Cipla’s Patent Application For HIV Drug rejected

The Indian Patent Office rejected Cipla’s patent application for its HIV drug composition comprising combination of “ritonavir” and “darunavir”. The application, in particular, was directed to a pharmaceutical composition comprising a solid unit dosage form comprising: (i) ritonavir; (ii) darunavir; (iii) a water insoluble polymer and/or water soluble polymer, wherein the ratio of the weight of the ritonavir or darunavir to the weight of the polymer is from 1:1 to 1:6. Further, the claimed composition was a tablet composition comprising ritonavir and polymer in first layer and darunavir in second layer. The first layer is obtainable by hot melt extruding, and the second layer is obtainable by direct compression or by wet granulation.

The application was rejected on the grounds of lack of inventive step in view of the prior published documents. The controller cited 6 prior art documents and heavily relied on one particular D6: US 2005/0048112 in his inventive step analysis which describes that solid pharmaceutical dosage forms comprising ritonavir and, a second species of HIV protease inhibitor, including TMC-114 (darunavir). Therefore, according to the Controller, D6 provides strong motivation to formulate a solid pharmaceutical dosage form that comprises both ritonavir and darunavir. D6 additionally discloses that dosage may be provided as dosage forms consisting of several layers and such “multilayer forms have the advantage of processing  two active ingredients which are incompatible with one another  or controlling the release characteristics of the active ingredient(s). The claims were therefore considered obvious by the Controller. in addition to this, the Controller held that the claimed subject matter does not clearly show advantage/surprising effect over prior art composition to show non-obviousness (no comparative data being provided by the Applicant).

The Controller also rejected the application under section 3(d) as he considered the  new layered form of a known combination of prior art, as being statutorily barred from the patentability u/s 3 (d).



Tofacitinib caught in section 3(d) turmoil

The Controller of Patents, Mumbai  issued an order rejecting a patent application of Pfizer for Tofacitinib for the second time. The primary ground for rejection of Tofacitinib was Section 3(d) and the Controller relied on the Supreme Court’s order on the Glivec case. The Controller said that the claimed form is an enantiomer of a compound (known compound) and the Applicant has failed to establish the enhanced therapeutic efficacy of the claimed compound over the base compound.  The Controller held that the base compound is a “known compound” for the purpose of section 3(d) even if the prior art which discloses it was not published before the priority date. The said prior art being Applicant’s own patent application was known to the them.

The Controller also held that the advantage of the claimed form over other possible enantiomer forms of the base compound does not prove enhanced efficacy over base compound.

The Controller also rejected the application on the grounds of Anticipation by prior claiming. The controller held that Example 14 of WO 01/42246 (D1) discloses the compound of present claim without reference to the stereo chemical configuration (base compound) which is also claimed in the prior art. Further the controller held that D1 teaches that the compounds have asymmetric centres and exist in different enantiomeric and diastereomeric forms. D1’s reference to enantiomeric and diastereomeric forms of the compounds was held to represent an unambiguous technical teaching making available to the public all four stereo chemical configurations of the compounds according to example 14. Therefore the form (3R, 4R) of the compound claimed by the applicant was considered disclosed in the prior art. The Controller also considered present form to be anticipated as he held that the Applicant has failed to compare the compound claimed with the compound of prior art D1 to overcome lack of novelty.

This is the second time that the same application has been rejected by the Indian Patent Office. The patent application was rejected for the first time by a different Controller and the Patent office in Mumbai was directed by Intellectual Property Appellate Board (IPAB) to re-consider Pfizer’s patent application on account of flagrant violation of principles of natural justice. The matter was heard afresh by Controller of patents  on January 2015. The application has been rejected again by the recent order on the 3rd of September, 2015