Merck and Pfizer fight cancer

Merck, the Darmstadt-based pharmaceuticals company, announced Monday that it had inked a deal with a US rival, New York-based Pfizer, to cooperate in the development and marketing of a new anti-cancer antibody developed by Merck. Pfizer will pay Merck 680 million euros ($851 million) immediately under the deal, and could eventually pay Merck up to 2.68 billion euros.

All of the development and marketing costs as well as all revenues associated with the antibody will be shared between the two companies.

Antibody therapies could turn some cancers from killers into treatable chronic diseases

Antibody therapies are seen as among the most promising new avenues for fighting cancer. #link:http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/immunotherapy/index:Anti-cancer immunotherapies# work by helping the patient's immune system to fight cancer cells more effectively.

Merck's product is an Anti-PD-L1 antibody that goes by the rather unpoetic name "MSB0010718C". It is an investigational antibody currently in development as a potential treatment for multiple tumor types. Merck and Pfizer will now cooperate in the further development and testing of the antibody.

The product will be tested as a single agent (used alone in oncological therapy) as well as in various combinations with other drugs and agents, both approved and investigational, in Merck and Pfizer's pipelines.

As part of the agreement, Merck will co-promote Pfizer's Xalkori, a medicine to treat non-small-call lung cancer, in the USA and several other markets.

Immunotherapies target regulatory molecules

The immune-system's killer T cells - or "cytotoxic T lymphocytes" - can recognize and destroy cancer cells, but T cells have various receptors on their cell surfaces for inhibitory signal that brake their activity.

One receptor on T cells is the PD-1 (programmed cell death 1) receptor. The signal molecule that activates the PD-1 receptor, thereby suppressing T cell activity, is called PD-L1, or PD-1 ligand.

Merck and Pfizer plan to co-develop antibodies that interfere with PD-L1's ability to reduce T cell activity.

Immunosuppressive signal molecules like PD-L1 may be produced either by cancer cells, or by normal cells that are part of the immune system - which produces a variety of such molecules as part of a web of feedback mechanisms meant to prevent the immune system from going haywire and becoming overactive. When such feedback mechanisms fail, auto-immune diseases can occur.

Immunotherapy antibodies affect this web of feedback mechanisms. As a result, they can increase the immune system's ability to attack malignant cells such as cancer cells - but they can also have a variety of side affects, since an immune system in overdrive may attack healthy cells as well.

Scientists expect more and more immunotherapy agents to emerge in coming years, aimed at enhancing the ability of the body's own immune system to recognize and fight cancer cells or infections.

The hope is that such therapies will be more effective and less damaging than the principal anti-cancer therapies used today, which usually target cancer cells with heavy doses of radiation, or with poisonous ("cytotoxic") chemicals. Such therapies tend to kill or damage not only cancer cells, but also normal cells, on a large scale.