Appeal No. 2004-0647 Page 8
Application No. 09/941,965
Claims 1-4 stand rejected under 35 U.S.C. § 103 as unpatentable over Kempf.
Kempf describes the effect of pepsin treatment at pH 4 and 37°C on the infectivity of
several enveloped viruses in intravenous immunoglobulin preparations. “[T]o study the
influence of pepsin treatment on [virus] inactivation[,]” Kempf “spiked IgG solutions with
VSV [(vesicular stomatitis virus)] in the presence or absence of pepsin . . . These
solutions were then adjusted to various pH values ranging from 3.7 to 7.4 and
incubated for 16 hrs at 37°C” (Kempf, page 425). Figure 3 (Kempf, page 425)
illustrates the results of an 8 hour time course of VSV inactivation in the presence of
pepsin at pH 4 and 37°C. The time-response curve shows that “inactivation of VSV at
low pH in the presence of pepsin is accomplished within 7 to 8 hours” (id., page 426).
According to the examiner, “claim 1 differs from [Kempf] . . . in that the acid
hydrolyzed fraction has been heated for from 15 minutes to 1 hour” (Answer, page 4);
and claim 2 differs . . . [in] that the acid hydrolyzed IgG fraction has been hydrolyzed
with from 0.1N to 0.2N acid” (id., page 5). However, the examiner concluded that “one
of ordinary skill in the art . . . would have been motivated” to “treat[ ] an immunoglobulin
solution with acid pH for 1 hour” “because Kempf [ ] teach[es] that treating any IgG
solutions at pH 4 and [ ] heating at 37°C for as little as one hour is useful to inactivate a
variety of envelope viruses” (id.). With respect to “[t]he recitation of centrifuged and
decanted in claim 1,” the examiner asserts that the recitation “has no patentable weight
because a product is a product, irrespective of how it is made” (id.). Alternatively, the
examiner asserts “it is within the purview of one [ ] skilled in the art . . . to separate any
precipitate in a solution by centrifugation and decanting” (id.).
To the extent the examiner argues that the claims’ “centrifuged and decanted”
requirement is of no importance, we disagree. On the one hand, the examiner has not
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007