Printer Friendly Version View printer-friendly version
« Back
Seattle Genetics Initiates Pivotal Phase 3 Trial of Vadastuximab Talirine (SGN-CD33A) for Patients with Newly Diagnosed Acute Myeloid Leukemia (AML)
May 25, 2016 at 8:00 AM EDT

-The Phase 3 Study, Called CASCADE, will Evaluate 33A in Combination with Hypomethylating Agents in Older AML Patients-

-Data Presented at the 2015 American Society of Hematology Annual Meeting Demonstrated Encouraging Anti-leukemic Activity and Support Advancing 33A into a Registrational Trial-

-Additional 33A Phase 1 Data to be Featured in an Oral Presentation at the European Hematology Association Congress in June 2016-

BOTHELL, Wash.--(BUSINESS WIRE)--May 25, 2016-- Seattle Genetics, Inc. (NASDAQ: SGEN) today announced initiation of a pivotal phase 3 clinical trial, called CASCADE, evaluating vadastuximab talirine (SGN-CD33A; 33A) in combination with azacitidine (Vidaza) or decitabine (Dacogen) in older patients with newly diagnosed acute myeloid leukemia (AML). 33A is an antibody-drug conjugate (ADC) targeted to CD33 utilizing Seattle Genetics’ newest technology, comprising an engineered cysteine antibody (EC-mAb) stably linked to a highly potent DNA binding agent called a pyrrolobenzodiazepine (PBD) dimer. CD33 is expressed on leukemic blasts in nearly all AML patients and expression is generally consistent regardless of age, cytogenetic abnormalities or underlying mutations. Azacitidine and decitabine are hypomethylating agents (HMAs) commonly used in the treatment of older AML patients.

“Acute myeloid leukemia, or AML, is a devastating disease representing a significant unmet medical need. It impacts approximately 20,000 people in the U.S. each year, with few effective treatment options. Older AML patients have a particularly poor prognosis as the majority have high risk disease characteristics and a median survival of ten months or less with available therapies,” said Clay Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. “We have a robust development strategy, with several ongoing clinical trials across multiple lines of therapy in myeloid malignancies to explore 33A as a treatment option broadly in AML. This pivotal phase 3 CASCADE trial is a significant corporate milestone and an important step in our goal to improve outcomes for AML patients.”

The phase 3 CASCADE study is a randomized, double-blind, placebo-controlled, global clinical trial. It is designed to evaluate if 33A in combination with azacitidine or decitabine can extend overall survival compared to azacitidine or decitabine alone in older patients with newly diagnosed AML. Patients will be randomized on a 1:1 ratio to be treated with an HMA plus 33A or an HMA plus placebo. The secondary endpoints include the comparison of composite complete remission rate (complete remission and complete remission with incomplete hematologic recovery; CR/CRi), event-free and leukemia-free survival, duration of response, safety, and 30- and 60-day mortality rates. The phase 3 trial will enroll approximately 500 patients globally. For more information about the trial, including enrolling centers, please visit

Interim results from the ongoing phase 1 study evaluating 33A in combination with HMAs in frontline AML and as monotherapy in primarily relapsed AML were presented at the 2015 American Society of Hematology (ASH) Annual Meeting and Exposition. Data from the phase 1 33A combination trial demonstrated that 15 of 23 (65 percent) evaluable patients achieved CR/CRi. At a median follow-up of 7.7 months, median survival had not yet been reached, and 72 percent of patients remained alive and on study.

Updated data from the ongoing phase 1 study of 33A in combination with HMAs will be presented in an oral presentation at the 2016 European Hematology Association (EHA) Congress taking place June 9 – 12, 2016, in Copenhagen, Denmark.

In addition to the phase 3 CASCADE trial, Seattle Genetics is evaluating 33A broadly across multiple lines of therapy in patients with AML and myelodysplastic syndromes (MDS), including the following ongoing trials:

  • A phase 1 trial of 33A monotherapy and in combination with HMAs in AML patients who have relapsed/declined intensive frontline therapy or are newly diagnosed;
  • A phase 1b trial in combination with standard-of-care intensive chemotherapy (7+3), consisting of cytarabine and daunorubicin, for younger fit patients with AML;
  • A phase 1/2 trial in patients with relapsed or refractory AML evaluating 33A monotherapy as a pre-conditioning regimen prior to an allogeneic stem cell transplant and also for use as maintenance therapy following transplant; and,
  • A phase 1/2 trial of 33A in combination with azacitidine in patients with previously untreated MDS.

More information about SGN-CD33A and ongoing clinical trials can be found at

With more than 15 years of experience and innovation, Seattle Genetics is the leader in developing ADCs. ADCs are monoclonal antibodies that are designed to selectively deliver cell-killing agents to tumor cells. This approach is intended to spare non-targeted cells and, thus, reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity.

About Acute Myeloid Leukemia

Acute myeloid leukemia, also called acute myelocytic leukemia or AML, is an aggressive type of cancer of the bone marrow and blood that progresses rapidly without treatment. AML is a cancer that starts in the cells that are supposed to mature into different types of blood cells. AML starts in the bone marrow (the interior part of bones, where new blood cells are made) and quickly moves into the blood. According to the American Cancer Society, in 2016 approximately 20,000 new cases of AML (mostly in adults) will be diagnosed and nearly 10,500 deaths will occur from AML (almost all will be in adults).

About Vadastuximab Talirine (SGN-CD33A)

Vadastuximab talirine (SGN-CD33A; 33A) is a novel ADC targeted to CD33 utilizing Seattle Genetics’ newest ADC technology. CD33 is expressed on most AML and MDS blast 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.

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 approved globally in more than 60 countries for relapsed classical Hodgkin lymphoma (HL) and relapsed systemic anaplastic large cell lymphoma (sALCL). Seattle Genetics is also advancing vadastuximab talirine (SGN-CD33A; 33A), an ADC that has moved into a phase 3 trial for acute myeloid leukemia in 2016. Headquartered in Bothell, Washington, Seattle Genetics is also advancing 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

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 vadastuximab talirine (SGN-CD33A; 33A) including activity and safety, the planned CASCADE trial, including anticipated initiation, timeline, trial conduct, endpoints and patient enrollment numbers, other anticipated clinical trials including potential patient and site enrollment and anticipated data announcements. 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 possible delays in the commencement of planned clinical trials due to regulatory action or other events, delays in the conduct of clinical trials and collection and analysis of data, lack of efficacy or adverse events as vadastuximab talirine advances in clinical trials and regulatory actions. 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, 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.

Source: Seattle Genetics, Inc.

Seattle Genetics
Peggy Pinkston, 425-527-4160
Tricia Larson, 425-527-4180