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 .
Claim Objections
Claims 13 and 14 are objected to because of the following informalities: the claims recite “Fey receptor” rather than “Fc-gamma receptor” or “Fcy receptor”. Appropriate correction is required.
Claim Rejections - 35 USC § 112
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 2-4, 7-9, 11-12, and 15 are 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.
Regarding claims 2-4, 7-9, and 11-12 the phrase "preferably" renders the claim indefinite because it is unclear whether the limitation(s) following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 15 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being incomplete for omitting essential steps, such omission amounting to a gap between the steps. See MPEP § 2172.01. The claim recites that the intended use of the trifunctional bispecific antibody is the treatment of cancer, yet the method steps that follow only include preparation of purified erythrocyte concentrate from intraoperatively salvaged blood. Thus, the claim omits a step for treatment of cancer in the intended use recitation.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-15 are rejected under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain an intraoperatively salvaged blood containing cell associates (i.e. aggregates) in which the trifunctional antibody and/or scaffold protein is cross-linked with tumor cells and/or immune cells, wherein said antibody or scaffold protein binds to a T cell, a tumor-associated antigen on a tumor cell, and an Fc-receptor positive cell via its Fc portion (Para. 0019, Claims 1, 2, and 10),
removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). Filtration is achieved using a leukocyte reduction/depletion filter wherein all leukocytes contaminated by tumor cells are removed while erythrocytes are collected (Para. 0142).
As such, the trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient (Abstract, Field of the Invention, and Summary of Invention).
The trifunctional antibody and/or scaffold protein used is applied in an amount of 1 μg to 1 to 5 μg per liter of intra-operatively salvaged blood (Claim 8). The incubation time of the antibody and/or the scaffold protein with said intra-operatively salvaged blood is between 10 and 180 minutes, preferably between 20 and 90 minutes, further preferably between 30 and 60 minutes, optionally wherein said incubation is performed at a temperature of between 19 to 25° C., preferably at room temperature (Claim 11).
The trifunctional antibody is a bispecific, trispecific, tetraspecific or multispecific antibody (Claim 1). The trifunctional bispecific antibody is preferably selected of a group of antibodies with the following isotype combinations: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (Claim 2).
The Fc-receptor positive cells that the trifunctional antibody/scaffold proteins bind to via its Fc portion include Fc-gamma receptor I/ IIa/III-positive accessory cells, preferably monocytes, macrophages, dendritic cells, natural killer cells, neutrophiles and/or eosinophile cells (Claim 3). The tumor associated antigen is selected from the group consisting of: EpCAM, Her2neu, EGFR, CD30, CD20, CD22, MUC1, MUC1*, PSMA, CD33, MCSP, cMet, EphA2, Endosialin, Carboanhydrase IX, IGF-1R, FAP-alpha, CD19, CD52, GD2, CEA, FR, proteoglycans, G250, GC182, GT468, GT512 (Claim 4). The trifunctional bispecific antibody recognizes a surface marker of T cells selected from the group consisting of CD3, CD2, CD4, CD5, CD6, CD6, CD8 and CD28 (Claim 5).
In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected. There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162). The purification protocol described in the examples can be adapted for the use of other trifunctional bispecific antibodies other than anti-EpCAM, wherein the method begins with 400-1500 mL of salvaged blood and may be repeated for multiple rounds to obtain a purified erythrocyte concentrate ready for reinfusion as shown by the schematic provided in Figure 3. The schematic of the method provided in Figure 3 shows a continuous cycle, indicating each step of the method for ex vivo removal of tumor cells from intraoperatively salvaged blood can be repeated sequentially starting from collection of the intraoperative blood salvage through removal of tumor cells and/or leukocytes via centrifugation and filtering to obtain a purified erythrocyte concentrate. The trifunctional bispecific antibody is a required element of the ex vivo method for removal of tumor cells from intraoperatively salvaged blood. As such, the trifunctional bispecific antibody of the instantly claimed method and product is taught by Lindhofer. The phrase “for use in a method for treating tumor or cancer” in claim 15 is a statement of intended use that does not result in a structural difference between the instantly claimed invention and that of the prior art.
Thus, Lindhofer meets the limitations of instant claims 1-15.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1-15 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of copending Application No. 18577197 in view of Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
This is a provisional nonstatutory double patenting rejection.
The co-pending claims recite an intact whole IgG bispecific antibody comprising the following properties: a) binding to a T cell and b) binding to a tumor associated antigen (co-pending claim 1), wherein the antibody is a trifunctional bispecific antibody (co-pending claim 3); the tumor associated antigen is the neuroblastoma-associated antigen GD2 (co-pending claim 4); and the T cell surface antigen that the bispecific antibody binds is selected from the group consisting of CD2, CD3, CD4, CD8, CD28, CD40L, and CD44 (co-pending claim 5).
The co-pending claims do not recite an ex vivo method for removal of tumor cells from intra-operatively salvaged blood using the trifunctional bispecific antibody.
However, Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
i) collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
ii) contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain an intraoperatively salvaged blood containing cell associates (i.e. aggregates) in which the trifunctional antibody and/or scaffold protein is cross-linked with tumor cells and/or immune cells, wherein said antibody or scaffold protein binds to a T cell, a tumor-associated antigen on a tumor cell, and an Fc-receptor positive cell via its Fc portion (Para. 0019, Claims 1, 2, and 10),
iii) removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
iv) additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). Filtration is achieved using a leukocyte reduction/depletion filter wherein all leukocytes contaminated by tumor cells are removed while erythrocytes are collected (Para. 0142).
As such, the trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient (Abstract, Field of the Invention, and Summary of Invention).
The trifunctional antibody and/or scaffold protein used is applied in an amount of 1 μg to 1 to 5 μg per liter of intra-operatively salvaged blood (Claim 8). The incubation time of the antibody and/or the scaffold protein with said intra-operatively salvaged blood is between 10 and 180 minutes, preferably between 20 and 90 minutes, further preferably between 30 and 60 minutes, optionally wherein said incubation is performed at a temperature of between 19 to 25° C., preferably at room temperature (Claim 11). The trifunctional bispecific antibody is preferably selected of a group of antibodies with the following isotype combinations: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (Claim 2). The Fc-receptor positive cells that the trifunctional antibody/scaffold proteins bind to via its Fc portion include Fc-gamma receptor I/ IIa/III-positive accessory cells, preferably monocytes, macrophages, dendritic cells, natural killer cells, neutrophiles and/or eosinophile cells (Claim 3). In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162). The purification protocol described in the examples can be adapted for the use of other trifunctional bispecific antibodies other than anti-EpCAM, wherein the method begins with 400-1500 mL of salvaged blood and may be repeated for multiple rounds to obtain a purified erythrocyte concentrate ready for reinfusion as shown by the schematic provided in Figure 3. The schematic of the method provided in Figure 3 shows a continuous cycle, indicating each step of the method for ex vivo removal of tumor cells from intraoperatively salvaged blood can be repeated sequentially starting from collection of the intraoperative blood salvage through removal of tumor cells and/or leukocytes via centrifugation and filtering to obtain a purified erythrocyte concentrate.
It would have been obvious to one of ordinary skill in the art to use the claimed whole IgG bispecific antibody in the ex vivo method for removal of tumor cells from intraoperatively salvaged blood taught by Lindhofer. One of ordinary skill in the art would have been motivated to do so since these trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient. Therefore, one of ordinary skill in the art would reasonably expect that the trifunctional bispecific antibody of the co-pending claims can be used effectively for the ex vivo removal of tumor cells from intraoperatively salvaged blood.
Claims 1-15 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1 and 10-24 of copending Application No. 16143889 in view of Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
This is a provisional nonstatutory double patenting rejection.
The co-pending claims recite a kit comprising a multispecific antibody comprising having specificity against a T cell surface antigen and specificity against a tumor-associated antigen (co-pending claim 23). The multispecific antibody can comprise an Fc moiety (co-pending claim 12). The tumor associated antigen can be selected from the group consisting of EpCAM, Her2neu, EGFR, CD30, CD20, CD22, MUC1, CD33, MCSP, EphA2, carboanhydrase IX, CD19, GD2, CEA, proteoglycans, GC182, GT468, and GT512 (co-pending claim 10). In particular, the multispecific antibody can be anti-EpCAM x CD3, anti-CD20 x CD3, anti-Her2/neu x CD3, anti-GD2 x CD3, or anti-CD19 x CD3 (co-pending claim 11). Thus, the T cell surface antigen that the multispecific antibody targets can be CD3.
The co-pending claims do not recite an ex vivo method for removal of tumor cells from intra-operatively salvaged blood using the trifunctional bispecific antibody.
However, Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
i) collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
ii) contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain an intraoperatively salvaged blood containing cell associates (i.e. aggregates) in which the trifunctional antibody and/or scaffold protein is cross-linked with tumor cells and/or immune cells, wherein said antibody or scaffold protein binds to a T cell, a tumor-associated antigen on a tumor cell, and an Fc-receptor positive cell via its Fc portion (Para. 0019, Claims 1, 2, and 10),
iii) removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
iv) additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). Filtration is achieved using a leukocyte reduction/depletion filter wherein all leukocytes contaminated by tumor cells are removed while erythrocytes are collected (Para. 0142).
As such, the trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient (Abstract, Field of the Invention, and Summary of Invention).
The trifunctional antibody and/or scaffold protein used is applied in an amount of 1 μg to 1 to 5 μg per liter of intra-operatively salvaged blood (Claim 8). The incubation time of the antibody and/or the scaffold protein with said intra-operatively salvaged blood is between 10 and 180 minutes, preferably between 20 and 90 minutes, further preferably between 30 and 60 minutes, optionally wherein said incubation is performed at a temperature of between 19 to 25° C., preferably at room temperature (Claim 11). The trifunctional bispecific antibody is preferably selected of a group of antibodies with the following isotype combinations: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (Claim 2). The Fc-receptor positive cells that the trifunctional antibody/scaffold proteins bind to via its Fc portion include Fc-gamma receptor I/ IIa/III-positive accessory cells, preferably monocytes, macrophages, dendritic cells, natural killer cells, neutrophiles and/or eosinophile cells (Claim 3). In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162). The purification protocol described in the examples can be adapted for the use of other trifunctional bispecific antibodies other than anti-EpCAM, wherein the method begins with 400-1500 mL of salvaged blood and may be repeated for multiple rounds to obtain a purified erythrocyte concentrate ready for reinfusion as shown by the schematic provided in Figure 3. The schematic of the method provided in Figure 3 shows a continuous cycle, indicating each step of the method for ex vivo removal of tumor cells from intraoperatively salvaged blood can be repeated sequentially starting from collection of the intraoperative blood salvage through removal of tumor cells and/or leukocytes via centrifugation and filtering to obtain a purified erythrocyte concentrate.
It would have been obvious to one of ordinary skill in the art to use the claimed whole IgG bispecific antibody in the ex vivo method for removal of tumor cells from intraoperatively salvaged blood taught by Lindhofer. One of ordinary skill in the art would have been motivated to do so since these trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient. Therefore, one of ordinary skill in the art would reasonably expect that the trifunctional bispecific antibody of the co-pending claims can be used effectively for the ex vivo removal of tumor cells from intraoperatively salvaged blood.
Claims 1-15 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 89-103 of copending Application No. 19262309 in view of Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
This is a provisional nonstatutory double patenting rejection.
The co-pending claims recite a combination therapy comprising an immune checkpoint inhibitor and a T-cell redirecting multifunctional antibody, wherein the multifunctional antibody is mouse IgG2a/rat IgG2b antibody selected from the group consisting of catumaxomab (anti-CD3 x EpCAM), lymphomum/FBTA05 (anti-CD3 x CD20), ertumaxomab (anti-CD3 x Her2-neu), and ektomab/ektomun (anti-CD3 x GD2) (co-pending claim 99). Thus, the co-pending claims recite trifunctional bispecific antibodies that target tumor associated antigens and T cell antigens recited in the instant claims.
The co-pending claims do not recite an ex vivo method for removal of tumor cells from intra-operatively salvaged blood using the trifunctional bispecific antibody.
However, Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
i) collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
ii) contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain an intraoperatively salvaged blood containing cell associates (i.e. aggregates) in which the trifunctional antibody and/or scaffold protein is cross-linked with tumor cells and/or immune cells, wherein said antibody or scaffold protein binds to a T cell, a tumor-associated antigen on a tumor cell, and an Fc-receptor positive cell via its Fc portion (Para. 0019, Claims 1, 2, and 10),
iii) removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
iv) additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). Filtration is achieved using a leukocyte reduction/depletion filter wherein all leukocytes contaminated by tumor cells are removed while erythrocytes are collected (Para. 0142).
As such, the trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient (Abstract, Field of the Invention, and Summary of Invention).
The trifunctional antibody and/or scaffold protein used is applied in an amount of 1 μg to 1 to 5 μg per liter of intra-operatively salvaged blood (Claim 8). The incubation time of the antibody and/or the scaffold protein with said intra-operatively salvaged blood is between 10 and 180 minutes, preferably between 20 and 90 minutes, further preferably between 30 and 60 minutes, optionally wherein said incubation is performed at a temperature of between 19 to 25° C., preferably at room temperature (Claim 11). The trifunctional bispecific antibody is preferably selected of a group of antibodies with the following isotype combinations: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (Claim 2). The Fc-receptor positive cells that the trifunctional antibody/scaffold proteins bind to via its Fc portion include Fc-gamma receptor I/ IIa/III-positive accessory cells, preferably monocytes, macrophages, dendritic cells, natural killer cells, neutrophiles and/or eosinophile cells (Claim 3). In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162). The purification protocol described in the examples can be adapted for the use of other trifunctional bispecific antibodies other than anti-EpCAM, wherein the method begins with 400-1500 mL of salvaged blood and may be repeated for multiple rounds to obtain a purified erythrocyte concentrate ready for reinfusion as shown by the schematic provided in Figure 3. The schematic of the method provided in Figure 3 shows a continuous cycle, indicating each step of the method can be repeated sequentially starting from collection of the intraoperative blood salvage through removal of tumor cells and/or leukocytes via centrifugation and filtering to obtain a purified erythrocyte concentrate.
It would have been obvious to one of ordinary skill in the art to use the claimed whole IgG bispecific antibody in the ex vivo method for removal of tumor cells from intraoperatively salvaged blood taught by Lindhofer. One of ordinary skill in the art would have been motivated to do so since these trifunctional bispecific antibodies can mediate the formation of multicellular complexes or associates comprising tumor cells and leukocytes thus facilitating their removal from intraoperatively salvaged blood by mechanical means including density gradient centrifugation and filtration in order to obtain a purified blood salvage or erythrocyte concentrate that can be reinfused into the patient. Therefore, one of ordinary skill in the art would reasonably expect that the trifunctional bispecific antibody of the co-pending claims can be used effectively for the ex vivo removal of tumor cells from intraoperatively salvaged blood.
Claims 1-11 and 13-15 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of copending Application No. 17628176 in view of Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
This is a provisional nonstatutory double patenting rejection.
The co-pending claims recite an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of:
providing intraoperatively salvaged blood which may contain tumor cells;
contacting said intraoperatively salvaged blood with at least one antibody selected from the group consisting of a bispecific, trispecific, tetraspecific, and multispecific antibody and/or with at least one scaffold protein with multispecific binding properties,
,wherein the at least one antibody and/or at least one scaffold protein comprises the following properties:
binding to a pan-leukocyte antigen. Pan leukocyte antigens would be present on all leukocytes including T cells. Thus, the antibodies recited by the co-pending claims can target T cells as well.
binding to a tumor associated antigen on a tumor cell; and
binding via the Fc portion to an Fc-receptor positive cell
, wherein the at least one antibody and/or scaffold protein is contacted with the intraoperatively salvaged blood for a time period of 10-240 minutes (preferably 10-180 minutes) to crosslink tumor cells leukocytes in order to obtain associates and/or aggregates comprising the antibody or scaffold protein; and
mechanically removing the associates and/or aggregates from the intraoperatively salvaged blood (co-pending claims 1, 17, and 18), wherein removal of the associates and/or aggregates is by centrifugation, filtration, or a combination thereof (co-pending claim 9).
In some embodiments, the at least one antibody can be a trifunctional bispecific antibody having the isotype selected from the following: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (co-pending claims 2 and 3). The incubation time of the antibody and/or scaffold protein with the intraoperatively salvaged blood is between 10 and 90 minutes (or preferably between 20 and 60 minutes) optionally wherein the incubation is performed at a temperature of between 19 to 25℃ or at room temperature (co-pending claim 9). The one or more antibodies or scaffold proteins are applied in an amount of 1-20 ug (preferably 1-10 ug or 1-5 ug or 1 to 2 ug) per liter of intraoperatively salvaged blood (co-pending claim 7). The method further comprises at least one of the following additional steps: a) mixing the intra-operatively salvaged blood before addition of the at least one antibody and/or scaffold protein with at least one anticoagulating agent; b) separating erythrocytes from the associates and further blood components via density gradient centrifugation; c) optionally filtering the mixture to remove potentially residual associates and residual cell complexes; and/or d) collecting the erythrocyte-containing fraction and further blood components in separate containers (co-pending claim 8). Filtration to remove the leukocytes and/or tumor cells can be achieved using a leukocyte adsorption/depletion filter in a separate step (co-pending claim 11).
The co-pending claims do not recite that the ex vivo method occurs according to the specific sequence recited in the instant claims, in particular, that after centrifugation to obtain an erythrocyte concentrate (EC), the EC is then washed and filtered to remove residual aggregates or cell complexes. Further, the co-pending claims do not recite that the intraoperatively salvaged blood obtained has a volume of 300 mL or more in the reservoir prior to application of the trifunctional antibody nor that the method steps are repeated from start to finish in multiple rounds, wherein the first round of collected blood is in a volume of 400-1500 mL.
However, Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
i) collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
ii) contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain associates (i.e. aggregates) (Para. 0019, Claims 1, 2, and 10),
iii) removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
iv) additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162). The purification protocol described in the examples can be adapted for the use of other trifunctional bispecific antibodies other than anti-EpCAM, wherein the method begins with 400-1500 mL of salvaged blood and may be repeated for multiple rounds to obtain a purified erythrocyte concentrate ready for reinfusion as shown by the schematic provided in Figure 3. The schematic of the method provided in Figure 3 shows a continuous cycle, indicating each step of the method can be repeated sequentially starting from collection of the intraoperative blood salvage through removal of tumor cells and/or leukocytes via centrifugation and filtering to obtain a purified erythrocyte concentrate.
It would have been obvious to one of ordinary skill in the art to modify the ex vivo method for removal of tumor cells from intraoperatively salvaged blood recited by the co-pending claims such that the method steps have the following sequence: centrifugation to obtain erythrocyte concentrate[Wingdings font/0xE0]washing of erythrocyte concentrate[Wingdings font/0xE0]filtering erythrocyte concentrate to remove residual tumor cells or antibody complexes. Further, artisans would have been motivated to collect 300 mL or more (e.g.400-1500 mL) of intraoperatively salvaged blood in a reservoir and repeat the method from blood collection through centrifugation and filtering to obtain purified erythrocyte concentrate. One of ordinary skill in the art would have been motivated to do so in order to effectively remove tumor cells and/or leukocytes from intraoperatively salvaged blood to yield a purified erythrocyte concentrate as demonstrated in the examples of Lindhofer. Therefore, one of ordinary skill in the art would expect that modifying the method of the co-pending claims such that it proceeds according to the sequence using the initial volume of collected blood set forth by Lindhofer, wherein the method steps are repeated one or more times.
Claims 1-15 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-15 of U.S. Patent No. 9605242B2 in view of Lindhofer et al (US20140369985A1), hereinafter Lindhofer.
The issued claims recite an ex vivo method for removal of tumor cells from blood of a tumor patient comprising the steps of:
providing blood suspected of containing tumor cells intra-operatively salvaged from a tumor patient;
contacting the intra-operatively salvaged blood for a time period of between 10 and 180 minutes with a crosslinking agent capable of forming a three-dimensional network comprising the tumor cells,
wherein the crosslinking agent comprises at least one antibody selected from the group consisting of a bispecific antibody, a trispecific antibody, a tetraspecific antibody, a multispecific antibody, a bivalent antibody, a trivalent antibody, a tetravalent antibody, and a multivalent antibody, or at least one scaffold protein with multispecific or multivalent binding properties similar to antibodies, or a combination thereof,
wherein the at least one antibody, scaffold protein, or combination thereof specifically binds to at least one epitope of the tumor cells to crosslink the tumor cells,
and wherein the time period of between 10 and 180 minutes is sufficient to form associates by cross-linking tumor cells present in the intra-operatively salvaged blood with the at least one antibody, scaffold protein, or combination thereof of a size sufficient to be retained by filtration or to be separated by centrifugation, optionally wherein the associates further comprise cross-linked immune cells and/or other tumor cells. Thus, the associates can comprise antibodies, tumor cells, and immune cells;
mechanically removing the associates from the intra-operatively salvaged blood by centrifugation, filtration, or a combination thereof;
readministering the intra-operatively salvaged blood to the patient after mechanically removing the associates (issued claims 1, 9, and 14).
The method further comprises removing leukocytes and/or tumor cell-containing cell complexes using a leukocyte adsorption filter (issued claim 15). In step (ii) the at least one antibody and/or scaffold protein is contacted with the intraoperatively salvaged blood in an amount of 1 μg to 5 μg per liter of said blood and for a time period of 20-90 minutes or 30-60 minutes at a temperature of between 19 to 25° C, or optionally at room temperature (issued claims 10 and 13). The amount of antibody/scaffold protein contacted with the intraoperatively salvaged blood encompasses the claimed range of 2.5 ug or more and 5.0 ug or less. The method further comprises at least one of the following additional steps: a) mixing the intra-operatively salvaged blood before addition of the at least one antibody and/or the at least one scaffold protein with at least one anticoagulating agent to obtain a mixture, and optionally filtering the mixture to remove potentially residual associates and residual cell complexes; and/or b) separating erythrocytes from the associates and further blood components via separate containers (issued claim 12). The antibody comprises a trifunctional bispecific antibody having the following properties: (a) binding to a T cell;( b) binding to a tumor-associated antigen on a tumor cell; and (c) binding via its Fc-portion to an Fc-receptor positive cell, wherein the trifunctional bispecific antibody is selected from among the following isotype combinations: (a) rat-IgG2b/mouse-IgG2a; (b) rat-IgG2b/mouse-IgG2b; (c) rat-IgG2b/human-IgG1; and (d) mouse-[VH-CH1; VL-CL]-human-IgG1/rat-[VH-CH1, VL-CL]-human-IgG1-[hinge]-human-IgG3*-[CH2-CH3] [*=Caucasian allotypes G3m(b+g)=no binding to protein A] (issued claim 2). The tumor associated antigen is selected from the group consisting of EpCAM, Her2/neu, EGFR, CD30, CD20, CD22, MUC1, MUC1*, PSMA, CD33, MCSP, cMet, EphA2, endosialin, carboanhydrase IX, IGF-1R, FAP-alpha, CD19, CD52, GD2, CEA, FR, a proteoglycan, G250, GC182, GT468, and GT512 (issued claim 6). The trifunctional bispecific antibody recognizes a surface marker of T cells selected from the group consisting of CD3, CD2, CD4, CD5, CD6, CD6, CD8 and CD28 (issued claim 7). The Fc-receptor positive cell is selected is an Fcy receptor type I, II, or III cell or selected from the group consisting of monocyte, a macrophage, a dendritic cell, a natural killer cell, a neutrophil, and an eosinophil (issued claims 5 and 6).
The issued claims do not recite that the ex vivo method occurs according to the specific sequence recited in the instant claims, in particular, that after centrifugation to obtain an erythrocyte concentrate (EC), the EC is then washed and filtered to remove residual aggregates or cell complexes. Further, the issued claims do not recite that the intraoperatively salvaged blood obtained has a volume of 300 mL or more in the reservoir prior to application of the trifunctional antibody nor that the method steps are repeated from start to finish in multiple rounds, wherein the first round of collected blood is in a volume of 400-1500 mL.
However, Lindhofer discloses an ex vivo method for removal of tumor cells from intraoperatively salvaged blood comprising the steps of
i) collecting an intraoperatively salvaged blood which may contain immune cells and/or tumor cells in a reservoir (Para. 0019 and 0030),
ii) contacting the intraoperatively salvaged blood with at least one trifunctional antibody and/or scaffold protein in order to obtain associates (i.e. aggregates) (Para. 0019, Claims 1, 2, and 10),
iii) removing said associates from the intraoperatively salvaged blood via centrifugation, filtration, or a combination thereof, wherein the centrifugation step precedes the filtration step (Claim 12 and Para. 0141). Centrifugation is performed generally by a density gradient centrifugation followed by washing with physiological saline for a time and with a rotational speed sufficient to remove said tumor cells-comprising associates and to separate erythrocytes from said tumor cell associates and optionally from leukocytes (Para. 0145). Centrifugation that pellets red blood cells and separates them from plasma results in an erythrocyte concentrate per step iii of the instantly claimed method. After centrifugation, washing the pelleted cells is equivalent to “washing the erythrocyte concentrate” per step iv of the instantly claimed method.
iv) additional filtration steps of the erythrocyte concentrate are performed in order to remove residual associates and/or leukocytes (Para. 0148). In an example, anti-EpCAM mediated removal of tumor cells through multicell complex depletion by centrifugation and/or filtration during intraoperative blood salvage was demonstrated. Specifically, 1500 ml patient blood was collected with addition of anti-coagulants during surgery. Thus, the intraoperatively salvaged blood collected has a volume of 300-400 mL or more. Further, with the addition of anti-coagulants, the intraoperatively salvaged blood is a mixture of blood and dilution. 1000 ml this blood was incubated for 1 h with 2 μg of the anti-EpCAM antibody catumaxomab. After incubation, 500 ml of the patient blood was centrifuged, purified with a leucocyte filter, and the resulting erythrocyte concentrate (EC) was collected. There were no detectable remaining tumor cells in the EC following the purification protocol (see Examples on Para. 0152-0162).