Leprosy Drug To Treat Cancer? CDRI Scientists Hunt For New Uses Of Old Medicines
NEW DELHI, 1 SEPT 2019:
Can a leprosy tablet priced at Rs 2 be the miracle cure to treat blood-cell cancer? Or can expensive injections given to treat osteoporosis in post-menopausal women be replaced with a pill that costs as little as Rs 100 for a month's supply? These are questions Indian scientists have set out to answer as they look towards repurposing old drugs as affordable treatments for new diseases.
At the Central Drug Research Institute (CDRI) in Lucknow, scientists recently found that certain leprosy drugs might help treat myeloma, a type of blood cancer. Sabyasachi Sanyal, a researcher at CDRI, in collaboration with the clinical haematology department of King George's Medical University, Lucknow, screened FDA-approved drugs in chronic myeloid leukemia (CML) cells and found that a leprosy drug-clofazimine, priced at Rs 2 per tablet-was a potent inhibitor of these cells.
Sanyal's colleague and chief scientist at CDRI Lucknow, Dr Naibedya Chattopadhyay, screened a library of over 1,000 drugs with the aim to discover an oral substitute for teriparatide - an injectable given to women suffering from post-menopausal osteoporosis. "Our pre-clinical studies found that Pentoxifylline, a drug prescribed for treatment of a disease of peripheral artery, when given to osteoporotic female rabbits mimicked effects of teriparatide including restoration of bone mass, strength, micro-structure and quality," Chattopadhyay told TOI.
The cost of launching a repurposed drug is approximately 85% less than that incurred on launching a new drug, said Chattopadhyay. "Strategic repurposing of old drugs for new uses can save time as their pharmacology formulation and potential toxicity are already available."
Doctors at AIIMS, New Delhi, are also conducting clinical trials on repurposed drugs. Dr Kameshwar Prasad, professor of neurology at AIIMS, recently wrote to the Indian Council of Medical Research (ICMR) to set up a task force to identify and validate low-cost alternatives to expensive drugs. He said doctors were already prescribing cheaper therapies. For instance, a single cycle immune therapy for treatment of Guillain-Barre-Syndrome (GBS), an acute inflammatory disorder of the peripheral nervous system, currently costs between Rs 3 lakh and Rs 8 lakh. To those who can't afford it, physicians are recommending steroids that cost less than Rs 5,000 and are equally effective.
"One of our residents, Dr Bhavna Kaul, conducted a survey of physicians in India to assess use of cheaper alternatives for GBS. We were surprised to find that most physicians and neurologists were prescribing them since the standard treatment, in this case immunoglobulin, was not affordable. They also claimed that the response of patients was satisfactory," he added. In Bengaluru as well, a pharmaceutical company is studying the impact of a type 2 diabetes drug on cardiovascular diseases.
The significance of repurposing drugs is considerable. Global spending on medicines is predicted to reach $1.4 trillion in 2020. Drug repositioning can help curb expenditure while safeguarding access to quality healthcare. But roadblocks remain.
New indications for a drug need huge investment to move from 'proof of concept' to registered therapeutic use. Often, researchers lack funding to undertake clinical trials and pharmaceutical companies can be disinterested in repurposing generic drugs as it would fetch them little financial returns.
Like in Australia, Canada or Europe, India does not offer patent protection for new uses of known drugs. Experts said that companies which hold a current patent for a medicine could invest in the discovery of additional indications. But if pharmaceutical companies aren't interested, governments could step in.
Chattopadhyay said financial support from the government could help institutions conduct clinical trials of drugs that can be repurposed. "Successful public-funded demonstration of efficacy of a repurposed drug in clinical trials approved by the Drug Controller General of India may pave the way for far more affordability where patients do not have to bear the burden of extra cost of development by the industry." The Times Of India