The Indian Patent Office's denial of patent for life-saving prostrate cancer drug, Xtandi (enzalutamide) has been welcomed by patent experts in the country, who say it will open up avenues for generic drugs costing less than half the price.

In India, prostrate cancer is the second most common cancer in males as per the Indian Council of Medical Research (ICMR) and various state cancer registries.

On November 10, India's patent office revoked the patent application filed by University of California in 2007. The University had discovered the drug. The patent on blockbuster cancer drug, Xtandi which is marketed by Japan's Astella Pharma, was opposed by Fresenius Kabi in 2012, and by Mumbai-based BDR Pharma in 2013. Indian Pharmaceutical Alliance, an organisation of 20 research based Indian drug companies also opposed the grant of patent.

The opponents contended that applicant is merely formulating an alternative compound for the androgen receptor antagonist with no demonstration of enhanced efficacy and therefore is not entitled to a patent and ought to be rejected in toto.

They argued that the application is not patentable under Section 3(d) of the Patents Act, 1970 as amended by the Patents (Amendment) Act, 2005 as it is a new form of known substance. The compound claimed in the opposed application is derivative of the earlier known compounds disclosed in prior art. Opponents argued that the complete specification of the alleged invention does not sufficiently and clearly describe the invention.

Considering lack of novelty, clarity, sufficiency and inventive step, assistant controller Patents & Designs Umesh Pandey rejected the Xtandi patent application. Pandey said in the order "in view of above, instant application is hereby refused as the claimed invention is lacking inventive step under section 2(1) (ja) and also not patentable under section 3(d) and 3(e)".

The denial of patent in India will pave the way for manufacturing of generics resulting in 70 per cent decline in existing price for monthly dosage. The drug costs about $129,000 per treatment course in USA, compared with $39,000 in Sweden and in Astellas' native Japan.

Developed by Medivation and Astellas, Xtandi is currently sold in India at $5014.60 per month by Astellas, costing around $44.77 per pill as compared to $26 per pill in Japan. Pfizer which acquired Medivation in August 2016 got rights to Xtandi.

BDR Pharma, the first generic manufacturer of the drug had introduced cheaper version of prostrate cancer treatment, Abiraterone. 120 tablets constituting a month's dosage were sold by Johnson & Johnson at Rs. 1.25 lakh.

Healthcare activists welcomed rejection of Xtandi patent. Dr IS Gilada, secretary of Peoples Health Organisation (India) said “$44.77 per pill cost of Xtandi in India where average incomes are just 10 per cent of the pill cost per day has restricted a large population's access to the drug. The rejection of Xtandi patent is a novel step to ensure availability of cheaper generic drugs for needy people. Big pharma companies who put heavy investment in R&D of drugs often recover cost of the drug from regulated markets. They generate additional revenue by marketing their patented products in emerging markets like India. Hence patent applications filed by drug manufacturers on the grounds of merely formulating an alternative compound of known substance ought to be rejected.”

The rejection of prostrate cancer drug patent has nothing to do with investment sentiments in pharma industry. The denial of patent applications constitutes less than 2 per cent of the total patents issued by government of India per year, said noted patent expert Dr Gopakumar Nair.

Dr Nair added that the rejection of patent has enabled generic drug makers to come up with cheaper version of Xtandi for wider access.