Patent office grants patent to MSD for HCV drug, rejecting pre-grant opposition of Natco

New Delhi, February 20, 2023 :

The patent office has decided to grant patent rights to US-based drug major Merck Sharp & Dohme (MSD) for its hepatitis C virus (HCV) drug by rejecting a pre-grant opposition filed by Hyderabad-based Natco Pharma Ltd. The patent application is related to the company’s elbasvir/grazoprevir formulation, which is sold in the US under the brand Zepatier.

The decision was on an application filed by the innovator company in January, 2011, for the title macrocyclic quinoxaline compounds as HCV NS3 protease inhibitors. Natco has filed a pre-grant opposition against the application and the matter was taken up for hearing by the patent office at the end of January, 2023.

The company claimed that the present invention relates to macrocyclic compounds that are useful as inhibitors of the HCV NS3 protease, the synthesis of such compounds, and the use of such compounds for treating HCV infection and reducing the likelihood or severity of the HCV infection.

Natco opposed the patent application on the grounds of anticipation, obviousness or lack of inventive step, insufficiency in the description of invention and method, and that it is not an invention and not patentable under the Patents Act. According to the documents from the patent office, Natco later in January, 2023, prior to the hearing, informed the patent authority that it does not wish to pursue the pre-grant opposition and it will not attend the hearing, and the matter may be decided on merits.

However, MSD has submitted a written document with response to the oppositions raised by Natco and refuted all the grounds raised in the pre grant opposition. It said that the company received patent from various major jurisdictions including Unites States of America, European Union, Japan, and others and the company argued that the Intellectual Property Appellate Board (IPAB), the erstwhile appellate board for intellectual property related disputes, has observed that some importance could be given when a similar patent was registered in many countries after having overcome the objection of novelty and obviousness.

The patent official, who analysed both the opposition and the submissions by MSD, rejected the ground of opposition that the invention is not novel, observing that the claimed invention is novel and that the claimed invention is inventive and non-obvious and rejected the ground for lack of inventive step.

The Authority also rejected the grounds of insufficient disclosure and others, and concluded, “After consideration of the submissions made by the applicant (MSD) and the amendments so far made by the applicant, as per Rule 55(6) of Patents Rules, 2003, I hereby reject the pre-grant representations and order that the instant application shall proceed for the grant of patent”, in an order issued on February 16, 2023.

MSD has announced in early 2016 that it received approval from the US Food and Drug Administration (FDA) for Zepatier (elbasvir and grazoprevir) for the treatment of adult patients with chronic HCV genotype 1 to 4 infection, with or without ribavirin. Zepatier is a once-daily, fixed-dose combination tablet containing the NS5A inhibitor elbasvir (50 mg) and the NS3/4A protease inhibitor grazoprevir (100 mg). It also announced a list price of $54,600 for a 12 week regimen of the drug and financial assistance programmes for those who need help with the cost of their medicine.

The company, in its Annual Report for 2021 has said that the global sales of Zepatier declined 23 per cent in 2021 primarily due to lower demand from competitive pressure in the US and Europe. Worldwide sales of the drug declined 55 per cent in 2020 driven by lower demand globally due to competition and declining patient volumes, coupled with the impact of Covid-19 pandemic, it added. Pharmabiz