The Chronicle of the Hepatitis C drug – Sofosbuvir

The High Court of Delhi will hear the challenge to the grant of patent to Gilead Pharmasset’s for a compound used for preparation of Sofosbuvir – a Hepatitis C drug, whose patent application has been a subject matter of challenge worldwide by civil society organisations and patient groups alike. In India, the patent was granted by the Patent Controller on 9th May 2016 on the oppostions filed by several patients’ rights groups as also generic companies.

Hepatitis C is a liver disease caused by a blood borne virus that spreads via shared unsterilized injection for drug use or tattooing, unscreened donor blood, from mother to infant; and from unprotected sex. Those suffering from chronic Hepatitis C are at a greater risk of developing liver cancer. The WHO estimates indicate that globally, 130–150 million people are affected by Hepatitis C. In India, the absence of a Hepatitis C Virus surveillance system contributes to lack of knowledge of the actual number of people living with Hepatitis C Virus-related liver disease (PLHCV). However, some studies estimate the number of PLHCV in India to be around 8.7 million. This is more than four times of the estimated People Living with HIV (PLHIV) at about 2.1 million. While India has a full scale programme for providing medicines for PLHIV there is no programme whatsoever for the PLHCVs.

Also known as the “silent epidemic” because of its tendency to show symptoms attributable to other illness during the earlier stages of infection, Hepatitis C was earlier treated using an antiviral called interferon. The treatment reported was poorly tolerated and had low cure rates. The landscape of Hepatitis C treatment changed with the introduction of a new class of drugs called direct acting anti-virals (DAAs) that are considered to be more effective. As the name suggests, this class of drug destroys inhibits the growth of the virus by attacking specific part of it, and thereby destroying the virus. Gilead Sciences Inc.’s alleged invention, Sofosbuvir is one such DAA that has shown impressive results with no side effects that the earlier treatment might have shown.

Within 6 months of its launch in United States and Europe in around December, 2013, Sofosbuvir was prescribed to more than 80,000 patients resulting in about $3.8 billion dollars in sales of the drug. Marketed under the name “Sovaldi”, Gilead was charging an exorbitant price for its version of Sofosbuvir at $1,000 a pill, bringing the complete 12 week course to a whopping $84,000. In India, the same treatment with the generic version of the drug came under INR 20,000.

Meanwhile, civil society organisations in different countries filed oppositions to Gilead’s patent application for Sofosbuvir on the ground that it was not eligible for a patent. A patent on a drug bestows a right on the patent holder, whereby for 20 years the patent holder can restrict anyone from making, selling or importing the patented drug in India. Therefore, in the interest of public health, the patent holder has a responsibility to make the patented drug available at affordable prices.


India’s tryst with Sofosbuvir

The story of patent application for Sofosbuvir in India is particularly peculiar one. Gilead had filed a patent application in India in December, 2005. In 2009, two parties (Delhi Network of Positive People and IMAK and the other, Natco Pharma Ltd., a generic pharmaceutical company) filed oppositions at the Patent Office against grant of patent to the application for Sofosbuvir.

In what appeared to be a tactic to avoid any further objections to the application by generic pharma companies, in late 2014 Gilead entered into licence agreements with 13 Indian generic pharma companies to manufacture and sell Sofosbuvir in countries identified in the license. Natco Pharma Ltd. being one such licensee withdrew its opposition to the patent application for Sofosbuvir in India. Important to note is that these licenses exclude most high-burden countries like Brazil, pushing one to probe the real intent of such licenses.

In 2015, the Patent Office after considering oppositions against the patent application for Sofosbuvir refused the grant it a patent. Gilead filed a writ petition before the Delhi High Court against this refusal. The Delhi High Court found that Gilead was not given proper notice of the objections and remanded back the matter to the Patent Office for fresh hearing. The High Court also allowed new pre-grant oppositions to be filed against the patent application.

Given the increased challenges worldwide on its patent eligibility and the importance of Sofosbuvir for persons not only affected by Hepatitis C but also HIV/AIDS, Lawyers Collective was approached by Sankalp Rehabilitation Trust, an NGO working with injecting drug users and persons affected by HIV/AIDS, to file an opposition against the patent application for Sofosbuvir in India. An opposition against the application was drafted and filed subsequent to the Delhi High Court’s order for fresh hearing of the oppositions against the patent application for Sofosbuvir.

The alleged inventive step in the patent application was Methyl (up) and Fluoro (down) at the 2’ position of nucleoside. It was argued by the Sankalp and the other Opponents that looking at the prior art set out in the application itself it would be obvious to the person skilled in the art to do what the patent applicant had done.

On hearing the pre-grant oppositions afresh, the Dy. Controller of Patents passed an order granting patent to the application related to Sofosbuvir on May 9, 2016. Contending that this order was not passed in accordance with the settled principles of law, Sankalp Rehabilitation Trust filed a writ before the Delhi High Court. Sankalp challenged the order of the Dy. Controller on the ground that the order was passed without taking into account relevant considerations, without applying the established principles of law and in violation of principles of natural justice. Another writ petition challenging the order granting the patent has been filed by the Delhi Network of Positive People and IMAK.

In the meantime the District Court of Northern District of California, San Jose Division, Merck & Co., Inc. had filed an infringement suit against Gilead. Merck had claimed that Gilead’s Sovaldi, particularly the feature of Methyl (up) and Fluoro (down) at the 2’ position of the nucleoside, infringed two of Merck’s patents (namely US 7,105,499 and US 8,481,712). Gilead failed to disprove the claim of infringement as it was unable to show that Merck’s patents did not teach Methyl (up) and Fluoro (down) at the 2’ position of nucleoside. In March, 2016 the jury found that Gilead infringed Merck’s patent awarded damages worth USD 200 million to Merck. The clear conclusion from the proceedings in the US is that Gilead’s Sovaldi was enabled by Merck’s patents US ’499 and US ’712. The Delhi Network of Positive People and IMAK and brought the US proceeding to the notice of the Dy. Patent Controller.

Sankalp, in its petition has pleaded that had the Dy. Controller taken into account this order (which he has failed to), he would have come to the conclusion that Gilead’s application is not eligible for a patent as it is obvious due to the teaching of Merck’s patents.

Gilead had also amended its patent application after the hearing and before the decision of the Dy. Patent Controller. Patent claims are that part of a patent application that defines the exact features of the invention that are sought to be protected. A patent applicant is allowed to amend these claims by way of disclaimer, correction or explanation. However, amendment to the claims is not allowed if the amendment is beyond the content of the matter disclosed in the patent application. In January, 2016 the Dy. Controller of Patents had heard the opposition against Gilead’s application on a set of 16 claims. After two months of the hearing of pre-grant oppositions, Gilead amended the claims of the application relating to Sofosbuvir at the Indian Patent Office, bringing down the total number of claims to 8. Sankalp in its petition has stated the amendments are substantive in nature and not such that merely narrows the scope of the claims. It is Sankalp’s case that by failing to notify the opponents of such amendment, the Dy. Controller of Patents has violated the principles of natural justice.

Sankalp has also challenged the order granting the patent on the ground that the Dy. Controller has failed to apply the settled principles of law in determining obviousness. To determine whether an application is eligible for a patent, it has to be examined whether a person having ordinary skill in that particular technology would have developed the same invention by referring to material available to the public as on the date of filing the patent application, i.e. whether the invention is obvious. It is trite law that in determining obviousness the prior teachings are not to be looked at in isolation but different teachings may be put together to examine whether an alleged invention is obvious. It is Sankalp’s case that the order granting the patent has looked at the prior teachings in isolation, thereby not following the established principles of determining obviousness.

Brazil, China, Egypt and Ukraine have already rejected the patent application relating to Sofosbuvir. Will the Hepatitis C affected population in India have to wait till the expiry of the patent term to access affordable Sofosbuvir? Only time will tell.


Priyam Lizmary Cherian works as a Legal Officer at Lawyers Collective.