Ex parte Pastan et al.

Board of Patent Appeals and Interferences

Jun 17, 1999

07620939 (B.P.A.I. Jun. 17, 1999)

Application for patent filed December 3, 1990.1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written for publication in a law
journal and (2) is not binding precedent of the Board.
Paper No. 38
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte IRA PASTAN, VIJAY CHAUDHARY
DAVID FITZGERALD and JANEDRA BATRA
_____________
Appeal No. 95-2052
Application 07/620,9391
______________
ON BRIEF
_______________
Before WINTERS, WILLIAM F. SMITH and LORIN, Administrative Patent Judges.
WINTERS, Administrative Patent Judge.
DECISION ON APPEAL
This appeal was taken from the examiner's decision rejecting claims 8, 10, 14 and 15. Claims
1 through 7, which are the only other claims pending in the application, stand withdrawn from further
Appeal No. 95-2052
Application 07/620,939
2
consideration by the examiner as directed to a non-elected invention.
The invention relates to specific fusion proteins in which a truncated diphtheria toxin (DT 388),
consisting of the first 388 amino acids of the toxin, is fused to the amino terminus of a heavy chain or a
light chain variable region of an antibody.
Claim 8, which is illustrative of the subject matter on appeal, reads as follows:
8. A DT388-antibody recombinant protein comprising a fusion protein including a diphtheria
toxin (DT) portion that consists of the first 388 amino acids of DT, wherein the toxin is at the
amino terminus of a heavy chain or light chain variable region of an antibody.
In setting forth the rejection under 35 U.S.C. § 103, the examiner relies on the following
references:
Janendra K. Batra, et al., "Antitumor activity in mice of an immunotoxin made with anti-
transferrin receptor and a recombinant form of Pseudomonas exotoxin", Proc. Natl. Acad.
Sci., USA, Vol. 86, pp. 8545-8549. (Nov. 1989)
Janendra K. Batra, et al., "Anti-Tac(Fv)-PE40: A Single Chain Antibody Pseudomonas
Fusion Protein Directed at Interleukin 2 Receptor Bearing Cells", The Journal of Biological
Chemistry, Vol. 265, No. 25, pp. 15198-15202. (Sep. 1990).
Ira Pastan, et al., "Immunotoxins", Cell Vol. 47, pp. 641-648, published Dec. 5, 1986 by Cell
Press.
R.J. Youle, et al., "Genetic engineering of immunotoxins", Immunotoxins, published 1988 by
Kluwer Academic Publishers (Boston) , pp. 113-122.
Toshihiko Kondo, et al., "Activity of Immunotoxins Constructed with Modified Pseudomonas
Exotoxin A Lacking the Cell Recognition Domain", The Journal of Biological Chemistry, Vol.
Appeal No. 95-2052
Application 07/620,939
Frankel, "Immunotoxins", published 1988 by Kluwer Academic Publishers (Boston), pages 123-2
140 .
Williams et al, J. Biol. Chem., vol. 265, pages 11885-11889, (1990).3
3
263, No. 19, pp. 9470-9475. (Jul. 1988).
Previously entered rejections of the claims under 35 U.S.C. § 112, first and second
paragraphs, have been withdrawn. See the Examiner's Answer, pages 2 and 5.
The issue remaining for review is whether the examiner erred in rejecting claims 8, 10, 14 and
15 under 35 U.S.C. § 103 as unpatentable over the combined disclosures of Batra 1989, Batra 1990,
Pastan, Youle, and Kondo.
On consideration of the record, we shall reverse the examiner's prior art rejection.
DISCUSSION
As a preliminary matter, we note the Frankel and Williams et al. references cited in the 2 3
Appeal Brief, pages 4 and 5. In the Examiner's Answer, page 6, the examiner states that these
references are relied on to "buttress" the rejection under 35 U.S.C. § 103. See also the Supplemental
Examiner's Answer (paper no. 31), sentence bridging pages 2 and 3, where the examiner again refers
to Frankel and Williams et al. The problem here is that Frankel and Williams et al. are not included in
Appeal No. 95-2052
Application 07/620,939
4
the statement of rejection. As stated in In re Hoch, 428 F.2d 1341, 1343-44 n3, 166 USPQ 406, 407
n3 (CCPA 1970),
Where a reference is relied on to support a rejection, whether or not in a "minor
capacity," there would appear to be no excuse for not positively including the reference
in the statement of the rejection.
Where, as here, Frankel and Williams et al. are not included in the statement of rejection under 35
U.S.C. § 103, we shall not consider them further. We have limited our review to the references
positively included in the examiner's statement of rejection, namely, Batra 1989, Batra 1990, Pastan,
Youle, and Kondo.
Turning to the merits, we find that independent claim 8 defines a specific fusion protein
"including a diphtheria toxin (DT) portion that consists of the first 388 amino acids of DT". In our
judgment, the prior art relied on by the examiner is insufficient to support a conclusion of obviousness of
claims containing that limitation.
Appellants argue strenuously that the prior art relied on by the examiner would not have
suggested a fusion protein "including a diphtheria toxin (DT) portion that consists of the first 388 amino
acids of DT." For example, see the Appeal Brief filed October 28, 1993, page 6, second paragraph;
and the Reply Brief filed March 4, 1994, page 3, third full paragraph; page 4, last paragraph; and page
5, first full paragraph. The examiner does not adequately come to grips with that argument. The
examiner relies on Youle's disclosure (page 117) of a portion of the diphtheria toxin extending from
Appeal No. 95-2052
Application 07/620,939
5
amino acid 1 to 382. On this record, however, the examiner has not established how a person having
ordinary skill would have been led from "here to there", i.e., from a portion of the diphtheria toxin
extending from amino acid 1 to 382 (Youle) to "a
diphtheria toxin (DT) portion that consists of the first 388 amino acids of DT" recited in independent
claim 8.
In resolving the question of obviousness, we must consider the claimed subject matter as a
whole. 35 U.S.C. § 103. Here, the claimed subject matter includes the limitation of a diphtheria toxin
(DT) portion that consists of the first 388 amino acids of DT. The examiner has not established how
the cited prior art, relied on in the statement of rejection, would have led a person having ordinary skill
to a fusion protein containing that limitation. In this regard, the reference to "variant forms" of DT
(Examiner's Answer, page 5, line 2) does not provide an adequate factual foundation to support the
rejection. Simply stated, the examiner has not established that the claimed subject matter as a whole,
including the limitation of a diphtheria toxin (DT) portion that consists of the first 388 amino acids of
DT, is unpatentable over the cited prior art.
For these reasons, we conclude that the examiner has not established a prima facie case of
obviousness of claims 8, 10, 14 and 15. Accordingly, we find in unnecessary to discuss the Pastan
Appeal No. 95-2052
Application 07/620,939
6
declaration, filed under the provisions of 37 CFR § 1.132 and executed June 23, 1993, or the
objective evidence presented in the specification, pages 22 and 23. Appellants rely on the Pastan
declaration and the specification evidence to rebut a prima facie case of obviousness if a prima facie
case were established by the examiner.
In conclusion, we do not sustain the rejection of claims 8, 10, 14 and 15 under 35 U.S.C. §
103 as unpatentable over the combined disclosures of Batra 1989, Batra 1990, Pastan, Youle, and
Kondo. The examiner's decision is reversed.
REVERSED
SHERMAN D. WINTERS )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
WILLIAM F. SMITH ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
HUBERT C. LORIN )
Administrative Patent Judge )
Appeal No. 95-2052
Application 07/620,939
7
vsh
Appeal No. 95-2052
Application 07/620,939
8
Townsend & Townsend & Crew
Two Embarcadero Center
Eighth Floor
San Francisco, CA 94111