Updated on 9 October 2013
Novogen adds a new class of cancer drugs called anti-tropomyosins (anti-Tms) to its pipeline
Singapore: Australia-based Novogen has acquired a novel drug technology that will be developed as a potentially major class of cancer drugs known as anti-tropomyosins (anti-Tms), joining the company's growing pipeline of super-benzopyran drugs, including Trilexium and related analogs.
The target of anti-Tm drugs is the protein, Tm5NM1, an integral part of the microfilament component of the cytoskeleton of a cell. Inhibition of Tm5NM1 effectively blocks the ability of a cancer cell to function and to divide.
The cytoskeleton is so-called because it gives a cell its shape and form, but more relevantly serves a wide range of functions that actively contribute to the ability of a cell to survive, to move, and to divide.
Drugs that target the cytoskeleton are highly effective anti-cancer drugs, mainly because they block the ability of the cytoskeleton to prepare the cell for division. After four decades they still remain among the most commonly prescribed chemotherapeutics. These include the taxanes (paclitaxel, docetaxel) and the vinca alkaloids (vincristine, vinblastine). Despite their common use and relative effectiveness, they bear a number of negative features including (a) non-specific activity against the cytoskeleton of non-cancer cells resulting in a range of serious side-effects, (b) limited or no effectiveness against many types of cancer, and (c) the rapid ability of the cancer cell to develop resistance. The taxanes and vinca alkaloids are both off-patent.
The taxanes and vinca alkaloids target that part of the cytoskeleton known as microtubules. There is a second component of the cytoskeleton that, while an obvious anti-cancer drug target, has to date successfully resisted drug development. That component is the microfilament, a series of filaments made up of inter-woven strands of two proteins, actin and tropomyosin. Drugs directed against the microfilaments have been too toxic to consider using because of the key role of microfilaments in muscle contraction, with muscle cells in the diaphragm and the heart being adversely affected.