London, July 2 : Nanotechnology researchers at Chidren's Hospital Boston say that they have developed the first oral drug that may offer a potential non-toxic therapy for a wide range of cancers.
The drug called Lodamin has shown promising results in a study on mice, the researchers say.
They believe that the drug may be useful as a preventive therapy for patients at high risk for cancer or as a chronic maintenance therapy for a variety of cancers, and prevent formation and recurrence of tumours by blocking the growth of blood vessels to feed them.
According to them, Lodamin may also be useful in other diseases that involve aberrant blood-vessel growth, such as age-related macular degeneration and arthritis.
Dr. Ofra Benny, the developer of Lodamin, describes it as a novel slow-release reformulation of TNP-470, one of the first angiogenesis inhibitors to undergo clinical testing.
The researcher highlights the fact TNP-470 had been found to suppress a wide range of cancers, including metastatic cancers, and to produce a few complete remissions in clinical trials. The trials had to be suspended in the 1990s due to the neurologic side effects that occasionally occurred at high doses, but TNP-470 still remains one of the broadest-spectrum angiogenesis inhibitors known. The researchers say that Lodamin seems to retain the potency of TNP-470 without any detectable neurotoxicity.
Unlike the existing angiogenesis inhibitors that are approved only for a small number of specific cancers, Lodamin has been found to reduce metastases-a fatal complication of many cancers for which there is no good treatment-in mouse models.
"The success of TNP-470 in Phase I and II clinical trials opened up anti-angiogenesis as an entirely new modality of cancer therapy, along with conventional chemotherapy, radiotherapy and surgical approaches," Nature magazine quoted Dr. Donald Ingber, co-interim director of the Vascular Biology Program at Children's, as saying.
When the researchers tested Lodamin in mice, they found that the drug significantly inhibited primary tumour growth in mouse models of melanoma and lung cancer, with no apparent side effects when used at effective doses.
"I had never expected such a strong effect on these aggressive tumour models," Benny said.
The researcher added that Lodamin accumulated in the liver without causing toxicity, preventing liver metastases and prolonging survival.
"This was one of the most surprising things I saw. When I looked at the livers of the mice, the treated group was almost clean. In the control group you couldn't recognize the livers -- they were a mass of tumours," Benny said.
She continues to study Lodamin's effects in other animal models of cancer, and in macular degeneration.