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
The present application is the U.S. National Stage Application, pursuant to 35 U.S.C.371, of PCT International Application No. PCT/CN2020/l10998, filed August 25, 2020 which claims priority to Foreign Patent No. CN201910792478.5, filed August 26, 2019.
Status of the Claims
Applicant has made the following changes in the response filed on October 29, 2025:
Claims 1, 12 and 32 are amended to replace the structure of formula I with a clearer version. Claims 1 and 32 are amended to specify that the second therapeutic agent for cancer treatment is an immune cell for adoptive cell therapy, and to further specify that the immune cell and the phenothiazine compound are both active ingredients, and that the phenothiazine compound is a free compound.
Claim 12 is amended to specify that the cancer is lung cancer or
lymphoma.
Claims 1, 3, 12, 22 and 32 are amended to remove the term "substituted or
unsubstituted". Claims 2, 4, 13 and 21 are amended to correct typographic errors.
Claims 17, 30-31 and 33-35 are canceled. Claim 8 is amended to depend on claim 1
accordingly.
New claims 36-37 are added to further specify R1 to R10, which corresponds to the
substituents in MTC and LMT, and therefore new claims 36-37 are supported by the specification. New method claims 38-43 are added.
Claims 1-4, 6, 8-10, 12, 13, 15, 21, 22, 32 and 36-43 are pending and are examined on their merits.
Claim Rejections Overcome by Amendment
35 U.S.C. § 112(b) Rejections for Claims 1-4, 6, 8-10, 12, 13, 15, 17, 21, 22 and 30-35 Overcome by Amendment
Applicant has replaced the structure of formula I with a clearer version that identifies the variable Y, thus overcoming the 112(b) rejections for claims 1-4, 6, 8-10, 12, 13, 15, 17, 21, 22 and 30-35.
35 U.S.C. § 102(a)(1) Rejections for Claims 1-4 and 6 Overcome by Amendment
Applicant has amended claim 1 to claim a pharmaceutical composition, comprising: (a) as a first active ingredient, a free phenothiazine compound having formula (I), or a hydrate, a solvate or a reduced form thereof, and (b) as a second active ingredient, an immune cell for adoptive cell therapy. The teaching of Wainwright does not specifically state methylene blue used as a “free” phenothiazine compound and does not teach a secondary treatment with an immune cell for adoptive therapy.
Accordingly, the rejection is withdrawn.
Claim Rejections - 35 USC § 103- Necessitated by Amendment
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.
Claims 1 and 32 are rejected under 35 U.S.C. 103 as being unpatentable over Sanchala, et.al., Anticancer activity of methylene blue via inhibition of heat shock protein 70, Biomedicine 2018), WO 2019/136335 Al hereinafter referred to as 6335 and in further view of Wainwright, (Photodiagnosis and Photodynamic Therapy, 2005 vol. 2, pages 263-272), hereinafter referred to as Wainwright.
Claim 1 has been amended to pharmaceutical composition, comprising
(a) as a first active ingredient, a free phenothiazine compound having formula (I), or a hydrate,
a solvate or a reduced form thereof,
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wherein,
Z is selected from a group consisting of s+, o+, C and N;
Y is N or N+; when Z is s+ or o+, Y is N; and when Z is C or N, Y is N+;
X- is one or more anions that form a salt with Z+ or N+ to achieve electric neutrality; and
R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are independently selected from a group consisting of hydrogen, alkyl, cycloalkyl, heterocyclic alkyl, aryl, heteroaryl, alkoxyl, arylalkoxyl, thioalkoxyl, amido, nitro, amino, and halogen, and
(b) as a second active ingredient, an immune cell for adoptive cell therapy.
Claim 32 purports a kit with the same limitations as claim 1; namely as a first active ingredient, a free phenothiazine and as a second active ingredient, an immune cell for adoptive cell therapy.
Applicants purport, in the remarks dated October 29, 2025, that the combination of a free phenothiazine of the compound of formula (I) and a second active ingredient of an immune cell for cell therapy and that each part of the combination is free and is active.
Sanchala details an investigation based on non-small cell lung cancer (NSCLC), using A549 non-small cell lung cancer cells. The decision to focus on this cancer type and these cells specifically is because the serum and tissue samples of patients with NSCLC versus healthy individuals that show elevated heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90). These two heat shock proteins are also known as apoptosis inhibitors. They evaluate and compare anticancer potential of methylene blue (MB) as an Hsp70 inhibitor, novobiocin (NB) a well-known Hsp90 inhibitor and their combination. Each of these compounds were evaluated for their anticancer effects in the “free” form (i.e. not conjugated to another anticancer agent). The rationale for the study is of these two proteins is described below.
“Hsp70 over-expression is associated with adverse prognosis and resistance to chemotherapy [10,11]. Lung cancer cells apart from being associated with Hsp70 are dependent on Hsp90 chaperone protein for their stability and protein refolding. Lung cancer cells are often dependent on Hsp70/Hsp90 chaperone network due to their high dependence on correctly folded oncogenic client proteins for their survival and proliferation. Hsp70 transfers specific oncogenic client proteins to Hsp90 via adapter proteins; the later effectuate their conformational maturation [12].”
Sanchala, page 1037, col. 2 (emphasis added).
The results are summarized in the abstract of the article:
“Using A549 NSCLC cells, we found MB demonstrated lower cell viability versus NB. Together, MB+NB resulted in further decrease in cell viability. SRB assay revealed significantly superior and similar potency for MB versus NB and MB+NB (1:1) versus MB, respectively. Fluorescent staining and flow cytometry analysis displayed early apoptosis by MB (11.4%); early and late apoptosis by MB+NB (13.8%). In vivo, MB significantly inhibited Hsp70. Furthermore, MB significantly alleviated tumor biomarkers (ADA and LDH) and improved lung histopathological features more than NB.”
And concludes,
“MB demonstrated potent anticancer activity in vitro and in vivo via inhibition of Hsp70 in benzo[a] pyrene induced lung carcinogenesis in mice.”
Sanchala, abstract, page 1037 (emphasis added).
Although Sancha teaches the “free” compound of methylene blue (MB) has potent anticancer effects treating A549 non-small cell lung cancer cells both in vitro and in vivo by targeting the Hsp70. They do not teach a cell therapy component. 6335 does teach a Chimeric antigen receptor (CAR) T-cell therapy is a way to get immune cells called T cells (a type of white blood cell) to fight cancer by changing them in the lab so they can find and destroy cancer cells. CAR T-cell therapy is also sometimes talked about as a type of cell-based gene therapy, because it involves altering the genes inside T cells to help them attack the cancer. For example, in [0008]:
“According to another embodiment, an effector cell comprising such a polynucleotide construct is provided. Such effector cells include, without limitation: lymphoid lineage cells, e.g., T cells Natural 25 Killer (NK) cells, cytotoxic T lymphocytes (CTLs), or regulatory T cells; or myeloid lineage
cells, e.g., neutrophils or macrophages; or other cells such as T-cells, Natural Killer T cells (NKT cells) or lymphokine-activated killer (LAK) cells. Such cells may be autologous cells (i.e., cells harvested from a patient and returned to the patient after introduction of a CAR vector into the cells) or heterologous cells, e.g., allogeneic cells.”
6335, [0008], lines 22-29, (emphasis added).
Sanchala teach that methylene blue (MB) significantly inhibits Hsp70 a protein associated with lung cancer cells that are dependent on Hsp90 chaperone protein for their stability and protein refolding. The administration of MB as a “free” phenothiazine is showed to be effective both in vitro and in vivo to significantly inhibited Hsp70 and therefore treat lung cancer. 6335 teach the use of effector cells used that may be autologous cells (i.e., cells harvested from a patient and returned to the patient after introduction of a CAR vector into the cells) a key feature of immune cell therapy.
The combination claimed therefore appears little more than an arrangement of old elements with each performing the same function it had been known to perform and yielding no more than one would expect from such an arrangement. KSR v. Teleflex, 127 S.Ct. 1727, 1740 (2007) (quoting Sakraida v. A.G. Pro, 425 U.S. 273, 282 (1976)) (indicating that “when the question is whether a patent claiming the combination of elements of prior art is obvious,” the relevant question is “whether the improvement is more than the predictable use of prior art elements according to their established functions.”).
Accordingly, the instant claims are rejected.
Regarding Claim 2 the instant claim is amended to drawn to the pharmaceutical composition of amended claim 1, wherein X- is selected from a group consisting of Cl-, Br-, I-, methanesulfonic ion, ethanesulfonic ion, p-toluenesulfonic ion, benzenesulfonic ion, ethanedisulfonic ion, propanedisulfonic ion, and naphthalene disulfonic ion.
Wainwright teaches that during the synthesis of phenothiazine by employing the oxidation of phenothiazine itself with, e.g., bromine or iodine furnishes a phenothiazinium chromophore which is reactive in positions 3- and 7-. Thus, water-insoluble amines and anilines can be attached to the ring in these positions, yielding products which are not easily preparable by the usual aqueous-based methods. A range of anilines, pyridines and long-chain dialkylamines were thus attached [7], page 266, col 2, paragraph 1. The ions listed in the instant claim are used to balance the electrical charges to achieve neutrality. By way of definition, Gupta, et.al., (Salts of Therapeutic Agents: Chemical, Physicochemical, and Biological Considerations) Molecules, 2018, vol. 23, pages 1-15, describes the choice of particular salt formulations can improve the overall therapeutic and pharmaceutical effects of an active pharmaceutical ingredient. Further, Gupta et. al., teach the selection of anions for pharmaceuticals should consider the current list of FDA-approved drugs including chloride, bromide and iodide as outlined in Table 1 below. For example:
“Currently, a wide range of validated counterions is available to prepare the salts of APIs (Table 1) [9]. One important criterion in the selection of counterions is to employ agents that have been previously used in FDA-approved drugs, and are thereby generally recognized as safe (GRAS) [7].”
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Gupta et.al., page 2, paragraph 1, Table 1, (emphasis added).
Therefore, Wainwright teaches the use of bromine or iodine to functionalize the phenothiazinium chromophore to result in a compound reactive in positions 3- and 7- to allow water-insoluble amines and anilines to be attached to the ring in these positions. Gupta, et.al. teach the use of cations Cl-, Br- and I- as among the list of cations that have been previously used in FDA-approved drugs, and are thereby generally recognized as safe (GRAS) and in the instant claim only serve to balance the charge of the compound.
Applicant is simply drawing from the use of known substitutions to functionalize the phenothiazinium chromophore to result in a compound of the instant claim.
As recognized by MPEP § 2144.09, a prima facie case of obviousness may be made when chemical compounds have (1) very close structural similarities and (2) similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979).”
Accordingly, the instant claim is rejected.
Claim 3 is amended to remove the variables relating to the use of the terms “substituted or unsubstituted” from the variables of the original claim and further limits amended claim 1. Wainwright teaches that even with the variety of methylene blue variations produced thus far it is possible to provide some idea of structure and function of the substitutions in phenothiazinium. As stated in the rejection July 7, 2025. For example, Figure 7 on page 270 shows modification to the core structure with the functional impacts.
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Wainwright further teaches the variations in substitution will direct
“In terms of increasing cellular uptake, neutrality can be conferred by deprotonation of an auxochromic —NH-moiety or by simply increasing overall lipophilic character by chromophore halogenation, or higher alkylation or arylation of the auxochromic groups. As with conventional drug discovery, the use of the substitutions/alterations discussed above implies that structure optimisation is also normally required to realise target compounds.”
Wainwright, page 271, column 1, paragraph 1 (emphasis added).
Therefore, Wainwright teaches the substitutions of H, alkyl, aryl, to the phenothiazinium compound to allow for optimization of the structure to specific target compounds including hydrogen, alkyl, and aryl of the instant claim.
Claim 4 is amended to further define X- is one or more anions to achieve electric neutrality and further limits amended claim 1. The claim is drawn to the phenothiazine compound is 3,7-bis (dimethylamino)-phenothiazine-5-ium salt (MTX) having formula (II), or a hydrate, a solvate, or a reduced form thereof, N wherein X- is one or more anion to achieve electric neutrality, or N3,N3,N7,N7-tetramethyl-10H-phenothiazine-3,7-diammonium salt (LMTX) having formula (III), or a hydrate or a solvate thereof, wherein X- is one or more anion to achieve electric neutrality.
As stated in the rejection July 7, 2025, the compound of formula (II) referred to in the instant claim is commonly referred to as methylene blue, and formula (III) is referred to as Leucomethylene blue mesylate; both are commercially available.
Wainwright teaches in the synthetic strategies in phenothiazinium production that the following scheme results in the chromophore modification of the core compound of methylene blue to the auxochrome, according to the following:
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Wainwright, page 266, Figure 3.
Therefore, Wainwright teaches the compound of formula II and formula III in the instant claim and the “X” identified in the instant claim as taught by Gupta et. al. as described in the rejection to claim 2 above.
Claim 6 is drawn to the pharmaceutical composition of amended claim 1, wherein the phenothiazine compound is 3,7-bis(dimethylamino)-phenothiazine-5-ium chloride, or N3, N3, N7, N7-tetramethyl-1OH-phenothiazine-3,7-diammonium dimesylate.
As described in the objection to claim 4 above, the compounds identified are commercially available and Wainwright teaches the core compound and the variations of the instant claim.
Claim 8 is amended to the pharmaceutical composition of amended claim 1, wherein the
immune cell is selected from a group consisting of a tumor infiltrating lymphocyte (TIL), a chimeric antigen receptor T cell (CAR-T cell), a chimeric antigen receptor NK cell (CAR-NK cell) and a T cell receptor (TCR) chimeric T cell (TCR-T cell).
As detailed in the rejection to claim 1 above, Sancha teaches the “free” compound of methylene blue (MB) has potent anticancer effects and 6335 does teach a Chimeric antigen receptor (CAR) T-cell therapy is a way to get immune cells called T cells (a type of white blood cell) to fight cancer by changing them in the lab so they can find and destroy cancer cells. CAR T-cell therapy is also sometimes talked about as a type of cell-based gene therapy.
Accordingly, the instant claim is rejected for the same obviousness reasons as claim 1.
Claim 9 further limits claim 8 wherein the immune cell is a T cell receptor (TCR) chimeric T cell (TCR-T cell).
6335 teaches in [0002]:
“Chimeric antigen receptors (CARs, also known as chimeric T cell receptors) are designed to be expressed in host effector cells, e.g., T cells, natural killer (NK), or neutrophil cells, and to induce an immune response against a specific target antigen and cells expressing that antigen.”
6335, [0002], (emphasis added).
Therefore, 6335 teaches the use CARs which are known as chimeric antigen receptor T cell receptors of the instant claim. Accordingly, the instant claim is rejected for the same obviousness reasons as claim 8.
Claim 10 depends from claim 9 wherein the TCR binds peptide SIINFEK.
By way of definition, Dersh et.al., (Methods Mol Biol. 2019; 1988: pages 109–122) define SIIFEKL and its use to probe antigen presentation on cells that are receptive to binding by T cells. For example:
“SIINFEKL genetically incorporated into viral or cellular source proteins can be used to precisely probe various aspects of antigen presentation, including the kinetics of peptide generation, MHC class I surface stability, and presentation efficiency following pharmacological and genetic manipulations including genome wide and high throughput drug screening.”
Dersh, Abstract, page 109 (emphasis added).
The instant claim using SIINFEKL to probe the binding of T cell receptors since it can be manipulated to present source proteins and can be used for high throughput drug screening is known in the art. It would be prima facie obvious to for an ordinary person skilled in the art to use the SIIFEKL peptide to evaluate the effectiveness of a therapeutic aimed at the binding of T cell receptors because it is known in the art for that purpose. Accordingly, the instant claim is rejected.
Claim 12 is amended to a method for treating lung cancer or lymphoma cancer, for inhibiting PD-1 signaling, for boosting immune cell function, or for blocking PD-1 recruitment of SHP2 protein, comprising administering to a subject an effective amount of a phenothiazine compound of formula (I), or a hydrate, a solvate or a reduced form as identified above.
As detailed in the rejection to claim 1 above, Sancha teaches the “free” compound of methylene blue (MB) has potent anticancer effects treating A549 non-small cell lung cancer cells both in vitro and in vivo by targeting the Hsp70. 6335 does teach that the co-stimulation domain of the compound serves to enhance the proliferation and survival of cytotoxic lymphocytes upon binding to the CAR to a targeted moiety in [0073]. Further, 6335 details in the same paragraph:
“Suitable co-stimulation domains include, without limitation: CD28 (Alvarez-Vallina et al., Eur J Immunol 26:2304-2309, 1996); CD137 (4-IBB), a member of the tumor necrosis factor (TNF) receptor family (Imai et al., Leukemia 18:676-684, 2004); CD134 (OX40), a member of the TNFR-superfamily ofreceptors (Latza et al., Eur J Immunol 24:677, 1994); CD278 20 (ICOS), a CD28-superfamily co-stimulatory molecule expressed on activated T cells (Hutloff et al., Nature 397:263, 1999); other co-stimulation domains include without limitation: CD2, CD7, CD27, CD30, CD40, DAPI0, DAP12, programmed cell death-I (PD-1,), cytotoxic T- lymphocyte antigen 4 (CTLA-4), CD276 (B7-H3), lymphocyte function-associated antigen-I (LFA-1), LIGHT, CD159c (NKG2C), and a ligand that specifically binds with CD83.”
6335, [0073], (emphasis added).
Therefore, Sancha teaches the “free” compound of methylene blue (MB) has potent anticancer effects treating A549 non-small cell lung cancer cells both in vitro and in vivo by targeting the Hsp70 and 6335 teaches the to target PD-1 to treat cancer with a reasonable expectation of success at the time the applicant filed the application.
Accordingly, the instant claim is rejected.
Claims 13, 15, 21 and 22 depend from claim 12 and have the identical limitations as claim 4 (claim 13), claim 6 (claim 15), claim 2 (claim 21) and 3 (claim 21) with respect to the limitations on claim 1.
Accordingly, the instant claims are rejected for the same obviousness reasons as claims 2-4 and 6 above.
Claim 36 is a new claim that further limits claim 3 wherein R1-R10 are independently hydrogen or C1-C6 alkyl.
Accordingly, the instant claim is rejected for the same obviousness reasons as claim 3 above.
Claim 37 is a new claim that further limits claim 36 where the pharmaceutical composition of claim 36, wherein R1, R2, R5, R6, R9 and R10 are hydrogen, and R3, R4, R7 and R8 are methyl.
Applicant is simply drawing from the use of known substitutions to functionalize the phenothiazinium chromophore to result in a compound of the instant claim.
As recognized by MPEP § 2144.09, a prima facie case of obviousness may be made when chemical compounds have (1) very close structural similarities and (2) similar utilities. "An obviousness rejection based on similarity in chemical structure and function entails the motivation of one skilled in the art to make a claimed compound, in the expectation that compounds similar in structure will have similar properties." In re Payne, 606 F.2d 303, 313, 203 USPQ 245, 254 (CCPA 1979).”
Accordingly, the instant claim is rejected.
Claim 38 is a new claim drawn to method for treating cancer, comprising administering to a subject a therapeutically effective amount of, as a first active ingredient, a free phenothiazine compound of formula (I), that requires the identical limitations as claim 32 requiring the method further comprises administering to the subject a therapeutically effective amount of, as a second active ingredient, an immune cell for adoptive cell therapy and the immune cell for adoptive cell therapy is administered prior to, concurrently with, or subsequent to administration of the phenothiazine compound of formula (I).
Although the instant claim is drawn to a method of treating cancer with the compound of formula (I) and an adoptive cell therapy agent, the kit described in claim 32 has the same components and limitations. Accordingly, the instant claim rejected for the same obviousness reasons as described in the rejection to claim 32 above.
Claims 39-41 and 43 further limits claim 38 and contains the identical limitations as claim 13 (as in claim 39), claim 15 (as in claim 40) and claim12 (as in claim 43) although instant claims are directed a method.
Accordingly, the instant claims are rejected for the same obviousness reasons as claims 12, 13 and 15 above.
Claim 42 further limits claim 38 wherein the subject is a human being.
Based on the teachings of Sanchala, 6335 and Wainwright as detailed above in the rejection to claims 1, 12 and 32, it would be prima facie obvious to one of ordinary skill in the art to administer the compound of formula (I) and a cell therapy with a reasonable expectation of success to a human.
Accordingly, the instant claim is rejected.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 date of this final action.
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/P.R.G./Examiner, Art Unit 1629
/JEFFREY S LUNDGREN/Supervisory Patent Examiner, Art Unit 1629