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 .
DETAILED ACTION
Claim 2 has been amended. Claims 10-12 have been canceled.
Claims 2 and 7-9, and 13-24 are pending in the instant application.
Rejections Withdrawn
The rejection of claims 10-12 are moot in view of claim cancelation.
The rejection of claims 2, 7-9, and 13-24 under 35 USC § 103 is withdrawn in view of the claim amendment.
Claim Rejections Necessitated by Amendment
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.
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.
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 2, 7, 9, and 13-23 are rejected under 35 U.S.C. 103 as being unpatentable over Müller P et al. (Science Translational Medicine 2015 7(315) 1-14 reference of record), Beerli RR (Cancer Research 2017 77(13)_Supp, abstract 66, IDS submitted), Gerber HP et al. (Biochemical Pharmacology 2016 102, 1-6 reference of record), WO 2016102679 (Grawunder U et al. reference of record), and Pfirschke C et al. (Immunity 2016 44(2):343–354, IDS reference) and evidenced by Jayaprakash P et al. (J Clin Invest. 2018;128(11):5137-5149 reference of record).
Müller taught human patients had tumors with sparse stromal tumor-infiltrating lymphocytes (TILs) at the time of diagnosis, but after administration of trastuzumab emtansine (T-DM1) stromal TILs increased (page 2, left column, last paragraph).
Jayaprakash evidenced tumors in which T cells are sparse are “cold” (page 5137, right column, last paragraph). Müller taught patients treated with T-DM1 had increased TILs that included effector CD4+ and CD8+ T cells (page 2, right column, first paragraph). Müller taught effector T cells are essential for full therapeutic activity (page 8, right column, first paragraph). Müller taught a method of administering the ADC T-DM1 to mice with HER2+ cancer in a Fo5 model, wherein untreated tumors had sparse CD4 and CD8 lymphocytes within the tumor, while T-DM1 administration caused CD4 and CD8 T cells to increase within the tumor (Fig 1F, 1G, and 1I). Müller taught a method of administering combination treatment of T-DM1 and anti–CTLA-4/PD-1 to subjects was curative to breast cancer tumors because it triggered innate and adaptive immunity, wherein tumor rejection was accompanied by massive T cell infiltration and TH1 (T helper 1) cell polarization (abstract). Müller taught although primary resistance to immune checkpoint-blocking antibodies occurred in tumors, combining T-DM1 treatment with blockade of the PD-1/CTLA-4 inhibitory pathway resulted in complete cures and greatly enhanced T cell responses, including complete tumor rejection and memory formation (page 8, right column, first paragraph). Müller taught a method of administering the ADC T-DM1 to mice with HER2+ cancer in a Fo5 model, wherein the tumors were resistant to administration of immune checkpoint inhibitors anti-CTLA-4 and anti-PD-1, wherein mice treated with the ADC T-DM1 had longer survival times than treatment with the immune checkpoint inhibitors anti-CTLA-4 and anti-PD-1 (Figure 2C).
Müller did not teach: 1) an ADC with a PNU-159682 anthracycline toxin moiety, but exchanging the DM1 toxin in the ADC for an anthracycline would be obvious in view of Beerli, Gerber, Grawunder, and Pfirschke.
Müller does not describe: 1) the specific attachment point of PNU-159682; 2) sortase as an enzymatic site specific conjugation linkage for the binding protein toxin conjugate ADC; and 3) treating a tumor characterized as having an immunoscore of I0 or I1, but this is obvious in view of Beerli, Gerber, Grawunder, and Pfirschke.
Beerli taught enzymatic, site-specific conjugation to generate homogenous ADCs based on a derivative of the highly potent anthracycline toxin PNU-159682 and a non-cleavable peptide linker, using the anti-HER-2 antibody trastuzumab (part of trastuzumab emtansine) and the anti-CD30 antibody cAC10 (part of brentuximab vedotin) (abstract). Beerli taught the ADCs were highly stable in vitro and in vivo and exhibited potencies exceeding those of ADCs based on conventional tubulin-targeting payloads, such as trastuzumab emtansine and brentuximab vedotin (abstract). Beerli taught anti-tumor activity in an immune-competent host involved activation of the immune system, as shown by evaluation of a trastuzumab-PNU ADC in a Kadcyla-resistant HER2-positive orthotopic breast cancer model (abstract). Beerli taught depletion of CD8 T cells severely reduced the anti-tumor activity of the ADC, demonstrating an important role for T cells in driving tumor regression. Beerli taught when tumor free animals were re-challenged with the same tumor, tumor growth was entirely inhibited in the absence of any further ADC administration, indicating the development of an immunological memory (abstract).
Gerber taught the fraction of patients experiencing durable responses to single agent immune checkpoint inhibitor treatment remains limited (abstract). Gerber taught clinical reports suggest patients that respond best to checkpoint blockade therapies display higher levels of CD8+ T-cells in the tumor prior to treatment (abstract). Gerber taught combination treatments of immune-checkpoint inhibitors with compounds that increase the number of tumor infiltrating CD8+ T cells would expand the therapeutic benefit of immuno-oncology drugs (abstract). Gerber taught immunogenic cell death (ICD) of tumor cells represents a potent stimulator of effector T-cell recruitment to tumors (abstract). Gerber taught anthracycline compounds induce high levels of immune cell death (page 3, right column, last paragraph). Gerber taught treatment regimens with anthracyclines appear attractive for combination with immuno-oncology compounds (page 4, right column, second paragraph). Gerber taught the impact of combining ADC with immuno-oncology compounds on response rates and overall survival of cancer patients (Figure 2).
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Gerber Figure 2
Grawunder taught a binding protein-drug conjugate (BPDC), wherein the
binding protein antibody binds CD30 and comprises Brentuximab (clone cAc10), which is the antibody component of the approved drug Adcetris/Brentuximab vedotin (page 24, lines 10-25). Grawunder taught the binding protein antibody had the heavy chain of SEQ ID NO: 3 and light chain of SEQ ID NO: 4, which includes: 1) a sortase enzyme recognition motif and poly-glycine of LPETGGGGG or LPET(G)5 wherein the polyglycine has an integer of 5; 2) a PNU-159682 derivative conjugated to the carboxy terminus of the CD30 antibody binding protein; 3) an amide bond for conjugation between the binding protein and the amino terminus of the oligo-glycine peptide (Gly)5 for the heavy chain (page 24, lines 26-27 and Figure 11B).
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Grawunder taught the anthracycline PNU-159682 derivative linker conjugate having the formula of formula (iii) or formula (iv), wherein attachment at Ring A either is direct or via a Ring A substituent carbonyl
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(page 9) wherein L1-L3 represent linkers and two of L1-L3 are mandatory, wherein X and Y represent each one or more optional linker, wherein BP is a binding protein, and n is an integer between 1 and 10 (page 9, last four lines). Grawunder taught direct attachment to the Ring A of PNU-159682 to the (Gly)5- PNU-159682 as:
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,which is expected to display stable drug conjugates after SMAC conjugation (Figure 6 and page 32, paragraph 2)
Grawunder taught the binding protein drug conjugate has the PNU-159682 and linker conjugate attachment as: 1)
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, which includes an alkyleneamino linker (EA in dashed box) conjugated to the (Gly)5 (Figure 6B), wherein L1 is EA and L2 is (Gly)5;
and would be the general formula
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formula (vi) (page 13)
and
2)
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, which includes an alkylenediamino linker (EDA in dashed box) conjugated to the (Gly)5 (Figure 3A), wherein L1 is EDA and L2 is (Gly)5 and would be the general formula
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(page 12). Grawunder taught the alkyleneamino linker is used to allow attachment of the (Gly)n linker for sortase conjugation, such that the coupling can occur via the C-terminus of the (Gly)n peptide, thus providing a free N-terminus of the final toxin-linker adduct for sortase conjugation (page 14, lines 5-8). Grawunder taught the binding protein-drug conjugate has the linker L3 comprising a peptide motif that results from specific cleavage of a sortase enzyme recognition motif (page 14, lines 12-14). The sortase recognition motif LEPTG (L3) conjugated to the polyglycine (L2) conjugated to the PNU derivative is shown in Figure 11 above. Grawunder taught the PNU-EDA-Gly5-LPETG-Brentuximab cAa10 anti-CD30 binding protein drug conjugate had a drug to antibody ratio of 4 (page 35, Table 2). Grawunder taught the sortase conjugated ADC PNU-EDA-Gly5-LPETG-Brentuximab cAa10 anti-CD30 binding protein drug conjugate potently killed cells expressing high levels of CD30, but not cells with low expression of CD30, indicating that the efficacy of this ADC is indeed specific and mediated by CD30 binding (Figure 4 and page 36, lines 7-12). Grawunder taught the sortase-mediated conjugation of PNU-EDA-Gly5-LPETG-Brentuximab cAa10 anti-CD30 binding protein drug conjugate yielded an ADC with a very high potency, even exceeding that of the reference ADC Adcetris (Figure 4 and page 36, lines 12-14). Grawunder taught the sortase conjugated ADC PNU-EDA-Gly5-LPETG-Brentuximab cAa10 anti-CD30 binding protein drug conjugate had better serum stability in comparison to the maleimide linked ADC Kadcyla (Figure 7 and page 38, lines 3-5).
Pfirschke taught immunogenic chemotherapeutics improve immune checkpoint blockade, wherein the anthracycline doxorubicin induces immunogenic cancer cell death and synergistically decreases tumor cell growth when combined with checkpoint inhibitors targeting PD-1 and CTLA-4 in tumors (Fig 7A). Thus, anthracyclines are known to synergistically enhance checkpoint inhibitors PD-1 and CTLA-4 antibody anticancer activity.
Regarding instant claims 2, 9, 13-16, and 18-23, it would have been obvious for a person having ordinary skill in the art to take the method of Müller for treating Her2 positive breast cancer patient cold tumors by administering the protein toxin conjugate ADC, T-DM1 – and:
1) exchange the ADC in the method for the protein toxin conjugate ADC, trastuzumab anthracycline, Tras-PNU-159682 with enzymatic, site-specific conjugation, of Beerli;
2) further include the immune checkpoint inhibitors anti–CTLA-4 and PD-1 with the ADC treatment as taught by of Müller;
3) attach the linker toxin conjugate PNU-159682 to the carboxy terminus of the antibody via a sortase site-specific Gly5-LPETG conjugation comprising a sortase enzyme recognition motif and poly-glycine of LPETGGGGG or LPET(G)5 wherein the polyglycine has an integer of 5, and wherein there is an amide bond for conjugation between the binding protein and the amino terminus of the oligo-glycine peptide (Gly)5 as taught by Grawunder;
and 4) treat a tumor characterized as having an immunoscore of I0 or I1 in view of an ADC plus immune checkpoint inhibitor was effective in tumors that had sparse immune cells as taught by Müller and Gerber who taught anthracyclines induce high levels of immune cell death and appear attractive for combination with immuno-oncology compounds.
This is obvious because:
1a) Beerli taught the ADCs were highly stable in vitro and in vivo and exhibited potencies exceeding T-DM1, induced CD8+ T cells to promote cancer cell death, and promoted immunological memory to prevent tumor growth after treatment; 1b) Gerber taught anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors; 1c) Beerli taught PNU-159682 is a highly potent anthracycline and an ADC comprising an enzymatic, site-specific conjugation to generate homogenous ADCs based of the highly potent anthracycline toxin PNU-159682 and the anti-HER-2 antibody trastuzumab was effective. Thus, enzymatic site specific conjugations to trastuzumab with PNU-159682 have been produced before;
2a) Müller taught a method of administering combination treatment of the ADC T-DM1 and the immune checkpoint inhibitors anti–CTLA-4 and ani-PD-1 to subjects was curative to breast cancer tumors because it triggered innate and adaptive immunity, wherein tumor rejection was accompanied by massive T cell infiltration and TH1 (T helper 1) cell polarization; 2b) Gerber taught anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors, so an anthracycline based ADC would be expected to also promote immune infiltration; 2c) Gerber taught combination treatments of immune-checkpoint inhibitors with compounds that increase the number of tumor infiltrating CD8+ T cells would expand the therapeutic benefit of immuno-oncology drugs;
3) Grawunder taught the binding protein drug conjugate has the PNU-159682 and linker conjugate attachment as:
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, wherein the alkyleneamino linker is used to allow attachment of the (Gly)n linker for sortase conjugation, such that the coupling can occur via the C-terminus of the (Gly)n peptide, thus providing a free N-terminus of the final toxin-linker adduct for sortase conjugation which produced a sortase conjugated ADC PNU-EDA-Gly5-LPETG antibody conjugate that was stable in serum and potently killed cells expressing the target, but not cells with low target expression, indicating that the efficacy of this ADC is indeed specific and mediated by target binding. Thus, the conjugation structure to PNU-159682 is effective and stable; and
4) the lowest immunoscore would define the tumor as having no T cells infiltrating the tumor and the binding protein toxin conjugate ADC Tras-PNU-159682 with enzymatic, site-specific conjugation would be expected to cause activation of immune cells to cause recruitment of cytotoxic effector T cells into the cold tumor with an immunoscore I0 or I1 and promote immunological memory to prevent tumor growth after treatment. Thus, an immunoscore I0 or I1 would not exclude treatment with the Tras-PNU-159682 because the treatment would not require immune cells to be within the tumor. Further, the ADC would promote T cell recruitment to the tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells.
There is a reasonable expectation of success because:
1a) the Tras-PNU-159682 with enzymatic, site-specific conjugation ADC is highly stable in vitro and in vivo and exhibited potencies exceeding T-DM1 which also induces CD8+ T cells to promote cancer cell death and promotes immunological memory to prevent tumor growth after treatment; 1b) the anthracycline of the ADC would be expected to stimulate effector T-cell recruitment to tumors, which would cause T cell infiltration into the previously cold tumor; 1c) PNU-159682 is a highly potent anthracycline; 1d) Pfirschke taught immunogenic chemotherapeutics improve immune checkpoint blockade, wherein the anthracycline doxorubicin induces immunogenic cancer cell death and synergistically decreases tumor cell growth when combined with checkpoint inhibitors targeting PD-1 and CTLA-4 in tumors. Thus, anthracyclines are known to synergistically enhance checkpoint inhibitors PD-1 and CTLA-4 antibody anticancer activity.
2a) the ADC would promote T cell recruitment to the tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells; 2b) anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors, so an anthracycline based ADC would be expected to also promote immune infiltration; 2c) combination treatments of immune-checkpoint inhibitors with compounds that increase the number of tumor CD8+ T cells would expand the therapeutic benefit of immuno-oncology drugs; and
3) Grawunder taught the binding protein drug conjugate with the PNU-159682 and linker conjugate attachment as:
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to produce an ADC PNU-EDA-Gly5-LPETG antibody conjugate that was stable in serum and potently killed cells expressing the target, but not cells with low target expression, indicating that the efficacy of this ADC is indeed specific and mediated by target binding. Thus, the conjugation structure to PNU-159682 is effective and stable; and
4) the lowest immunoscore would define the tumor as having no T cells in the tumor and the binding protein toxin conjugate ADC Tras-PNU-159682 with enzymatic, site-specific conjugation would be expected to cause activation of immune cells and recruitment of cytotoxic effector T cells into the cold tumor with an immunoscore I0 or I1 and promote immunological memory to prevent tumor growth after treatment. Thus, an immunoscore I0 or I1 would not exclude treatment with the Tras-PNU-159682 because the treatment would not require immune cells to be within the tumor. Further, the ADC would promote T cell infiltration to the tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells.
This would produce a method of treating Her2 positive breast cancer patients with cold tumors by administering a combination therapy of:
the protein toxin conjugate ADC, trastuzumab anthracycline, Tras-PNU-159682 with enzymatic, sortase site-specific conjugation to an antibody (instant claim 23) conjugate that targets HER2 (instant claim 9), wherein the binding protein drug conjugate has the PNU-159682 attached to the carboxy terminus of the antibody (instant claim 21) and linker conjugate attachment as:
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(instant claim 16) which includes an alkylenediamino linker (EDA in dashed box) conjugated to the (Gly)5 (instant claim 14), wherein L1 is EDA and L2 is (Gly)5 (instant claim 13) and would be the general formula
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(instant claim 15), wherein there is an amide bond for conjugation between the binding protein and the amino terminus of the oligo-glycine peptide (Gly)5 (instant claim 22), wherein the alkyleneamino linker EDA is used to allow attachment of the (Gly)5 linker for sortase conjugation, such that the coupling can occur via the C-terminus of the (Gly)5 peptide, which produces a sortase enzyme recognition motif (instant claim 18) conjugated ADC PNU-EDA-Gly5-LPETG, with a LPETG sortase recognition motif (instant claim 19) conjugated to a (Gly)5 (instant claim 20), wherein ; and
the immune checkpoint inhibitors anti–CTLA-4 and ani-PD-1,
wherein the combination of the protein-toxin conjugate and immune checkpoint inhibitor have a synergistic effect. This further meets the claim limitation of combination administration simultaneously or sequentially in any order (instant claim 2).
Regarding instant claim 7, it would have been obvious for a person having ordinary skill in the art to take the method of Müller, Beerli, Gerber, Grawunder, and Pfirschke above – and further include patients wherein the cold tumor is resistant to immune checkpoint inhibition.
This is obvious because: 1) Müller showed treatment with an ADC that causes effector T cells tumor infiltration increased survival of mouse patients with Fo5 tumors resistant to the immune checkpoint inhibitors anti–CTLA-4 and PD-1; 2) Beerli taught administration of Tras-PNU-159682 with enzymatic, site-specific conjugation was efficacious against tumors in vivo, activated CD8+ T cells, and promoted immunological memory to prevent tumor growth after treatment; and 3) Gerber taught anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors.
There is a reasonable expectation of success because: 1) treatment with an ADC that causes effector T cells tumor infiltration increased survival of mouse patients with Fo5 tumors resistant to the immune checkpoint inhibitors anti–CTLA-4 and PD-1; 2) Tras-PNU-159682 with enzymatic, site-specific conjugation was efficacious against tumors in vivo more than T-DM1, activated CD8+ T cells, and promoted immunological memory to prevent tumor growth after treatment; and 3) Gerber taught anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors. Thus, the anthracycline ADC would promote T cell recruitment into the cold tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells.
Regarding instant claim 17, it would have been obvious for a person having ordinary skill in the art to take the method of Müller, Beerli, Gerber, Grawunder, and Pfirschke above – and further exchange the EDA linker for an alkyleneamino linker (EA) also taught by Grawunder conjugated to the (Gly)5 which would comprise the general formula
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conjugated to PNU-159682 for sortase antibody conjugation.
This is obvious because: 1) This is obvious because Grawunder taught L1 could be either EA or EDA.
There is a reasonable expectation of success because: 1) the alkyleneamino linker allows attachment of the (Gly)n linker for sortase conjugation, such that the coupling can occur via the C-terminus of the (Gly)n peptide, thus providing a free N-terminus of the final toxin-linker adduct for sortase conjugation; and 2) the PNU would still be covalently attached via a non-cleavable linker to the (Gly)5. Thus, the ADC with the EA linker would be expected to kill target expressing tumor cells effectively and promote effector T cell immune recruitment to the tumor and tumor memory. Further, the ADC would promote T cell recruitment to the tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells.
Response to Arguments
Independent claim 2 has been amended to include further subject matter.
The updated rejection is above.
Applicant disagrees that the combination of Müller, Beerli, Gerber, and Grawunder teaches or suggests the claimed method, for at least the reasons discussed below. Applicant argues Müller does not teach an ADC with an anthracycline toxin moiety. Instead, Müller states that the DM-1 precursor, P3, induces robust anti-tumor responses via antigen uptake by dendritic cells and potentiation of tumor-specific T-cell responses. This provides motivation for Müller to further study the effects of DM-1. Müller used a system that "allowed us to exclusively focus on the therapeutic and immunologic effects of the cytotoxic payload DM-1, as well as its interaction with immune checkpoint blockade." See p.2, left col. However, Müller just analyses DM-1 and remains silent about other toxins (e.g., anthracyclines). Moreover, Müller states that the "[ ... ] finding strongly suggests that the immune modulatory properties of the cytotoxic payload DM1 are mainly responsible for the pronounced immune infiltration," thus not only failing to incentivize the exchange of the payload, but rather teaching that the used payload DM-1 is essential for the observed effect. See p. 5, left col. Accordingly, modifying the ADC of Müller to replace the payload DM-1 payload would result in the loss of this observed effect, and thus would render the DM-1 ADC of Müller unsatisfactory for its intended purpose. If a proposed modification would render the prior art invention being modified unsatisfactory for its intended purpose, there may be no suggestion or motivation to make the proposed modification. MPEP § 2142 states in re Gordon, 733 F.2d 900,221 USPQ 1125 (Fed. Cir. 1984). In light of this, a person of ordinary skill in the art would not have been motivated to consider any other payloads (e.g. anthracyclines) in the ADC of Müller.
Applicant argues Müller further teaches that "using the orthotopic breast cancer model, we found an increase in Tregs [ ... ], which was most pronounced with the combination treatment at the tumor site (Fig. 6A and fig SSA). Whereas, the CD8+/CD4+ ratio remained essentially unchanged, the CD8+/Treg ratio declined for the combination group with T-DM 1 (Fig. S8b), in striking contrast to the other treatment groups (Fig. S8B)." Seep. 8, left col. However, Gerber states that "[a]n increased number of CD3+ lymphocytes as well as an increased ratio of cytotoxic CDS+ T-lymphocytes (CTLs) over FOXP3+ regulatory T-cells (Treg) within tumors following chemotherapy treatment was predictive of favorable therapeutic responses in human breast and colorectal cancer patients treated with anthracyclines and oxaliplatin, respectively [15-17]." Seep. 2, left col. This is in striking contrast to the statement that Müller found a decrease in the (CD8+ T-cell / Treg) ratio and hence a person of ordinary skill in the art would not have consider combining the teachings of Müller with those of Gerber, or at least to combine the teachings of Müller with anthracycline treatment. Moreover, both Gerber and Müller demonstrate the unpredictability associated with payloads, as replacing DM-1 (which is not an anthracycline) with an anthracycline in the Mueller ADC results in a decrease in the CD8+ Treg ratio, whereas anthracycline treatment results in an increase in the ratio as taught by Gerber. Accordingly, since substitution of one known element for another would not yield predictable results to one of ordinary skill in the art, the claim cannot have been obvious. See MPEP 2143(8).
Applicant argues in general, Gerber does not teach the use of anthracycline conjugated ADCs in combination with ICls. Anthracycline compounds (e.g., doxorubicin) induce high level of immune cell deaths (ICD), which stimulates effector T-cell recruitment to the tumor. Contrary to the Examiner's allegations, Gerber mentions that "doxorubicin is a strong inducer of ICD as a free payload, however, the induction of ICD by a representative ADC, such as CD74-doxorubicin ADC [58], has not yet been evaluated pre-clinically." See p. 4, left col. Interestingly, Gerber refers to Govindan et al. (Mal Cancer Ther; 12(6), "Govindan," submitted herein as "Exhibit A", and also included in the accompanying IDS), which is completely silent about TlLs and the combination of anthracycline conjugated ADCs with ICls. In contrast, Govindan shows in several cancer cell lines that a doxorubicin-conjugated ADC is less effective against solid tumors than a SN38-conjugated ADC, where e.g. "Despite giving a 2-fold higher dose of the milatuzumab-doxorubicin than the SN-38 conjugates, the median survival was no better than the saline-treated animals (10.5 days)." Seep. 974, left col.
In the discussion section, Govindan further states that "[t]hese results and the in vitro studies showing unconjugated SN-38 had a 5- to 20-fold higher potency than doxorubicin in more solid tumor cell lines led to our decision to abandon further evaluation of the doxorubicin conjugate for solid tumor therapy." Consequently, neither Gerber, nor Govindan teach that anthracycline based ADCs would be expected to promote immune infiltration. Govindan rather does not suggest or teach the use of anthracycline-based ADCs, such as doxorubicin conjugates, in the treatment of solid tumors. Gerber merely state that "While there are not many ADCs employing anthracyclines as payload in the clinic, other delivery systems such as liposomes carrying doxorubicin (Doxil) are clinically approved. Therefore, it will be interesting
to test potential combination synergies in clinical trials combining Doxil and 10 drugs." See p.4, left col. Of note, Gerber refers to the liposome packaged doxorubicin, Doxil, and not to doxorubicin-conjugated ADCs.
Applicant argues consequently, a person of ordinary skill in the art, equipped with the teachings of Gerber, would neither consider a combination of anthracycline-conjugated ADCs with ICls for the treatment of tumors, especially not of cold tumors, nor be incentivized to combine the teachings with Müller, as explained above, or Beerli, as Gerber, and Govindan refer to, rather teach away from, using an anthracycline-conjugated ADC. A person of ordinary skill in the art would not have been motivated to use anthracyclines because Govindan teaches that SN-38 (a camptothecin) had higher potency compared to doxorubicin (an anthracycline).
Accordingly, Fig. 2 of Gerber is also not teaching a combination of anthracycline conjugated ADCs with ICls. See p. 4. Besides the ambiguous statement in the figure itself, which is manifested in the question mark ("?") next to "ADCs + IOs", the further mentioning of "ADC Payloads Calich, MTls," can only be interpreted as providing the specific examples calicheamicins and microtubule inhibitors but remain completely silent about the use of anthracyclines as a payload. Furthermore, considering the general teaching of Gerber, a person of ordinary skill in the art would not consider anthracycline-conjugated ADCs for the combination with 10 drugs, but rather different anthracycline delivery systems, such as liposomes carrying doxorubicin. See p.4, left and right col.
The Applicant asserts that Fig. 2 of Gerber is not conclusive. Of note, Gerber does not disclose experimental data, but is highly speculative. Gerber states "anthracyclines appear attractive for combination with immuno-oncology compounds," the "potential impact of combining ADC with 10 compounds on response rates and overall survival of cancer patients," "compounds that induce ICD and/or stimulate dendritic cell activation are promising candidates for combination treatment," and "conventional cytotoxic cancer therapies, including taxanes and other microtubule inhibitors (MTls), DNA targeting agents, or targeted therapies, frequently induce the formation of adaptive resistance, ultimately leading to disease progression," and as shown by the question mark ("ADCs + IOs?") in the graph of Fig. 2.
In addition, Gerber teaches that "anthracyclines (doxorubicin) and oxaliplatin appear attractive for combination with 10 compounds," indicating that said compounds are attractive only in their combination. Hence, in summary, Gerber cannot be considered as a reliable source, but is of speculative nature. Gerber does not relate to cold tumors either.
Applicant argues Beerli, on the other hand, does not teach, as alleged by the Examiner, that ADCs induced CD8+ T cells to promote cancer cell death, but rather merely states that "[d]epletion of CD8 T cells severely reduced the anti-tumor activity of the ADC, demonstrating an important role for T cells in driving tumor regression." Hence, based on the teachings of Beerli, a person of ordinary skill in the art would not consider using an anthracycline-conjugated ADC in a cold tumor, which is per definition. As also stated, a person of ordinary skill in the art would not consider it as it does not relate to the claimed subject matter, depleted of CD8 T cells. With no expectation of success of the treatment with an anthracycline-conjugated ADC or an ICI alone, there would also be a priori no expectation of success of a treatment with the combination of an anthracycline-conjugated ADC with an ICI. It was rather a surprising and unexpected finding of the inventors of the present application that there is a synergy between the two treatment approaches.
Applicant argues a person of ordinary skill in the art would also not consider combining the teachings of Beerli with the teachings of Müller. While Müller teaches that the observed effect depends on the increase of TILs, Müller also teaches that "the immune modulatory properties of the cytotoxic payload DM 1 are mainly responsible for the pronounced immune infiltration" and hence provides no motivation to exchange the payload. See p. 5, left col. Beerli did neither disclose nor recommend a combination of the ADCs described with any immune checkpoint inhibitor, nor did it relate specifically to cold tumors at all. Consequently, Beerli does not present any findings on a potential combination of the ADC as described and immune checkpoint inhibitors.
The observation in the present application that a poorly immunogenic ("cold") tumor, with no significant effect of the immune checkpoint inhibitor, a strong synergy between the evaluated immune checkpoint inhibitor and the targeted PNU derivative-comprising ADC was found, was not obvious, but was unexpected and surprising. The observation was made in B16 melanoma mouse model ("cold" tumor) in vivo, overexpressing the target hROR1 and provides evidence for an advantageous technical effect of said strong synergy between the evaluated ICI and the targeted PNU derivative-comprising ADC demonstrated by in vivo experiments in cold tumors. See Example 7, Figs. 6 to 9, and p. 42. As stated in the present application, "Figure 7 presents the colony volumes of the different treatment groups of Table 5. These results suggest, in a poorly immunogenic ("cold") tumor with no significant effect of the immune checkpoint inhibitor, a strong synergy between the evaluated immune checkpoint
inhibitor and the targeted PNU derivative-comprising ADC."
This synergistic effect in particular is surprising when taking into consideration that T lymphocytes, to which the immune checkpoint inhibitors are targeted, are among the very poorly represented immune cells in cold tumors. This implies that the state of the art was teaching away from combining immune checkpoint inhibitors with ADCs in the first place, and did not suggest or encourage applying such combination, due to rather low expectation of success. Particularly of note, the experimental data in the present application show that complete elimination of tumor cells can be achieved. See Fig. 7.
Applicant argues further in conclusion, none of the documents cited appear to relate specifically to "cold tumors," without any relation to ADCs at all. For at least these reasons, in addition to the unexpected technical effect of strong synergy as detailed above, the rejection should be withdrawn.
In response, Applicant's arguments filed 6/11/2025 have been fully considered
but they are not persuasive. While Müller does not teach an ADC with an anthracycline toxin moiety, exchange of the DM1 for anthracycline is obvious with a reasonable expectation of success as described in the obvious rational above. Further, Müller is aware of other compounds, including anthracyclines, stimulating an immune response which could be used in combination with immune checkpoint inhibitors. Müller taught the field of cancer immunotherapy is rapidly expanding with the demonstration of improved overall survival and durable responses mediated by PD-1 and PD-L1 inhibitors across multiple cancer types and even in patients refractory to standard treatments (page 8, right column, last paragraph). Müller taught exciting perspectives include combining immunotherapy with chemotherapy or targeted therapy, wherein Zitvogel L et al. Mechanism of Action of Conventional and Targeted Anticancer Therapies: Reinstating Immunosurveillance. (Immunity 2013 39(1) 74-88) is cited. Zitvogel taught anthracyclines: A) elevate the intratumoral CD8+ to FOXP3+ T cell ratio after one single cycle of anthracycline-based neoadjuvant chemotherapy and predicts the pCR to the entire chemotherapeutic regimen (six cycles) which indicates that chemotherapy-elicited immune responses are ultimately responsible for tumor eradication (page 76, left column, second to last paragraph); B) is able to trigger immunogenic cell death (ICD), which can stimulate protective anticancer immune responses (page 78, left column, last paragraph); C) induce the differentiation of DC precursors and/or promote DC maturation and wherein in response to anthracycline-based chemotherapy, DC precursors have been shown to infiltrate the tumor bed, localize in the close proximity of nests of dying cancer cells, and mature (page 80, left column first paragraph). Thus, Müller is aware of the immune activating properties of compounds such as anthracycline. Müller taught from a mechanistic point of view, these therapies may act on tumor cells by destroying them and/or modulating their propensity to elicit antitumor immune responses, or alternatively by stimulating immune effector cells, either directly or by relieving immunosuppressive mechanisms in the tumor microenvironment (page 8, right column, last paragraph). Müller taught additionally, the immunologic profile of the tumor may be substantially altered by neoadjuvant chemotherapy and may lead to accumulation of effector T cells and/or depletion of potentially immunosuppressive cells such as Tregs, which may correlate with an increased likelihood of pathological responses and, ultimately, better prognosis (page 8-9, bridging paragraph). Additionally, Pfirschke taught immunogenic chemotherapeutics improve immune checkpoint blockade, wherein the anthracycline doxorubicin induces immunogenic cancer cell death and synergistically decreases tumor cell growth when combined with checkpoint inhibitors targeting PD-1 and CTLA-4 in tumors. Thus, anthracyclines were known to synergistically enhance checkpoint inhibitors PD-1 and CTLA-4 antibody anticancer activity. Thus, exchanging DM1 in the ADC of Müller for the anthracycline PNU-159682 would not result in the loss of the observed immunological effect, and is obvious with a reasonable expectation of success for its intended purpose.
Regarding Müller further found an increase in Tregs with the combination treatment at the tumor site (Fig. 6A and fig SSA), the CD8+/CD4+ ratio remained essentially unchanged, and the CD8+/Treg ratio declined for the combination group with T-DM1, combination treatment with T-DM1 and CTLA-4/PD-1 treatment led to increased survival overall in Fig. 2C despite the increase in Tregs. Potential issues with the T-DM1 increase of Tregs that may lead to non-curative results further support it being obvious to exchange DM1 for an anthracycline in the ADC. Anthracyclines were known to induce high levels of immune cell death and immunogenic cell death of tumor cells represents a potent stimulator of effector T-cell recruitment to tumors as taught by Gerber. Further, as described above, Zitvogel taught anthracyclines elevate the intratumoral CD8+ to FOXP3+ T cell (Treg) ratio after one single cycle of anthracycline-based neoadjuvant chemotherapy and predicts the pCR to the entire chemotherapeutic regimen (six cycles) which indicates that chemotherapy-elicited immune responses are ultimately responsible for tumor eradication (cited above). Thus, exchange of DM1 with an anthracycline in the ADC for combination therapy with an immune checkpoint inhibitor would be preferred and obvious with a reasonable expectation of success for treatment of cold tumors.
Regarding Gerber does not teach the use of anthracycline conjugated ADCs in combination with ICls and Govindan, an ADC would be expected to target the anthracycline payload to the tumor cells. Further, the obvious rational includes Beerli above. An anthracycline toxic payload of an ADC would thus also stimulate effector T-cell recruitment to tumors. Thus, anthracycline conjugated ADC would be expected to cause immune invasion into “cold” tumors. As described above, Beerli taught enzymatic, site-specific conjugation to generate homogenous ADCs based on a derivative of the highly potent anthracycline toxin PNU-159682 using the anti-HER-2 antibody trastuzumab (part of trastuzumab emtansine T-DM1) (abstract). Beerli taught the anthracycline toxin PNU-159682 ADC was highly stable in vitro and in vivo and exhibited potencies exceeding those of ADCs based on conventional tubulin-targeting payloads, such as trastuzumab emtansine (T-DM1) vedotin (abstract). Beerli taught anti-tumor activity in an immune-competent host involved activation of the immune system, as shown by evaluation of a trastuzumab-PNU ADC in a Kadcyla-resistant HER2-positive orthotopic breast cancer model (abstract). Beerli taught depletion of CD8 T cells severely reduced the anti-tumor activity of the ADC, demonstrating an important role for T cells in driving tumor regression. Beerli taught when tumor free animals were re-challenged with the same tumor, tumor growth was entirely inhibited in the absence of any further ADC administration, indicating the development of an immunological memory (abstract). Additionally, Pfirschke taught immunogenic chemotherapeutics improve immune checkpoint blockade, wherein an anthracycline induces immunogenic cancer cell death and synergistically decreases tumor cell growth when combined with checkpoint inhibitors targeting PD-1 and CTLA-4 in tumors. Thus, anthracyclines were known to synergistically enhance checkpoint inhibitors PD-1 and CTLA-4 antibody anticancer activity. Thus, exchange of DM1 for PNU-159682 in the ADC for combination treatment with a checkpoint inhibitor would be obvious with a reasonable expectation of success. Govindan teaching that SN-38 (a camptothecin) had higher potency compared to doxorubicin (an anthracycline) is not teaching away from exchanging DM1 for PNU-159682 in the ADC for combination treatment with a checkpoint inhibitor. SN-38 is not DM1 and anthracyclines have properties described above that make it preferable to DM1.
Regarding Gerber and there are not many ADCs employing anthracyclines as payload in the clinic and other delivery systems such as liposomes carrying doxorubicin (Doxil) are clinically approved, Beerli taught an ADC anthracycline PNU-159682 conjugate which is known to demonstrate an important role for T cells in driving tumor regression and development of an immunological memory when administered. Consequently, a person of ordinary skill in the art, equipped with the teachings of Müller, Beerli, Gerber, Grawunder, and Pfirschke would find it obvious with a reasonable expectation of success to combine an ADC anthracycline PNU-159682 conjugate with an immune checkpoint inhibitor for treatment of a cold tumor as described in the obvious rational above.
Regarding Gerber Figure 2, Gerber taught that there is the expectation that combination antibody drug conjugates (ADC) and immuno-oncology drugs would increase patient survival more. Arguments to suggest the teachings of Gerber are speculative and therefore is not conclusive are incorrect. Pfirschke taught immunogenic chemotherapeutics improve immune checkpoint blockade, wherein the anthracycline doxorubicin induces immunogenic cancer cell death and synergistically decreases tumor cell growth when combined with checkpoint inhibitors targeting PD-1 and CTLA-4 in tumors. Thus, anthracyclines were known to synergistically enhance checkpoint inhibitors PD-1 and CTLA-4 antibody anticancer activity. Müller taught although primary resistance to immune checkpoint-blocking antibodies occurred in tumors, combining T-DM1 treatment with blockade of the PD-1/CTLA-4 inhibitory pathway resulted in complete cures and greatly enhanced T cell responses, including complete tumor rejection and memory formation (page 8, right column, first paragraph). Thus, the effectiveness of ADC + checkpoint inhibitor combinations have been shown by Müller and support Gerber. The teachings of Gerber that anthracycline compounds induce high levels of immune cell death (page 3, right column, last paragraph), immunogenic cell death (ICD) of tumor cells represents a potent stimulator of effector T-cell recruitment to tumors (abstract), and that treatment regimens with anthracyclines appear attractive for combination with immuno-oncology compounds (page 4, right column, second paragraph) further support the combination of an anthracycline ADC with checkpoint inhibitors in cold tumors that would benefit from the immune infiltration. Thus, the anthracycline ADC would promote T cell infiltration into the cold tumor, while the immune checkpoint inhibitor would prevent the cancer from inactivating the cytotoxic effector T cells.
Regarding Beerli and "[d]epletion of CD8 T cells severely reduced the anti-tumor activity of the ADC, demonstrating an important role for T cells in driving tumor regression", the ADC anthracycline PNU-159682 conjugate is taught by Beerli to have an immunological activating component wherein CD8 T cells and immunological memory drive tumor regression (cited above). Additionally, as described in the obvious rational above, Gerber taught anthracycline compounds induce high levels of immune cell death, which is known to stimulate effector T-cell recruitment to tumors, so an anthracycline based ADC would be expected to also promote immune infiltration. Gerber taught combination treatments of immune-checkpoint inhibitors with compounds that increase the number of tumor infiltrating CD8+ T cells would expand the therapeutic benefit of immuno-oncology drugs. Thus, the ADC conjugate with PNU-159682 would be expected to recruit T cells to the cold tumor and induce CD8 T cells and immunological memory to drive tumor regression. Further, combination treatment with an immune checkpoint inhibitor would with compounds that increase the number of tumor CD8+ T cells to expand the therapeutic benefit. A person having ordinary skill in the art would expect the combination therapy to be more effective.
Regarding a surprising and unexpected finding of the inventors of the present application that there is a synergy between the two treatment approaches, 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." Thus, while tumor responses in Figs 4, 6, 7, and 9 of cold tumors administered combination treatment of the immune check point inhibitors targeting CTLA-4 or PD-1/PD-L1 in combination with the ROR-1 targeted ADC XBR1-402-G5-PNU and XBR1-402-17-G5-PNU with sortase conjugation at the C-terminal may be surprising, the instant claims do not reflect the method used to obtain the unexpected results.
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references of Beerli and Müller or Müller, Beerli, Gerber, and Grawunder, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, as detailed above, it would have been obvious for a person having ordinary skill in the art to take the method of Müller for treating Her2 positive breast cancer patient cold tumors by administering the protein toxin conjugate ADC, T-DM1 – and:
1) exchange the ADC in the method for the protein toxin conjugate ADC, trastuzumab anthracycline, Tras-PNU-159682 with enzymatic, site-specific conjugation, of Beerli;
2) further include the immune checkpoint inhibitors anti–CTLA-4 and PD-1 with the ADC treatment as taught by of Müller;
3) attach the linker toxin