Mumbai: After dragging leading multinational drug makers Pfizer Inc. and F Hoffman-La Roche Ltd into a licensing spat over their cancer drugs Sutent and Tarceva, Hyderabad-based Natco Pharma Ltd, a cancer drugs specialist, is planning another patent fight against Pfizer’s new anti-HIV/AIDS drug Celzentry.
While Natco’s earlier licensing pleas, which await final decisions of the Indian patent controller, were intended for exporting the two cancer drugs to Nepal, the new move is to launch a copycat version in India of Celzentry, a second-line HIV/AIDS drug used in patients who develop resistance to medication given in the early stages of infection.
Sales of HIV/AIDS drugs in India currently is about Rs65 crore with up to 130,000 patients under preliminary treatment, also referred to as first-line treatment, for the virus according to industry estimate at the price level of Rs5,048 per patient a year, fixed for government drug supply.
However, experts estimate the potential market in the world’s second largest HIV/AIDS-infected country to be up to Rs1,200 crore annually if all of the country’s estimated 2.5 million people infected with the virus are treated.
In June last year, Pfizer was granted a patent for Celzentry, known as maraviroc in generic terms, in India. It is a new class of oral medicine prescribed for follow-up treatment for HIV patients. However, Pfizer is yet to launch the drug in the local market.
“We are currently working with Indian regulators to obtain the necessary approval. We will launch the life-saving drug as soon as this process is complete,” a spokesperson for Pfizer Ltd, the Indian unit of the world’s biggest drug firm by sales, said.
“In the interim, we have a licence that allows us to provide limited access in line with a clinical trial we are conducting for patients with this class of HIV infection, who have limited or no approved treatment options due to resistance or intolerance to existing drugs,” the spokesperson added.
The spokesperson declined to comment on Natco’s plan.
A senior executive from Natco, who did not want to be identified, said the “company will soon approach the patent controller seeking a compulsory licence for manufacturing this drug in India for the local market as well as exporting it to other least developed countries.” A compulsory licence essentially sets aside a patent in the larger interest of the public, to tackle a national emergency, or in a few other situations.
Among doctors, maraviroc is considered a salvage therapy for patients not responding to preliminary HIV/AIDS medication, also known as anti-retroviral, or ARV, drugs. The drug costs around $32 (about Rs1,280) for a day’s treatment in the US.
Since the treatment is advised for patients only after a pathological test, costing some $1,800, the treatment cost with this drug, which has to be combined with other ARVs, is considered to be too expensive even in the US. The drug, marketed by Pfizer under the brand name Celzentry in the US and Selzentry in other countries, was first approved for marketing in the US in August 2007.
However, Indian patent law in its current form does not allow issue of compulsory licences for local market requirement within the first three years of a patent grant, unless a medical emergency is declared.
“But, if there is an issue with medical access on account of high prices or inadequate supply, the authority may intervene for a cheaper alternative,” said a Mumbai-based patent lawyer, who did not want to be named.
Last month, the Delhi high court had allowed Cipla Ltd, India’s leading generic drug maker, to continue selling a copy of Roche’s lung cancer drug Tarceva after hearing a patent infringement case filed by the multinational company. The Delhi court’s decision was on the grounds of public interest considering the huge price difference between the patented drug and its generic variant.
The Indian patent for Celzentry drew ire of patient groups such as Medicines Sans Frontiers, or MSF, and activist law group Lawyers Collective as they are sceptical about certain claims of innovation in the patent application. “We are studying Pfizer’s claims to ensure the patent grant is fair,” a Lawyers Collective official said in an earlier interview.
“The new patent, if not justified, should not block affordable generics. We are evaluating the importance of this drug for patients here,” said MSF’s India coordinator Leena Menghaney. Indian patent laws allow one year’s time from the date of patent publication (or notification that a patent has been granted) for interested parties, who object to this patent, to file a post-grant opposition.
As Mint reported on 28 March, some multinational drug firms, under criticism by patient groups for charging high prices on patented drugs, are considering what they call differential pricing in India which will allow them to offer these medicines at different and lower prices for government supply, patient access programmes, hospitals in rural areas and non-profit organizations. This move is aimed at avoiding situations that can trigger compulsory licences, as permitted under Indian patent law. Firms such as Novartis AG and Pfizer had already launched patient assistance schemes for their cancer drugs Glivec and Sutent to provide treatment either free or with discounts.
Critical of such schemes, the Natco executive said most such patient assistance programmes were for drugs prescribed for a small number of patients. “They will think twice to implement such schemes for diseases like HIV/AIDS where the patient population is huge,” the executive said.
India is estimated to have 2.5 million HIV-infected people, of whom 400,000 require treatment. The government, through National AIDS Control Organization (Naco), provides first-line treatment with drugs such as zidovudine, lamivudine, statuvudine and efavirenz to between 95,000 and 130,000 people. This treatment is estimated to cost between Rs8,400 and Rs24,000 a year.
According to the UNAIDS agency, between 2% and 5% of the AIDS patient population develops resistance to the initial line of drugs and needs the next level of stronger, more effective drugs.
This means up to 20,000 people could be requiring second-line drugs such as tenofovir, atazanavir, indinavir, ritonavir and lopinavir, which are up to 10 times costlier than the first-line treatment, and newly introduced medication such as maraviroc.