Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
Applicant’s claim for the benefit of a prior-filed application (PRO 63/174,418, filed 04/13/2021) under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claims 4 and 14 are rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Regarding Claims 4 and 14, the claims require that “the mean pore size ranges from about 15 microns to about 80 microns”. However, their respective parent Claims 1 and 11 have required a “mean pore size ranging from about 20 microns to about 150 microns”, i.e., the instant claims are of improper dependent form for failing to include all the limitations of the claims upon which they depend. Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 2, 4-12, and 14-24 is/are rejected under 35 U.S.C. 103 as being unpatentable over BRANSBY et al. (US 2020/0362290 A1; effectively filed date 25 May 2018).
Regarding Claim 1, BRANSBY discloses hollow fiber tangential flow depth filters (p0006) generally comprising a housing having an interior, a fluid inlet, a retentate fluid outlet, a permeate fluid outlet, and at least one hollow fiber comprising a porous wall (i.e., (a)-(d) and partially (e); p0008); the at least one hollow fiber further having an interior surface, and an exterior surface wherein the interior surface forms an interior lumen having a width range from 0.75 mm to 13 mm (p0008), which reads on the claimed range of a width ranging from about 0.75 mm to about 30.0 mm, and extending through the at least one hollow fiber (p0008).
The at least one hollow fiber is further disclosed to be formed from a plurality of filaments (p0010); the filaments are extruded polymer filaments (i.e., said fiber being formed from a plurality of extruded polymer filaments; p0011), and each hollow fiber having mean pore sizes ranging from 0.5 microns to 50 microns (p0078), which overlaps with the claimed range of a mean pore size ranging from about 20 microns to about 150 microns and therefore, establishes a case of prima facie obviousness (MPEP 2144.05). Finally, the at least one hollow fiber is disclosed to be positioned in the housing interior, the fluid inlet and the retentate fluid outlet are in fluid communication with the interior lumen of the at least one hollow fiber, and the permeate fluid outlet is in fluid communication with the housing interior and the exterior surface of the porous wall (p0008).
While the prior art does not explicitly disclose the claimed density range of from 40% to 50%, BRANSBY discloses the hollow fibers have a density (p0081), e.g., 51-56%, of the density of an equivalent solid volume polymer filament (p0034). BRANSBY further discloses that by varying and optimizing filament density, desired mean pore sizes and pore distribution can be obtained (p0078) and thus can be tailored for the use of the filter unit in filtering cell cultures without fouling (p0081). Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation absent unexpected results or evidence indicating such optimum or workable ranges are critical (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP§2144.05). Thus, although the prior art is deficient in explicitly disclosing the claimed density range of 40% to 50%, such a range obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention because the prior art teaches that by optimizing the density of the fibers, a desired pore size and pore distribution can be obtained.
Regarding Claim 11, as discussed in the rejection of Claim 1, BRANSBY makes obvious the hollow fiber tangential flow filter unit of Claim 1 (i.e., a hollow fiber tangential flow filter unit of claim 1). BRANSBY further discloses a pulsed flow may be introduced into the fluid inlet (p0022) via a pumping system (i.e., a pumping system configured to provide pulsed flow to the fluid inlet; p0025).
Regarding Claims 2 and 12¸ BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY further discloses the extruded polymer filaments are either mono-component filaments or bi-component filaments (p0011).
Regarding Claims 4 and 14, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY further discloses each hollow fiber having mean pore sizes ranging from 0.5 microns to 50 microns (p0078), which overlaps with the claimed range of a mean pore size ranging from about 15 microns to about 80 microns and therefore, establishes a case of prima facie obviousness (MPEP 2144.05).
Regarding Claims 5 and 15, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. While the prior art does not explicitly disclose the claimed density range of about 47%, BRANSBY discloses the hollow fibers have a density (p0081), e.g., 51-56% of the density of an equivalent solid volume polymer filament (p0034). BRANSBY further discloses that by varying filament density, the mean pore sizes and pore distribution can also be optimized (p0078) and thus can be tailored for the use of the filter unit in filtering cell cultures without fouling (p0081). Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation absent unexpected results or evidence indicating such optimum or workable ranges are critical (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP§2144.05).
Regarding Claims 6 and 16, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY further discloses each hollow fiber having a wall thickness ranging from 1 mm to 10 mm (p0008), which reads on the claimed range of a wall thickness ranging from about 1 mm to about 10 mm.
Regarding Claims 7 and 17, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY further discloses each interior lumen having a width ranging from 1 mm to 5 mm (p0008), which overlaps with the claimed range of a width ranging from about 5 mm to about 20 mm and therefore, establishes a case of prima facie obviousness (MPEP 2144.05).
Regarding Claims 8 and 18, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY further discloses a plurality of hollow fibers (p0014).
Regarding Claims 9 and 19, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 8 and 18, respectively. The instant limitation requiring that “the hollow fiber tangential flow filter unit is configured to couple with a silicone potting gasket” is directed toward an intended use of the claimed hollow fiber tangential flow filter unit and does not require any additional limitation to the claimed hollow fiber tangential flow filter unit other than to have the capability to couple to a silicone potting gasket. If a prior art structure is capable of performing the intended use as recited, then it meets the limitations of the claim (In re Schreiber, 128 F.3d 1473, 1477, 44 USPQ2d 1429, 1431 (Fed. Cir. 1997); MPEP §2111.02 II).
Regarding Claims 10, 20, and 27, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. The instant limitation requiring that “said filter [unit]/system is a hollow fiber tangential flow depth filter/system” is directed toward an intended use of the claimed hollow fiber tangential flow filter unit and does not require any additional limitation to the claimed filter unit. If a prior art structure is capable of performing the intended use as recited, then it meets the limitations of the claim (In re Schreiber, 128 F.3d 1473, 1477, 44 USPQ2d 1429, 1431 (Fed. Cir. 1997); MPEP §2111.02 II).
Regarding Claim 21, BRANSBY makes obvious the hollow fiber tangential flow filtering system of Claim 11. BRANSBY further discloses a pulsatile pump (p0025).
Regarding Claim 22, BRANSBY makes obvious the hollow fiber tangential flow filtering system of Claim 11. BRANSBY further discloses a flow controller that causes the pump to provide the pulsed flow (p0026).
Regarding Claim 23, BRANSBY makes obvious the hollow fiber tangential flow filtering system of Claim 22. BRANSBY further discloses the flow controller comprises an actuator, e.g., an electrically controlled actuator, a pneumatically controlled actuator, or a hydraulically controlled actuator (p0027).
Regarding Claim 24, BRANSBY makes obvious the hollow fiber tangential flow filtering system of Claim 22. The instant limitation requiring that the flow controller is configured to provide a pulsed flow at a rate determined by a change in viscosity when fluid is present in said system is directed toward material or article worked upon and manner or method by which the system is used. The inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims (In re Young, 75 F.2d 996, 25 USPQ 69 (CCPA 1935); MPEP §2115). The manner or method in which an apparatus is to be utilized is not subject to the issue of patentability of the apparatus itself (In re Casey, 370 F.2d 576, 152 USPQ 235 (CCPA 1967); MPEP §2115).
Claim(s) 3 and 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over BRANSBY et al. (US 2020/0362290 A1), as applied to Claims 1 and 11 above, and further in view of OGAWA et al. (US 2010/0219122 A1).
Regarding Claims 3 and 13, BRANSBY makes obvious the hollow fiber tangential flow filter unit and system of Claims 1 and 11, respectively. BRANSBY is deficient in disclosing the at least one hollow fiber comprises two or more layers of varying density.
OGAWA discloses a hollow fiber membrane for treating liquids using cross-flow filtration (p0026) comprising a plurality of layers having varying densities (p0029); advantageously, such a structure enables easier backwashing and recoverability of the membrane thereby improving membrane performance (p0029). Thus, prior to the effective filing date of the claimed invention, one of ordinary skill in the art would have found it obvious to provide two or more layers of varying density as disclosed by OGAWA for the hollow fiber tangential flow filter unit made obvious by BRANSBY.
Claim(s) 25 and 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over BRANSBY et al. (US 2020/0362290 A1), as applied to Claim 24 above, and further in view of SCHRIVE et al. (FR 2761899 A1; machine translation provided and referenced herein).
Regarding Claims 25 and 26, BRANSBY makes obvious the hollow fiber tangential flow filter system of Claim 24. BRANSBY is deficient in disclosing a viscosity sensor (Claim 25) or a viscosity sensor communicatively coupled to a second controller, wherein said second controller is configured to adjust the rate of the pulsed flow based on a measurement of the viscosity sensor (Claim 26).
SCHRIVE discloses a method and apparatus for the tangential filtration of a viscous fluid or liquid (abstract). The prior art recognizes the difficulty of filtering viscous fluids with tangential/cross-flow filtration (pg. 5, middle). SCHRIVE discloses that the fluidity of the process can be optimized by controlling the viscosity of the fluid by optimizing viscosity over time (pg. 13-14); variable pumps used for introducing liquids to the apparatus (pg. 11, bottom) and are operated dependent on the viscosity of the fluid to ensure that any pressure drop across the filtration membrane during tangential filtration is overcome (pg. 12, middle). Finally, SCHRIVE discloses that the apparatus further comprises “regulating means” (i.e., a second controller) such that fluid flow is at all times balanced (pg. 13, middle) and further that the regulation is based on transmembrane pressure in the tangential filtration process (pg. 13, bottom). Although not explicitly disclosed, the claimed limitations requiring a viscosity sensor and a second controller communicatively coupled to the viscosity sensor are inherent in the prior art—SCHRIVE requires viscosity measurements, which implies the use of a viscosity sensor (e.g., viscometers are commonly known in the art), and the ability for the apparatus pumps to adjust flow based on transmembrane pressure drop due to changing viscosity, which implies the use of a controller to take viscosity sensing information from a viscosity sensor and communicate that information to a pump to adjust pumping speed. Thus, prior to the effective filing date of claimed invention, one of ordinary skill in the art would have found it obvious to provide a viscosity sensor and a controller for communicating with the viscosity sensor as taught or suggested by SCHRIVE for the filter system made obvious by BRANSBY.
Response to Arguments
Applicant’s amendments and arguments filed 21 August 2025 have been fully considered.
Regarding the Claim Objections of Claims 1, 5, 6, and 15-20, Applicant’s amendments are persuasive; these objections have been withdrawn.
Regarding the rejections of Claims 1-27 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite, Applicant’s amendments are persuasive; these rejections have been withdrawn.
Please note the added 35 U.S.C. 112(d) rejections of Claims 4 and 14.
Regarding the rejections of Claim(s) 1, 2, 4-12, and 14-24 under 35 U.S.C. 103 as being unpatentable over BRANSBY et al. (US 2020/0362290 A1), Applicant’s amendments and arguments are not persuasive. (1) Applicant argues that the claimed filter arrangements “are configured, in one embodiment, to allow passage therethrough of ‘individual cells’” whereas the BRANSBY-disclosed filters are configured to exclude cells, citing p0068 of BRANSBY (pg. 9, top). (2) Applicant further argues BRANSBY fails to explicitly teach filament density can be optimized, i.e., that even though BRANSBY does relate filament density with a variable cell density at which the filter can operate, “this does not necessarily mean that it would be obvious to provide the claim 1 combination of mean pore size, density, and lumen width” (pg. 9, bottom). As further support, Applicant argues that BRANSBY seemingly also teaches that a filter having 51% density fibers resulted in undesirable filtering characteristics, i.e., “one of ordinary skill in the art would not be motivated to modify Bransby's filter to have an even lower density (10-50%) as recited in current claim 1, because to do so would render the resulting device unsuitable for Bransby's intended purpose. See MPEP, § 2143.0l(V)” (pg. 10, middle).
The Examiner respectfully disagrees.
While the Examiner appreciates Applicant’s invention is designed to allow for the passage of individual cells, no such limitation has been claimed. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Even if such a feature were to be claimed, the feature would not have any patentable weight given that such a limitation would be considered an intended use of the hollow fiber tangential flow filter unit. Even further, even if arguendo patentable weight were given to such a feature, the prior art teaches a pore size range 0.5-50 µm that overlaps with the broadly claimed 20-150 µm pore size range—a range which indeed includes the size range of the majority of cells (e.g., CHO cells—as cited in the Specification—are approximately 12-16 µm in diameter, which is well within the range of particle sizes that could pass through a 0.5-50 µm pore size range). While BRANSBY may have indeed stated that the disclosed tangential flow filters are useful for excluding cells, BRANSBY states this in the alternative and does not necessitate the use of such a disclosed filter for this purpose: “tangential flow filters having pore sizes and depths that are suitable for excluding large particles” (emphasis added; p0068). Even if BRANSBY teaches a use of the disclosed filter is to exclude cells, such a teaching is merely a preferred embodiment. Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments (In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971)). “A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use” (In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994); MPEP §2123 II). Even further such a teaching by the disclosure, much like the instantly argued use of the tangential flow filter, is an intended use and not given any patentable weight.
Regarding Applicant’s arguments pertaining to filament density, it is acknowledged that BRANSBY teaches a range outside the claimed range and may have even stated a preference for a filament density outside the claimed range. However, as noted above, such a statement is merely a preferred embodiment. However, it is noted that the Applicant-cited example of BRANSBY does indicate that more CHO cells are passed through the 51% lower density fiber, i.e., it is reasonable to assume that lower density fibers, such as those in the range claimed by Applicant, would pass even more cells, which would actually make BRANSBY’s filter much more appealing for the intended use of passing cells as desired by Applicant. Thus, one of ordinary skill would be convinced and persuaded to use BRANSBY’s filter for such a purpose.
Applicant’s argument regarding that though BRANSBY does relate filament density with a variable cell density at which the filter can operate, “this does not necessarily mean that it would be obvious to provide the claim 1 combination of mean pore size, density, and lumen width” (pg. 9, bottom) misconstrues the rejection and prior art. The rejection did not relate filament density with all variables of pore size, density and lumen width. The rejection indicated—as taught by BRANSBY in p0078—filament density can be optimized to achieve a desired pore size and distribution.
All other arguments have been indirectly addressed.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN B HUANG whose telephone number is (571)270-0327. The examiner can normally be reached 9 am-5 pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Vickie Kim can be reached at (571)272-0579. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Ryan B Huang/Primary Examiner, Art Unit 1777