MUMBAI: The Indian Patent Office has refused a patent on US firm Abraxis BioSciences ' anti-cancer drug Abraxane, paving the way for domestic companies to launch affordable versions in the local market. The application was refused on the grounds of the US firm's claims lacking of inventive step, not being patentable and insufficiency, legal sources say.

One of the main grounds under which the patent was rejected is Section 3 (d) - the provision under which Novartis lost protection on its blockbuster drug Glivec last year. The Patent Office relied on the decision of the Supreme Court in the landmark Glivec case while hearing the application.

The Supreme Court ruling defends Section 3(d) - an important safeguard in the patent law specifically relevant for pharma and chemical industries, which prohibits grant of patents to new forms of known substances unless it results in enhanced efficacy over the known substance.

Since there is now clarity that there is no patent on the US firm's drug, it may give a boost to generic production, sources say, adding that the US firm has the option of filing an appeal in the IPAB or a writ petition in the high court.

Earlier, the Patent Office had denied the patent in 2009 on the grounds of obviousness and lack of inventive step. The US firm appealed against the order in the IPAB (Intellectual Property Appellate Board). In January this year, the IPAB directed the matter to be reheard by the Patent Office for fresh consideration, and to be decided within a specific time frame. The matter was heard afresh in April this year, and an order was passed on June 18, rejecting the application again, legal sources say. In addition to the grounds upon which the application was rejected in the 2009 order, the application was rejected for being a new form of a known substance under Section 3(d) as it failed to exhibit enhanced therapeutic efficacy, a lawyer close to the development told TOI.

Domestic company Natco had filed an opposition before the patent was issued to the US firm. The company first launched the drug in 2008, challenging a patent application filed by the US company. Abraxis launched the drug through Bangalore-based Biocon. When contacted, Natco said that it had not taken the decision yet to launch the drug.

Natco's version, Albupax, was the first indigenously developed nanotech-based cancer drug. But it landed into problems after a year of launch, being charged with safety concerns by the drug controller.

After clearing the hurdles, Natco is yet to launch the drug. Other companies like Cipla launched the drug Paclitax Nab (nano particle albumin bound) for the treatment of metastatic breast cancertion in 2012, at around Rs 11,000 per injection.