DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action is in response to the paper filed 20 May 2026. Claims 2-3 remain withdrawn. Claim 1 is currently pending and under examination.
The present application is a divisional of U.S. Patent Application No. 15/523746, filed May 2, 2017, which is the National Stage of International Application No. PCT/JP2015/081408, filed November 6, 2015, which claims benefit of priority to Japanese Application No. 2014-226682, filed November 7, 2014.
Maintenance of Rejections:
Claim Rejections - 35 USC § 103
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.
Claim 1 is rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (US 2013/0028909; Published Jan. 31, 2013 – Previously presented), in view of Van de Donk et al., Brentuximab vedotin, Landes Bioscience, Vol. 4, Iss. 4, (July/August 2012), pp. 458-465 – Previously presented).
With regard to claim 1, Tang et al. teach a method of producing a cell population including liver cells, which are differentiated cells, obtained by inducing differentiation of pluripotent stem cells in a culture medium, where the amount of undifferentiated stem cells in the population is reduced as compared to an amount prior to performance of the method (Abs.; Para. 41-43, 55). The method including culturing a mixed population of cells comprising differentiated cells and pluripotent cells, and depleting the pluripotent cells by affinity separation techniques, including utilizing antibodies and a cocktail of pluripotent markers, including CD30, and using a cytotoxic agent conjugated with an affinity reagent, which includes an antibody, bound to one or more markers, including CD30 (Para. 41, 45-47, 55). Which encompasses affinity separation using a cytotoxic agent, which is a drug having cell-killing activity, conjugated with a linker cleavable in an intracellular environment to an antibody bound to one or more markers including CD30, which is an anti-CD30 antibody.
Tang et al. do not specifically teach that the anti-CD30 antibody is used as a sole antibody-drug conjugate in the method.
Van de Donk et al. teach that Brentuximab vedotin is an anti-CD30 antibody conjugated via a protease-cleavable linker to a potent anti-microtubule agent, wherein binding to CD30-positive cells leads to cell cycle arrest and apoptosis (Abs.).
It would have been obvious to one of ordinary skill in the art to combine the teachings of Tang et al. and Van de Donk et al., because both teach the use of an anti-CD30 antibody conjugated via a cleavable linker to a cell-killing agent, to bind to CD30+ cells and cause their destruction. The use of an anti-CD30 antibody as the sole antibody-drug conjugate to target and eliminate CD30+ cells is known in the art as taught by Van de Donk et al. Tang et al. teach that an anti-CD30 antibody-drug conjugate is one of the antibody-drug conjugates usable for eliminating CD30+ undifferentiated cells, and Van de Donk et al. teach that an anti-CD30 antibody can be used as the sole antibody-drug conjugate to eliminate CD30+ cells. As such, an ordinary artisan would have been motivated from the teachings of Van de Donk et al. to eliminate CD30+ cells, including the undifferentiated cells of Tang et al., using an anti-CD30 antibody as the sole antibody-drug conjugate. The use of a sole antibody-drug conjugate would have been expected to predictably and successfully eliminate undifferentiated CD30+ cells as desired by Tang et al., while also simplifying the method by using one antibody-drug conjugate to accomplish the desired goal of eliminating CD30+ cells from the mixed culture.
Response to Arguments
Applicant urges that Tang uses a cocktail of antibodies to deplete pluripotent stem cells from a mixed cell population, where the present invention uses only a complex comprising an anti-CD30 antibody and a drug possessing cytotoxic activity as the antibody-drug conjugate. Additionally, Applicant urges that Van de Donk focuses on the anticancer activity of Adcetris and does not suggest using Adcetris alone for the purification of differentiated cells. Additionally, it would not have been foreseeable that highly purified differentiated cells could be obtained by the present invention, because Tang teaches the use of multiple agents while only one is used in the claimed method.
Applicant’s arguments have been fully considered, but have not been found persuasive.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Here, the rejection is based on the combination of Tang et al. and Van de Donk et al. It would have been obvious to one of ordinary skill in the art to combine the teachings of Tang et al. and Van de Donk et al., because both teach the use of an anti-CD30 antibody conjugated via a cleavable linker to a cell-killing agent, to bind to CD30+ cells and cause their destruction. The use of an anti-CD30 antibody as the sole antibody-drug conjugate to target and eliminate CD30+ cells is known in the art as taught by Van de Donk et al. Tang et al. teach that an anti-CD30 antibody-drug conjugate is one of the antibody-drug conjugates usable for eliminating CD30+ undifferentiated cells, and Van de Donk et al. teach that an anti-CD30 antibody can be used as the sole antibody-drug conjugate to eliminate CD30+ cells. As such, an ordinary artisan would have been motivated from the teachings of Van de Donk et al. to eliminate CD30+ cells, including the undifferentiated cells of Tang et al., using an anti-CD30 antibody as the sole antibody-drug conjugate. The use of a sole antibody-drug conjugate would have been expected to predictably and successfully eliminate undifferentiated CD30+ cells as desired by Tang et al., while also simplifying the method by using one antibody-drug conjugate to accomplish the desired goal of eliminating CD30+ cells from the mixed culture.
With regard to Applicant’s argument that Tang et al. teaches away from the claimed invention because Tang et al. uses multiple agents, it is again noted that the current rejection is based on the combination of Tang et al. and Van de Donk et al., as discussed above. It is further noted that there is no claim limitation requiring the produced cell population to contain highly purified differentiated cells, only to comprise differentiated cells where a content ratio of undifferentiated to differentiated cells is reduced.
Conclusion
No claims are allowable.
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JENNIFER M.H. TICHY/Primary Examiner, Art Unit 1653
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