DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
The instant application is the national stage entry of PCT/IN2022/051132 filed 28 December 2022. Acknowledgement is made of the Applicant’s claim of foreign priority to application IN202121029892 filed 2 January 2022.
Status of the Claims
Claims 1-26 are pending.
Claims 1-26 are rejected.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-26 are rejected under 35 U.S.C. 103 as being unpatentable over Glauser et al. (US 2007/0280991) in view of Zhao et al. (Journal of Vascular Surgery, 56, 6, pgs 1680-1688).
Glauser teaches a coating composition capable of controlling the release of a hydrophilic drug and a hydrophobic drug [0010] for use on an implantable device such as a stent [0051]. The coating can be made of any biocompatible polymer and can be hydrophilic or hydrophobic [0041]. The coating can comprise both hydrophilic and hydrophobic drugs which can be in different coating layers [0036]. The base layer can include a polymer and a hydrophilic drug and another layer can include a hydrophobic drug and hydrophobic polymer [0036-0037]. Examples of the hydrophobic polymer include PLGA [0042]. Regarding hydrophilic options, hydrophilic polymers recited include PEG and hydroxy-functional PVP [0042]. Regarding the bioactive agents (drug), examples can include anti-proliferative agents such as everolimus, anti-inflammatory agents such as dexamethasone, and antithrombotic agents such as argatroban [0036, 0048-0049]. Hydrophilic drugs can also include cRGD peptide [0011]. Additional sealant layers comprising hydrophobic polymers, and omitting drug, can be included between layers [0011]. Regarding the release rate of the drugs in the coating, the burst of release can be controlled by decreasing or increasing the thickness of the topcoat, by using a sealant between layers, or by reducing the drug to polymer ratio in the drug containing layer [0038].
Glauser does not teach a single embodiment of the layered structure of the instant claims. Glauser does not teach where the coated implant inhibits neointimal growth.
Zhao teaches that treatment with locally delivered everolimus significantly reduces neointimal hyperplasia (abstract).
It would have been prima facie obvious to prepare a multiple polymer layer coated biomedical device, such as an implantable stent, wherein the layers comprise a first layer of a hydrophobic drug (such as everolimus) and hydrophobic polymer (such as PLGA) and a second layer of hydrophobic sealant layer devoid of any drug, as taught by Glauser. The direction of drug release would have been determined based on the coating of the stent. By coating only the outer surface of the stent, the direction of release would necessarily been abluminal and by coating the inner surface, the direction of release would have been luminal.
Regarding the release rate of the drug, the release rate can be controlled by the thickness of the topcoat. Thus, the thickness of the coat can result in the drug being delayed to release and then releasing slowly over time so that it only partially releases after a week or a month. That being said and in lieu of objective evidence of unexpected results, the release rate of the drug can be viewed as a variable which achieves the recognized result of successfully treating a specific patient. The optimum or workable range of drug release can be accordingly characterized as routine optimization and experimentation (see MPEP 2144.05 (II)B). “[Discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art.” In re Boesch, 617 F.2d 272, 276 (CCPA 1980).
The stent can alternatively comprise additional layers including a hydrophilic drug (such as argatroban or cRGD peptide) with a hydrophilic polymer layer (such as polyvinyl pyrrolidone, PVP), a hydrophilic drug with a hydrophobic polymer layer, a layer with a hydrophobic drug and hydrophobic polymer, and a hydrophobic sealant layer without drug. The order of and amounts of each layer can be determined experimentally by the skilled artisan (see MPEP 2144.04 (VI)).
Since Glauser teaches that the hydrophilic cRGD peptide drug can be used to attract endothelial progenitor cells [0014], by using said drug, the multi-layer stent is necessarily resulting in endothelialization occurring. The use of anti-thrombonic drugs such as the hydrophilic agratroban would necessarily result in inhibiting of thrombus formation.
Claims 1-26 are accordingly rejected as obvious in view of the prior art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANDREW S ROSENTHAL whose telephone number is (571)272-6276. The examiner can normally be reached M-F 8-5pm EST.
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/ANDREW S ROSENTHAL/ Primary Examiner, Art Unit 1613
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