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 .
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 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.
Priority
The instant application, filed 08/28/2023, is a continuation of 16/320,029, filed 01/23/2019, which is a 371 filing of PCT/US17/41491, filed 07/11/2017, and claims domestic benefit to 62/366,826, filed 07/26/2016.
Status of Application, Amendments, and/or Claims
Applicant’s response of 11/03/2025 is acknowledged. No claims are amended, cancelled, or new. Claims 1, 17, 20, and 28-44 are currently pending and are examined on the merits herein.
The following rejections are maintained.
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.
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, 17, 20, 28-30, 33-34, 37, and 40-42 are rejected under 35 U.S.C. 103 as being unpatentable over Amory, J.K., et al (2014) Melphalan, alone or conjugated to an FSH-β peptide, kills murine testicular cells in vitro and transiently suppresses murine spermatogenesis in vivo Theriogenology 82; 152-159 in view of US 2013/0164300 A1 (Isabelle Teulon and Andre Pelegrin) 27 June 2013, Wang, M., et al (2014) Combinatorially Designed Lipid-like Nanoparticles for Intracellular Delivery of Cytotoxic Protein for Cancer Therapy Angew. Chem. Int. Ed. 53; 2893-2898 (herein “M.Wang”), and Wang, R., et al (2012) Application of poly(ethylene glycol)-distearopylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery International Journal of Nanomedicine 7; 4185-4198 (herein “R.Wang”).
Amory teaches that the most common method of sterilizing male animals relies on removal of the testes, which requires skilled personnel and can cause significant postprocedural pain. Removal of the testes also deprives the animal of testosterone, which may lead to health and behavioral problems and increase the risk of prostate cancer or osteoporosis later in life. An alternative approach is the injection of a solution of calcium chloride or zinc gluconate directly into the testes. These injections are very effective from a contraceptive standpoint; however, severe injection site reactions requiring surgery can occur in up to 4% of recipients, with others experiencing scrotal ulceration or dermatitis (page 153, left column, paragraph 1). Several investigators have examined the potential of gonadotoxicants for the purposes of male sterilization; however suppression of spermatogenesis was incomplete and systemic toxicity was limited (page 153, left column, paragraph 2).
Amory teaches an approach to male sterilization using the potent gonadotoxin melphalan. Melphalan is an alkylating agent that is widely used in the treatment of lymphomas and multiple myelomas in both humans and animals. Amory investigated whether melphalan effect could be facilitated and toxicity reduced by targeting the melphalan specifically to the testes via conjugation to peptides derived from the beta chain of human FSH-β (page 153, left column, paragraph 2).
Amory teaches that FSH is a protein hormone produced by the pituitary and binds to the FSH (FSHr) receptor on Sertoli cells within the seminiferous tubules on the testis, stimulating them to nurture the developing germ cells. Amory further teaches that FSHβ has been shown to be an effective gonad-specific drug delivery vehicle for experimental forms of reversable contraception in mice. In one such study, the contraceptive efficacy of adjudin was increased 10,000 fold by conjugation to FSHβ. In another, FSHβ conjugated to a peptide that interrupted the integrity of the blood-testes barrier caused significant loss of germ cells and a decrease in fertility (page 153, left column, paragraph 3).
Amory tested the conjugate in vitro in male C57/B16 mice (page 154, right column, 2.3). Amory teaches that after 4 weeks of treatment, all animals dosed with either melphalan or FSHβ-melphalan had greater than 75% reduction in testicular spermatid counts compared with the placebo group. Unfortunately, 12 weeks after treatment, quantitively and histologically, normal spermatogenesis had returned in all treatment groups. Notably, however, one animal that received the single high-dose of FSHβ-melphalan had no apparent spermatogenesis at 12 weeks after the injection, suggesting that this animal might have been sterilized by treatment (page 155, right column, 3.2).
Amory demonstrates that drug conjugates that target Sertoli cells had been considered in the prior art for non-surgical sterilization and had demonstrated efficacy in suppressing spermatogenesis after administration. Amory, however, does not disclose that the conjugate comprises the claimed antibody-conjugated nanoparticle.
US’300 teaches monoclonal antibodies and fragments directed against the human anti-Mullerian Hormone type II receptor (AMHR-II) (abstract). The anti-Mullerian Hormone type II receptor is involved in Mullerian duct regression associated with the development of the male reproductive system and that the receptor is frequently expressed on human epithelial ovarian tumor cells as well as in cell lines derived from tissues such as breast and prostate tissues (page 1, [0009], [0010]). US’300 further teaches that in 2004, a monoclonal antibody against the human AMHR-II was developed and characterized and immunohistochemistry demonstrated strong expression of AMHR-II by human granulosa cell tumors (GCTs) and by Sertoli and Leydig cells on human testis (page 1, [0011]). US’300 teaches that AMHR-II is specifically expressed in the natural tissue targets, the reproductive organs, and the gonads and that mutations in AMHR-II or AMH cause male sexual abnormalities (page 4, [0047]).
US’300 further teaches immunoconjugates comprising the antibody conjugated to a cytotoxic agent (page 9, [0125]). US’300 teaches that the “cytotoxic agent” is a substance that inhibits or prevents the function of the cells and/or causes destruction of the cells and provides a list of toxins which includes melphalan, paclitaxel, and docetaxel (page 9, [0127]). US’300 further teaches that cytotoxic agents include natural toxins derived from bacteria, fungal, plant, or animal origins including saporin (page 9, [0127]).
M.Wang teaches that an efficient and safe method to deliver active proteins into the cytosol of targeted cells is highly desirable to advance protein-based therapeutics. A novel protein delivery platform has been created by combinatorial design of cationic lipid-like materials, termed “lipidoids”, coupled with a reversible chemical protein engineering approach (abstract). M.Wang teaches that lipidoids had previously been used for siRNA, DNA, and mRNA delivery. It was further hypothesized and demonstrated that the lipidoids could be used as a novel protein delivery platform, as the charge-charge and hydrophobic interactions between lipidoids and proteins can load proteins into the lipidoid nanoparticles. In turn, the hydrophobic nature of the lipidoid nanoparticles allows easy protein transport through the cell membrane (page 2893, right column, paragraph 2).
In an attempt to strengthen the charge-charge and hydrophobic interactions between the proteins and lipidoids, M.Wang teaches that the lysine residues of the protein were modified with cis-aconitic anhydride. The conjugation reaction between the amine groups of lysine and cis-aconitic anhydride converts the positively charged lysines into negatively charged carboxylate groups, thus increasing the negative charge density of the protein and its binding with cationic lipidoids (page 2893, right column, paragraph 2). In the studies performed by M.Wang, RNase A and saporin were used as representative cytotoxic proteins along with the cis-aconitic anhydride modified versions, RNase A-Aco and saporin-Aco (page 2893, right column, paragraph 3).
M.Wang teaches that using RNase A, RNase A-Aco, Saporin, and Saporin-Aco, it is demonstrated that the lipidoid nanoparticles can deliver protein into cells and inhibit cell proliferation for potential applications such as cancer therapy. RNase A and saporin have both been used in clinical trials in cancer patients that are refractory to traditional chemotherapy and, in an in vivo study, it is demonstrated that lipidoid/saporin nanoparticle formulation suppresses tumor growth in breast cancer models by accumulating saporin at the tumor site (paragraph bridging pages 2893-2894).
The library of lipidoids used in M.Wang was synthesized through the ring opening-reaction between 1,2-epolyhexadecane and amine under mild conditions. The lipidoids are named “EC16” followed by the amine number in the library as shown in Figure 1, where EC16 indicates 1,2-epoxyhexadecane (page 2894, left column, paragraph 2). M.Wang Figure 1 (page 2894) shows the route of synthesis for lipidoids and is reproduced below for convenience:
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The 1,2-epoxyhexadecane epoxide disclosed by M.Wang is identical to the epoxide of the instant claims and amine 12 in Figure 1b is identical to the first amine recited in instant claim 1 and that recited in claim 30. M.Wang further demonstrates delivery of saporin and saporin-Aco with EC16-12 (page 2894, Figure 2; right column, paragraph 1).
M.Wang further teaches the development of a general protein delivery formulation in which the lipidoid/protein formulations were post-modified with DSPE-PEG2000-biotin to target tumor cells and tissues. Biotinylated polymers or nanoparticles can be selectively taken up by cancer cells and accumulate in the tumor tissue, improving therapeutic efficacy. The lipidoid/RNase A-Aco, lipidoid/saporin, and empty lipidoid formulations are all disclosed by M.Wang as having a size of about 120 nm as determined by DLS analysis (page 2895, right column, paragraph 2).
M.Wang teaches that in breast cancer models, lipidoid and free saporin treated groups had similar tumor volumes to PBS control mice, but lipidoid/saporin nanoparticle-treated mice had significantly reduced tumor volumes, by 80%, compared to control groups (page 2897, left column, paragraph 1; page 2896, right column, paragraph 4).
R.Wang teaches that PEG-DSPE block copolymers are biocompatible and amphiphilic polymers that can be widely utilized in the preparation of liposomes, polymeric nanoparticles, polymer hybrid nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, and microemulsions. Particularly, the terminal groups of PEG can be activated and linked to various targeting ligands, which can prolong the circulation time, improve the drug bioavailability, reduce undesirable side effects, and especially target specific cells, tissues, and even intracellular localization in organelles. R.Wang provides a review of recent developments in drug carriers exploiting PEG-DSPE and the incorporation of different ligands to the end groups of PEG-DSPE to target delivery (abstract).
R.Wang further teaches that antibody-mediated targeting therapeutics have been explored with the development of antibody engineering and phage display technologies and have been employed to realize high specificity for target tissues, a wide range of binding affinities, and small molecular sizes. When proper antibodies are linked to the reactive terminal of PEG-DSPE, the carriers can be targeted to the selected tissue, depending on the ability of the antibody or ligand that facilitates cell-specific docking. For instance, a postinsertion method was adopted to incorporate anti-CD22-PEG-DSPE into liposomes containing anti-cancer drugs. The anti-CD22 immunoliposomes exhibited increased efficacy and reduced toxicity compared to unmodified ones (page 4187, right column, Antibody targeting moieties).
R.Wang further teaches lipid nanoparticles that have been fabricated for delivery of both doxorubicin (page 4187, right column, paragraph 4; page 4192, right column, paragraph 5) and paclitaxel (page 4191, right column, paragraph 1; page 4192, right column, paragraph 2).
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have modified the method of sterilization using the FSHβ-melphalan conjugate disclosed by Amory by substituting the conjugate with an anti-AMHR-II antibody conjugated to a cytotoxin, such as saporin, as taught by US’300. It would have further been obvious to modify the conjugate to include the lipidoid nanocomplex delivery system of M.Wang where the lipidoid nanocomplex delivery system comprises the cytotoxin and is conjugated to the anti-AMHR-II antibody as taught by M.Wang and further supported by R.Wang
It would have been obvious to one of ordinary skill in the art to use the anti-AMHR-II conjugate of US’300 in the non-surgical sterilization methods of Amory as US’300 teaches that AMHR-II is expressed by Sertoli and Leydig cells on human testis, which are the same cell types targeted by the FSHβ conjugates of Amory. It would have been obvious to use saporin as the cytotoxin as US’300 teaches saporin as an alternative to melphalan for inhibition, function prevention, and/or destruction of target cells suggesting analogous properties. Thus, an ordinarily skilled artisan would have had a reasonable expectation of success.
An ordinarily skilled artisan would have been motivated to use the lipidoid nanocomplex delivery systems of M.Wang in the anti-AMHR-II conjugates in order to increase delivery of the drug into the cytosol of the target cells which M.Wang demonstrates can inhibit cell proliferation for therapeutic applications. Additionally, M.Wang demonstrates that using lipidoids can significantly reduce tumor volumes compared to the free drug demonstrating increased delivery of therapeutics to the cytosol of cells. An ordinarily skilled artisan would have had a reasonable expectation of success as US’300 teaches conjugates using cytotoxins, including saporin, which M.Wang demonstrates can be delivered using the disclosed lipidoids and both US’300 and M.Wang disclose methods of targeted delivery of saporin to cells. An ordinarily skilled artisan would have had a reasonable expectation of success in conjugating the anti-AMHR-II antibody of US’300 to the lipidoid of M.Wang as M.Wang further demonstrates the post modification of the lipidoids with DSPE-PEG2000-biotin for targeting and R.Wang teaches that DSPE-PEG has been used to functionalize lipid nanoparticles with targeting agents including antibodies. An ordinarily skilled artisan would have had a reasonable expectation of success in using the antibody-conjugated lipidoid in the methods of Amory as the AMHR-II antibody would still function in the targeted delivery of the cytotoxin in the lipidoid to Sertoli cells which would be expected to result in a significant reduction in testicular spermatid counts.
Regarding claim 29, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to substitute the saporin cytotoxin taught by the combination of Amory, US’300, M.Wang, and R.Wang with saporin-Aco as disclosed by M.Wang. It would have been obvious to make this substitution with a reasonable expectation of success as M.Wang teaches that saporin Aco is a cis-aconitic anhydride modified version of saporin (page 2893, right column, paragraph 3) and demonstrates effective use of the therapeutic in the disclosed lipidoid nanoparticles for delivery to target cells (page 2894, Figure 2). An ordinarily skilled artisan would have reasonably expected that saporin Aco would be capable of inducing sterilization when used in the method as US’300 teaches saporin as an alternative cytotoxin to the melphalan disclosed by Amory.
Regarding claims 37 and 40-42, while Amory performed in vitro studies in male mice, not male rats, Amory further teaches that in vitro cytotoxicity assays and imagine were performed using cells derived from male Sprague Dawley rat pups. Testes of the rat pups were dissected for testing (page 154, left column, 2.2). Amory teaches that the cell cultures with melphalan and FSHβ-melphalan exhibited marked cell death and significant toxicity compared to controls (page 155, right column, paragraph 1).
US’300 further teaches that the AMHR-II gene has been isolated in rats, rabbits, humans, and mice (page 4, [0047]).
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to have treated male rats using the method disclosed by the combination of Amory, US’300, M.Wang, and R.Wang based on the teachings of Amory. It would have been obvious to use the method in non-surgical sterilization of male rats and a person of ordinary skill in the art would have had a reasonable expectation of success as Amory demonstrates that the conjugate is capable of significant toxicity and marked cell death in cells obtained from male rats. Furthermore, US’300 teaches that AMHR-II is expressed in rats demonstrating that an antibody drug conjugate that targets AMHR-II would be effective in also treating rats.
Claims 31-32, 43 and 44 are rejected under 35 U.S.C. 103 as being unpatentable over Amory, J.K., et al (2014) Melphalan, alone or conjugated to an FSH-β peptide, kills murine testicular cells in vitro and transiently suppresses murine spermatogenesis in vivo Theriogenology 82; 152-159 in view of US 2013/0164300 A1 (Isabelle Teulon and Andre Pelegrin) 27 June 2013, Wang, M., et al (2014) Combinatorially Designed Lipid-like Nanoparticles for Intracellular Delivery of Cytotoxic Protein for Cancer Therapy Angew. Chem. Int. Ed. 53; 2893-2898 (herein “M.Wang”), and Wang, R., et al (2012) Application of poly(ethylene glycol)-distearopylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery International Journal of Nanomedicine 7; 4185-4198 (herein “R.Wang”) as applied to claim 1 above, and in further view of Altinoglu, S., et al (2015) Combinatorial library strategies for synthesis of cationic lipid-like nanoparticles and their potential medical applications Nanomedicine (Lond.) 10(4); 643-657.
The combination of Amory, US’300, M.Wang, and R.Wang teach the method of claim 1 as discussed in detail above.
For the reasons discussed in detail above, the combination of Amory, US’300, M.Wang, and R.Wang also teach that the subject is a rat.
The combination of Amory, US’300, M.Wang, and R.Wang, however, do not disclose the amine structures of the instant claims.
Altinoglu provides a review of methods used for combinatorial lipidoid synthesis, the application of high-throughput screening, and the current medical applications of candidate lipidoids (abstract).
Altinoglu teaches epoxide-amines and teaches that a ring-opening reaction between epoxide and amine to develop a new lipidoid library had been adapted. The epoxide-amine addition is an efficient, straightforward, and fast reaction. A key advantage to using this synthesis method is that the reaction is rapid and, by using the epoxide group instead of an acrylate or acrylamide adds more diversity to the type of lipidoid structures that can be synthesized (page 645, paragraph bridging columns). Altinoglu teaches chemical approaches that have been used for combinatorial synthesis of cationic lipids including the ring opening reaction of epoxide (page 645, Figure 1B), which is the method disclosed by M.Wang.
Altinoglu further teaches amine core structures used in library synthesis (Figure 2B, pages 646-647). The amine core structures disclosed by Altinoglu for use in the synthesis of lipidoids comprise structures that overlap with those disclosed by M.Wang, for example amines 7, 10, 20, 22, 25, 31, 34, 63, 80, 87, 90, and 93. Altinoglu further discloses amine structures 99 and 100, which match the amines of the instant claims, as shown below:
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It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to substitute the amines of the lipidoid in the method taught by the combination of Amory, US’300, M.Wang, and R.Wang with the amines disclosed by Altinoglu as both M.Wang and Altinoglu are teaching combinatorial synthesis of lipidoids and amines that can be used to synthesize lipidoids for drug delivery platforms. An ordinarily skilled artisan would have had a reasonable expectation of success as Altinoglu teaches amines that overlap with those of M.Wang as well as additional amines that can be used in synthesis suggesting that the amine groups have analogous properties when used in lipidoid synthesis.
Claims 35-36 and 38-39 are rejected under 35 U.S.C. 103 as being unpatentable over Amory, J.K., et al (2014) Melphalan, alone or conjugated to an FSH-β peptide, kills murine testicular cells in vitro and transiently suppresses murine spermatogenesis in vivo Theriogenology 82; 152-159 in view of US 2013/0164300 A1 (Isabelle Teulon and Andre Pelegrin) 27 June 2013, Wang, M., et al (2014) Combinatorially Designed Lipid-like Nanoparticles for Intracellular Delivery of Cytotoxic Protein for Cancer Therapy Angew. Chem. Int. Ed. 53; 2893-2898 (herein “M.Wang”), and Wang, R., et al (2012) Application of poly(ethylene glycol)-distearopylphosphatidylethanolamine (PEG-DSPE) block copolymers and their derivatives as nanomaterials in drug delivery International Journal of Nanomedicine 7; 4185-4198 (herein “R.Wang”) as applied to claim 1 above, and in further view of Johnston, S. and L. Rhodes (2015) No Surgery Required: The future of feline sterilization Journal of feline medicine and surgery 17; 777-782 and Axner, E. and B.S.Holst (2015) Concentrations of anti-Mullerian hormone in the domestic cat. Relation with spay or neuter status and serum estradiol Theriogenology 83; 817-821.
The combination of Amory, US’300, M.Wang, and R.Wang teach the method of claim 1 as discussed in detail above.
US’300 further teaches that in the female, AMHR-II expression is maintained along the length of the Mullerian duct, and is detected in the normal and gravid uterus. AMH and AMHR-II are co-expressed in the testicular Sertoli and ovarian granulosa cells, and in derived cells (page 4, [0047]).
The combination of Amory, US’300, M.Wang, and R.Wang, however, do not disclose that the subject is a female, cat, or female cat.
Johnston teaches that for over 30 years, researchers have been investigating non-surgical technologies that might be used to suppress fertility in cats and dogs (page 777, paragraph 1). Surgical ovariohysterectomy (or ovariectomy) and castration remain the cold standard for inducing permanent sterility in cats and dogs. Surgical sterilization not only prevents generation of offspring, but it also prevents undesirable behavior associated with estrogen secretion in the female and testosterone secretion in the male that can be barriers to successful pet ownership. Johnston teaches that surgical sterilization is associated with undesirable sequelae in some pets including obesity, urinary incontinence, joint disease, and some cancers (page 777, paragraph 3).
Johnston teaches that such research includes targeted delivery of cytotoxins. Instead of surgically removing reproductive organs such as the uterus, ovaries, or testes, some scientists are exploring whether it might be possible to specifically target and kill cells that are vital to maintain reproduction. In order for this approach to work, three things are required: a method for targeting a particular subtype of cell; a potent toxin that can kill cells when delivered by the targeting mechanism; and finally, a way to get the drug-toxin conjugate to the specific cells. This approach is used to kill cancer cells in human medicine. For example, a prostate cancer therapy has been developed that uses antibodies to a protein specific to many prostate cancer cells and conjugates this antibody to a potent toxin. Once the antibody has bound to the prostate cancer cell surface, the toxin is delivered and kills only the cancer cells (page 779, right column, paragraphs 3-4).
Johnston teaches that a number of grants using this type of approach have been funded and researches are targeting neurons in the brain that secrete GnRH with the understanding that, if these neurons are killed, the entire reproductive cascade is shut down in both male and female cats and dogs. Johnston further teaches that another brain target is the population of gonadotrophs in the anterior pituitary (page 779, right column, paragraph 5). Another exciting target are the stem cells in the gonads- the cells that differentiate into ovarian follicles and sperm. If those cells could be specifically destroyed, then cats or dogs could be made sterile (page 780, left column, paragraph 2). Several grants have been awarded to study these approaches. Grantees are targeting GnRH neurons with IV administration of the peptide kisspeptin, which binds receptors on GnRH neurons, conjugated to the toxin saporin. Others are linking GnRH analogs with toxins that are expected to bind to, and kill, gonadotrophs. Scientists targeting gonadal stem cells are searching for homing peptides that can specifically deliver an agent to those sells, and seeking agents that can be internalized into the cells and destroy them (page 780, left column, paragraph 3).
Axner teaches that female cats with unknown history can be diagnosed as spayed or intact with a GnRH stimulation test or an LH test independent of the stage in the estrous cycle; however, the sensitivity and specificity are not 100%. Axner teaches that granulosa cells are the only cell type in females that produce anti-Mullerian hormone (AMH), whereas Sertoli cells produce AMH in males. Axner compared AMH levels in intact and spayed/neutered female and male cats and teaches that AMH testing had 100% sensitivity and specificity when used to diagnose the presence or absences of ovaries/testis. (abstract).
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method taught by the combination of Amory, US’300, M.Wang, and R.Wang to try the method in a subject that is female, a cat, or a female cat, as taught by Johnston and further supported by US’300 and Axner. A person of ordinary skill in the art would have been motivated to try the non-surgical sterilization method on a female cat as Johnston teaches that researchers have been studying non-surgical technologies for fertility suppression in female and male cats and dogs and that surgical sterilization can lead to undesirable sequelae including obesity, urinary incontinence, joint disease, and some cancers. A person of ordinary skill in the art would have had a reasonable expectation of success as US’300 teaches that AMHR-II is expressed on ovarian granulosa cells, which Axner teaches is the only cell type that produces AMH in females, which is shown to be linked to sterility.
Response to Arguments
Applicant’s arguments in the response filed 11/03/2025 have been fully considered, but were not persuasive.
Applicant argues that the cited references do not disclose the claimed antibody conjugate or its use in a method of sterilization. Applicant argues that Amory discloses FSH-β peptides conjugated to the cytotoxic agent melphalan and that Amory does not disclose an antibody, a nanoparticle, the protein toxin saporin, and that the conjugate targets FSH receptor, not AMHRII. With regards to the other applied references, applicant argues that Teulon and Wang 1 does not teach an anti-AMHRII antibody conjugated to a nanoparticle as claimed; that Wang 2 is silent to an anti-AMHRII antibody; and that these references are silent regarding non-surgical sterilization. Applicant argues that Johnston and Axner do not alter this conclusion as the references relate to animal fertility and sterilization techniques, but do not say anything about anti-AMHRII antibody or conjugates thereof.
Applicant’s arguments pertain to what each reference teaches or fails to teach. The rejections of the instant office action, however, are based on the combination of the applied references and what the references would have suggested to one of ordinary skill in the art prior to the effective filing date of the claimed invention. Therefore, none of the references individually are required to teach each and every limitation of the claimed invention in order to render the claims obvious over the prior art.
MPEP 2145 (IV) states “One cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., Inc., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). Where a rejection of a claim is based on two or more references, a reply that is limited to what a subset of the applied references teaches or fails to teach, or that fails to address the combined teaching of the applied references may be considered to be an argument that attacks the reference(s) individually. Where an applicant’s reply establishes that each of the applied references fails to teach a limitation and addresses the combined teachings and/or suggestions of the applied prior art, the reply as a whole does not attack the references individually as the phrase is used in Keller and reliance on Keller would not be appropriate. This is because "[T]he test for obviousness is what the combined teachings of the references would have suggested to [a PHOSITA]." In re Mouttet, 686 F.3d 1322, 1333, 103 USPQ2d 1219, 1226 (Fed. Cir. 2012).”
In this case, Amory is not required to teach an AMHRII antibody, a nanoparticle, or saporin because these limitations are supported by the other applied references, specifically US’300 (referenced by applicant as “Teulon”), M. Wang (referenced by applicant as “Wang 1”) and R. Wang (Referenced by applicant as “Wang 2). Amory is applied in the rejection of the independent claim in order to demonstrate that methods of sterilizing animals using conjugated cytotoxins targeting Steroli cells had been studied in the prior art. US’300 is applied to demonstrate that anti-AMHRII antibodies were known in the art, that AMHRII was known to have strong expression on human granulosa cell tumors (GCTs) and Steroli and Leydig cells on human testis. US’300 also teaches conjugates comprising the antibody conjugated to cytotoxic agents that include both melphalan, which is the toxin disclosed by Amory, and the alternative cytotoxin saporin. M. Wang and R. Wang are cited to demonstrate that lipidoids were known in the art as a means to increase drug delivery to the cytosol of cells and to support the conjugation of the lipidoid to a targeting agent by functionalizing the lipid nanoparticles, for example using DSPE-PEG. Specific motivations and rationales for combination as well as a reasonable expectation of success are discussed in detail in the rejections of record.
With regards to Amory, applicant further argues that Amory failed to induce useful sterilization. Applicant argues that, although Amory observed killing of Sertoli cells in vitro, it acknowledges that its method failed to kill Steroli cells in vivo. Applicant cites Amory as stating that after 12 weeks, only Steroli cells present on histologic examination and that the behavior of Sertoli cells in vitro may be different from their behavior in vivo. Steroli cells in culture can proliferate and, therefore, may be more sensitive to the effects of melphalan compared with Sertoli cells in vivo, which are nonreplicating. Applicant argues that Amory only observed temporary sterilization, noting that most tubules appear to have recovered at 12 weeks. Applicant argues that the rejection points out one animal that had no apparent spermatogenesis at 12 weeks after injection, suggesting that this animal might have been sterilized by treatment. Applicant argues that single animal out of an entire study having been possibly sterilized, while all other animals achieved transitory sterilization would not have indicated that the approach was successful. Applicant argues that this is especially the case because Amory teaches that additional research will be needed to develop a single dose method of permanent sterilization for male animals.
These arguments, however, are not persuasive. In the studies performed by Amory, all animals dosed with either melphalan or the FSHβ conjugate had greater than 75% reduction in testicular spermatid counts compared with a placebo group at 4 weeks. Amory discloses that 12 weeks after treatment, quantitatively and histologically, normal spermatogenesis had returned to all treatment groups. While this is suggestive of temporary sterilization, the instant claims do not require any degree or length of sterilization and even transitory sterilization could be interpreted to meet the instant claim limitation which only requires that the method induce sterilization. Additionally, while applicant argues that only 1 of 24 animals studied by Amory had been fully sterilized with no apparent spermatogenesis at 12 weeks after injection, this result suggests that full sterilization is possible, even if Amory calls for additional studies to be performed. Overall, the results disclosed by Amory demonstrate that conjugates are able to target Steroli cells and, at least temporarily, result in sterilization.
Applicant further argues that the claimed method results in unexpected sterilization results. Applicant argues that the combination of applied references would not have led an ordinarily skilled artisan to predict that the claimed antibody-conjugated nanoparticles would successfully provide sterilization when administered to male or female rats, as has been experimentally demonstrated by applicant. Applicant cites the instant specification page 12, paragraph 2 for support as well as the previously submitted declaration of 06/05/2025 by Dr. Sandra L. Ayres.
Applicant’s citation to the specification is to an example in which the anti-AMHRII antibody conjugated nanoparticle was used for sterilization in male and female rats. The example discloses that eight male and eight female Sprague Dawley rats (7 weeks of age) were divided into two groups with one group injected with the AMHRII antibody conjugated nanoparticles (N1-N8) and the other group with sterile saline (S1-S8). Specifically, N1-N8 received 8.2 nmol intravenous dose of the nanoparticle followed by a saline flush. All rats, injected on Day 0, were housed for 4 weeks and weighed twice a week on Mondays and Thursdays. Females were assessed for estrous cyclicity during weeks 3 and 4. The rats were then sacrificed, blood was collected, testes and uteri were weighed, epididymides were collected for semen evaluation, and ovaries and testes were preserved in 10% formaldehyde for histological processing. The example teaches that the rats treated with the conjugated nanoparticle demonstrated acyclicity an indicium of sterilization, compared to those treated with saline. The example concludes that the conjugate is capable of inducing sterilization in male and female rats.
The declaration under 35 CFR 1.132 by Dr. Ayres demonstrates that the claimed methods are also efficacious at sterilizing female cats. In the study, it is shown that one group of cats were treated with the claimed method and compared to a group of controls not treated with the method. Following the study it was found that the vast majority, 83%, in the control group underwent spontaneous ovulation compared to only a single cat, 20%, in the treated group.
While the results presented by applicant do demonstrate that the claimed method is efficacious in reducing sperm in male rats, and sterilizing female rats and cats, applicant does not provide a comparison to the closest prior art, which is the conjugate of Amory, in order to establish that the results are unexpected.
MPEP 716.02 (e) states “An affidavit or declaration under 37 CFR 1.132 must compare the claimed subject matter with the closest prior art to be effective to rebut a prima facie case of obviousness. In re Burckel, 592 F.2d 1175, 201 USPQ 67 (CCPA 1979).” MPEP 716.02 (b)(III) states “Evidence of unexpected properties may be in the form of a direct or indirect comparison of the claimed invention with the closest prior art which is commensurate in scope with the claims.”
In the specification and the Dr. Ayres declaration, the outcomes of the claimed method are compared to controls that did not receive treatment. Applicant does not provide a comparison to the closest prior art in order to demonstrate that the claimed method results in unexpected outcomes. For instance, the closest prior art could be considered to be Amory and a comparison between the FSHβ-melphalan conjugate taught by Amory and the claimed conjugate could be used to demonstrate unexpected results compared to the closest prior art.
It is also noted that MPEP 716.02 states that “difference of degree is not as persuasive as a difference in kind – i.e., if the range produces ‘"a new property dissimilar to the known property,’" rather than producing a predictable result but to an unexpected extent.”
With regards to a comparison with Amory, applicant argues that Amory failed to achieve durable sterilization in vivo and that the conjugate is “particularly unsuited” for inducing non-surgical sterilization. Applicant argues that, because of this, Amory evidences the unexpectedness of applicant’s successful, non-surgical sterilization data.
A comparison between Amory and the provided data, however, cannot clearly be envisioned. For instance, as discussed above, the examples of the instant disclosure indicate that the treated rats were sacrificed 4 weeks following injection of the conjugate. In the study of Amory, Amory discloses that at 4 weeks after in vivo administration of the FSHβ-melphalan conjugate, the conjugate markedly suppressed spermatogenesis. Amory doesn’t teach that normal spermatogenesis had returned until week 12. The examples of the disclosure do not demonstrate that the duration of sterilization achieved with the instantly claimed conjugate was longer or more significant compared to that of Amory.
It is noted that, in the declaration, female cats were provided the conjugate on March 7, 2023 and spayed on May 24, 2023, indicating >12 weeks of sustained sterilization in 4/5 cats; however, it is unclear how this data compares to the conjugate of Amory because Amory studied the conjugate only in male rats. Additionally, while applicant argues that the examples demonstrate that male rats displayed more apoptotic cells than female rats, the examples appear to demonstrate sterilization only at 4 weeks and it is unclear if such a difference would be observed over longer periods of time.
Additionally, sterilization would have been expected in view of the teachings of the prior art.
MPEP 716.02 states “Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected.”
For instance, Amory demonstrates that targeting Sertoli cells with FSHβ-melphalan conjugates resulted in greater than 75% reduction in testicular spermatid counts compared to placebo groups after 4 weeks (page 155, right column, paragraph 2). US’300 teaches that AMHR-II is also expressed on testicular Sertoli cells as well as ovarian granulosa cells (page 4, [0047]) and also teaches saporin as an alternative cytotoxin to melphalan (page 9, [0127]). Based on these teachings of US’300, a person of ordinary skill in the art would reasonably expect similar outcomes to those disclosed by Amory when Sertoli cells in males, or ovarian granulosa cells in females, are targeted with an anti-AMHR-II antibody conjugated to saporin. Additionally, as M.Wang teaches that the use of lipidoids can increase intracellular delivery, a person of ordinary skill in the art would also expect that increased delivery of the saporin could be achieved possibly resulting in higher levels of inhibition, prevention of function, or destruction of cells.
Additionally, the results are not commensurate in scope with the claims. MPEP 716.02(d) states “Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range.”
In the examples of the instant specification, two AMHRII antibody-conjugated nanoparticles were prepared and characterized using the lipidoid EC16-1 prepared according to the methods reported in Sun et al. and a nanocomplex was formed saporin or saporin Aco using the methods reported in Wang et al (page 12, Example 1). The specification further specifies that the AMHRII antibody was purchased from Sigma-Aldrich.
The disclosure does not explicitly identify the structure of EC16-1; however, based on the teachings of Wang, EC16-1 comprises 1, 2-epoxyhexadecane, which is the claimed epoxide, and the following amide (Page 2894, Figure 1):
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The declaration also states that the method in the study used an anti-AMHRII antibody, saporin, and a nanoparticle formed from EC16-1 and an epoxide. According to Wang, EC16-1 already comprises an epoxide and it is unclear from the description in the declaration (page 1, 4.) if there is an additional epoxide in the nanoparticle or if the nanoparticle comprised only the EC16-1 lipidoid described by Wang which already contains the epoxide 1, 2-epoxyhexadecane.
The results provided are not commensurate in scope with the claimed invention which recites 3 alternative amides and does not include the amide that is in EC16-1. Additionally, the instant claim encompasses any AMHRII antibody and the sterilization of any subject in need thereof; however only one AMHRII antibody is demonstrated as resulting in the presented outcomes and only in the sterilization of male/female rats and female cats.
Conclusion
No claims are allowed.
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.
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/AUDREY L BUTTICE/Examiner, Art Unit 1647
/SCARLETT Y GOON/Supervisory Patent Examiner
Art Unit 1693