For the past 17 years, Dr Navin Khanna has been hard at work in his lab at the International Centre for Genetic Engineering and Biotechnology (ICGEB) in Delhi to develop ways to combat dengue.
After developing a test kit, he and his team have acquired an international patent on the world’s first drug to combat dengue – Cipa. This comes at a time when there 25,000 deaths and 400m cases of dengue worldwide annually. The dengue fighter spoke to Sunday Times:
Dengue has been a health hazard since WW II. Why did it take so long to develop a drug?
This virus is a master of deception and very difficult to pin down. It has remarkable survival skills. To start with, it has four serotypes (distinctive surface structures). Each type has more than five different genotypes (what lies within). And each genotype has been found, as recently as 10 months ago, to change into four different shapes. All this elaborate charade is to mask its true identity and evade the body’s immunological response.
Yet you outsmarted it. How?
It was a collective effort of ICGEB and Ranbaxy (later acquired by Sun Pharma) and funded by the department of biotechnology (DBT). A group of scientists in Ranbaxy was already engaged in finding an antidote for dengue using our traditional knowledge of Ayurveda. They had shortlisted 19 plant extracts, including from neem, aloe and basil, which could provide relief from dengue symptoms. Now our job was to find the actual winner. We put these extracts through rigorous tests for over five years. Cissampelos pareira (patha in Hindi and abuta in English) emerged a clear winner with its ability to destroy the virus as well as being non-toxic to human cells. Traditionally, it’s been used among other things to treat women’s reproductive health problems. In some countries it’s called the midwife’s herb as it induces labour. Sun Pharma, ICGEB and DBT filed for a US patent in August 2016 and also published our findings.
At what stage of development is this drug?
We are awaiting clinical trials on humans, and it will take a few years to complete those. Since it is non-toxic there’s no risk involved. In fact, I tried it on myself when I got dengue. I boiled the leaves of the plant and drank the extract, twice a day for three days. And I got better. Later my daughter also got dengue and I successfully repeated the treatment on her.
Why a botanical instead of a chemical drug?
Most chemical drugs are highly pure single molecules. Over time pathogens can develop resistance against such simple molecules. Botanical drugs, on the other hand, are a mixture of various molecules and, hence, harder to develop a resistance against. Now the USFDA too recognises botanical drugs, and approved three last year. As long as the drug is well researched and manufactured following the best practices, it works. And it’s inexpensive.
Are there other botanical drugs in the works?
Dr Dinkar Sahal and his team here are developing a plant-based drug for malaria. Researchers are also exploring possible anti-malarial activity exhibited by certain fungi from Andaman and Nicobar Islands, and marine organisms.
You are also developing a dengue vaccine…
Yes, in collaboration with Sun Pharma. It’s a tetravalent vaccine i.e. effective against four virus types. We have an international patent on it and it is awaiting clinical trials.