The transfer into clinical development of a patient-specific vaccine represents a milestone for Bayer Innovation GmbH. Following approval of the phase-I study by the US FDA (Food & Drug Administration) in the United States, the vaccine is now being tested in human subjects. This is the first time that proteins obtained from tobacco plants using magnICON technology undergo clinical testing. The patient-specific vaccines produced in the pilot plant operated by the Bayer-subsidiary Icon Genetics in Halle, Germany, are intended for the treatment of non-Hodgkin’s lymphoma (NHL), a type of cancer affecting lymphocytes. The objective of the therapy is to activate the patient’s immune system, enabling the malignant cells to be targeted and destroyed by the body’s own defense system.

“This personalized vaccine is being developed with the aim of keeping patients who have responded well to chemotherapy in complete remission,” explains Dr Detlef Wollweber, head of Bayer Innovation GmbH. “In other words, it should prevent a recurrence of the tumour. The initiation of this clinical trial also demonstrates that our magnICON technology is suitable for manufacturing proteins for potential pharmaceutical applications.”

The magnICON technology is a new process for the rapid production of high yields of recombinant proteins such as biopharmaceuticals in tobacco plants. The plant is not genetically modified: The blueprint for the required product is inserted temporarily into the plant using a species of Agrobacterium and distributed throughout the plant cells. The protein is subsequently be extracted from the plant’s leaves in a very pure form. The process can also be carried out in a large-scale closed facility.

“The goal of cancer therapy in the future will be to tailor treatment to the individual patient as far as possible,“ says John Butler-Ransohoff, project manager for Plant-made Pharmaceuticals at Bayer. “Haematological tumours such as B-cell lymphomas are a good starting point for the further development of personalized medicine because the idiotypic antibodies formed by the lymphomas are highly specific tumour markers.”

Scientists have been trying to trigger an immune response to this type of patient-specific idiotypic antibody (surface immunoglobulins) since the 1990s in the hope of substantially delaying the recurrence of the tumour. In 2006 a team of researchers working with Professor Maurizio Bendandi at the University of Navarra (Spain), succeeded in this objective in a groundbreaking research study involving patients who had previously achieved complete remission with chemotherapy. Bayer’s new Phase I study is carried out in close cooperation with Bendandi.

The focus of the currently started first clinical study in volunteers who have NHL is on the safety, tolerability and – to the extent that this can be determined from laboratory tests - immunological effects of the vaccine. In this study, 20 patients will each be given six subcutaneous injections of the personalized vaccine over a six-month period. The humoral and cellular immune responses in these patients will subsequently be characterized in Bendandi’s laboratory at the University of Navarra. If the results of this study are sufficiently positive and promising, an application will be made to carry out a phase-III study for registration purposes. The phase-I clinical study which has just started is being performed at the renowned University of Texas Southwestern Medical Center in Dallas (United States). The study is being coordinated locally by DAVA Oncology.

Idiotype vaccination is a new type of therapy which has not yet been given regulatory approval. It is referred to as active immunotherapy and, unlike most other biological therapies, is specific to the individual patient.

DAVA Oncology is a Dallas (Texas, USA) based oncology drug developments company focusing on accelerating clinical trials.