Prosecution Insights
Last updated: April 19, 2026
Application No. 18/426,706

ANTICANCER DRUG-CONTAINING PLANT VIRUS PARTICLES

Final Rejection §103§DP
Filed
Jan 30, 2024
Examiner
BARSKY, JARED
Art Unit
1628
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Massachusetts Institute Of Technology
OA Round
2 (Final)
50%
Grant Probability
Moderate
3-4
OA Rounds
2y 8m
To Grant
73%
With Interview

Examiner Intelligence

Grants 50% of resolved cases
50%
Career Allow Rate
461 granted / 915 resolved
-9.6% vs TC avg
Strong +23% interview lift
Without
With
+23.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
88 currently pending
Career history
1003
Total Applications
across all art units

Statute-Specific Performance

§101
1.3%
-38.7% vs TC avg
§103
48.6%
+8.6% vs TC avg
§102
9.8%
-30.2% vs TC avg
§112
16.0%
-24.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 915 resolved cases

Office Action

§103 §DP
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 . Response to Amendments Applicant’s amendments to the claims of July 28, 2025, in response to the Office Action of April 28, 2025, are acknowledged. Response to Arguments The Terminal Disclaimers filed on July 28, 2025, were disapproved by the Office on July 29, 2025. As such those rejections are maintained. With respect to the § 103 traversal, the examiner responds. The examiner notes that unexpected results have not been shown and alleged. As such, he is determining if a prima facie showing is established for the record. Applicant argues that Manchester does not teach covalent conjugation of cationic platinum based anti-cancer agents. Further, Applicant argues that Manchester does not teach attachment to the interior of virus capsid. The examiner notes that Manchester teaches covalent attachment to the viral particle. See par. 7-9, 29, 105, 108, and throughout. Further, a therapeutic agent to be attached is cisplatin as preferred among a list of only 6 preferred agents. Thus, a POSA would immediately envisage cisplatin as an API. It is cationic. Further, attachment to the interior of the capsid is taught throughout including in paragraphs 323-325 and prior art claims 26 and 112. Attachment to the interior of a CPMV particle is recited in paragraph 431, e.g. Applicant argues that Steinmetz does not teach a cationic platinum-based anticancer agent covalently and directly attached to a thiol in the interior cavity. The examiner notes that Steinmetz teaches CPMV as a filamentous plant virus particular to carry antitumor agents. Steinmetz also explains that an agent can be coupled to a filamentous virus particle through chemical coupling via thiol-selective chemistry. Not only does Steinmetz teach thiol selective chemistry to couple an antitumor agent, but this is the same and only reference to enable to the covalent attachment of claimed API to an interior cavity of the virus particle described in the instant disclosure. See instant Specification @ par. 43. Thus, if this does not enable the same, the examiner would be required to make an enablement rejection in view of the lack of teaching a POSA how to make the claimed invention. Even further, Steinmetz teaches cationic nanoparticles have enhanced tumor homing properties and exhibit higher vascular permeability compared to their anionic counterparts. Johnson teaches phenanthriplatin is a cationic platinum based anticancer agent that has superior features to cisplatin. Overall, Manchester teaches covalent attachment to the interior of a virus, including CPMV and teaches using cisplatin as a preferred cationic API. Steinmetz teaches cationic nanoparticles have enhanced tumor homing properties and exhibit higher vascular permeability. Further, antitumor agents can be coupled to a CPMV virus particle through thiol-selective chemistry using the same paragraph used in the Steinmetz et al., (WO2013/181557). The support in the instant Specification to enable thiol attached is identical to the section provide by Applicant’s own prior art. See par. 43 of the instant Specification and par. 39 of Steinmetz. Johnson is cited merely to show that phenanthriplatin would substituted for cisplatin as it is a structural similar derivative with substantially increased potency. There is a reasonable and predictable expectation of success in arriving at the claimed CPMV particle by covalently attaching cisplatin or phenanthriplatin or another cationic anticancer agent to the interior of a CPMV particle. Thiol-selective chemistry is a manner of achieving this and the only manner described by Applicant’s disclosure. Applicant’s representative is encouraged to reach out to the examiner if anything stated in this action is not clear and he is willing to conduct an After Final interview should such discussion expedite prosecution on the merits. Alternatively, Applicant can provide an explanation for the record how the described thiol selective chemistry does not yield the claimed product and/or how such attachment provides an unexpected results as compared to the closest prior art. If the described thiol-selective chemistry does not yield the claimed attachment, Applicant should explain how the Specification discloses how to make and use the claimed invention. Status of the Claims Claims 1, 8, 11, 14-17, 20, 24, and 26 are pending and examined. 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. Claims 1, 8, 11, 14-17, 20, 24, and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Manchester et al., (US2006/0216238), in view of Steinmetz et al., (WO2013/181557), and in view of Johnstone et al., “Understanding and Improving Anticancer Drugs- Phenanthriplatin,” Anticancer Res. 2014 January; 34(1): 471-476. Manchester teaches plant viral particles for targeting and methods for treatment of disease. See Abstract. The plant viral particle can be a cowpea mosaic virus (CPMV). See par. 11. The therapeutic agent can be used to treat cancer. See par. 19. Examples include CPMV particles with anticancer agents, including doxorubicin, among others. Cancers that can be treated include colon, brain, breast, and others. See par. 164. The interior of the virus capsid was used. See par.’s 10 and 30, among others. Suitable therapeutic agents for use also include doxorubicin, cisplatin, and others as preferred. See par. 136. The targeting molecules can be attached by covalent conjugation. See par. 128. Steinmetz teaches CPMV as a filamentous plant virus particular to carry antitumor agents. See par. 6. Further, PEGylation is used to reduced immunogenicity and enhance stability and pharmacokinetics. See par. 8 and 59 Steinmetz also explains that an agent can be coupled to a filamentous virus particle through chemical coupling via thiol-selective chemistry. See par. 39. Steinmetz also teaches many cancers to be treated, including breast, colon, and others. See par. 56. Even further, cationic nanoparticles have enhanced tumor homing properties and exhibit higher vascular permeability compared to their anionic counterparts. See par. 87. Manchester and Steinmetz do not teach phenanthriplatin. Johnstone teaches phenanthriplatin is a cisplatin derivative in which a chloride ion is replaced with a phenanthridine. It is cationic and is 7-40 times more active than cisplatin in initial screens of human cancers from a variety of organs. It would have been prima facie obvious to a person of ordinary skill in the art prior to the filing of the instant application to arrive at the claimed products and methods in view of Manchester, Steinmetz, and Johnstone. One would be motivated to do so because using the CPMV to administer therapeutic anticancer agents to a subject is taught. Further, PEGylation has multiple advantages for treatment, including reducing immunogenicity and enhancing stability. Even further, cationic targeting molecules exhibit benefits compared to anionic particles, including increased vascular permeability. Manchester teaches using the interior of the viral particle and cisplatin, e.g., can be covalently or non-covalently attached. Johnstone teaches phenanthriplatin to be a cationic derivative of cisplatin with enhanced potency against numerous cancer cell lines in humans. Overall, Manchester teaches covalent attachment to the interior of a virus, including CPMV and teaches using cisplatin as a preferred cationic API. Steinmetz teaches cationic nanoparticles have enhanced tumor homing properties and exhibit higher vascular permeability. Further, antitumor agents can be coupled to a CPMV virus particle through thiol-selective chemistry using the same paragraph used in the Steinmetz et al., (WO2013/181557). The support in the instant Specification to enable thiol attached is identical to the section provide by Applicant’s own prior art. See par. 43 of the instant Specification and par. 39 of Steinmetz. Johnson is cited merely to show that phenanthriplatin would substituted for cisplatin as it is a structural similar derivative with substantially increased potency. There is a reasonable and predictable expectation of success in arriving at the claimed CPMV particle by covalently attaching cisplatin or phenanthriplatin or another cationic anticancer agent to the interior of a CPMV particle. Thiol-selective chemistry is a manner of achieving this and the only manner described by Applicant’s disclosure. As such, there is a reasonable and predictable expectation of success in arriving at the claimed product and using the claimed products in methods of treating cancers. Each claimed limitation is taught and/or taught to be advantageous for the claimed products and methods. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1, 8, 11, 14-17, 20, 24, and 26 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-19 of U.S. Patent No. 12,247,228, in view of Manchester et al., (US2006/0216238), in view of Steinmetz et al., (WO2013/181557), and in view of Johnstone et al., “Understanding and Improving Anticancer Drugs- Phenanthriplatin,” Anticancer Res. 2014 January; 34(1): 471-476. Although the claims at issue are not identical, they are not patentably distinct from each other because the claims of the ‘228 patent include a CPMV particle with a cationic cargo molecule, including antitumor drug cisplatin. See claim 12. The particle can be PEGylated and include a carrier or other antitumor agent. See claims 11, 17. The loading described in the ‘228 claims merely makes those claims a product by process claim evaluated based on the product itself. See claim 1, e.g. Claims 1, 8, 11, 14-17, 20, 24, and 26 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of U.S. Patent No. 11,371,025, in view of Manchester et al., (US2006/0216238), in view of Steinmetz et al., (WO2013/181557), and in view of Johnstone et al., “Understanding and Improving Anticancer Drugs- Phenanthriplatin,” Anticancer Res. 2014 January; 34(1): 471-476. Although the claims at issue are not identical, they are not patentably distinct from each other because the claims of the ‘025 patent include a CPMV particle loaded with an antitumor molecule. See claims 15, 16, and 18. The particle can be PEGylated. See claim 9. A carrier can be included. See claim 20. Cisplatin is a described antitumor agent within the disclosure thereof. Conclusion 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 extension fee 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to JARED D. BARSKY whose telephone number is (571)-272-2795. The examiner can normally be reached on Monday through Friday from 8:30 to 5:30. If attempts to reach the examiner by telephone are unsuccessful, the examiner's supervisor, Amy L. Clark can be reached on 571-272-1310. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JARED BARSKY/Primary Examiner, Art Unit 1628
Read full office action

Prosecution Timeline

Jan 30, 2024
Application Filed
Apr 23, 2025
Non-Final Rejection — §103, §DP
Jul 28, 2025
Response Filed
Oct 29, 2025
Final Rejection — §103, §DP (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
50%
Grant Probability
73%
With Interview (+23.0%)
2y 8m
Median Time to Grant
Moderate
PTA Risk
Based on 915 resolved cases by this examiner. Grant probability derived from career allow rate.

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