaneous T-cell lymphoma, from which data were submitted in a supplemental BLA.

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.

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 for metastatic urothelial cancer, in a planned pivotal trial in collaboration with Astellas. 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

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.

Forward-Looking Statements

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the therapeutic potential, and the possibility of market approval of ADCETRIS (brentuximab vedotin) for uses including CTCL and other CD30-expressing lymphomas for which ADCETRIS has not received regulatory approval. 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 that the supplemental BLA submission will not be sufficient 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 March 31, 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.

Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Tricia Larson, 425-527-4180
tlarson@seagen.com

Contacts

Seattle Genetics, Inc.
Investors:
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com
or
Media:
Tricia Larson, 425-527-4180
tlarson@seagen.com