BioWorld International Correspondent
Affimed Therapeutics AG raised €25 million (US$33.5 million) in a Series B round to fund its two lead programs, in non-Hodgkins lymphoma (NHL) and Hodgkin's disease. Each is in preclinical development at present.
The Hodgkin's disease program, based around AFM13, is due to enter the clinic in the first or second quarter of 2008, Affimed CEO Rolf Günther told BioWorld International.
The NHL program comprises two lead molecules, AFM11 and AFM12, and is due to enter the clinic in 2009.
"We have proof of concept for both, and we also have very nice data showing a combination of both has a synergistic effect," Günther said.
The company may pursue a cocktail of the two molecules in NHL, depending on the outcome of additional confirmatory preclinical studies, as well as on the outcome of discussions with regulatory authorities.
Affimed, based in Heidelberg, Germany, was spun out of the recombinant antibodies research group headed by Melvyn Little at the German Cancer Research Center (DKFZ), also in Heidelberg. It is developing two proprietary, single-chain antibody-based formats, TandAbs and flexibodies, although the latter remains at an early stage.
"Our core expertise, coming out of the German Cancer Research Center, is in cancer, of course," Günther said. However, the company also has built up some capabilities in immunology as well, and it has an earlier-stage program in psoriasis, as well as in thrombosis.
TandAbs are tetravalent, bispecific proteins - that is, each TandAb contains four binding sites, two that recognize a particular epitope on an antigen and two that recognize an activating receptor on an immune effector cell, such as a natural killer (NK) cell or a cytotoxic T-lymphocyte, so an immune response is targeted toward tumor cells expressing a specific antigen.
The company's three lead candidate drugs are based on that format. AFM13 recognizes both the lymphoid activation antigen CD30, which is expressed by the tumor cells associated with Hodgkin's disease, and the CD16 surface receptors found on NK cells.
AFM11 recognizes the B-cell antigen CD19 and CD3, a component of the T-cell antigen receptor complex. AFM also recognizes CD19 but mobilizes an antibody-dependent cellular cytotoxicity response by binding CD16.
The company aims to partner or out-license AFM13 once it has demonstrated evidence of safety and efficacy in man, Günther said. Rituxan (rituximab), marketed by Genentech Inc., of South San Francisco, already has attained blockbuster status in that indication. And the same condition also is the focus of the blockbuster deal involving HuMax-CD20, which Copenhagen, Denmark-based Genmab A/S concluded with London-based GlaxoSmithKline plc last year. Targeting CD19 rather than CD20 widens the population of B precursor cells that can be targeted, Günther said.
As Hodgkin's disease is an orphan indication, the company may itself undertake full clinical development of the drug candidate.
About 132,000 people live with the condition, and about 4,000 of those are eligible for biologic therapy, Günther said. The condition has a prevalence of about one-tenth that of NHL, with two peaks - among men in their 30s and in their 50s.
About 85 percent respond to treatment with chemotherapy and radiotherapy, but those who relapse are very difficult to treat. "This is where medical need is greatest," he said. AFM13 also could be used as frontline therapy to reduce the dose required in existing chemotherapy regimens.
TandAbs can be produced in mammalian and bacterial expression systems, although Affimed has not yet attempted large-scale production in a bacterial system, Günther said. It is studying the feasibility of such an approach via a collaboration with Xoma Ltd., of Berkeley, Calif.
The company previously raised €5.7 million in equity financing, plus a further €2.5 million in debt financing.
New investors included BioMedInvest AG, of Basel, Switzerland, New York-based OrbiMed Advisors LLC and Life Sciences Partners, of Amsterdam, the Netherlands. Existing investor firstVentury Equity GmbH, of Heidelberg, also participated.