While the disease is a slow killer, Hepatitis C can lead to chronic liver disease in as many as 80 per cent of patients, many of whom will develop liver cirhossis or, worse, hepatocellar carcinoma. Standard treatment for eradicating the virus so far was combination of Pegalyated Interferon injections and Ribavirin tablets, which was expensive, carried a host of side effects and was not very effective in treating difficult strains, such as Genotype-1. But Dr Anil Arora, Chairman-Director of Institute of Liver Gastroenterology and Pancreatico Bilary Sciences, Sir Ganga Ram Hospital, tells Namit Gupta in an e-mail interview, that there is hope for patients now, with a slew of new and more effective drugs entering the Indian market. Excerpts:
How large is the HCV-infected population in India? Is the disease on par, or perhaps even larger than HIV, but is being under-reported?
How many Indians succumb to this disease every year? Also, how long can a patient typically survive it without medication? Is it as rapid a killer as HBV or HIV?
It is very difficult to estimate the number of people who succumb to HCV, since the disease is under-screened. It takes 15-20 years before health problems related to Hepatitis C start cropping up, if the patient does not have other health issues. But if a person’s immunity is already compromised, or if he has undergone dialysis or a liver or kidney transplant, or has taken steroids then he can have problems earlier.
HCV does not spread as rapidly as HBV or HIV; it is a slow and silent killer. If 100 people get infected with Hepatitis B and aren't treated for it, over the next six months, 95 per cent will be free of the virus and only 5 per cent will remain chronic carriers of HBV. However, as many as 80 per cent of the people infected with Hepatitis C are at risk of becoming chronic carriers. HCV is almost always chronic. Once the HCV enters the blood stream it is unlikely that a person will get rid of it without medication. This is why an infected person must not wait and start treatment as early as possible.
Could you elaborate on the clinical trials of Sofosbuvir that were conducted in 2013? How successful was the drug in eradicating common strains in India such as type 2 and 3, and how effective was it in eliminating type 1 and 4?
Clinical trials of Sofosbuvir are ongoing in India with the drug just having been launched in the market, and so the results will arrive in due course. At Sir Ganga Ram Hospital, New Delhi, data for more than 35 patients who are being administered Sofosbuvir is available, where after two months of treatment it has been observed that the virus is getting suppressed in all patients.
Is the drug to be had standalone or in combo with conventional drugs such as PEG Interferon and Ribavirin?
Sofosbuvir base has to be given in combination with other drugs. Sofosbuvir, in combination with Ledipasvir, is effective in curing HCV genotype 1 and 4. Sofosbuvir plus Daclatasvir is a pan-genotypic drug combo, which means that it can cure HCV genotype 1 to 6. Ledipasvir and Daclatsvir are soon to make their entry in India within the next 6-9 months. Currently, Sofosbuvir is being given with Ribavirin, which also makes for a pan-genotypic drug but takes longer (six months) to cure than the aforementioned drugs . Combination of drugs is important for the virus of a disease like Tuberculosis or for HIV or HCV. Treatment with a single drug allows viruses to develop a resistance to the drug.
The drug was available for as much as $1,000 a pill in the US, some time ago. That’s $84,000 for a 12-week course and twice that amount for therapy lasting 24 weeks. How much does it typically cost in India, with and without combo drugs?
The Sofosbuvir drug base is now available at Rs 10,000-20,000 per month for a period of six months, which means anywhere from Rs 60,000 to Rs one lakh.
How effective has the drug been in eradicating HCV after it has become commercially available in the market?
The medicine is being administered to around 50 patients. About 8-10 patients have completed 2 months of the treatment, because the availability of the medication started in April. The results have been very good because in everybody a complete suppression of the virus is being witnessed. As for the eradication of the virus, the effectiveness of the drug can only be found out 6 months after the completion of the course of the medicine.
Sofosbuvir is like a new magic drug for HCV infection and it has some of the following advantages:
a. It can be given at any stage of HCV disease.
b. It is almost 100% effective.
c. It is quite inexpensive compared to existing therapy.
d. Shorter duration of therapy is required with this medicine.
e. It is in form of tablets (unlike peginterferon which is injectable).
However we must try to eradicate HCV as it is possible. People now believe that by 2030 the US may become free of Hepatitis C. So while India has been late in screening, diagnosis, treatment, our goal should be to start these as soon as possible and get rid of the disease from our country by 2040-50. With the launch of this medicine in India, we hope more and more patients of HCV will benefit.
How is Sustained Virological Response (SVR) defined, and has it been achieved in any patient either at the clinical trial level or in any patient who bought the drug after it was made available commercially?
On medication the virus level comes down but after medication is stopped it is likely to go up. SVR is defined as the eradication of the disease six months after the medication has been stopped and the person tests negative for the HCV RNA. With the Sofosbuvir drug base a success rate of 80-90% has been achieved.
Is the drug effective in eradicating the virus in patients who have advanced liver disease such as cirrhosis or hepatocellular carcinoma? What is the success percentage?
The data for the complete recovery of patients suffering from advanced liver disease is still not available. Our learning from the example of Hepatitis B suggest that some of these patients may be helped. The objective is to kill the active virus so that ongoing injury to the liver can be stopped. Whatever damage that has already occurred cannot be undone. Not all patients who have advanced liver damage will respond but the virus will get suppressed. And in the case of a transplant for patients who might be facing liver failure, if the virus is not suppressed then after the transplant the virus will come back with a vengeance because of the use of immuno-suppressive drugs during the transplant.
Is there any scheme to subsidize the drug for the very poor section of society?
There is no particular scheme but I think the treatment in itself is reasonably priced. Indian pharmaceutical companies selling generic versions of the drug cannot bring the prices down further. The cost of the drug is now one per cent of the cost at which the drug was available earlier in India (the treatment cost has come down from 1 crore to 1 lakh), and stretched to the brim.
What are the documented side-effects of the drug, if any? Are any of them potentially life-threatening?
There are no major side-effects of Sofosbuvir, but the drug cannot be used for treating patients with advanced kidney failure.
What is the typical life cycle of a new anti-HCV discovery? Will interferon and ribavirin go out of the market if they are not used in combo with Sofosbuvir? Vertex had announced last year that it is withdrawing incivek (telapravir).
Once Ledipasvir and Daclatasvir enter the Indian market, Interferon will go out very soon and ribavirin will follow.