DETAILED ACTION
Response to Amendment
Applicant’s response to the office action filed on December 22, 2025 has been entered. The claims pending in this application are claims 1-13. The objections and rejections not reiterated from the previous office action are hereby withdrawn in view of applicant’s amendment filed on December 22, 2025. Claims 1-13 will be examined.
Claim Objections
Claim 1 is objected to because of the following informalities: (1) “the diluted blood sample” in step b) should be “the fixed diluted blood sample”; (2) “that has been treated with an anticoagulant, had red blood cells lysed” in step b) should be “that has been treated with the anticoagulant, has the red blood cells lysed”; and (3) “from a)” in step b) should be “from step a)”.
Claim 3 is objected to because of the following informality: “the analyzing DNA molecules” should be “said analyzing DNA molecules”.
Claim 6 is objected to because of the following informality: “the analyzing” should be “the analyzing step”. Note that applicant has not addressed this issue in the response filed on December 22, 2025.
Claim 6 or 8 is objected to because of the following informality: “identifying the
mutated DNA molecules” should be “identifying the mutated DNA molecules in the rare cells”.
Claim 7 is objected to because of the following informality: “said DNA molecules that are different from DNA molecules from leukocytes, from said rare cells isolated from blood obtained from a subject identify that the subject has CTCs in the blood sample obtained from the subject” should be “said DNA molecules from said rare cells isolated from the blood obtained from the subject identify whether the subject has CTCs in the blood sample”.
Claim 9 is objected to because of the following informality: “said identified mutated DNA molecules from said rare cells isolated from blood obtained from a subject determine that the subject’s blood sample contains CTCs with identified mutated DNA molecules” should be “said identifying the mutated DNA molecules from the rare cells from step e) determine whether the blood sample from the subject contains CTCs with the mutated DNA molecules”.
Claim 10 is objected to because of the following informality: “said analyzing the DNA molecules” should be “said analyzing the DNA molecules from the rare cells”.
Claim 13 is objected to because of the following informality: “a volume of fluid filtered” to a filtration surface” should be “a volume of fluid filtered to the filter to a filtration surface of the filter”.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Scope of Enablement
Claims 1-13 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, because the specification, while being enabling for perform step a) of claim 1, does not reasonably provide enablement for analyzing DNA molecules in rare cells isolated from blood obtained from a subject using the methods recited in claims 1-13. The specification does not enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to use the invention commensurate in scope with these claims.
In In re Wands, 858 F.2d 731,737, 8 USPQ2d 1400, 1404 (Fed. Cir. 1988) the court considered the issue of enablement in molecular biology. The Court summarized eight factors to
be considered in a determination of “undue experimentation”. These factors include: (a) the quantity of experimentation necessary; (b) the amount of direction or guidance presented; (c) the presence or absence of working examples; (d) the nature of the invention; (e) the state of the prior art; (f) the relative skill of those in the art; (g) the predictability of the art; and (h) the breadth of the claims. The Court also stated that although the level of skill in molecular biology is high, results of experiments in molecular biology are unpredictable.
To begin, there is no direction or guidance to show that DNA molecules in rare cells isolated from blood obtained from a subject can be analyzed using the methods recited in claims 1-13. While the relative skill in the art is very high (the Ph.D. degree with laboratory experience), there is no predictability whether DNA molecules in rare cells isolated from blood obtained from a subject can be analyzed using the methods recited in claims 1-13.
First, although it is known that “[A]mmonium Chloride Solution is recommended for the lysis of red blood cells (RBCs) in preparations of human and mouse peripheral blood, spleen, or bone marrow cells. It is buffered and optimized for gentle lysis of erythrocytes, with minimal effect on leukocytes. It does not contain a fixative agent, therefore leukocytes are viable following RBC lysis” (see “Ammonium Chloride Solution for Red Blood Cell Lysis”) and the specification shows that “[T]o extract and enrich rare tumor cells from blood, a blood sample is diluted 20-fold using a buffer for red blood cell lysis. Lysis is allowed to proceed for 5 minutes at room temperature with a gentle agitation” (see page 33, last paragraph), since claim 1 does not indicate that red blood cells in the diluted blood sample is lysed with a lysis buffer which only lyses red blood cells, if red blood cells in the diluted blood sample is lysed with a lysis buffer which can lyse both red blood cells and rare cells, it is unpredictable how the rare cells can be recovered on the filter or can be detached from the filter such that the rare cells cannot be isolated from blood obtained from a subject and DNA molecules in the rare cells cannot be analyzed using the methods recited in claims 1-13.
Second, although the specification shows that “the invention relates to a process for separating biological particles and the fluid that contains them for the purposes of purification or analysis and possibly for diagnosis, comprising at least one vertical filtration stage through a filter the porosity of which is suited to the nature of the biological particles to be separated so that said biological particles are retained by the filter, characterised in that a filter is used comprising at least one elementary filtration area, each elementary filtration area having a limited surface, and in that the surface of each elementary filtration area and the number of elementary filtration areas is chosen according to the nature of the fluid to be filtered, the nature of the biological particles to be separated and the volume of fluid to be filtered” and “[E]ach elementary filtration area of said process has a surface equal to that of a disk with a diameter of between 0.6 cm and 3 cm, and the number of elementary filtration area is chosen so that the ratio of the volume of fluid filtered to the filtration surface is less than 40 ml/cm2, and preferably greater than 0.14 ml/cm2” (see page 14, fourth and fifth paragraphs), since the specification and available arts do not indicate how the ratio of a volume of fluid filtered to a filter to a filtration surface of the filter is determined based on a chosen elementary filtration area, it is unpredictable how the ratio of a volume of fluid filtered to the filter to a filtration surface of the filter is less than 40 ml/cm² can be determined based on at least one elementary filtration area which has a surface equal to that of a disk with a diameter of between 0.6 cm and 3 cm as recited in claim 13.
Case law has established that “(t)o be enabling, the specification of a patent must teach those skilled in the art how to make and use the full scope of the claimed invention without ‘undue experimentation’.” In re Wright 990 F.2d 1557, 1561. In re Fisher, 427 F.2d 833, 839, 166 USPQ 18, 24 (CCPA 1970) it was determined that “[T]he scope of the claims must bear a reasonable correlation to the scope of enablement provided by the specification to persons of ordinary skill in the art”. The amount of guidance needed to enable the invention is related to the amount of knowledge in the art as well as the predictability in the art. Furthermore, the Court in Genentech Inc. v Novo Nordisk 42 USPQ2d 1001 held that “[I]t is the specification, not the knowledge of one skilled in the art that must supply the novel aspects of the invention in order to constitute adequate enablement”.
In view of above discussions, the skilled artisan will have no way to predict the experimental results. Accordingly, it is concluded that undue experimentation is required to make the invention as it is claimed. These undue experimentation at least includes to test whether DNA molecules in rare cells isolated from blood obtained from a subject can be analyzed using the methods recited in claims 1-13.
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.
Claim 11 is 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.
Claim 11 is rejected as vague and indefinite. Since step a) of claim 1 requires treating a diluted blood sample with an anticoagulant and fixing the diluted blood sample, it is unclear why the blood sample is still required to be subjected to dilution and fixation in claim 11 since claim 1 has limitations such as dilution and fixation. Please clarify. Note that applicant has not addressed this issue in the response filed on December 22, 2025.
Claim Rejections - 35 USC § 103
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter 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 under pre-AIA 35 U.S.C. 103(a), the examiner presumes that the subject matter of the various claims was commonly owned at the time any inventions covered therein were made absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and invention dates of each claim that was not commonly owned at the time a later invention was made in order for the examiner to consider the applicability of pre-AIA 35 U.S.C. 103(c) and potential pre-AIA 35 U.S.C. 102(e), (f) or (g) prior art under pre-AIA 35 U.S.C. 103(a).
Claims 1-6, 8, and 10-12 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tang et al., (US 2013/0330721 A1, priority date: November 21, 2011) in view of Bacehowski (US Patent No. 4,152,184, published on May 1, 1979) and Desitter et al., (Anticancer Research, 31, 427-442, 2011).
Regarding claims 1-6, 8, and 10-12, Tang et al., teach a) lysing red blood cells in a diluted blood sample and fixed the diluted blood sample; b) filtering the diluted blood sample that has red blood cells lysed from step a) and has been fixed by vertical filtration with negative pressure through a microfilter, wherein the filter has a pore size from 3 to 30 µm (ie., 7-8 microns or µm) and is suitable for retention of rare cells (ie., CTCs) but which permit passage of cells smaller than the rare cells (ie., some cells smaller than the rare cells such as bacteria), wherein the rare cells are nucleated cells larger than neutrophils and mature lymphocytes; c) recovering the rare cells on the filter or the rare cells detached from the filter; d) lysing the recovered rare cells; and e) analyzing DNA molecules from the rare cells as recited in claim 1 wherein the subject has a cancer or a tumor, is suspected of having a cancer or a tumor, or is at risk of having a cancer or a tumor as recited in claim 2, in step e), said analyzing DNA molecules comprise one or more of PCR analyses, high throughput sequencing, and methylation analyses as recited in claim 3, the recovered rare cells comprise circulating tumor cells (CTCs) as recited in claim 4, the DNA molecules (ie., DNA molecules with gene mutations) from the rare cells comprising CTCs are different from DNA molecules from leukocytes as recited in claim 5, the DNA molecules analyzed in step e) comprise mutated DNA molecules and the analyzing step comprises identifying the mutated DNA molecules as recited in claims 6 and 8, said analyzing the DNA molecules from the rare cells comprises detecting the presence or absence of DNA mutations in circulating tumor cells (CTCs) as recited in claim 10, the blood is subjected to treatment with a cell lytic agent (ie., by lysing red cells) prior to the filtering as recited in claim 11 and the filter has a pore size of 5 to 25 µm (ie., 7-8 microns or µm) as recited in claim 12 (see paragraphs [0078], [0135], [0177], [0178], [0215] to [0232], [0255] to [0260], [0262] to [0264], [0266], [0268], [0270], [0271], [0277], and [0288]).
Tang et al., do not disclose a) treating a diluted blood sample with an anticoagulant and b) filtering the treated diluted blood sample that has been treated with the anticoagulant, has the red blood cells lysed, and has been fixed from a) by vertical filtration with negative pressure through a polycarbonate filter wherein the filter has a pore density from 3x10³ to 5x 10⁶ pores/cm² as recited in claim 1. However, Tang et al., teach lysing red blood cells in a diluted blood sample and fixed the diluted blood sample (see paragraphs [0266] and [0288]).
Bacehowski teaches to add an anticoagulant solution to a blood bag to prevent blood clotting (see column 4, sixth paragraph).
Desitter et al., teach diluting a blood sample in order to lyse red blood cells, selectively lysing red blood cells in the diluted blood sample, fixing the diluted blood sample, and filtering the diluted blood sample that has the red blood cells lysed and has been fixed by vertical filtration through a polycarbonate filter wherein the filter has a pore size from 3 to 30 µm (ie., 7.5±0.36 µm or 6.5±0.33 µm) and a pore density of from 3×10³ to 5×10⁶ pores/cm2 (ie., 1×105 pores/cm2) (see page 428, right column and Figure 1).
Therefore, it would have been prima facie obvious to one having ordinary skill in the art at the time the invention was made to have performed the method recited in claim 1 by treating a diluted blood sample with an anticoagulant and filtering the treated diluted blood sample that has been treated with the anticoagulant, has the red blood cells lysed, and has been fixed by vertical filtration with negative pressure through a polycarbonate filter wherein the filter has a pore density of from 3x10³ to 5x 10⁶ pores/cm² in view of the prior arts of Tang et al., Bacehowski and Desitter et al.. One having ordinary skill in the art would have been motivated to do so because Tang et al., teach lysing red blood cells in a diluted blood sample and fixed the diluted blood sample (see paragraphs [0266] and [0288]), Bacehowski teaches to add an anticoagulant solution to a blood bag to prevent blood clotting (see column 4, sixth paragraph), Desitter et al., teach diluting a blood sample in order to lyse red blood cells, selectively lysing red blood cells in the diluted blood sample, fixing the diluted blood sample, filtering the diluted blood sample that has the red blood cells lysed and has been fixed by vertical filtration through a polycarbonate filter wherein the filter has a pore size from 3 to 30 µm (ie., 7.5±0.36 µm or 6.5±0.33 µm) and a pore density of from 3×10³ to 5×10⁶ pores/cm2 (ie., 1×105 pores/cm2) (see page 428, right column and Figure 1), and the simple substitution of one kind of filter (ie., the microfilter taught by Tang et al.,) from another kind of filter (ie., the polycarbonate filter taught by Desitter et al.,) during the process of performing step b) of the method recited in claim 1, in the absence of convincing evidence to the contrary, would have been prima facie obvious to one having ordinary skill in the art at the time the invention was made since the microfilter taught by Tang et al., and the polycarbonate filter taught by Desitter et al., are used for the same purpose (ie., passing a blood sample from a subject and recovering a fraction of rare cells that do not pass through the filter). One having ordinary skill in the art at the time the invention was made would have a reasonable expectation of success to perform the method recited in claim 1 by adding an anticoagulant to a diluted blood sample in order to prevent the blood sample clotting and substituting the microfilter taught by Tang et al., from the polycarbonate filter taught by Desitter et al., in view of the prior arts of Tang et al., Bacehowski and Desitter et al., such that red blood cells in the treated diluted blood sample would be selectively lysed, the treated diluted blood sample would be fixed, and the treated diluted blood sample that has been treated with the anticoagulant, has the red blood cells lysed, and has been fixed would be filtered by vertical filtration with negative pressure through a polycarbonate filter having a pore density from 3x10³ to 5x 10⁶ pores/cm² as recited in claim 1.
Furthermore, the motivation to make the substitution cited above arises from the expectation that the prior art elements will perform their expected functions to achieve their expected results when combined for their common known purpose. Support for making the obviousness rejection comes from the M.P.E.P. at 2144.06, 2144.07 and 2144.09.
Also note that there is no invention involved in combining old elements is such a manner that these elements perform in combination the same function as set forth in the prior art without giving unobvious or unexpected results. In re Rose 220 F.2d. 459, 105 USPQ 237 (CCPA 1955).
Claims 7 and 9 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Tang et al., in view of Bacehowski and Desitter et al., as applied to claims 1-6, 8, and 10-12 above, and further in view of Peck et al., (Cancer Research, 58, 2761-2765, 1998).
The teachings of Tang et al., Bacehowski and Desitter et al., have been summarized previously, supra.
Tang et al., Bacehowski and Desitter et al., do not disclose that said DNA molecules from said rare cells isolated from the blood obtained from the subject identify whether the subject has CTCs in the blood sample as recited in claim 7 and said identifying the mutated DNA molecules from the rare cells from step e) determine whether the blood sample from the subject contains CTCs with the mutated DNA molecules as recited in claim 9.
Peck et al., teach detection and quantitation of circulating cancer cells in the peripheral blood of lung cancer patients by RT-PCR of cytokeratin 19 RNA isolated from the cells of the peripheral blood of lung cancer patients (see pages 2761 and 2762, page 2764, right column, second paragraph, and page 2765, right column).
Therefore, it would have been prima facie obvious to one having ordinary skill in the art at the time the invention was made to have performed the methods recited in claims 7 and 9 wherein said DNA molecules from said rare cells isolated from the blood obtained from the subject identify whether the subject has CTCs in the blood sample and said identifying the mutated DNA molecules from the rare cells from step e) determine whether the blood sample from the subject contains CTCs with the mutated DNA molecules in view of the prior arts of Tang et al., Bacehowski, Desitter et al., and Peck et al.. One having ordinary skill in the art would have been motivated to do so because Peck et al., teach detection and quantitation of circulating cancer cells in the peripheral blood of lung cancer patients by RT-PCR of cytokeratin 19 RNA isolated from the cells of the peripheral blood of lung cancer patients (see pages 2761 and 2762, page 2764, right column, second paragraph, and page 2765, right column). One having ordinary skill in the art at the time the invention was made would have a reasonable expectation of success to perform the methods recited in claims 7 and 9 by analyzing whether the DNA molecules from the rare cells contain mutated DNA molecules such that said DNA molecules from said rare cells isolated from the blood obtained from the subject would identify whether the subject has CTCs in the blood sample and said identifying the mutated DNA molecules from the rare cells from step e) would determine whether the blood sample from the subject contains CTCs with the mutated DNA molecules as recited in claims 7 and 9.
Response to Arguments
Applicant’s arguments with respect to claims 1-13 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any 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.
No claim is allowed.
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/FRANK W LU/
Primary Examiner, Art Unit 1683
January 16, 2026