Seattle Genetics, Inc. (NASDAQ: SGEN) today highlighted novel antibody-drug conjugate (ADC) technology advances presented at the 107th Annual Meeting of the American Association for Cancer Research (AACR) being held April 16 through 20, 2016 in New Orleans, LA. Data in multiple presentations demonstrate the company’s leadership and innovation in the field of ADCs. Presentations will showcase a new auristatin-based drug-linker as well as several novel linkers that expand Seattle Genetics’ proprietary ADC technology platform and may enable application of previously inaccessible cytotoxic payloads.

“We have a comprehensive scientific understanding of the multiple components necessary to develop antibody-drug conjugates for the potential treatment of hematologic malignancies and solid tumors,” said Jonathan Drachman, M.D., Chief Medical Officer and Executive Vice President, Research and Development at Seattle Genetics. “Our data presentations at the AACR Annual Meeting illustrate novel linker systems and cell-killing payloads as well as continued progress in understanding the chemical and biological properties of ADCs to inform potential future development. We believe ADCs will continue to play an increasingly important role in cancer treatment.”

ADCs are monoclonal antibodies designed to deliver cytotoxic agents selectively to tumor cells. Seattle Genetics has developed proprietary technology employing synthetic cytotoxic agents and stable linker systems that attach these cytotoxic agents to the antibody. Seattle Genetics’ linker systems are designed to be stable in the bloodstream and release the potent cell-killing agent once inside targeted cancer 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.

Multiple oral and poster presentations are being featured at AACR that highlight Seattle Genetics’ ADC technology advances. Abstracts can be found at www.aacr.org and include the following:

  • Three poster presentations on Sunday and Monday, April 17 and 18, 2016 (Abstracts #0351, 1285, 2082) will highlight the role of the tumor microenvironment in ADC clearance, antitumor activity and uptake. Importantly, preclinical data demonstrate the potential for tumor associated macrophages to contribute to antitumor activity through release of MMAE.
  • The development of novel quaternary ammonium linkers for the stable conjugation and efficient release of tertiary amine-containing payloads will be presented in a poster presentation on Monday, April 18, 2016 (Abstract #2056). Preliminary data demonstrate that this technology enables the evaluation of drug classes previously inaccessible as ADCs, including auristatin E and tubulysin.
  • The development of a novel methylene-alkoxy-carbamate (MAC) linker that enables direct conjugation of drugs through alcohol functional groups will be presented in an oral presentation at 3:50 p.m. ET on Tuesday, April 19, 2016 (Abstract #4334). This linker has the potential to expand the types of payloads utilized in ADCs.
  • Data from a novel monomethyl auristatin E (MMAE) linker technology will be highlighted in a poster presentation on Tuesday, April 19, 2016 (Abstract #2956). By incorporating a short polyethylene glycol (PEG) unit, a self-hydrolysing maleimide and a glucuronidase release mechanism, the new MMAE drug-linker demonstrates pronounced activity with an increased therapeutic index in preclinical models.

About Seattle Genetics

Seattle Genetics is a biotechnology company focused on the development and commercialization of innovative antibody-based therapies for the treatment of cancer. Seattle Genetics is leading the field in developing antibody-drug conjugates (ADCs), a technology designed to harness the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. The company’s lead product, ADCETRIS® (brentuximab vedotin), is a CD30-targeted ADC that, in collaboration with Takeda Pharmaceutical Company Limited, is commercially available in more than 60 countries, including the U.S., Canada, Japan and members of the European Union. Additionally, ADCETRIS is being evaluated broadly in more than 70 ongoing clinical trials in CD30-expressing malignancies. Seattle Genetics is also advancing vadastuximab talirine (SGN-CD33A; 33A), an ADC that is expected to advance into a phase 3 trial for acute myeloid leukemia in 2016. Beyond ADCETRIS and 33A, the company is developing a robust pipeline of clinical-stage programs, including denintuzumab mafodotin (SGN-CD19A; 19A), SGN-LIV1A, ASG-15ME, ASG-22ME (enfortumab vedotin), SGN-CD70A, SEA-CD40 and SGN-CD19B. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including AbbVie, Agensys (an affiliate of Astellas), Bayer, Genentech, GlaxoSmithKline and Pfizer. More information can be found at www.seattlegenetics.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 of Seattle Genetics’ ADC technology platform, including potential future development and evaluation opportunities and Seattle Genetics’ expectations regarding the role of ADCs in the treatment of cancer, 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 difficulty and uncertainty of pharmaceutical product development, including the risks that Seattle Genetics may experience delays in its planned clinical trial initiations or otherwise experience failures or setbacks in its ADC development program and that, due to the potential lack of efficacy or risk of adverse events as Seattle Genetics’ ADC product candidates advance in development or other factors, it is possible that none of Seattle Genetics’ ADC product candidates will ever become commercial products. More information about the risks and uncertainties faced by Seattle Genetics is contained under the caption “Risk Factors” included in the company’s Annual Report on Form 10-K for the year ended December 31, 2015 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.