Tobacco-based vaccine to treat non-Hodgkin’s lymphoma by Bayer in human trials

A tobacco-based vaccine to treat non-Hodgkin’s lymphoma developed by Bayer is currently undergoing early-phase human studies.

This is the first time that proteins obtained from tobacco plants using magnICON technology undergo clinical testing, Bayer said.

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.

The tobacco-based vaccine should prevent a recurrence of the tumor in non-Hodgkin’s lymphoma, he added.

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.

This means that each patient is treated with a product tailored to his or her specific needs. The vaccine consists of an antibody – an immunoglobulin – which is present only on the diseased lymphocytes and not on healthy lymphocytes or other cells in the body.
This protein is known as an “idiotype.” The intention is to produce an individual drug product for each patient and administer it as a vaccine. The objective of the new 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.

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.

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 tumor.

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 non-Hodgkin’s lymphoma 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 University of Texas Southwestern Medical Center in Dallas (United States). The study is being coordinated locally by DAVA Oncology.

What is non-Hodgkin’s lymphoma?

Non-Hodgkin’s lymphoma is a type of malignant disease that occurs within the lymphatic system, and it is the fifth most common cause of death due to cancer after breast, prostate, lung, and colon cancer. It originates from lymphocytes, a type of white blood cells. There are two main types of lymphocytes: B lymphocytes and T lymphocytes (also called B-cells and T-cells).

Non-Hodgkin’s lymphoma can be divided into two general clinical categories: indolent lymphomas, the most common forms of which include follicular lymphomas which tend to grow relatively slowly; and aggressive lymphomas, which include diffuse large B-cell lymphomas (DLBCL), which grow more rapidly.

The overall prevalence of NHL in the European Union is approximately 230,000, with an annual incidence of about 70,000 new cases. Follicular lymphoma is one of the most common types of indolent NHL, accounting for 25?30 percent of all NHL lymphomas. It is a type of cancer which is long-lasting and difficult to treat.

Bayer Innovation GmbH (BIG), a wholly owned subsidiary of Bayer AG.

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

Bayer posted sales of EUR 32.9 billion, last fiscal. Capital expenditures amounted to EUR 2.0 billion, R&D expenses to EUR 2.7 billion.