IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`In re Patent oi:
`
`Shmuel Cabilly, Herbert L. Heyneker, Wiliiam E. Holmes, Arthur D.
`
`Riggs and Ronald B. Wetzel
`
`Patent No.:
`
`6,331,415
`
`Issued:
`
`18 December 2001
`
`Assignee:
`
`Genentech, Inc. and City of Hope
`
`TITLE:
`
`METHODS OF PFtODUCiNG IMMUNOGLOBULINS, VECTORS AND
`
`TRANSFORMED HOST CELLS FOR USE THEREIN
`
`Docket No.: 469201-743
`
`VIA EXPRESS MAIL
`
`Commissioner for Patents
`P.O. Box 1450
`
`Alexandria, VA 22313-1450
`
`Mail Stop: Ex Pane Fteexam
`
`REQUEST FOR REEXAMINATION
`
`UNDER 35 U.S.C. §302 AND 37 C.F.R. 1.510
`
`Sir:
`
`_
`
`Reexamination of U.S. Patent No. 6,331,415 (hereafter, Cabilly II), a copy of
`which is attached hereto as an Appendix E, is requested pursuant to 35 U.S.C. §302
`
`and 37 C.F.Fi. §1.501, based on the prior art cited in the accompanying Form 1449 and
`MERCK v. GENENTECH
`MERCK V. GENENTECH
`IPR2016-01373
`S39
`GENENTECH 2029
`
`

`
`on U.S. Patent No. 4,816,567, copies of all of which references are attached hereto.
`
`In
`
`compliance with 37 C.F.Ft. §1.33(c) and 37 C.F.Ft. §1.510(b)(5), the present Request for
`
`Reexamination is being served on the Attorney of Record for U.S. Patent No. 6,331,415
`
`and on Co—Assignee City of Hope. Duarte, CA.
`
`

`
`TABLE OF CONTENTS
`
`REQUEST FOR REEXAMINATION _________________________________________________________________________________________ __‘I
`
`I. CLAIMS FOR WHICH REEXAMINATION IS REQUESTED_____________________________________________5
`
`n. A SUBSTANTIAL NEW QUESTION OF PATENTABILITY
`
`A. PRIOR REQUEST_____________________________________________________________________________________________________________
`
`B. THIS CURRENT REQUEST ____________________________________________________________________________________________
`
`C. CABILLY II IS NOT SHIELDED BY 35 U.S.C.
`
`D. THE PTO POSITION DURING PROSECUTION IS NOT RELEVANT TO
`THIS REQUEST______________________________________________________________________________________________________________ __11
`
`E. OBVIOUSNESS-TYPE DOUBLE PATENTING________________________________________________________"12
`
`F. OBVIOUS-TYPE DOUBLE-PATENTING IN REEXAMINATION ____________________________13
`
`m. THIS REQUEST IS BASED ON 0BV|0USNESS—TYPE
`DOUBLEPRTENNNGMmmmwmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmj3
`
`A. THE PRIOR ART RELIED ON BY REQUESTOR______________________________________________________13
`
`1- Gabi“)!............................................................................................................................-14
`
`2- Deacon..........................................................................................................................-14
`
`3. 1982 Valle______________________________________________________________________________________________________________________,15
`
`4- 1931
`
`5. Dallas WO 82/03088___________________________________________________________________________________________________,17
`
`5- Kaplan............................................................................................................................-18
`
`7- AXBI.................................................................................................................................19
`
`8. Rice_________________________________________________________________________________________________________________________________,19
`
`9-
`
`10. Oi____________________________________________________________________________________________________________________________________20
`
`

`
`B. DISCLOSURE OF CABILLY II AND SCOPE OF CABILLY ll CLAIMS_________________20
`
`0. APPLICATION OF PRIOR ART TO CLAIMS OF CABILLY ll_________________________________22
`
`1. Comparison of Prior Art to Claims of Cabilly ll ______________________________________________________22
`
`(a)
`
`Introductory Portion of Claim 1 of Cabilly I____________________________________________________22
`
`(b) Part (i) of Claim 1 of Cabilly II___________________________________________________________________________22
`
`(0) Part (ii) of Claim 1 of Cabiily ll________________________________________________________________________"23
`
`2. Difference Between Claim 1 of Cabilly ll and Claims of Cabilly I______________________24
`
`3. Claim 1 of Cabilly II is an Obvious Variant of the claims of Cabilly
`
`A. Claims of Cabilly I in Combination with Deacon or 1981 Valle or
`1982 Valle .............................................................................................................25
`
`B. Claims Of Cabilly I In Combination With Ochi_______________________________________________ __34
`
`4. Claims Dependent on Claim 1 ___________________________________________________________________________________35
`
`5. Independent Claim 15 of Cabilly ii and the Claims Dependent Thereon________40
`
`6. Claim 18 of Cabilly II and the Claims Dependent Thereon_________________________________41
`
`7. Claim 21 of Cabilly ll____________________________________________________________________________________________________42
`
`8. Claim 33 of Cabilly II____________________________________________________________________________________________________43
`
`D. REJECTION OF THE CLAIMS OF CABILLY II IS IN ACCORDANCE WITH
`THE POLICY OF OBVlOUSNESS—TYPE DOUBLE PATENTINGW;____________________44
`
`V. CONCLUSION_______________________________________________________________________________________________________________________ __45
`
`APPENDIX A — Claims of the '415 Patent
`
`APPENDIX B — Claims of the '56? Patent
`
`APPENDIX C — European Opposition
`
`1". APPENDIX D - Declaration of Dr. David Baltimore
`
`

`
`I. CLAIMS FOR WHICH REEXAMINATION IS REQUESTED
`
`U.S. Patent No. 6,331,415 (Cabilly ll) contains claims 1-36. Reexamination is
`
`herein being requested specifically for claims 1-36. This request for reexamination is
`
`based on the ground of double patenting, more specifically, obviousness-type double
`
`patenting. The claims of Cabilly II are unpatentable for obviousness-type double
`patenting over claims 1-7 of U.S. Patent No. 4,816,567 (Cabilly I) in view of the prior art
`
`attached to this Request.
`
`II. A SUBSTANTIAL NEW QUESTION OF PATENTABILITY EXISTS
`
`A. PRIOR REQUEST
`
`A request, by a third party, for re-examination of the claims of Cabilly ll based on
`
`obviousness-type double patenting of Cabilly ll over Cabilly I has already been granted
`(see Reexamination Control No. 90/007,542), resulting in rejection of claims 1-36 of
`
`Cabilly II for obviousness-type double patenting over the claims of Cabilly I. The owner
`
`filed a response on November 25, 2005.
`
`B. THIS CURRENT REQUEST
`
`Although
`
`this
`
`current
`
`request
`
`also
`
`requests
`
`reexamination based on
`
`obviousness-type double patenting over Cabilly I, this current request relies on certain
`
`prior art that was not employed in the initial request for reexamination or the rejection
`based thereon; namely Deacon ("Antibody Synthesis in Xenopus Oocytes with
`
`Messenger Ribonucleic Acid from immunized Rats," Biochemical Society Transaction ,
`
`4:818-20 (1976)): Dallas (WO 82103088); 1981 Valle (fla;tu_ne, Vol. 291, pp. 338-340 (28
`
`May 1931)): 1932 Valle (mini, Vol. 300, pp. 71-74 (4 November 1932)), and Ochi
`
`(E, Vol. 302, pp. 340-342 (24 March 1983).
`
`

`
`Deacon,
`
`1981 Valle
`
`and
`
`1982 Valle
`
`each disclose
`
`that
`
`exogenous
`
`immunoglobulin heavy and light chains, when expressed in a single cell, are assembled
`
`into an immunoglobulin. (See Section III A of this current request)
`
`In particular,
`
`in this current request, the claims of Cabilly l are combined with
`
`Deacon and/or 1981 Valle and/or 1982 Valle and/or Ochi, plus other references for
`
`certain dependent claims. Such combination demonstrates that the claims of Cabilly II
`
`are unpatentable based on obviousness type of double patenting.
`
`ln
`
`Reexamination
`
`Control
`
`No.
`
`90/007,542
`
`(hereinafter
`
`"Pending
`
`Reexamination"),
`
`in which the- claims of Cabilly II were rejected over the claims of
`
`Cabilly I based on obviousness-type double patenting, the owner has argued in the
`
`response filed on November 25, 2005 (the "Owners' Response") that the rejection is
`
`improper in that neither the claims of Cabilly I nor any of the other prior art relied on by
`
`the Examiner in such rejections suggest expressing two exogenous immunoglobulin
`
`chains in a single cell
`
`to produce an immunoglobulin. For example,
`
`the Owners‘
`
`Response states as follows:
`
`Thus, the Office may not cite the ‘567 patent [Cabilly I] claims to
`suggest that the '56? patent claims "enable" the production of one or more
`immunoglobulin chains, or that
`they "suggest" the production of
`two
`immunoglobulin chains in a single host cell. Rather, such evidence must
`come from the prior art used in conjunction with the patent claims at issue.
`As explained above, Axel
`[U.S. Patent 4,399,216] provides no such
`evidence. [Page 38, first full paragraph, lines 5-9] '
`
`that the Owners‘ Response asserts that Axel does not suggest
`To the extent
`‘
`expressing two immunoglobulin chains in a single cell, such assertion is wrong. Claim 7
`of Axel defines that DNA I codes for an antibody whereby the DNA I expressed in the
`cell, by necessity, encodes heavy and light chains. Moreover, the Abstract of Axel
`discloses that the DNA coding for the desired protein includes "a gene or genes
`(emphasis added)", thereby further indicating that the DNA I disclosed in Axel can
`encode more than one protein. Although Axel does not include a specific example with
`respect to immunoglobulin expression, it is incorrect to argue that Axel does not suggest
`that DNA I can encode two proteins and that Axel does not suggest that such two
`proteins can be the proteins that form an immunoglobulin (heavy chain and light chain).
`
`

`
`Funhen
`
`expression of
`requirels]
`ll]
`[Cabilly
`invention
`claimed
`The
`recombinant DNA sequences encoding exogenous heavy a_n_q exogenous
`light chain polypeptides. As Dr. Harris points out in his declaration at
`paragraph 36:
`
`In my view, the Rice paper does not address the question of
`whether exogenous light ml heavy chain polypeptides,
`if
`expressed by a transformed host cell, will be assembled into
`an "intact" immunoglobulin moiecule.
`Instead, what Rice
`shows is that it
`is possible to express an exogenous light
`chain polypeptide in a particular mature B-cell subclone that
`was already expressing an endogenous heavy chain and
`had lost
`its previous ability to produce endogenous light
`chain.
`
`Thus, contrary to the Examiner's suggestions, the Rig paper does
`not even address the question of expressing exogenous heavy and light
`chain genes in a single host cell. The Examiner also mischaracterizes the
`actual observations
`in
`the BE paper
`regarding the formation of
`immunoglobulins from the 81A—2 cell line.2 [Page 42, lines 1-14]
`
`Although such arguments do not establish that the rejection in the Pending
`
`Reexamination is incorrect (see Footnote 1 and the Declaration of Dr. Baltimore
`
`(Appendix D), a coauthor of Rice and a Nobel Laureate, tiled herewith to explain the
`
`teachings of Rice and to support the present re-examination request as to certain
`
`dependent claims of Cabilly ll), each of Deacon, 1981 Valle and 1982 Valle remedy the
`
`alleged deficiencies asserted by the Owner in response to the rejection in the Pending
`
`the
`Owners‘ Response and accompanying Declarations correctly note that
`2
`immunoglobulin produced in Rice was not demonstrated to be functional. However,
`they ignore the fact that (i) the independent claims of Cabilly ll do not recite that the
`immunoglobulin is
`''functional;‘'
`(ii) Rice teaches one skilled in the art
`that an
`immunoglobulin light chain that is exogenously produced in a cell assembles with a
`heavy chain produced in the cell to produce an immunoglobulin; and (iii) such teaching
`by Rice would suggest to one skilled in the art that the expression of an exogenous
`heavy chain and an exogenous light chain as disclosed by the claims of Cabilly I,
`if
`expressed in a single cell, would be expected to assemble into an immunoglobulin,
`even if the chains are from different immunoglobulins with different specificities.
`In this
`respect, see the accompanying Declaration of Dr. Baltimore (Appendix D).
`
`

`
`Fteexamination. Each of such references discloses the production of two exogenous
`
`immunoglobulin chains in a single host cell to produce an assembled immunogtobulin.
`
`Moreover, each of Deacon and 1982 Valle tested the assembled immunoglobulin, and
`
`such testing demonstrated that the immunoglobulin is functional;
`
`i.e.,
`
`it binds to its
`
`anflgen.
`
`Since each of Deacon, 1981 Valle and 1982 Valle teach one skilled in the art to
`
`produce two exogenous immunoglobulin chains in a single cell and that such chains are
`
`assembled into an immunoglobulin, it would have been obvious to one of ordinary skill
`
`to perform the expression of heavy and light chains as set forth in the claims of Cabilly I
`
`in a single cell to produce an assembled immunoglobulin.
`
`This combination presents a substantial new question as to patentability in that
`
`such a combination was not applied during the prosecution that led to the granting of
`
`Cabilly II or in the Pending Reexamination.
`
`Dallas discloses expressing two different proteins (in addition to a selectable
`
`marker) in a single cell by independently expressing each of the proteins from DNA
`
`encoding such proteins using two different vectors or by independently expressing the
`
`two proteins from such DNA in the same vector.
`
`This teaching of Dallas in combination with the claims of Cabilly I is relevant to
`
`the claims of Cabilly II that are limited to a vector that includes DNA encoding both the
`
`immunoglobulin heavy chain and the immunoglobulin light chain.
`
`This combination presents a substantial new question as to patentability in that
`
`such a combination was not applied during prosecution that led to the granting of Cabilly
`
`II or in the Pending Reexamination.
`
`There is also another substantial new question of patentability based on the
`
`claims of Cabilly I in combination with Ochi.
`
`

`
`Ochi discloses that an exogenous light immunoglobulin chain that is produced in
`
`the same mammalian cell as a heavy immunoglobulin chain assembles into a functional
`
`immunoglobulin that is secreted from the cell as a functional immunoglobulin. Based on
`
`such teachings of Ochi, one skilled in the art would have found it to be obvious to
`express the heavy and light chains specified in the claims of Cabilly I in a single cell to
`produce a functional antibody. Such combination demonstrates that the Claims of
`Cabilly II are unpatentable based on obviousness-type double patenting.
`
`Such a combination presents a substantial new question of patentability in that
`
`such combination was not applied during prosecution or during the Pending
`
`Reexamination.
`
`Appendix A, attached hereto, contains a complete set of the claims of Cabilly ll.
`
`Appendix B contains a complete set of the claims of Cabilly I.
`
`C. CABILLY It IS NOT SHIELDED BY 35 U.S.C. 121
`
`35 U.S.C. 121 states in part as follows:
`
`A patent issuing on an application with respect to which a requirement for
`restriction under this section has been made, or on an application filed as
`a result of such a requirement, shall not be used as a reference either in
`the Patent and Trademark Office or in the courts against a divisional
`application or against the original application or any patent issued on
`either of them, if the divisional application is filed before the issuance of
`the patent on the other application.
`
`As observed by the Federal Circuit, "[w]hen the PTO requires an applicant to
`withdraw claims to a patentably distinct
`invention (a restriction requirement), §121
`
`shields those withdrawn claims in a later divisional application against rejection over a
`
`

`
`patent
`
`that
`
`issues from the original application." Geneva Pharmaceuticals inc.
`
`1/.
`
`GiaxoSmithKline, 349 F.3d 1373, 1379, 68 USPQ2d 1865, 1869 (Fed. Cir. 2003)
`
`The courts have held that a patentee is entitled to invoke this statutory prohibition
`
`gm if the divisional application was filed as a result of a restriction reguirement that
`
`caused the patentee to pursue separate applications for the issued fig subsequent
`
`patent and is consonant with the restriction requirement. Bristol-Myers Squibb Co. v.
`
`Pharmachemie B. V., 361 F.3d 1343. 70 USPQ2d 1097 (Fed. Cir. 2004).
`
`In order to claim the protection of §121, this section requires "that the earlier
`
`application must contain formally entered claims that are restricted and removed, and
`
`that claims to the second invention reappear in a separate divisional application after
`
`the restriction. The text of §121 does not suggest that the original application merely
`
`needs to provide some support for claims that are first entered formally in the later
`
`divisional application." Geneva Pharmaceuticals lnc., 349 F.3d at 1379, 68 USPQ2d at
`
`1870.
`
`No restriction requirement was entered by the examiner during prosecution of the
`
`application maturing into Cabilly I. Since no restriction was applied in Cabilly l, the
`
`inventors of Cabilly I voluntarily filed the application that matured into Cabilly ll, whereby
`the "shield" of 35 USC § 121 is not available with respect to the claims of Cabilly ll.’
`
`Because of the absence of any restriction requirement during prosecution of
`
`Cabilly l, a 35 U.S.C. §121 "shield" is not available in Cabilly II to protect the claims of
`
`Cabilly II from being held invalid for obviousness-type double patenting over the claims
`
`of Cabilly I.
`
`in Cabilly ll, such restriction
`Although there was a restriction requirement
`3
`requirement may only be asserted as a "shield" under 35 USC § 121 with respect to a
`later application that is filed as a result of such restriction requirement, e.g. Geneva
`Pharmaceuticals v. G|axoSmithKline, supra.
`
`10
`
`

`
`D.
`
`THE PTO POSiT|ON DURlNG PROSECUTION IS NOT RELEVANT TO THIS
`
`REQUEST.
`
`As indicated in Part 0 above, 35 USC 121 does not bar the PTO from
`
`considering the issue of obviousness-type of double patenting.
`
`The Owners Response (for example, pages 83-14) asserts that the issue of
`
`double patenting,
`
`in effect, was previously decided by the PTO and, therefore, the
`
`Examiner shouid not reconsider the issue.
`
`However,
`
`the basis
`
`of
`
`the Pending Reexamination and this present
`
`reexamination request is the raising of new issues of patentability. Therefore, there is
`
`no merit to the Owners‘ position because both requests for reexamination are based on
`
`arguments that were not previously presented to the PTO.
`
`In particular, the present
`
`reexamination sets forth that the expression of the heavy and light chains of the claims
`
`of Cabilly l in a single cell is an obvious modification of such claims based on prior art
`
`that was not previously employed to support such an argument. In the absence of the
`
`shield of 35 USC 121 (there is no shield in the instant case), the PTO is not precluded
`
`from reaching a conclusion that the-claims of Cabilly II are not separately patentable
`
`based on the arguments and the prior art of record in the applicable reexamination
`
`proceeding.‘
`
`“ It is noted that the Owners Response in this respect is particularly misleading in that in
`the Pending Reexamination the owners did not challenge that
`the reexamination
`request presented a substantial new question. Since the request was granted, by
`definition, new issues were presented. The Owners had every opportunity to respond to
`the Prior Request before it was granted, but chose not to do so. As a result, the owners
`should not be permitted to argue that the issue of double patenting was previously
`decided and. therefore, the PTO cannot reexamine the claims of Cabilly It and conclude
`that such claims are unpatentable based on obviousness-type double patenting.
`
`ll
`
`

`
`E. OBVIOUSNESS-TYPE DOUBLE PATENTING
`
`Obviousness-type double patenting is "a judicially-created doctrine grounded in
`
`public policy rather than statute and primarily intended to prevent prolongation of
`
`monopoly by prohibiting claims in a second patent not patentably distinguishing from
`
`claims of a first patent."
`
`in re Thcrington, 418 F.2d 528, 534, 163 USPQ 644, 648
`
`(CCPA 1969). The legal rationale for this doctrine was made clear by the Federal Circuit
`
`in Geneva Pharrnaceuticais inc. v. GiaxoSmr'thKiine, 349 F.3d 1377, 1378, 68 USPQ2d
`
`1865, 1868 (Fed. Cir. 2003), where it noted that 35 U.S.C. 101 "only prohibits a second
`
`patent on subject matter identical to an earlier patent.
`
`id. Thus, applicants can evade
`
`this statutory requirement by drafting claims that vary slightly from the earlier patent."
`
`Accordingly, obviousness-type double patenting "prevents an applicant from extending
`
`patent protection for an invention beyond the statutory term by claiming a slight variant."
`
`[Genet/a, 349 F.3d at 1378, 68 USPQ2d at 1869]
`
`Obviousness-type double patenting extends the doctrine of double patenting so
`
`as to bar obvious variants of what has already been patented.
`
`In re Berg, 140 F.3d
`
`1428, 1432, 46 USPQ 2d 1226, 1229 (Fed. Cir. 1998). Such double patenting of the
`
`obviousness-type thereby serves to preclude issuance of a patent where there is no
`
`in re
`"patentable difference" or no "patentab|e distinction" between the two claims.
`Goodman, 11 F.3d 1046, 1052, 29 USPQ2d 2010, 2015 (Fed. Cir. 1993). As a result,
`
`the public is free to practice obvious variations of the first patented invention after
`
`expiration of the earlier patent.
`
`in re Lcngi, 759 F.2d 887, 892, 225 USPQ 645, 648
`
`(Fed. Cir. 1985). " '[O]bviousness-type‘ double patenting" is a judge—made doctrine that
`
`prevents an unjustified extension of the patent rights beyond the statutory time limit. It
`
`requires rejection of an application claim when the claimed subject matter is not
`
`patentably distinct from the subject matter claimed in a commonly owned patent when
`
`the issuance of a second patent would provide an unjustified extension of the term of
`
`the right to exclude granted by a patent." [emphasis in original] Ex parte Davis, 56
`
`USPQ2d 1434, 1435-36 (Bd. Pat. App. & Int. 2000).
`
`12
`
`

`
`"Obviousness—type double patenting is a question of law.'‘
`
`in re Goodman, 11
`
`F.3d at 1052. 29 USPQ2d at 2015.
`
`F. OBVIOUS-TYPE DOUBLE-PATENTING IN REEXAMINATION
`
`"A doubie patenting issue may raise a substantial new question of patentability of
`
`a claim of a patent, and thus be addressed in a reexamination proceeding." (MPEP
`
`§804(I)(D)).
`
`"[T]he issue of double patenting is appropriate for consideration in
`
`reexamination, both as a basis for ordering reexamination and during subsequent
`
`examination on the merits. The issue of double patenting is to be considered by the
`
`examiner when making the decision on the request
`
`for
`
`reexamination." (MPEP
`
`§2258(|)(D)) Furthermore, "The issue of double patenting is also to be considered
`
`during the examination stage of a reexamination proceeding. In the examination stage,
`the examiner should determine whether a rejection based on double patenting is
`
`appropriate." (lbid.) Obviousness-type "jdjouble patenting rejections are analogous to
`rejections under 35 U.S.C. 103 and depend on the presence of a prior patent as the
`
`basis for the rejection." (Ex parte Obiaya, 1985 WL 71916, 227 USPQ 58, 60 (Bd. Pet.
`
`App. & Inter. 1985), and at MPEP §2258(l)(D))
`
`In
`
`reaching a conclusion of obviousness-type double patenting,
`
`the usual
`
`obviousness grounds of rejection as discussed in Graham v. John Deere Co., 383 U.S.
`
`1, 148 USPQ 459 (1966) are relevant. The MPEP §804(lI)(B)(1) prescribes that "the
`
`analysis employed in an obviousness-type double patenting determination parallels the
`
`guidelines for a 35 U.S.C. 103(a) rejection:"
`
`III.
`
`This Fteguest ls Based on Obviousness-Type Double Patenting
`
`A.
`
`The Prior Art Relied on by Fieguestor
`
`13
`
`

`
`1.
`
`Cabillyl (U.S. Patent No. 4,816,567)
`
`(i) preparing a DNA sequence encoding a
`The @L of Cabilly I disclose:
`specific type of immunoglobulin light chain (a chimeric light chain) or heavy chain (a
`chimeric heavy chain);
`(ii)
`inserting the DNA sequence into a vector iinked to a
`promoter; (iii) transfonning a host cell with such vector; (iv) culturing the host cell; and
`(v) recovering such heavy or light chain from the host cell culture.
`
`Since the heavy chain or light chain is recovered from the host cell culture, the
`heavy or light chain was expressed in the cell. As a result, the claims of Cabilly i teach
`the independent expression of a chimeric heavy chain or chimeric light chain in a host
`cell, and a vector that contains such chimeric heavy chain or chimeric light chain.
`
`Deacon ("Antibody Synthesis in Xenopus Oocytes with Messenger Ribonucleic
`2.
`Acid from immunized Flats," Biochemical Society Transactions, 4:818-20 (1976))
`
`Deacon modified oocytes by injecting mFiNA encoding heavy and light
`immunoglobulin chains which assembled into an immunoglobulin of defined specificity.
`
`Deacon immunized adult rats with an antigen (some with hemocyanin and some
`
`with ferritin) and subsequently extracted RNA from the spleens of these rats. The total
`RNA fraction was subjected to cellulose fractionation to collect mFiNA (which sticks to
`the cellulose because of its polyA tail) and the mRNA fraction was used for injection into
`Xenopus oocytes. Each of 40 oocytes was injected with RNA and 358-methionine (the
`latter would be incorporated as a radiolabel into any newly synthesized proteins) and
`incubated for 24 hours in L15 medium. The oocytes were then homogenized,
`
`centrifuged and the supernatants collected for analysis. (See Page 818)
`
`Deacon used rat
`immunoglobulin antiserum to precipitate proteins from the
`supernatant for analysis by SDS-PAGE (polyacrylamide gel electrophoresis), which
`showed the presence of tetrameric immunoglobulin molecules as well as free heavy and
`
`14
`
`

`
`light chains. The specificity of
`
`the immunoglobulin was demonstrated by passing
`
`supematant from the oocytes through a Sepharose-coupled antigen column (containing
`
`either hemocyanin or ferritin). Material that bound to the column was subsequently
`
`eluted with buffer, then assayed for protein and radiolabel. Peak fractions were pooled
`
`and analyzed by SDS-PAGE. These showed the presence of material with mobilities
`
`similar to those of marker heavy and light chains run in parallel gels.
`
`(see Page 819
`
`and Figure 2)
`
`Deacon concluded (at page 820,
`
`lines 1-5) that "mFiNA from hyperimmunized
`
`rats, when injected into oocytes, is translated into heavy and light chains" and that "in
`
`the oocytes, heavy and light chains can be assembled into immunoglobulin molecules,
`
`which can behave as antibodies directed against antigen."
`
`Deacon, therefore, discloses a process in which a cell that does not normally
`
`produce an immunoglobulin is modified with genetic material that encodes the heavy
`
`and light chains of an immunoglobulin and in which the heavy and light chains
`
`expressed in such cell assemble into a functional immunoglobulin.
`
`3.
`
`1982 Valle, Anti-Ovalbumin monoclonal antibodies interact with their antigen in
`
`internal membranes of Xenopus oocytes, Nature, Vol. 300, pp. 71-74 (4 November
`
`1982).
`
`1982 Valle expressed a functional
`
`immunoglobulin from heterologous mRNA
`
`introduced into oocytes.
`
`Valle prepared two hybridomas (dubbed 7/2 and 7/4, both of IgG1 type) by fusing
`
`spleen cells (from mice immunized with ovalbumin) with myeloma cells. Binding studies
`
`showed that these hybridomas recognized different single antigenic determinants on the
`
`ovalbumin.
`
`lmmunoprecipitates of these immunoglobulins had the same electrophoretic
`
`mobility as analogous immunoprecipitates from oocytes injected with the hybridoma
`
`mRNAs. (see page 71, column 2, ‘[12 and 113, lines 1-4)
`
`15
`
`

`
`in the experiment depicted in Figure 1, 1982 Valle disclosed exogenous
`
`expression of the heavy and light chains of immunoglobulin 7/2 in oocytes by use of
`
`mFlNA. 1982 Valle demonstrated that the exogenously expressed chains assembled
`
`into an immunoglobulin that was immunologically functional
`
`in that
`
`it bound to
`
`ovalbumin.
`
`(See Figure 1C,
`
`lane 1). 1982 Valle performed the same successful
`
`experiment with immunoglobulin 3/4 (See Figure 1C, lane 2).
`
`Accordingly, Deacon and 1982 Valle teach one skilled in the art at least the
`
`following:
`
`(a)
`
`An immunoglobulin can be produced in a cell that does not normally
`
`produce such immunoglobulin by expressing in a single cell the proteins that form such
`
`immunoglobulin (the heavy chain and the light chain);
`
`(b)
`
`The exogenous expression of the two immunoglobulin chains in a single
`
`cell produces an assembled immunoglobulin;
`
`(c)
`
`The immunoglobulin expressed in such cell is immunologically functional
`
`in that it binds to the antigen against which the immunoglobulin was originally produced;
`
`(d)
`The production of such an immunoglobulin does not require any changes
`to the cell other than providing the genetic material that encodes the immunoglobulin
`
`heavy chain and the immunoglobulin light chain followed by expression of such two
`
`chains from such genetic material;
`
`(e)
`
`No special techniques are required in order to assemble the expressed
`
`two chains into a functional immunoglobulin.
`
`16
`
`

`
`4.
`
`1981 Valle, Synthesis and secretio of mouse immunoglobulin chains in Xenopus
`
`oocytes, Nature, Vol. 291, pp. 388-340 (28 May 1981).
`
`1981 Valle discloses the production and secretion of tetrameric immunogiobulin
`
`molecules from Xenopus oocytes.
`
`In one of the disclosed experiments, 1981 Valle
`
`injected X83 mRNA (from a P3/X83 cell
`
`line producing MPOC 21 immunoglobulin,
`
`consisting of a gamma 1 heavy chain and a kappa light chain) into Xenopus oocytes,
`
`incubated the cells, collected extracellular medium and analyzed this by non-reducing
`
`gels to show the formation of tetrameric immunoglobulins (HQL2) (see the gel in Figure
`
`2b,
`
`track 4). 1981 Valle concludes that "the oocyte both assembles and secretes
`
`immunoglobulin" (page 339, column 2, 112,
`
`lines 1-7). Although Valle discloses with
`
`respect to Figure 2a (Track 3) that little secreted tetrameric immunoglobulin is found in
`
`the oocyte media, Valle explains that after secretion, the immunoglobulin is oxidized in
`
`the oocyte culture medium. (See Page 338, Col. 2) Therefore, Valle adds horse serum
`
`to the oocyte medium to prevent such oxidation after secretion (Figure 2b, Track 4 and
`
`explanation of Page 338, Col. 2). As shown in Figure 2b, Track 4, most of the secreted
`
`immunoglobulin is in a tetrameric form.
`
`1981 Valle teaches modifying a cell with genetic material encoding the heavy
`
`chain and light chain of an immunoglobulin, followed by expressing both chains in a
`
`single cell, which chains assemble into an immunoglobulin that is secreted from the cell.
`
`Valle is pertinent to the dependent claims of Cabilly II that recite that the expressed
`
`immunoglobulin is secreted from the cell in which produced.
`
`5.
`
`Dallas WO 82/03088
`
`Dallas teaches that two different proteins (in addition to a selectable marker) can
`
`be expressed in a single cell and such expression may be accomplished by the use of
`
`two vectors. each containing DNA encoding one of the proteins, or by use of a single
`
`vector that contains DNA encoding each of the proteins. (See Example IV, as well as
`
`17
`
`

`
`page 8, lines 9-11, which disclose the use of a single vector, and page 9, lines 27-29,
`
`which discloses the use of two vectors).
`
`Dallas teaches the production of a plasmid expressing two heteroiogous proteins.
`
`A Hindlll fragment containing DNA encoding one of the proteins was removed from a
`
`plasmid and inserted into a second plasmid that included DNA encoding the second
`
`protein as a BamHl fragment (page 8, lines 11-17 and at page 7, lines 29-33). As a
`
`result, the two plasmids used for expressing the two proteins in a single cell were used
`
`to generate a single plasmid for expressing both proteins in a single cell. Because the
`
`DNA encoding each heterologous protein was inserted using a different restriction site
`
`(BamHI and Hindlll have no isoschizomers and each recognizes a unique restriction
`
`sequence), the DNAs were necessarily inserted into different insertion sites of the same
`
`plasmid or vector.
`
`Dallas is pertinent to the claims of Cabilly ii that are directed to the use of a
`
`single vector for expressing the heavy and light chains (for example, claims 3 and 15).
`
`6.
`
`Kagtan —- European Patent Application No. 0 044 722 (Published January 27,
`
`1982)
`
`Kaplan teaches methodology for producing an immunoglobulin by recombinant
`DNA technology. Briefly, Kaplan discloses production of an immunoglobulin by isoiating
`
`mFtNA from a hybridoma cell, selecting mFtNA encoding heavy and light chains using
`
`specific probes that hybridize to this mRNA, preparing the corresponding cDNA using
`
`reverse transcriptase,
`
`inserting said cDNA into a suitable vector, such as the plasmid
`
`pBFt322, and using this to transform bacterial and yeast