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 Status
Claims 1-2, 83, 158-166, and 174-176 are currently pending in this application and have been considered on the merits.
Priority
Acknowledgement is made of applicant’s claim for priority to Feb. 9, 2018 based on US 62/628,632. The sequences 40-54 are not disclosed in the priority document, therefore the earliest effective filing date of claims 163 and 164 is Feb. 11, 2019.
Previous Rejections
Status of the rejections: the previous claim rejections under section 112(b) are withdrawn in view of applicant’s claim amendments.
35 USC § 112(a) – Scope of Enablement (modified)
Claims 1-2, 83, 158-166, and 174-176 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because while enabled for wherein the subject is a mouse expressing human SOD1-G93A, the CAR comprises a CD28 transmembrane domain, intracellular CD28-CD3ζ domains, the ABD comprises SEQ ID NO: 5, the ALS symptom is weight loss/paralysis onset or lifespan extension, and the amount administered is 7 x 106 or more cells; the specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, for treating a subject with ALS by administering an “effective amount” of the “regulatory cells” (Tregs) as recited in any of claims 1-2, 83, 158-166, and 174-176.
Enablement is considered in view of the Wands factors (MPEP 2164.01 (a)). The court in Wands states that "Enablement is not precluded by the necessity for some experimentation such as routine screening. However, experimentation needed to practice the invention must not be undue experimentation. The key word is 'undue.' Not 'experimentation;" (Wands, 8 USPQ2d 104). Clearly, enablement of a claimed invention cannot be predicated on the basis of quantity of experimentation required to make or use the invention. "Whether undue experimentation is needed is not a single, simple factual determination, but rather is a conclusion reached by weighting many factual considerations." (Wands, 8 USPQ2d 1404).
The factors to be considered when determining whether there is sufficient evidence to support a determination that a disclosure does not satisfy the enablement requirement and whether any necessary experimentation required is “undue” include, but are not limited to:
(A) The breadth of the claims;
(B) The nature of the invention;
(C) The state of the prior art;
(D) The level of one of ordinary skill;
(E) The level of predictability in the art;
(F) The amount of direction provided by the inventor;
(G) The existence of working examples; and
(H) The quantity of experimentation needed to make or use the invention based on the content of the disclosure.
Furthermore, the USPTO does not have laboratory facilities to test if an invention will function as claimed when working examples are not disclosed in the specification. Therefore, enablement issues are raised and discussed based on the state of knowledge pertinent to an art at the time of the invention. And thus, skepticism raised in the enablement rejections are those raised in the art by artisans of expertise.
All of the Wands factors have been considered with regard to the instant claims, with the most relevant factors discussed below.
Nature of the invention:
The claims are directed to methods of treating a subject with amyotrophic lateral sclerosis (ALS) comprising administering FoxP3+ CD4+ CD25+ regulatory T cells (Tregs) expressing BDNF and expressing a chimeric antigen receptor (CAR) comprising at least one signaling domain and an antigen binding domain (ABD) which binds to a mutant human superoxide dismutase 1 comprising a G93A mutation (mSOD1), wherein said ABD comprises the amino acid sequence of any one of SEQ ID NOs: 5-7; and whereby upon administering an “effective amount” of said Tregs, one or more symptoms of ALS in the subject is reduced.
The claims are broad in that the subject encompasses any subject with ALS, the CAR may comprise any signaling domain selected from CD28-CD3ζ, 4-1BB-CD3ζ, DAP10-CD3ζ, CD44-CD3ζ, DAP10, and CD3ζ, and the ABD of the CAR may comprise any one of SEQ ID NOs: 5-7, some of which share less than 77% sequence identity with each other in this domain alone. Importantly, any subject with ALS encompasses many different biological species, including rodents, dogs, and primates, as well as drosophila as discussed below.
Moreover, an “effective amount” is a functional property that is dependent upon many different variable parameters, including, but not limited to: the type of subject [parameter 1], the ALS symptom being reduced [parameter 2], the administration route (e.g., localized or systemic) [parameter 3], the dosage administered, i.e. total of multiple doses via different administration events [parameter 4]; and importantly, the exact CAR structure, i.e., selection of signaling domain(s) and ABD species [parameter 5].
The state of the art:
The prior art teaches ALS subjects include humans and other mammals, such as model organisms like rats, pigs, fish, as well as the insect drosophila (Browne and Abbott, Eur J Med Chem 121: 918-25 (2016) at pg. 919, right col., 2nd para.; pg. 918, 1st para.; Casci and Pandey, Brain Res 1607: 47-74 (2015) at Table 1).
The art teaches CAR architecture impacts signaling kinetics, exhaustion/anergy, cytokine profiles, and engineered immune cell persistence in subjects, and this is also affected by target antigen density (i.e., mSOD1), at least for CAR-T cells (Weinkove et al., Clin Transl Immunology 8: e1049 (2019) at Abstract).
The art teaches that the direct administration of Treg cells to subjects has challenges with in vitro isolated Tegs being dysfunctional and lacking proliferative ability as well as in obtaining effective numbers of Tregs and maintaining FoxP3 expression (Harkins et al., Crit Rev Immunol 42: 1-27 (2022) at pg. 10, left col., 2nd para., to pg. 15, left col., 1st para.; pg. 17). For example specifically for ALS patients, their own Treg cells are often defective in the ability to produce or maintain effector function of Tregs which present challenges with isolating and expanding this population in vitro for therapeutic uses (Harkins at pg. 14, left col., last para., to right col., 1st para.). Thus, there is unpredictability in using any Treg cell population as a therapeutic in a subject having ALS, especially for autologous Tregs.
The art teaches methods of treating human patients using engineered CAR-Tregs have been investigated in animals but not humans or insects. Regarding ALS patients specifically, as of the earliest effective filing date only one type of Treg adoptive cell therapy was ever tried in humans using autologous FoxP3+ Tregs lacking any genetic engineering (Harkins at Table 1; pg. 14, left col., last, to right col., 1st para.). However research in mice has shown the beneficial effects of adoptive Treg cell therapies in neurodegenerative disease models generally, such as by conferring neuroprotection, decreasing the expression of pro-inflammatory cytokines, and increasing the expression of anti-inflammatory cytokines (pg. 10, left col., 2nd para., to pg. 15, left col., 1st para.). Thus, there is considerably uncertainty for a given ALS treatment working in a human ALS patient, even if the treatment works in mice or shows in vitro promise with human cell culture.
The amount of direction and guidance and working examples provided by Applicant:
The disclosure provided by the applicant, in view of prior art, must encompass a wide area of knowledge to a reasonably comprehensive extent. In other words, each of these aspects must be shown to a reasonable extent so that one of the ordinary skills in the art would be able to practice the invention without any undue burden being on such Artisan, such as to perform the method on subjects that are not mice, e.g., rats, pigs, fish, or drosophila, and/or using autologous Tregs.
The instant application shows examples of PBMC-derived FoxP3+CD4+CD25+ human Treg cells (FIG. 7, 9) engineered to express CARs specifically targeting mutant SOD1 associated with ALS but only with in vitro evidence related to reducing an inflammatory symptom of ALS in a subject (via increasing IL-10 or IFN-gamma), e.g., in mouse spinal cord explants (Examples 4-5, 8, 10-11, and 13; FIG. 8-13, 16, 18-19, and 21). These Treg cells expressing the CARs are activated by human SOD1 antigens in vitro (e.g., human mutant SOD1 (mSOD1)) (FIG. 3, 5, 11-12, 15-16). Activated human Treg cells expressing exemplary CARs suppressed CD8+ T cells in vitro (FIG. 4 and 13), inhibited PMA or zymosan stimulated superoxide generation by cocultured macrophages in vitro and LPS-stimulated TNF-α and IL-6 production by cocultured macrophages in vitro (FIG. 21-22), and/or increased expression of GITR, PD-1, and CTLA-4 in vitro (FIG. 18).
Graber et al. shows that Tregs engineered to express both a SOD1-G93A CAR and brain-derived neurotrophic factor (BDNF) were capable of reducing symptoms of ALS in a mouse subject (hSOD1-NSG) exemplified by weight loss onset, survival age, and decreases in inflammatory markers (NOX-2, TNF-a, CCL2, and CCL4) in the spinal cord. This one working embodiment of a CAR-Treg was administered via injection at a dose of 7-20 x 106 cells per subject. According to applicant’s statement on the record (Remarks filed 1/23/26, pg. 10-11), this CAR embodiment comprises instant SEQ ID NO: 5 as well as CD28 and CD3ζ signaling domains as in instant FIG. 6 and was constructed from 16L-40 as described in Graber2 (Graber et al., Cytotherapy 26: 126-35 (2024)). Thus, no working example is provided by Graber et al. wherein the CAR comprises SEQ ID NO: 6 or 7 or an intracellular signaling domain comprising 4-1BB-CD3ζ, DAP10-CD3ζ, CD44-CD3ζ, DAP10, and just CD3ζ.
By reciting “effective amount,” claim 1 admits there are amounts that may be administered which are not effective and thus there exists a definable boundary between effective and ineffective amounts. While routine experimentation may allow identification of effective amounts of a pharmaceutical to produce an outcome in a particular type of subject (e.g., a mouse subject), one needs guidance as to what results-effective variable to look for and a general idea of a starting amount to test and then routinely vary the amount from there.
The only guidance in the instant application is to examine recipients subject’s weight loss progression, neuroinflammation (e.g., via markers like IL-10, IFN-γ and IL-4), inhibiting microglia cells, or promotion of neuronal survival, such as in a spinal tissue explant. Also, the only specific guidance as to a starting dose is limited to compositions with 7-20 x 106 cells cells/subject wherein the subject is a mouse, and which may not be equivalent for a human subject. At instant [00244]-[00247], dosing is discussed for any subject at a high level of generality with extreme ranges from 1 million to 100 billion Tregs per subject or per kg weight of subject. Alternatively, guidance is given at 103 to 109 Tregs per kg body weight. This is not guidance but rather virtually any imaginable Treg dose and, thus, represents an invitation to experiment with different sized subjects, e.g., a dog or insect. But as noted above, dose/dosage is not the sole parameter at play.
Thus, while varying 4 other parameters, the effective amount must be determined with guidance only from one subject, a mouse (i.e., about 7-20 x 106 cells cells/subject) while the functional readout is any symptom of ALS guided by neuroinflammation (e.g., via markers like IL-10, IFN-γ and IL-4), inhibiting microglia cells, or promotion of neuronal survival but which was only described in vitro settings, not in a subject.
From the empirical data, it is not predictable that an effective dose exists across the scope of subject encompassed by the claims would result in a reduction of any ALS symptom in vivo. Nowhere does the specification provide any working example in a subject and post-filing data is provided for only a single species of CAR. There is no post-filing working example using either SEQ ID NO: 6 or 7 or with CAR comprising the signaling domains limited to 4-1BB-CD3ζ, DAP10-CD3ζ, CD44-CD3ζ, DAP10, and CD3ζ.
Furthermore, the term “effective amount” has been held to be indefinite when the claim fails to state the function which is to be achieved and more than one effect can be implied from the specification or the relevant art. In re Fredericksen, 213 F.2d 547, 102 USPQ 35 (CCPA 1954). MPEP 2173.05(c). Thus, claims 1-2, 83, 158-166, and 174-176 are indefinite by reference to an “effective amount” which is a variable (MPEP §2173.05(b)) depending on at least 5 parameters simultaneously as discussed above. The dependent claims are included in the basis of the rejection because they do not correct the primary deficiencies of the independent claim.
The quantity of experimentation needed to make and/or use the invention:
Extensive experimentation would be required to determine how reduce, even minimally, one symptom of ALS by administering the recited Treg cells across the scope of subjects and/or CAR architecture choices. The science of medicine has not evolved such that, without guidance or working examples in the specification for any effect occurring in a subject, the claims lack enablement for the full scope of the claimed invention. Extensive experimentation would be required to determine how to generate sufficient amounts of autologous functional Treg cells for adoptive cell therapy of ALS in any subject having ALS, such as a human.
In summary, the claims are rejected under 35 U.S.C. 112(a) because the specification does not reasonably provide enablement to a person skilled in the art to which it pertains or with which it is most nearly connected to perform the claimed invention to treat ALS in the genus of subjects using the recited Treg cells comprising the CAR genus encompassed by the claims. Given the lack of working examples (including post-filing publications), the limited guidance provided in the specification, the lack of guidance in the prior art, and the broad scope of the claims with regard to any subject, undue experimentation would have been required for one skilled in the art to use the claimed methods to predictably produce the recited result of reducing a symptom of ALS and to determine the effective amount(s) to do so.
Response to Arguments
Contrary to statements in the Remarks filed 1/23/26 (pg. 7), claim 1 is not currently amended to recite the Tregs are administered in an amount of at least 1x106 cells. Instead, applicant argues that an effective amount to administer is within the skills of one in the art without undue or unreasonable experimentation. This argument is not persuasive.
As the only actual data in a subject is post-filing data, the application as filed as did not provide this working examples and instead gave generic guidance of 1 million to 100 billion Tregs per subject or per kg subject weight or, alternatively, 103 to 109 Tregs per kg body weight. Thus, for any non-mouse subject, such as a dog, monkey or drosophila applicant is relying solely on the knowledge of the skilled artisan in view of the prior art. As Treg adoptive cell therapy has never successfully been performed in any human or insect, and mouse data is not predictably translated to either, undue experimentation is needed just to search for an effective amount, and one may never be found.
Regarding the choice between SEQ ID NOs: 5-7, Applicant argues (pg. 12) the post-filing data in Graber and Graber2 is sufficient evidence the instant application prophetically predicted the method would work. This is not found persuasive because the post-filing validation is limited in scope to a single CAR species and a single subject species specifically having human mSOD1. This mouse data does not extrapolate to all subjects, especially ones lacking human mSOD1 expression. Furthermore, applicant argues that the data in Graber regarding 16L-40 scFv applies to all three of DG05, DG06 and DG07; however this fact is not clear (pg. 12). Instead, this Office action finds in vitro evidence regarding scFv’s in isolation is not reliably predictive for the CAR-expressing Tregs comprising a complex architecture only partially based on the scFv component as noted in the modified rejection above.
In addition, new evidence of a lack of enablement for claims 1-2, 83, 158-166, and 174 has arisen from an examination of Graber2 at Fig. 1, which is corroborated by Broering at Fig. 3E at Table 2 (Broering et al., PLoS One 8: e61210 (2013)). There is sufficient evidence that any antibody (e.g., any scFv) based on the CDRs of 16L-40 will not bind human SOD1 having a glycine at position 93 (or the equivalent unmutated SOD1 of another mammalian species) with high enough affinity to enable these methods, (Graber2 at Fig. 1). Therefore, the post-filing data shows the Tregs will not work in vivo across the scope of these claims comprising wildtype and/or nonhuman SOD1.
Conclusion
No claim is allowed.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ERIC J ROGERS whose telephone number is (571)272-8338. The examiner can normally be reached Monday - Friday 9:00-6:00.
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/ERIC J ROGERS/Examiner, Art Unit 1638
/Tracy Vivlemore/Supervisory Primary Examiner, Art Unit 1638