HOLMQUIST, Brett et al.

Patent Trials and Appeals Board

Nov 21, 2019

14267014 - (D) (P.T.A.B. Nov. 21, 2019)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/267,014 05/01/2014 Brett HOLMQUIST 054769-9945 3727
109855 7590 11/21/2019
Quest Diagnostics
Attn: Legal Department
33608 Ortega Highway
San Juan Capistrano, CA 92675
EXAMINER
GERIDO, DWAN A
ART UNIT PAPER NUMBER
1797
NOTIFICATION DATE DELIVERY MODE
11/21/2019 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
ipdocketing@foley.com
joel.s.white@questdiagnostics.com
joshua.e.kim@questdiagnostics.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte BRETT HOLMQUIST, NIGEL J. CLARKE,
ANNE CASTON-BALDERRAMA, and RICHARD E. REITZ

Appeal 2019-001084
Application 14/267,014
Technology Center 1700
____________

Before JEFFREY R. ROBERTSON, MONTÉ T. SQUIRE, and
MICHAEL G. McMANUS, Administrative Patent Judges.

McMANUS, Administrative Patent Judge.

DECISION ON APPEAL

Pursuant to 35 U.S.C. § 134(a), Appellant1 seeks review of the
Examiner’s decision to reject claims 1–38. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies the real party in interest as Quest
Diagnostics Investments Incorporated. Appeal Br. 1.
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CLAIMED SUBJECT MATTER

The present application generally relates to the detection of vitamin D
metabolites and particularly to the detection of dihydroxyvitamin D
metabolites by mass spectrometry. Specification (May 1, 2014) (“Spec.”)
¶ 2.
There are two forms of vitamin D: vitamin D2 (ergocalciferol) and
vitamin D3 (cholecalciferol). Id. ¶ 3. Vitamin D2 is derived from fungal and
plant sources. Id. ¶ 4. Vitamin D3 is synthesized de novo by animals and
people. Id. ¶ 3.
In the body, vitamin D2 is metabolized to form “the metabolites 25-
hydroxyvitamin D2(25OHD2) and 1,25-dihydroxyvitamin D3 [sic D2]
(1,25(OH)2D2).” Id. ¶ 4. Vitamin D3 is taught to be metabolized by
hydroxylation to form the intermediate metabolite 25-hydroxyvitamin D3
(25-hydroxychole calciferol; calcifediol; 25OHD3). Id. ¶ 3. Calcifediol is
the major form of vitamin D3 in circulation and is converted to 1,25-
dihydroxyvitamin D3 (calcitriol; 1,25(OH)2D3) “which is generally believed
to be the metabolite of vitamin D3 with the highest biological activity.” Id.
The Specification teaches that serum levels of 25-hydroxyvitamin D3 and 25-
hydroxyvitamin D2 (total 25-hydroxyvitamin D; “25OHD”) in humans are a
useful index of vitamin D nutritional status. Id. ¶ 5.
The Specification teaches methods for detecting the amount of a
dihydroxyvitamin D metabolite in a sample by mass spectrometry. One
such method is described as follows:
(a) immunopurifying one or more dihydroxyvitamin D
metabolites from the sample; (b) further purifying the
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immunopurified dihydroxyvitamin D metabolite(s) by
HPLC; (c) determining the amount of the vitamin D
metabolites obtained from step (b) by tandem mass
spectrometry by: (i) generating a precursor ion of the
dihydroxyvitamin D metabolite(s); (ii) generating one or
more fragment ions of the precursor ion; and (iii) detecting
the presence or amount of one or more of the ions generated
in step (c) or (d) or both and relating the detected ions to the
presence or amount of the dihydroxyvitamin D metabolite(s)
in the sample.
Id. ¶ 9. The Specification further teaches that, in an embodiment, a method
is taught for determining “the presence or amount of 1α,25(OH)2D2 and
1α,25(OH)2D3 in a single assay.” Id.
Claim 1 is illustrative of the subject matter on appeal and is
reproduced below with certain limitations bolded for emphasis:
A method for determining an amount of one or more
dihydroxyvitamin D metabolites in a biological sample by
tandem mass spectrometry; the method comprising:
(i) adding one or more internal standards to the sample;
(ii) purifying the one or more dihydroxyvitamin D
metabolites and the one or more internal standards;
(iii) derivatizing the one or more dihydroxyvitamin D
metabolites and the one or more internal standards with 4-
phenyl-1,2,4-triazoline-3,5-dione (PTAD);
(iv) analyzing the amount of the derivatized one or more
dihydroxyvitamin D metabolites and the derivatized one or
more internal standards in the sample by tandem mass
spectrometry, wherein the tandem mass spectrometry comprises
electrospray ionization (ESI) or atmospheric pressure chemical
ionization (APCI).
Appeal Br. 10 (Claims App’x) (emphasis added).

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REFERENCES
The Examiner relies upon the following prior art:
Name Reference Date
Clarke US 2006/0228808 A1 Oct. 12, 2006
Singh US 2006/0094125 A1 May 4, 2006
Weiskopf Weiskopf et al. “Examination of
structurally selective
derivatization of vitamin D3
analogues by electrospray mass
spectrometry.” J. Mass
Spectrom. 2001; 36: 71–78
2001

REJECTIONS
The Examiner maintains the following rejections:
1. Claims 1–12 and 14–23 are rejected under pre-AIA 35 U.S.C.
§ 103(a) as being unpatentable over Clarke in view of
Weiskopf. Final Act. 3–4.
2. Claims 13 and 24–38 are rejected under pre-AIA 35 U.S.C.
§ 103(a) as being unpatentable over Clarke in view of Weiskopf
and further in view of Singh. Id. at 5–7.
DISCUSSION
Rejection 1. The Examiner rejects claims 1–12 and 14–23 as obvious
over Clarke in view of Weiskopf. Id. at 3–4. Appellant argues the rejected
claims as a group. See Appeal Br. 7–9. We select claim 1 as a
representative claim and the remaining claims will stand or fall therewith.
See 37 C.F.R. § 41.37(c)(1)(iv).
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The Examiner finds that Clarke teaches each element of claim 1 other
than derivatizing the vitamin D metabolites and the internal standards with
PTAD. Id. at 3. In this regard, Clarke teaches as follows:
The present invention provides methods for detecting the
presence or amount of a vitamin D metabolite in a test sample
by mass spectrometry, including tandem mass spect[r]ometry.
Preferably, the methods of the invention do not include
derivatizing the sample or the vitamin D metabolites prior to
the mass spectrometry analysis.

Clarke ¶ 7 (emphasis added).
The Examiner finds that Weiskopf teaches a method of examining
vitamin D3 analogues by mass spectrometry where vitamin D is derivatized
with PTAD. Final Act. 3. The Examiner further finds that Weiskopf
teaches “that PTAD derivatization is advantageous because it provides
structurally selective ions for monitoring side chain metabolism in triple
quadrupole and quadrupole ion mass spectrometers.” Id.
Weiskopf is a journal article that examines mass spectrometry of a
vitamin D analogue known as EB 1089. Weiskopf, Abstract. Weiskopf
teaches to derivatize (react) EB 1089 with PTAD prior to conducting mass
spectrometry. Id. at 72. Weiskopf explains, in part, the benefit of PTAD
derivatization.
When compared with GC/MS, one drawback of using
API-MS/MS techniques for qualitative analysis is the paucity of
structurally informative ion fragments. While this proves to be
a considerable disadvantage with underivatized vitamin D
compounds, PTAD derivatives yield somewhat more
information. PTAD derivatives of most 1-hydroxylated vitamin
D compounds, including calcitriol, yield a major ion product at
m/z 314. The ubiquity of the m/z 314 fragment among a wide
range of analogues and metabolites has allowed its use as a
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diagnostic ion for both parent-scanning and multiple-reaction
monitoring.

Id.
The Examiner concludes that “it would have been obvious to one of
ordinary skill in the art at the time the invention was made to modify Clarke
et al., wherein PTAD is utilized as a derivatization agent in order to provide
structurally selective ions for monitoring side chain metabolism with triple
quadrupole and quadrupole ion mass spectrometers as taught by Weiskopf et
al.” Final Act. 3–4.
Appellant asserts that the rejection is in error on several bases.
Appeal Br. 7–9. First, Appellant briefly asserts that “[n]one of the cited
references discloses that dihydroxyvitamin D metabolites are derivatized
with PTAD.” Id. at 7. This is not persuasive.
Weiskopf teaches that “PTAD derivatives of most 1-hydroxylated
vitamin D compounds, including calcitriol, yield a major ion product at m/z
314.” Weiskopf 72. Calcitrol is dihydroxyvitamin D3, a vitamin D3
metabolite. See Spec. ¶ 3. Further, Weiskopf teaches the derivatization of
EB 1089 with PTAD. EB 1089 is a dihydroxyvitamin D metabolite. See
Weiskopf, Figure 1(b); Spec. ¶ 13 (regarding the definition of “metabolite”).
Accordingly, we do not find this argument to be persuasive.
In view of the foregoing passage from Weiskopf, we are also not
persuaded by Appellant’s argument (Appeal Br. 7; Reply Br. 2) that one of
ordinary skill in the art would have understood the derivatization techniques
disclosed therein to be limited to synthetic vitamin D analogues. Rather, the
quoted passage in Weiskopf appears to be general in nature. Further, as the
Examiner points out, the prior art and the instant Specification are inclusive
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of both natural and synthetic analogues of vitamin D. Ans. 3–4 (citing
Clarke ¶ 11 and Spec. ¶ 13).
Second, Appellant argues that “the state of the art teaches away from
using APCI to quantitate derivatized vitamin D metabolites.” Appeal Br. 7.
In support, Appellant argues that a 1993 article by Yeung cited in an
Information Disclosure Statement (IDS) during prosecution, but not relied
upon by the Examiner, teaches that PTAD derivatives of vitamin D3 are “too
polar to be ionized by traditional EI or chemical ionization techniques.”
Id.
The ultimate determination of obviousness under § 103 is a question
of law based on underlying factual findings. In re Baxter Int'l, Inc., 678 F.3d
1357, 1361 (Fed. Cir. 2012). These underlying factual considerations
include secondary considerations of non-obviousness such as commercial
success, long-felt but unsolved needs, failure of others, etc. KSR Int'l Co. v.
Teleflex Inc., 550 U.S. 398, 406, (2007) (citing Graham v. John Deere Co.,
383 U.S. 1, 17–18 (1966)). Evidence of industry skepticism is a question of
fact that weighs in favor of non-obviousness. WBIP, LLC v. Kohler Co., 829
F.3d 1317, 1335 (Fed. Cir. 2016). When evidence of secondary
considerations is submitted, we begin anew and evaluate the rebuttal
evidence along with the evidence upon which the conclusion of obviousness
was based. In re Rinehart, 531 F.2d 1048, 1052 (CCPA 1976).
In the Answer, the Examiner takes the position that Yeung was
published in 1993 and does not reflect the state of the art at the time of
application. Answer 4. The Examiner finds that Weiskopf “clearly shows
an improvement over the teachings of Yeung et al., as the teachings of
Weiskopf et al., provides a clear advantage of derivatizing vitamin D
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analogues with PTAD.” Id. This is well-supported by the record. Weiskopf
teaches as follows:
Atmospheric pressure ionization methods, such as
electrospray and atmospheric pressure chemical ionization
(APCI), alleviate the thermal degradation problems encountered
with GC/MS. Used with liquid chromatography (LC), these
ionization techniques have permitted the low-level quantitation
of vitamin D analogue metabolites from biological fluids and
their structural identification by MS/MS. Underivatized
vitamin D analytes, as with many steroidal compounds, provide
excellent sensitivity by APCI. Sensitive electrospray
ionization (ESI) of vitamin D analytes generally requires the
addition of a tagging agent to provide suitable sites for
protonation or cationization. Because a cisoid diene system
is a feature common to most vitamin D compounds, dienophilic
reagents such as triazolinediones are particularly attractive.
Triazolinediones react with the C-10--19: C-5--6 diene by
Diels--Alder cycloaddition (Fig. 2), and thereby derivatize
vitamin D analytes in a structurally selective fashion, allowing
their facile identification and isolation from other interferents in
the analysis. While a number of triazolinedione variants for
mass spectrometry have been described in the analytical
literature, our laboratory has adopted 4-phenyl-1,2,4-
triazoline-3,5-dione (PTAD) as the reagent of choice.

Weiskopf 72 (internal citations omitted). Thus, Weiskopf teaches to use
PTAD-derivatized vitamin D analytes for electrospray ESI. Accordingly,
Appellant has not shown that, at the time of application, there was
widespread skepticism toward use of ESI and/or APCI to quantitate
derivatized vitamin D metabolites. Nor has Appellant shown that any cited
reference “teaches away” from the use of ESI or APCI to quantitate
derivatized vitamin D metabolites.
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Third, as best understood, Appellant argues that the claims are not
obvious because mass spectrometry analysis of an analyte in a complex
sample matrix is unpredictable and requires significant inventive effort.
Appeal Br. 7–9. In support, Appellant cites to several journal articles said to
“evidence the unpredictability of ionization efficiency in mass spectrometric
methods across sample types.” Id. at 8. Appellant concludes “[g]iven the
well-recognized unpredictability of mass spectrometric methods with
complex biological samples, therefore, such a disclosure does not render the
claimed subject matter obvious over the prior art.” Id. at 9.
The thrust of Appellant’s argument appears to be that a person of
ordinary skill in the art would not have been led to the present invention by
the teachings of the cited art because of certain inherent unpredictability
therein. By implication, Appellant argues that ordinary artisans are
incapable of practicing the art. Appellant, however, has not explicitly
addressed the level of ordinary skill in the art. See Graham v. John Deere
Co., 383 U.S. at 17. Accordingly, Appellant has not shown that one of
ordinary skill would have been incapable of implementing the teachings of
Clarke and Weiskopf.
Further, Clarke teaches that “[t]he skilled artisan will understand that
the choice of ionization method can be determined based on the analyte to be
measured, type of sample, the type of detector, the choice of positive versus
negative mode, etc.” Clarke ¶ 39. Similarly, Singh teaches that a “sample
can be treated to remove components that could interfere with the mass
spectrometry technique.” Singh ¶ 20. Singh further teaches that “[a] variety
of extraction and analytical columns with appropriate solvent mobile phases
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and gradients can be chosen by those having ordinary skill in the art.” Id. ¶
23.
In addition, the Examiner finds that one of the references relied upon
by Appellant, Fiehn, “teaches that chemical derivatization can be utilized as
a means of overcoming the stated drawbacks of ion suppression.”
Answer 5 (emphasis added). This finding is not rebutted. Further, Weiskopf
teaches that triazolinediones “derivatize vitamin D analytes in a structurally
selective fashion, allowing their facile identification and isolation from
other interferents.” Weiskopf 72 (emphasis added). The above indicates
that the stated ion suppression problem is not applicable to the Examiner’s
hypothetical combination.
In view of the foregoing, we determine that Appellant has not shown
reversible error in the rejection of claim 1. As Appellant relies upon the
same arguments in support of its appeal of the rejection of claims 2–12 and
14–23, we determine that Appellant has not shown reversible error in the
rejection of those claims.

Rejection 2. The Examiner rejects claims 13 and 24–38 as obvious
over Clarke in view of Weiskopf and further in view of Singh. Final Act. 5–
7. Appellant relies upon the same arguments described above in support of
its appeal of the rejection of claims 13 and 24–38. Appeal Br. 7–9. As we
have found such arguments not to be persuasive, we determine that
Appellant has not shown reversible error with regard to the rejection of
claims 13 and 24–38.

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CONCLUSION

The Examiner’s rejections are affirmed.
In summary:
Claims
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1–12, 14–23 103(a) Clarke, Weiskopf 1–12, 14–23
13, 24–38 103(a) Clarke, Weiskopf,
Singh
13, 24–38
Overall
Outcome
1–38

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED