http://showbizandstyle.inquirer.net/...ticle_id=98546
Atom-sized solution to cut cancer drug toxicity
By Tessa Salazar
Inquirer
Last updated 03:29am (Mla time) 11/03/2007
MANILA, Philippines—In the decades that chemotherapy has become the preferred (albeit dreaded) form of cancer treatment, parallel efforts have been exerted to address the issue of its toxic effects on patients.
Extensive research has produced new cancer drugs almost every three to six months. Still, the chemotherapy drug with less toxicity has proven elusive.
And then the first wave of commercial nanotechnology products to reduce cancer drug toxicity was born. The proper carrier or vehicle which can take drug molecules to the targeted site has been claimed to be developed. There are currently two approved carrier molecules (or novel drug delivery systems): polymer from
India’s Dabur Research and human albumen (from the US-based Abraxis Bioscience Inc., Los Angeles).
Nanotechnology is the development and engineering of devices so small that they are measured on a molecular scale. It is being applied in electronics, magnetics, optics,
information technology, materials development, and biomedicine.
Experts noted that nanoscale devices, for instance, are 100 to 10,000 times smaller than human cells. Nanoscale devices smaller than 50 nanometers can easily enter most cells, while those smaller than 20 nanometers can move out of blood vessels as they circulate through the body.
Emerging ‘targeted therapy’
In cancer treatment, nanotechnology belongs to the emerging “targeted therapy,” which, in theory, would bring the fight against cancer to the molecular level (ferrying large doses of chemotherapeutic agents into malignant cells while sparing healthy cells), thus eliminating “collateral damage” to noncancerous cells and also eliminating the toxicity of the drug on the patient as a whole.
Dr. Shiva Kant Mishra, vice president for Dabur Research Foundation’s clinical research and medical services, said nanopaclitaxel uses a polymer compound to convert the drug into its nano-sized molecules. “The polymer basically holds the molecule from all the sides and takes it everywhere. It’s like a nanopack pocket.”
Dabur began its project eight years ago after licensing a nanopolymer base from Delhi University.
During the Dabur Pharma-Philippine Society for Medical Oncology symposium Mishra discussed that since its launch in India in January 2007 Nanoparticle paclitaxel (Nanoxel) has been administered to more than 900 patients. He claimed that it has shown “good efficacy and safety profile.”
The objective response has been more than 40 percent in metastatic breast cancer patients, who failed earlier on anthracycline, Mishra said.
Metastasis means the cancer has spread to other parts of the body.
Clinical trial
During the clinical trial of Nanoxel in 2004, more than 200 advanced breast cancer patients were studied. Mishra claimed that they had shown better response as well as safer compared to cremophore paclitaxel. Dabur is now evaluating the survival rates, as patients are being closely monitored and their conditions followed up.
Majority of the patients for Nanoxel are relapsed/metastatic breast cancer patients.
It is also being prescribed in other indications such as non-small cell lung cancer and ovarian cancer.
Dr. Dinesh Pendharkar, department head of the Batra Cancer Center at Batra Hospital in New Delhi, India, told the Inquirer that what nanotechnology essentially does is to carry the drug directly to the tumor cell.
Reach cancerous site only
“For example, in breast cancer where cancerous cells lie in the breast tissue or have spread to the bones, nanotechnology will enable the drug to reach the cancerous site only. In maximum concentration, the drug molecules will be able to kill the tumor much, much better. So nanotechnology will be able to deliver a drug at a site where it is required and in a higher dose,” Pendharkar explained.
Pendharkar, who talked about “Nanoparticle Technology in Oncolytics” during the PSMO convention, said the drug requires administration with a special intravenous set, as regular IV sets react with it.
Glenn Baria, Dabur Pharma Ltd country manager for the
Philippines, Taiwan and Hong Kong, said Dabur is still undergoing the process of approval from the Bureau of Food and Drug for a Compassionate Special Permit.
“After approval we have lined up a number of patients and we are looking at providing some for free… but should fit the indication given by BFAD (metastatic stage). I’m working hard for the Philippines to be the first country after India (where the molecule was invented) to enjoy the benefits of nanotechnology.”
Linear Mode
