Seagen Announces Multiple ADCETRIS® (brentuximab vedotin) Presentations at the 2020 ASH Annual Meeting

Rhea-AI Summary

Seagen Inc. (Nasdaq:SGEN) presented multiple data updates for ADCETRIS® (brentuximab vedotin) at the 62nd American Society of Hematology Annual Meeting. The five-year results from phase 3 ECHELON-1 and ECHELON-2 clinical trials showed that ADCETRIS combined with chemotherapy resulted in improved progression-free survival (PFS) in patients with advanced classical Hodgkin lymphoma and CD30-expressing peripheral T-cell lymphoma. Additionally, initial findings from a phase 2 trial combining ADCETRIS with Opdivo® for relapsed mediastinal gray zone lymphoma were disclosed, highlighting a 70% objective response rate.

Positive

• Five-year PFS rates for ADCETRIS plus AVD in Hodgkin lymphoma were 82.2%, superior to the 75.3% of ABVD.
• ADCETRIS plus CHP showed a 30% reduction in progression risk in peripheral T-cell lymphoma with a 51.4% five-year PFS.
• The combination with Opdivo in gray zone lymphoma demonstrated a 70% objective response rate.

Negative

• High rates of peripheral neuropathy were reported, with 67% experiencing symptoms compared to 43% in the ABVD arm.
• ADCETRIS and Opdivo are not approved for relapsed or refractory mediastinal gray zone lymphoma.

BOTHELL, Wash.--(BUSINESS WIRE)--Seagen Inc. (Nasdaq:SGEN) today announced multiple ADCETRIS^® (brentuximab vedotin) data presentations at the 62^nd American Society of Hematology (ASH) Annual Meeting and Exposition, taking place virtually December 5-8, 2020. Data presentations include five-year updates from the phase 3 ECHELON-1 and ECHELON-2 clinical trials evaluating ADCETRIS plus a chemotherapy combination regimen in frontline advanced stage classical Hodgkin lymphoma (HL) and CD30-expressing frontline peripheral T-cell lymphoma (PTCL), respectively. In addition, first results were presented from an ongoing phase 2 clinical trial evaluating ADCETRIS in combination with Opdivo^® (nivolumab) in relapsed or refractory mediastinal gray zone lymphoma (MGZL), a rare type of non-Hodgkin lymphoma that express CD30 with no standard of care. ADCETRIS is an antibody-drug conjugate (ADC) directed to CD30, a defining marker of classical HL and expressed on the surface of several types of non-Hodgkin lymphoma, including PTCL. ADCETRIS is being evaluated globally in more than 70 corporate- and investigator-sponsored clinical trials across multiple settings in lymphoma and other indications. ADCETRIS and Opdivo are not approved alone or in combination for the treatment of relapsed or refractory MGZL.

“After five years of follow-up, an important clinical milestone, both the ECHELON-1 and ECHELON-2 clinical trials demonstrate that ADCETRIS plus chemotherapy resulted in superior and durable outcomes when compared with standard chemotherapy regimens,” said Roger Dansey, M.D., Chief Medical Officer at Seagen. “As most relapses in Hodgkin lymphoma occur within five years of frontline treatment, the results of the ECHELON-1 study suggest that patients treated with ADCETRIS plus chemotherapy are more likely to experience long-term remissions compared to those treated with the ABVD regimen.”

Brentuximab Vedotin with Chemotherapy for Patients with Previously Untreated, Stage III/IV Classical Hodgkin Lymphoma: 5-Year Update of the ECHELON-1 Study (Abstract #2973, poster presentation on Monday, December 7, 2020)

The ECHELON-1 clinical trial is evaluating ADCETRIS in combination with AVD (Adriamycin [doxorubicin], vinblastine, dacarbazine) compared to ABVD (Adriamycin [doxorubicin], bleomycin, vinblastine, dacarbazine) in patients with Stage III or IV frontline classical HL. As previously reported, the ECHELON-1 trial achieved its primary endpoint with the combination of ADCETRIS plus AVD resulting in a statistically significant improvement in modified progression-free survival (PFS) compared to the control arm of ABVD as assessed by independent review facility (IRF; hazard ratio (HR), 0.77; p=0.035). A five-year exploratory analysis was conducted to examine PFS outcomes per investigator assessment in the intent-to-treat population of 1,334 patients. Results include:

• Patients in the ADCETRIS plus AVD arm had a 32 percent reduction in the risk of a progression event compared to patients in the ABVD arm. The five-year PFS rate for patients in the ADCETRIS plus AVD arm was 82.2 percent compared to 75.3 percentin the ABVD arm, an absolute difference of 6.9 percent (HR, 0.681 [95% CI: 0.534, 0.867]). Median follow-up time was 60.9 months.
• Consistent benefit in PFS was observed among patients treated with ADCETRIS plus AVD compared with ABVD, independent of disease stage, age and prognostic score.
  • Consistent improvements compared to ABVD were observed in patients with Stage III (HR, 0.593; [95% CI: 0.385, 0.915]) and Stage IV (HR, 0.731; [95% CI: 0.545, 0.980]) disease.
• As previously reported for the primary analysis, on the ADCETRIS plus AVD arm, peripheral neuropathy events were observed in 67 percent of patients compared to 43 percent in the ABVD arm. The five-year update shows that among patients with peripheral neuropathy, 85 percent in the ADCETRIS plus AVD arm and 86 percent in the ABVD arm reported complete resolution or improvement at last follow-up.
• There were fewer secondary malignancies in the ADCETRIS plus AVD arm. Among 48 patients with reported secondary malignancies, 19 [(nine hematological malignancies and 10 solid tumors)] were in the ADCETRIS plus AVD arm and 29 [(15 hematological malignancies and 14 solid tumors)] were in the ABVD arm.
• There were a higher number of pregnancies in the ADCETRIS plus AVD arm compared to the ABVD arm. A total of 150 pregnancies were reported among study participants and their partners, including 89 on the ADCETRIS plus AVD arm and 61 on the ABVD arm.

The ECHELON-2 Trial: 5-Year Results of a Randomized, Double-Blind, Phase 3 Study of Brentuximab Vedotin and CHP (A+CHP) Versus CHOP in Frontline Treatment of Patients with CD30-Positive Peripheral T-Cell Lymphoma (Abstract #1150, poster presentation on Saturday, December 5, 2020)

The ECHELON-2 clinical trial is evaluating ADCETRIS in combination with CHP (cyclophosphamide, Adriamycin [doxorubicin], prednisone) compared to CHOP (cyclophosphamide, Adriamycin [doxorubicin], vincristine, prednisone) in frontline CD30-expressing PTCL. As previously reported, the ECHELON-2 trial met its primary endpoint with the combination of ADCETRIS plus CHP resulting in a statistically significant improvement in PFS versus the control arm of CHOP per blinded independent central review (HR, 0.71; p=0.0110). A five-year post-hoc exploratory analysis was conducted to examine PFS outcome and overall survival (OS) per investigator assessment in the intent-to-treat population of 452 patients. Key findings include:

• Patients in the ADCETRIS plus CHP arm had a 30 percent reduction in the risk of a progression event compared to patients in the CHOP arm. The five-year PFS rate for patients in the ADCETRIS plus CHP arm was 51.4 percent compared to 43 percent in the CHOP arm, an absolute difference of 8.4 percent (HR, 0.70 [95% CI: 0.53, 0.91]).
• OS in the ADCETRIS plus CHP arm was improved compared to CHOP (HR=0.72 [95% CI: 0.53, 0.99]). This represents a 28 percent reduction in the risk of death. Median follow-up time was 66.8 months.
• Among 316 systemic anaplastic large-cell lymphoma (sALCL) patients on study, patients in the ADCETRIS plus CHP arm had a 45 percent reduction in the risk of a progression event compared to patients in the CHOP arm (HR, 0.55 [95% CI: 0.39, 0.79]). There was a 34 percent reduction in the risk of death. Median follow-up time for PFS was 42.7 months.
• Consistent improvement in both PFS and OS was observed among patients treated with ADCETRIS plus CHP arm compared to the CHOP arm across the majority of pre-specified subgroups.
• The five-year update shows that among patients with peripheral neuropathy, 72 percent in the ADCETRIS plus CHP arm and 78 percent in the CHOP arm reported complete resolution or improvement at last follow-up. For ongoing peripheral neuropathy events, 98 percent in the ADCETRIS plus CHP arm and 98 percent in the CHOP arm were Grade 1 or 2.

Nivolumab Combined with Brentuximab Vedotin for Relapsed/Refractory Mediastinal Gray Zone Lymphoma: Primary Efficacy and Safety Analysis of the Phase 2 CheckMate 436 Study (Abstract #2045, poster presentation on Sunday, December 6, 2020)

Data from the ongoing CheckMate 436 phase 2 clinical trial of 10 patients with relapsed or refractory MGZL who received a combination of ADCETRIS plus Opdivo treatment after autologous stem cell transplant or two or more lines of multi-agent chemotherapy if ineligible for transplant will be presented for the first time. Patients were treated once every three weeks or until disease progression or unacceptable toxicity. The median age of patients was 35 years. Key findings include:

• Of 10 response-evaluable patients, seven patients (70 percent) had an objective response, including five patients (50 percent) with a complete response and two patients (20 percent) with a partial response. Two patients (20 percent) had progressive disease and in one patient (10 percent) death occurred prior to disease assessment.
• Median follow-up time was 12.4 months. Time to complete response was 1.2-4.8 months and the duration was 1.5+ to 3.2+ months before patients were assessed for subsequent therapy. All patients who achieved a complete response underwent a hematopoietic cell transplant and follow-up is ongoing.
• The most common adverse events of any grade in at least 20 percent of patients were neutropenia and paresthesia (30 percent each); thrombocytopenia, anemia and peripheral sensory neuropathy (20 percent each). The most common Grade 3 adverse events were neutropenia and thrombocytopenia (10 percent each). Three patient deaths occurred due to disease progression.

About ADCETRIS

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 Seagen’s 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 cells.

ADCETRIS for injection for intravenous infusion has received FDA approval for six indications in adult patients with: (1) previously untreated systemic anaplastic large cell lymphoma (sALCL) or other CD30-expressing peripheral T-cell lymphomas (PTCL), including angioimmunoblastic T-cell lymphoma and PTCL not otherwise specified, in combination with cyclophosphamide, doxorubicin, and prednisone, (2) previously untreated Stage III or IV classical Hodgkin lymphoma (cHL), in combination with doxorubicin, vinblastine, and dacarbazine, (3) cHL at high risk of relapse or progression as post-autologous hematopoietic stem cell transplantation (auto-HSCT) consolidation, (4) cHL after failure of auto-HSCT or failure of at least two prior multi-agent chemotherapy regimens in patients who are not auto-HSCT candidates, (5) sALCL after failure of at least one prior multi-agent chemotherapy regimen, and (6) primary cutaneous anaplastic large cell lymphoma (pcALCL) or CD30-expressing mycosis fungoides (MF) who have received prior systemic therapy.

Health Canada granted ADCETRIS approval with conditions in 2013 for patients with (1) HL after failure of autologous stem cell transplant (ASCT) or after failure of at least two multi-agent chemotherapy regimens in patients who are not ASCT candidates and (2) sALCL after failure of at least one multi-agent chemotherapy regimen. Non-conditional approval was granted for (3) post-ASCT consolidation treatment of patients with HL at increased risk of relapse or progression in 2017, (4) adult patients with pcALCL or CD30-expressing MF who have received prior systemic therapy in 2018, (5) for previously untreated patients with Stage IV HL in combination with doxorubicin, vinblastine, and dacarbazine in 2019, and (6) for previously untreated adult patients with sALCL, peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS) or angioimmunoblastic T-cell lymphoma (AITL), whose tumors express CD30, in combination with cyclophosphamide, doxorubicin, prednisone in 2019.

ADCETRIS received conditional marketing authorization from the European Commission in October 2012. The approved indications in Europe are: (1) for the treatment of adult patients with previously untreated CD30-positive Stage IV Hodgkin lymphoma in combination with doxorubicin, vinblastine and dacarbazine (AVD), (2) for the treatment of adult patients with CD30-positive Hodgkin lymphoma at increased risk of relapse or progression following ASCT, (3) for the treatment of adult patients with relapsed or refractory CD30-positive Hodgkin lymphoma following ASCT, or following at least two prior therapies when ASCT or multi-agent chemotherapy is not a treatment option, (4) for the treatment of adult patients with previously untreated sALCL in combination with cyclophosphamide, doxorubicin and prednisone (CHP), (5) for the treatment of adult patients with relapsed or refractory sALCL, and (6) for the treatment of adult patients with CD30-positive cutaneous T-cell lymphoma (CTCL) after at least one prior systemic therapy.

ADCETRIS has received marketing authorization by regulatory authorities in more than 70 countries for relapsed or refractory Hodgkin lymphoma and sALCL. See U.S. important safety information, including Boxed Warning, below.

Seagen and Takeda are jointly developing ADCETRIS. Under the terms of the collaboration agreement, Seagen has U.S. and Canadian commercialization rights and Takeda has rights to commercialize ADCETRIS in the rest of the world. Seagen 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.

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 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: Fatal and serious cases of febrile neutropenia have been reported with ADCETRIS. Prolonged (≥1 week) severe neutropenia and Grade 3 or 4 thrombocytopenia or anemia can occur with ADCETRIS.

Administer G-CSF primary prophylaxis beginning with Cycle 1 for patients who receive ADCETRIS in combination with chemotherapy for previously untreated Stage III/IV cHL or previously untreated PTCL.

Monitor complete blood counts prior to each ADCETRIS dose. Monitor more frequently 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: Fatal and serious cases 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: Fatal cases of JC virus infection resulting in PML have been reported in ADCETRIS-treated patients. First onset of symptoms occurred at various times from initiation of ADCETRIS, 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 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: Fatal and serious events of noninfectious pulmonary toxicity, including pneumonitis, interstitial lung disease, and acute respiratory distress syndrome, 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: Fatal and serious cases of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported with ADCETRIS. If SJS or TEN occurs, discontinue ADCETRIS and administer appropriate medical therapy.

• Gastrointestinal (GI) complications: Fatal and serious cases of acute pancreatitis have been reported. Other fatal and serious GI complications include perforation, hemorrhage, erosion, ulcer, intestinal obstruction, enterocolitis, neutropenic colitis, and ileus. Lymphoma with preexisting GI involvement may increase the risk of perforation. In the event of new or worsening GI symptoms, including severe abdominal pain, perform a prompt diagnostic evaluation and treat appropriately.

• Hyperglycemia: Serious cases, such as new-onset hyperglycemia, exacerbation of pre-existing diabetes mellitus, and ketoacidosis (including fatal outcomes) have been reported with ADCETRIS. Hyperglycemia occurred more frequently in patients with high body mass index or diabetes. Monitor serum glucose and if hyperglycemia develops, administer anti-hyperglycemic medications as clinically indicated.

• 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% in any study) Adverse Reactions

Peripheral neuropathy, fatigue, nausea, diarrhea, neutropenia, upper respiratory tract infection, pyrexia, constipation, vomiting, alopecia, decreased weight, abdominal pain, anemia, stomatitis, lymphopenia, and mucositis.

Drug Interactions

Concomitant use of strong CYP3A4 inhibitors or inducers 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 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.

Please see the full Prescribing Information, including BOXED WARNING, for ADCETRIS here.

About Seagen

Seagen is a global biotechnology company that discovers, develops and commercializes transformative cancer medicines to make a meaningful difference in people’s lives. Seagen is headquartered in the Seattle, Washington area, and has locations in California, Canada, Switzerland and the European Union. For more information on the company’s marketed products and robust pipeline, visit www.seagen.com and follow @SeagenGlobal on Twitter.

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 of ADCETRIS plus chemotherapy combination regimens in frontline advanced stage Hodgkin lymphoma, and frontline peripheral T-cell lymphoma, and in combination with Opdivo^® (nivolumab) in relapsed or refractory mediastinal gray zone lymphoma (MGZL). Actual results or developments may differ materially from those projected or implied in these forward-looking statements due to factors such as unexpected adverse events, adverse regulatory actions, the degree of utilization and adoption of an approved treatment regimen by prescribing physicians, the difficulty and uncertainty of pharmaceutical product development, negative or disappointing clinical trial results and risks related to the duration and severity of the COVID-19 pandemic. More information about the risks and uncertainties faced by Seagen is contained under the caption “Risk Factors” included in the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2020 filed with the Securities and Exchange Commission. Seagen disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.