HAMBURG, Germany - Mologen AG, a company focusing on genetic vaccines, entered a second Phase II/III clinical trial of its proprietary MIDGE technology of non-viral DNA constructs.

In cooperation with the University Clinic of Cologne, Germany, the trial was started last week with patients suffering from multiple myeloma, a cancer of the immune system in which huge amounts of antibodies are produced. "We hope to finish the trial in the first quarter of 2001," Burghardt Wittig, President and CEO of Mologen, told BioWorld International. "We have designed novel DNA constructs carrying DNA motifs so that they are very potent stimulators of the immune system. That way we hope to generate beneficial autoimmunity in these patients."

Berlin-based Mologen's technology is being used in a Phase II/III trial for the treatment of colon cancer, and the company is in the process of filing for a third Phase II/III study to treat renal cell cancer. The colon cancer study involving more than 100 patients was started in collaboration with the University Clinic of Cologne and Rhone Poulenc (now Aventis) last year, and will be finished by the end of this year.

The immunostimulatory DNA constructs (d-SLIM) used in the new trial are a derivative of Mologen's MIDGE vector platform. Contrary to conventional vectors, these vectors do not carry helper sequences such as origins of replication, antibiotic resistance or bacterial genes. Hence, Mologen calls such vectors MIDGE, derived from "minimalistic immunologically defined gene expression."

"The lack of potentially dangerous viral sequences and of production-derived bacterial sequences with unwanted antigenic potential, coding for antibiotic resistance, and probably integrating in the patient's genome, is a considerable advantage for approvals and registration," Wittig said.

In the trials antigen-presenting cells are treated ex-vivo with antigenic peptides of tumor origin combined with the d-SLIM immunostimulatory DNA constructs. The treated cells are then re-injected into the patients

"They are able to raise an immune response against a broad spectrum of tumor cell antigens and against the specific tumor-derived peptide," Wittig said. "The immune system then should be able to recognize the tumor in general and to eliminate the residual cancer cells."