Appeal No. 1997-2392
Application No. 08/089,990
One of ordinary skill in the art would have reasonably expected to
obtain cell lines producing antibodies capable of neutralizing HIV-1
infectivity in vitro in view of the teaching of Gilbert that polyclonal
antibodies elicited against a peptide having a sequence which is
nearly identical to that of Seq ID No:1 of the present application, had
the ability to inhibit HIV-1 infection in vitro and in view of the art-
recognized importance of the CD4 binding region of gp120 in virus
attachment to CD4 on T cells during the infection process, as
evidenced by the teaching of Lasky that antibodies specific for the
CD4 binding region of HIV gp120 block viral attachment to CD4 and
that anti-CD4 antibodies had been shown to inhibit CD4-gp-120
interaction and inhibit virus infectivity (page 975).
Appellants argue (Brief, bridging paragraph, pages 4-5) that Lasky state
that:
“[T]he virus may have evolved mechanisms whereby only low titers of
antibodies are directed against CD4 interaction sites, so that the
virus may effectively escapes immunosurveillance.” To support this,
they [Lasky] note that “in the case of picornaviruses, the receptor-
binding site(s) may be buried in a cleft within the viral attachment
protein that is unavailable for antibody binding or generation. They
[Lasky] also note that the HIV-1 virus may be able to escape
neutralization by small mutations in the CD4-binding region. All these
statements indicate that neutralizing monoclonal antibodies against
the CD4-binding region, as claimed, may be largely ineffective in
therapy” [footnote omitted].
To establish a prima facie case of obviousness, there must be both some
suggestion or motivation to modify the references or combine reference teachings
and a reasonable expectation of success. In re Vaeck, 947 F.2d 488, 493, 20
USPQ2d 1438, 1442 (Fed. Cir. 1991). Appellants’ arguments, based on the
teaching of Lasky, that “the receptor-binding site(s) may be buried in a cleft within
the viral attachment protein that is unavailable for antibody binding or generation,”
and the fact that appellants’ found that Lasky’s monoclonal antibody does not inhibit
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