Genmab and ADC Therapeutics Enter Co-Development Collaboration for an Antibody Drug Conjugate Combining HuMax-TAC and PBD Warhead

Genmab A/S (OMX: GEN) and ADC Therapeutics Sarl, announced today an agreement to develop a new antibody-drug conjugate (ADC) product combining Genmab’s HuMax-TAC antibody and ADC Therapeutics’ PBD-based warhead and linker technology. The Companies have been conducting in vitro and in vivo studies since 2012 to investigate different warhead and linker combinations with HuMax-TAC, and now have the product ready for pre-IND preclinical development.The product will be developed for multiple cancer indications.

Genmab and ADC Therapeutics will each initially have an equal share in the product. In the first instance, ADC Therapeutics will lead and fund preclinical development. Prior to the submission of an application to conduct clinical studies in patients (IND filing), Genmab may elect to retain equal ownership of the product. Genmab will not incur any development costs prior to the IND filing decision and Genmab will maintain a minimum 25% ownership stake in the product as it moves into clinical development. No other financial terms were disclosed.

“We believe our unique HuMax-TAC antibody has optimal characteristics for creation of an ultra-potent antibody-drug conjugate when used in combination with ADC Therapeutics’ novel PBD-based warhead and linker technology, which employs an emerging class of highly potent anticancer agents. This agreement is another example of a win-win partnership combining Genmab’s state-of-the-art antibody development expertise with the latest advance in antibody-payload technology,” said Jan van de Winkel, Ph.D., Chief Executive Officer of Genmab.

Dr. Peter B. Corr, Chairman of ADC Therapeutics said: “We are very excited to be developing an ADC with our new partner Genmab and incorporating our next generation PBD-based toxins into this product. Our warhead payload technology enjoys exquisite potency, optimised conjugation and pharmaceutical properties that maintain activity in highly resistant cancers. Our pre-clinical data for this product indicate the potential for curative efficacy in highly resistant populations at low ADC doses of this product in several oncology indications, an area with critical unmet needs.

This agreement does not affect Genmab’s 2013 financial guidance.

About HuMax-TAC

HuMax-TAC is a high-affinity fully human antibody targeting CD25, a therapeutic target with strong clinical validation. CD25 is expressed on a variety of hematological tumors and shows limited expression on normal tissues, which makes it a very attractive target for antibody-payload approaches. With HuMax-TAC-ADC, we aim to develop a first-in-class antibody-drug conjugate for the potential treatment of CD25-expressing lymphomas and leukemias.

About PBD Warheads & Linkers

ADCs developed using ADC Therapeutics’ technology combine monoclonal antibodies specific to particular tumor targets with highly potent pyrrolobenzodiazepine (PBD) based warheads developed by ADC Therapeutic’s partner Spirogen Limited. These PBD warheads are joined to antibodies by linkers that release the PBD warhead in the targeted cancer cells. This technology has attracted the attention of other biotechnology companies such as Genentech and Seattle Genetics.

About ADC Therapeutics

ADC Therapeutics sarl (ADCT) is a Swiss-based oncology drug development company that specializes in the development of proprietary Antibody Drug Conjugates (ADCs) targeting major cancers such as breast lung, prostate, renal and blood. The Company’s ADCs are highly targeted drug constructs which combine monoclonal antibodies specific to particular types of tumor cells with a novel class of highly potent pyrrolobenzodiazepine (PBD)-based warheads. As its PBD-based chemistries do not distort the structure of the DNA it gives the prospect of highly potent, target-selective cancer therapies with fewer side effects and the potential to pre-empt resistance issues faced by other anti-cancer products on the market. The company was formed in 2012 with a $50m commitment from private equity firm Auven Therapeutics (previously known as Celtic Therapeutics). ADCT has a strategic collaboration with Spirogen Ltd, also an Auven Therapeutics’ portfolio company, for the supply of warhead chemistries and R&D services. It operates a virtual business model based in Lausanne, Switzerland.

For further information please see: www.adctherapeutics.com

About Genmab A/S

Genmab is a publicly traded, international biotechnology company specializing in the creation and development of differentiated human antibody therapeutics for the treatment of cancer. Founded in 1999, the company’s first marketed antibody, ofatumumab (Arzerra®), was approved to treat chronic lymphocytic leukemia in patients who are refractory to fludarabine and alemtuzumab after less than eight years in development. Genmab’s validated and next generation antibody technologies are expected to provide a steady stream of future product candidates. Partnering of innovative product candidates and technologies is a key focus of Genmab’s strategy and the company has alliances with top tier pharmaceutical and biotechnology companies. For more information visit www.genmab.com.

This Media Release contains forward looking statements. The words “believe”, “expect”, “anticipate”, “intend” and “plan” and similar expressions identify forward looking statements. Actual results or performance may differ materially from any future results or performance expressed or implied by such statements. The important factors that could cause our actual results or performance to differ materially include, among others, risks associated with pre-clinical and clinical development of products, uncertainties related to the outcome and conduct of clinical trials including unforeseen safety issues, uncertainties related to product manufacturing, the lack of market acceptance of our products, our inability to manage growth, the competitive environment in relation to our business area and markets, our inability to attract and retain suitably qualified personnel, the unenforceability or lack of protection of our patents and proprietary rights, our relationships with affiliated entities, changes and developments in technology which may render our products obsolete, and other factors. For a further discussion of these risks, please refer to the risk management sections in Genmab’s most recent financial reports, which are available on www.genmab.com. Genmab does not undertake any obligation to update or revise forward looking statements in this Media Release nor to confirm such statements in relation to actual results, unless required by law.

Genmab A/S and its subsidiaries own the following trademarks: Genmab®; the Y-shaped Genmab logo®; HuMax®; HuMax-CD20®; DuoBody®, HexaBodyTM and UniBody®. Arzerra® is a trademark of GlaxoSmithKline.