Prosecution Insights
Last updated: April 19, 2026
Application No. 18/032,680

NOVEL CXCR4-TARGETING COMPOUNDS

Non-Final OA §103§112§DP
Filed
Apr 19, 2023
Examiner
SABILA, MERCY HELLEN
Art Unit
1654
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
The University of British Columbia
OA Round
1 (Non-Final)
59%
Grant Probability
Moderate
1-2
OA Rounds
2y 8m
To Grant
99%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allow Rate
152 granted / 257 resolved
-0.9% vs TC avg
Strong +46% interview lift
Without
With
+45.7%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
56 currently pending
Career history
313
Total Applications
across all art units

Statute-Specific Performance

§101
3.2%
-36.8% vs TC avg
§103
42.0%
+2.0% vs TC avg
§102
15.9%
-24.1% vs TC avg
§112
20.8%
-19.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 257 resolved cases

Office Action

§103 §112 §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 . Priority This application was filed on and is a U.S. national Stage application under 35 U.S.C. 371 of International Patent Application No. PCT/CA2021/051486 filed 10/21/2021, which claims the benefit of the priority of US Provisional application 63/094,839 filed 10/21/2020. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Information Disclosure Statement The information disclosure statements submitted on 09/19/2023, 09/10/2024, 12/04/2024, 07/11/2025, and 12/15/2025 have been considered by the examiner. Election/Restrictions Claims 103-104, 108, and 110-111 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group 2 and 3 or based on the elected species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 12/15/2025. Applicant’s election without traverse of Group I drawn to a compound, in the reply filed on 12/15/2025 is acknowledged. Applicant further elects the species BL34 as shown below PNG media_image1.png 532 437 media_image1.png Greyscale As a result, claims 30, 34, 38, 40, 42, 69-70, and 77 are withdrawn. A search of the elected species of BL34 did not uncover prior art. The search was thus expanded to the genus and the rejection is set forth below. Claim Status Claims 1-3, 15, 19, 25, 30, 34, 38, 40, 42-44, 46-48, 50, 61, 63-66, 69-74, 77, 101, 103-104, 108, 110-111 are pending. Claims 30, 34, 38, 40, 42, 69-70, 77, 103-104, 108, and 110-111 are withdrawn. Claims 1-3, 15, 19, 25, 43-44, 46-48, 50, 61, 63-66, 71-74, 101 are being examined on the merits in this office action. Claim Rejections - 35 USC § 112 The following is a quotation of the first paragraph of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 1-3, 15, 19, 25, 43-44, 46-48, 50, 61, 63-66, 71-74, 101 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. MPEP § 2137 states that "the written description requirement for a genus must be satisfied through sufficient description of a representative number of species by actual reduction to practice, reduction to drawings, or by disclosure of relevant, identifying characteristics, i.e., structure or other physical and/or chemical properties, by functional characteristics coupled with a known or disclosed correlation between function and structure, or by a combination of such identifying characteristics, sufficient to show the applicant was in possession of the claimed genus (see i)(C), above). See Eli Lilly, 119 F.3d at 1568, 43 USPQ2d at 1406. For written description, the analysis (a) considers actual reduction to practice, (b) disclosure of drawings or structural chemical formulas, (c) sufficient relevant identifying characteristics in the way of complete/partial structure or physical and/or chemical properties, functional characteristics when coupled with known or disclosed and (d) representative number of examples. Actual reduction to practice and (b) disclosure of drawings or structural chemical formulas: Instant claim 1 recites the compound of Formula A, B or C PNG media_image2.png 426 665 media_image2.png Greyscale Wherein the compound comprises ten variables and each variables is selected from numerous options. Examiner notes that the number of compounds that can be generated from the combination of all the variables, including all the linkers, therapeutic moiety, fluorescent group or a radiolabeled group are numerous and it is unclear if the combination of all the variants of the compounds would have the function of treating cancer. Applicant has only reduced to practice the compounds BL34, and BL40-BL45 (See Fig. 1-9) while still claiming a vast number of compounds that can be generated from the variables of the compound of Formula A-C. sufficient relevant identifying characteristics in the way of complete/partial structure or physical and/or chemical properties Examiner notes that the different variables would result in numerous compounds that are structurally diverse and it would be challenging to ascertain if the compounds would all have the same property. The claims thus cover an exceedingly broad scope of compounds. As such, the recited claims cover an exceedingly broad scope of compounds. Representative number of examples A “representative number of species” means the species which are adequately described are a representative of the entire genus. Therefore, when there is a substantial variation within a genus, the applicant must describe a sufficient variety of species to reflect the variation within the genus. The disclosure of only one species encompassed within a genus adequately describes a claim directed to that genus only if the disclosure "indicates that the patentee has invented species sufficient to constitute the gen[us]." See Enzo Biochem, 323 F.3d at 966, 63 USPQ2d at 1615; Noelle v. Lederman, 355 F.3d 1343, 1350, 69 USPQ2d 1508, 1514 (Fed. Cir. 2004) (Fed. Cir. 2004) ("[A] patentee of a biotechnological invention cannot necessarily claim a genus after only describing a limited number of species because there may be unpredictability in the results obtained from species other than those specifically enumerated."). See MPEP 2163.3 (ii). The instant specification contains no guidance on the core structure required on the compounds to have the function of imaging a CXCR4-expressing tissue. Applicants have reduced to practice the six compounds disclosed BL34, and BL40-BL45 is insufficient to establish that the entire genus of compounds with the numerous recited types of linkers is capable for use as imaging agents. BL34 and BL42 seem to have the same sequence, so does BL40 and BL41, BL38 and BL39 and they don’t seem to be a representative of the genus. Examiner notes that BL34, and BL40-BL45 are adequately described and claims directed to the compounds would overcome the 112(a) rejection. Thus, claims 1-3, 15, 19, 25, 43-44, 46-48, 50, 61, 63-66, 71-74, 101 are rejected under 35 U.S.C. 112(a) as failing to comply with the written description requirement. Given this lack of description in the specification, the application fails to describe the claimed invention in such a full, clear, and concise and exact terms that a skilled artisan would recognize that applicants were in possession of the genus of claimed invention. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 74 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 74 refers to Table 2 in line 4. Examiner notes that Table comprises numerous chelators and isotopes. Where possible, claims are to be complete in themselves so as to ensure that the scope of the claims is clear. Incorporation by reference to a specific figure or table "is permitted only in exceptional circumstances where there is no practical way to define the invention in words and where it is more concise to incorporate by reference than duplicating a drawing or table into the claim (See MPEP 2173.05(s). 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 1-3, 15, 19, 25, 43-44, 46-48, 50, 61, 63-66, 71-74, 101 are rejected under 35 U.S.C. 103 as being unpatentable over Suzuki et al. (Sci Rep 9, 15284 (2019)). Suzuki teaches the CXCR4 compound below PNG media_image3.png 325 1013 media_image3.png Greyscale (Fig. 1). Suzuki teaches the compound has the sequence (cyclo[Phe-Tyr-Lys(iPr)-D-Arg-2-Nal-Gly-D-Glu]-Lys(iPr)-NH2) (bottom of Page 1), which meets the limitations on the instant compound A of claim 1. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the teachings of Suzuki and generate the compounds that are encompassed by the instant Formula A-C. One of ordinary skill in the art would have had a reasonable expectation of success in using the teachings of Suzuki to arrive to compounds of the instant claims. The disclosure render obvious claim 1. Regarding claims 2-3, Suzuki teaches the compound PNG media_image3.png 325 1013 media_image3.png Greyscale Wherein from the compound, a) R2a is (CH2)-R2b)-(phenyl), wherein is substituted 4-substituted with OH, b) R3a is R3bR3c wherein R3b is a linear C1 -C 5 alkylenyl, wherein R3c is —N(R3d)2-3 wherein each R3d is branched C1-C3 alkyl. c) R4a is R4bR4c wherein R4b is a linear C2-C5 alkenylenyl, wherein R4c is guanidino, d) R5a is —(CH2)1-3—R5b, wherein R5b is: phenyl optionally substituted with one or a more of the following: 4-substituted with O-phenyl; R6c is —CH2—(R6b), wherein R6b is CH2. RA7a is N, RA8a is R8bR8c, wherein R8b is a linear C1-C5 alkylenyl, wherein R8c is -N(R8d)2-3, wherein each R8d is a linear or branched C1-C3 alkyl; RA9a is —C(O)NH2, RA10 is absent and RA1a is NH-C(O)-(phenyl). Further, Suzuki teaches the compound has the sequence (cyclo[Phe-Tyr-Lys(iPr)-D-Arg-2-Nal-Gly-D-Glu]-Lys(iPr)-NH2) (bottom of Page 1). Regarding claim 15, Suzuki from the compound of Fig 1, that -NH-CH(R6a)-C(O)-NH-of is replaced with PNG media_image4.png 118 172 media_image4.png Greyscale (Fig. 1). PNG media_image3.png 325 1013 media_image3.png Greyscale Regarding claim 19, Suzuki from the compound of Fig 1, that R9a is -C(O)NH2 (Fig 1). Regarding claim 43-44, 46-48, 50, Suzuki teaches the CXCR4 compound below PNG media_image3.png 325 1013 media_image3.png Greyscale (Fig. 1). Suzuki teaches the compound has the sequence (cyclo[Phe-Tyr-Lys(iPr)-D-Arg-2-Nal-Gly-D-Glu]-Lys(iPr)-NH2) (bottom of Page 1). Suzuki teaches that the compound is conjugated with 1,4,7,10-tet raazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) via a cysteine linker as shown in Fig. 1, which is a radiolabel. As shown in Fig. 1, the linker comprises sulfonic acid and PNG media_image5.png 90 122 media_image5.png Greyscale Regarding claim 63-66, Suzuki teaches the compound PNG media_image3.png 325 1013 media_image3.png Greyscale Suzuki teaches the compound has the sequence (cyclo[Phe-Tyr-Lys(iPr)-D-Arg-2-Nal-Gly-D-Glu]-Lys(iPr)-NH2) (bottom of Page 1). Wherein from the compound, R2a is (CH2)-R2b)-(phenyl), wherein is substituted 4-substituted with OH, R3a is R3bR3c wherein R3b is a linear C1 -C 5 alkylenyl, wherein R3c is —N(R3d)2-3 wherein each R3d is branched C1-C3 alkyl. R4a is R4bR4c wherein R4b is a linear C2-C5 alkenylenyl, wherein R4c is guanidino, R5a is —(CH2)1-3—R5b, wherein R5b is: phenyl optionally substituted with one or a more of the following: 4-substituted with O-phenyl; R6c is —CH2—(R6b), wherein R6b is CH2. RA7a is N, RA8a is R8bR8c, wherein R8b is a linear C1-C5 alkylenyl, wherein R8c is -N(R8d)2-3, wherein each R8d is a linear or branched C1-C3 alkyl; RA9a is —C(O)NH2, RA10 is absent and RA1a is NH-C(O)-(phenyl). Further, Suzuki teaches the compound has the sequence (cyclo[Phe-Tyr-Lys(iPr)-D-Arg-2-Nal-Gly-D-Glu]-Lys(iPr)-NH2) (bottom of Page 1). Regarding claims 71-74, c that the compound is conjugated with 1,4,7,10-tet raazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) via a cysteine linker as shown in Fig. 1, which is a radiolabel, and forms a complex with 67/68Ga, 90Y, and 177Lu isotopes (Abstract; page 1, last paragraph). Suzuki teaches that the compound is conjugated to meta chelating molecules (Abstract), that the radiolabeled agents include gallium-68 (68Ga)-NOTA-NFB and copper-64 (64Cu)-AMD3100 (plerixafor)9,10. Among them, FC131 (cyclo[D-Tyr-Arg-Arg-2-Nal-Gly]) derivative 68Ga-pentixafor (cyclo(D-Tyr-D-[NMe]Orn-[AMBS-DOTA]-Arg-2-Nal-Gly) [where AMBS represents 4-(aminomethyl) benzoic acid)] (Page 1). Regarding claim 101, Suzuki teaches the radio isotopes 67/68Ga, 90Y, and 177Lu (Abstract; page 1, last paragraph). Double Patenting Claims 1-3, 15, 19, 25, 43-44, 46-48, 50, 61, 63-66, 71-74, 101 provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 67-69, 71, 78-80, 85-86, 90-93, 96, 100-101, 105, 111, 120-121, 124, 127, 129, 141, and 146 of copending Application No. 18/855,675. Although the claims at issue are not identical, they are not patentably distinct from each other because the claims of the copending application recite a compound of Formula A-C or solvate PNG media_image6.png 497 736 media_image6.png Greyscale (claim 1, 129). Examiner notes that the claim 1 of the copending application anticipates instant claims. Regarding claim 2-3, 15, 19, 43 the claims of the copending application recite PNG media_image7.png 602 700 media_image7.png Greyscale (claims 67-68, 85, 86). Regarding claim 25, 44, the copending claims recite PNG media_image8.png 171 685 media_image8.png Greyscale (claim 69). Regarding claim 46-48, 50, the copending claims recite the limitations recited in claim 71, 90. Regarding claim 61, the copending claims recite PNG media_image9.png 113 637 media_image9.png Greyscale (claim 93). Regarding claim 63, the copending claims recite PNG media_image10.png 88 658 media_image10.png Greyscale (claim 92). Regarding claim 65, the copending claims recite PNG media_image11.png 246 615 media_image11.png Greyscale (claim 96). Regarding claims 71-74, the claims of the copending application recite wherein each Rx is therapeutic moiety, a fluorescent label, a radiolabeled group, or a group capable of being radiolabelled, wherein each group capable of being radiolabelled is independently selected from: a metal chelator optionally in complex with a radiometal or radioisotope-bound metal; a prosthetic group containing trifluoroborate (BF3); or a prosthetic group containing a silicon-fluorine-acceptor moiety, a sulphonyl fluoride, or a phosphoryl fluoride, wherein the metal chelator is a polyaminocarboxylate chelator, DOTA, MACROPA, or a derivative thereof (claim 1, 85-86, 100-101, 105, 120-121, 124). Regarding claim 101, the claims of the copending application recite wherein the metal chelators, such as those listed in Table 3 (claim 101, 127, 141, 146). This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Conclusion No claims are allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Mercy H. Sabila whose telephone number is (571)272-2562. The examiner can normally be reached Monday - Friday 5:00 am - 3:00 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lianko G. Garyu can be reached at (571)270-7367. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /MERCY H SABILA/Examiner, Art Unit 1654
Read full office action

Prosecution Timeline

Apr 19, 2023
Application Filed
Jun 27, 2024
Response after Non-Final Action
Feb 06, 2026
Non-Final Rejection — §103, §112, §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

1-2
Expected OA Rounds
59%
Grant Probability
99%
With Interview (+45.7%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 257 resolved cases by this examiner. Grant probability derived from career allow rate.

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