Meditech on course for Phase II after capital raising

Melbourne biotech company Meditech Research has launched a $3.5 million capital raising, underwritten by Intersuisse, to fund initial Phase II clinical trials of its HyACT anti-cancer treatments.

Under their agreement, signed at a meeting of Meditech shareholders on October 17, Intersuisse Corporate agreed to underwrite a share purchase plan for the lesser of 25 million shares, or the number of shares equal to $3.5 million, depending on price.

Meditech's CEO, Chris Carter, said his company's successful capital raising in a tight economic market was evidence of the investment community's belief that the Meditech compounds have "huge potential" as cancer therapeutics.

Earlier this year the company conducted two small Phase I clinical trials of its HyDOX compound in 16 patients with end-stage, metastatic cancers of the lung, prostate and breast.

HyDOX combines the company's patented hyuluronan formulation with the cytotoxic drug doxyrubicin. The tumours shrank significantly in four cases, and stabilised in three others.

In the other Phase I trial, nine patients with advanced colorectal cancers were treated with HyFIVE, which combines HyACT and the anti-cancer drug Flurouracil. Twp patients showed a partial reduction in tumour size, and another patient remained stable.

Given that the trials were conducted only to demonstrate the safety of the two combination therapies, the company described the results as "particularly encouraging."

The HyACT formulations emerged from research by Dr Tracy Brown's team at Monash University into the action of a naturally occurring sugar molecule in the body, called hyaluronic acid.

Hyaluronic acid binds strongly to two types of receptor, called CD44 and RHAMM, found on cells throughout the body. While CD44 and RHAMM are present on normal cells, a wide range of tumour cells over-express them by several orders of magnitude -- in some breast tumours, by a factor of 10,000.

Hyaluronic acid binds strongly to both types of receptor. When conventional cancer drugs like doxyrubicin and Flurouracil are linked to hyaluronic acid molecules, the drugs are targeted to cancer cells in proportion to the number of receptors on their surface.

Brown says that hyaluronic acid is superior to monoclonal antibody-based targeting systems because it is effectively invisible to the immune system -- even human monoclonal antibodies can provoke a hostile immune response in some patients.

Antibodies are also difficult to produce in bulk, whereas hyaluronic acid can easily be produced by bacterial fermentation.

By focusing the drug at the site of the cancer, and minimising its concentration in healthy tissues, the molecules minimise side-effects such as hair loss and nausea.

A further benefit, says Brown, is that research shows that hyaluronic acid is a tumour killer in its own right. When it binds to cells over-expressing CD44 or RHAMM receptors, it destabilises the cell's outer cell membrane, triggering apoptosis -- programmed cell death.

The Phase II trials will be conducted at the Centre for Development Cancer Therapeutics in Melbourne, with what the company describes as "significant input" from Prof Dick Fox, of the Royal Melbourne Hospital.