Prosecution Insights
Last updated: April 19, 2026
Application No. 18/671,711

PLINABULIN COMPOSITIONS

Non-Final OA §112§DP
Filed
May 22, 2024
Examiner
KIFLE, BRUCK
Art Unit
1624
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Beyondspring Pharmaceuticals Inc.
OA Round
2 (Non-Final)
79%
Grant Probability
Favorable
2-3
OA Rounds
2y 0m
To Grant
95%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
1356 granted / 1712 resolved
+19.2% vs TC avg
Strong +16% interview lift
Without
With
+15.9%
Interview Lift
resolved cases with interview
Fast prosecutor
2y 0m
Avg Prosecution
27 currently pending
Career history
1739
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
12.2%
-27.8% vs TC avg
§102
13.0%
-27.0% vs TC avg
§112
53.7%
+13.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1712 resolved cases

Office Action

§112 §DP
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 . Applicant’s amendments and remarks filed January 23, 2026 have been received and reviewed. Claims 54-72 are now pending in this application. 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 63-72 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 enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention. The treatment of cancer or tumor generally cannot possibly be considered enabled. As a general rule, enablement must be commensurate with the scope of claim language. MPEP 2164.08 states, “The Federal Circuit has repeatedly held that “the specification must teach those skilled in the art how to make and use the full scope of the claimed invention without undue experimentation’.” In re Wright, 999 F.2d 1557, 1561, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993)” (emphasis added). The “make and use the full scope of the invention without undue experimentation” language was repeated in 2005 in Warner-Lambert Co. v. Teva Pharmaceuticals USA Inc., 75 USPQ2d 1865, and Scripps Research Institute v. Nemerson, 78 USPQ2d 1019 asserts: “A lack of enablement for the full scope of a claim, however, is a legitimate rejection.” The principle was explicitly affirmed most recently in Auto. Tech. Int’l, Inc. v. BMW of N. Am., Inc., 501 F.3d 1274, 84 USPQ2d 1108 (Fed. Cir. 2007), Monsanto Co. v. Syngenta Seeds, Inc., 503 F.3d 1352, 84 U.S.P.Q.2d 1705 (Fed. Cir. 2007), and Sitrick v. Dreamworks, LLC, 516 F.3d 993, 85 USPQ2d 1826 (Fed. Cir. 2008). See also In re Cortright, 49 USPQ2d 1464, 1466 and Bristol-Myers Squibb Co. v. Rhone-Poulenc Rorer Inc., 49 USPQ2d 1370. Pursuant to In re Wands, 858 F.2d 731, 737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988), one considers the following factors to determine whether undue experimentation is required: (A) The breadth of the claims; (B) The nature of the invention; (C) The state of the prior art; (D) The level of one of ordinary skill; (E) The level of predictability in the art; (F) The amount of direction provided by the inventor; (G) The existence of working examples; and (H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure. Some experimentation is not fatal; the issue is whether the amount of experimentation is “undue”; see In re Vaeck, 20 USPQ2d 1438, 1444. The analysis is as follows: (1) Breadth of claims. (a) Scope of the compounds. The scope of compound is not objected to. (b) Scope of the diseases covered. Cancer or tumor is not a single disease, or cluster of closely related disorders. There are hundreds of them, which have in common only some loss of controlled cell growth. They are highly heterogeneous at both the molecular and clinical level, something seen especially in, for example, the cancers of the breast, brain and salivary glands. They can occur in pretty much every part of the body. For example, leukemia is any malignant neoplasm of the blood-forming tissues. Leukemia can arise from many different sources. These include viruses such as EBV, which causes Burkitt's lymphoma, and HTLV-1, linked to certain T cell leukemias. Others are linked to genetic disorders, such as Fanconi's anemia, which is a familial disorder, and Down's syndrome. Other leukemias are caused by exposure to carcinogens such as benzene, and some are actually caused by treatment with other neoplastic agents. Still other leukemias arise from ionizing radiation, and many are idiopathic. Leukemias also differ greatly in the morphology, degree of differentiation, body location (e.g., bone marrow, lymphoid organs, etc.) There are dozens of leukemias. There are B-Cell Neoplasms such as B-cell prolymphocytic leukemia and Hairy cell leukemia (HCL, a chronic Lymphoid leukemia). There are T-Cell Neoplasms such as T-cell prolymphocytic leukemia, aggressive NK cell leukemia, adult T cell leukemia/lymphoma (ATLL), and T-cell granular Lymphocytic leukemia. There are different kinds of acute myeloid leukemias (undifferentiated AML, acute myeloblastic, acute myelomonocytic leukemia, acute monocytic leukemias, acute monoblastic, acute megakaryoblastic (AmegL), acute promyelocytic leukemia (APL), and erythroleukemia). There is also lymphoblastic leukemia, hypocellular acute myeloid leukemia, Ph-/BCR- myeloid leukemia, and acute basophilic leukemia. Chromic leukemias include chronic lymphocytic leukemia (CLL, which exists in a B-cell and a T-cell type), prolymphocytic leukemia (PLL), large granular lymphocytic leukemia (LGLL, which goes under several other names as well), chronic myelogenous leukemia (CML), chronic myelomonocytic leukemia (CMML), chronic neutrophilic leukemia, chronic eosinophilic leukemia (CEL), and many others. (2) The nature of the invention and predictability in the art: With specific reference to cancer, Ex parte Kranz, 19 USPQ2d 1216, 1219 notes the “general unpredictability of the field [of] …anti-cancer treatment.” In re Application of Hozumi et al., 226 USPQ 353 notes the “fact that the art of cancer chemotherapy is highly unpredictable”. More generally, the invention is directed toward medicine and is therefore physiological in nature. It is well established that “the scope of enablement varies inversely with the degree of unpredictability of the factors involved,” and physiological activity is generally considered to be an unpredictable factor. See In re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 (CCPA 1970). (3) Direction or Guidance: That provided is very limited. There is no dosage information. (4) State of the Prior Art: The claimed composition is plinabulin. So far as the examiner is aware this has not been successfully used as a general anticancer or antitumor agent. (5) Working Examples: Applicants have not presented any results against any cancer or tumor. (6) Skill of those in the art: The prior art knows that there never has been a compound capable of treating cancers generally. “The cancer therapy art remains highly unpredictable, and no example exists for efficacy of a single product against tumors generally.” (<http://www.uspto.gov/web/offices/pac/dapp/1pecba.htm#7> ENABLEMENT DECISION TREE, Example F, situation 1). A similar statement appears at In re Application of Hozumi et al., 226 USPQ 353: “In spite of the vast expenditure of human and capital resources in recent years, no one drug has been found which is effective in treating all types of cancer. Cancer is not a simple disease, nor is it even a single disease, but a complex of a multitude of different entities, each behaving in a different way.” There are compounds that treat a modest range of cancers, but no one has ever been able to figure out how to get a compound to be effective against cancer generally, or even a majority of cancers. The attempts to find compounds to treat the various cancers arguably constitute the single most massive enterprise in all of pharmacology. This has not resulted in finding any treatment for tumors generally. Indeed, the existence of such a "silver bullet" is contrary to our present understanding in oncology. This is because it is now understood that there is no “master switch” for cancers generally; cancers arise from a bewildering variety of differing mechanisms. Even the most broadly effective antitumor agents are only effective against a small fraction of the vast number of different cancers known. This is true in part because cancers arise from a wide variety of sources, primarily a wide variety of failures of the body's cell growth regulatory mechanisms, but also such external factors such as viruses (an estimated at least 20% are of viral origin e.g. Human papillomavirus, EBV, Hepatitis B and C, HHV-8, HTLV-1 and other retroviruses, and quite possibly Merkel cell polyomavirus, and there is some evidence that CMV is a causative agent in glioblastoma), exposure to chemicals such as tobacco tars, excess alcohol consumption (which causes hepatic cirrhosis, an important cause of HCC), ionizing radiation, and unknown environment factors. Accordingly, there is substantive “reason for one skilled in the art to question the objective truth of the statement of utility or its scope” (In re Langer, 183 USPQ 288, 297). Similarly, In re Novak, 134 USPQ 335, 337-338, says “unless one with ordinary skill in the art would accept those allegations as obviously valid and correct, it is proper for the examiner to ask for evidence which substantiates them.” There is no such evidence in this case. Likewise, In re Cortright, 49 USPQ2d 1464, states: “Moreover, we have not been shown that one of ordinary skill would necessarily conclude from the information expressly disclosed by the written description that the active ingredient” does what the specification surmises that it does. That is exactly the case here. Even if applicants’ assertion that cancer in general could be treated with these compounds were plausible--- which it is not ---, that would not suffice, as was stated in Rasmusson v. SmithKline Beecham Corp., 75 USPQ2d 1297, 1301: “If mere plausibility were the test for enablement under section 112, applicants could obtain patent rights to “inventions” consisting of little more than respectable guesses as to the likelihood of their success.” Different types of cancers affect different organs and have different methods of growth and harm to the body, and different vulnerabilities. The skill thus depends on the particular cancer involved. There are some cancers where the chemotherapy skill level is high and there are multiple successful chemotherapeutic treatments. The mechanism in these situations, however, is not necessarily the same as is alleged for these compounds. (7) The quantity of experimentation needed: Given the fact that, historically, the development of new cancers drugs has been difficult and time consuming, and especially in view of factors 1 and 4 and 6, the quantity of experimentation needed is expected to be great. MPEP 2164.01(a) states, “A conclusion of lack of enablement means that, based on the evidence regarding each of the above factors, the specification, at the time the application was filed, would not have taught one skilled in the art how to make and/or use the full scope of the claimed invention without undue experimentation. In re Wright, 999 F.2d 1557, 1562, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993).” That conclusion is clearly justified here. 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 54-62 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 of U.S. Patent No. 10,155,748. Claims 54-62 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of U.S. Patent No. 10,550,104. Claims 54-62 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-16 of U.S. Patent No. 11,254,657. Although the claims at issue are not identical, they are not patentably distinct from each other because the instant claims embraced the plinabulin monohydrate compositions of the reference patents. The instant claims are presented broadly but embrace the reference claims non the less. The instant compounds and compositions are made using the same process as those in the reference claims. Note, also, a later genus claim is not patentable over an earlier species claim, In re Berg, 46 USPQ2d 1226, 1233. See also In re KAUFFMAN, II, 68 USPQ 178. Claims 63-72 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 of U.S. Patent No. 10,155,748; claim 1 of U.S. Patent No. 10,550,104 or claims 1-16 of U.S. Patent No. 11,254,657. Although the claims at issue are not identical, they are not patentably distinct from each other because the instant claims simply claim the use disclosed in the reference patents as a method of use claim. See Pfizer, 518 F.3d at 1363; Geneva, 349 F.3d at 1385. See Sun Pharmaceutical Industries v. Eli Lilly and Co., 611 F.3d 1381, 1389 (2010). In AbbVie Inc. v. Kennedy Institute of Rheumatology Trust, 764 F.3d 1366, 112 USPQ2d 1001 (Fed. Cir. 2014), the court explained that it is also proper to look at the disclosed utility in the reference disclosure to determine the overall question of obviousness in a nonstatutory double patenting context. See also Pfizer, Inc. v. Teva Pharm. USA, Inc ., 518 F.3d 1353, 86 USPQ2d 1001 (Fed. Cir. 2008); Geneva Pharmaceuticals Inc. v. GlaxoSmithKline PLC, 349 F3d 1373, 1385-86, 68 USPQ2d 1865, 1875 (Fed. Cir. 2003). Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRUCK KIFLE whose telephone number is (571)272-0668. The examiner can normally be reached 8 AM - 6 PM, M-F. 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, Jeffrey H. Murray can be reached at 571-272-9023. 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. March 27, 2026 /BRUCK KIFLE/Primary Examiner, Art Unit 1624
Read full office action

Prosecution Timeline

May 22, 2024
Application Filed
Sep 10, 2024
Response after Non-Final Action
Sep 22, 2025
Non-Final Rejection — §112, §DP
Jan 23, 2026
Response Filed
Mar 27, 2026
Non-Final Rejection — §112, §DP (current)

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Prosecution Projections

2-3
Expected OA Rounds
79%
Grant Probability
95%
With Interview (+15.9%)
2y 0m
Median Time to Grant
Moderate
PTA Risk
Based on 1712 resolved cases by this examiner. Grant probability derived from career allow rate.

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