Ex Parte Engel

Board of Patent Appeals and Interferences

Jan 5, 2010

10347178 (B.P.A.I. Jan. 5, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte JURGEN ENGEL
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Appeal 2009-013051
Application 10/347,178
Technology Center 1600
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Decided: January 5, 2010
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Before TONI R. SCHEINER, DEMETRA J. MILLS, and
FRANCISCO C. PRATS, Administrative Patent Judges.

SCHEINER, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from the final rejection of
claims 1, 2, 6-10, and 12-16, directed to a method of preventing visceral
leishmaniasis. The claims have been rejected as lacking enablement. We
have jurisdiction under 35 U.S.C. § 6(b).
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STATEMENT OF THE CASE
Claim 1 is representative of the subject matter on appeal:
1. A process for preventing visceral leishmaniasis, which
comprises administering to a human in whom prevention of the visceral
leishmaniasis is desired a pharmaceutical composition comprising an alkyl
phosphocholine selected from the group consisting of hexadecyl
phosphocholine (miltefosin), and octadecyl 1,1-dimethyl-piperidino-4-yl
phosphate (perifosin), wherein said administration of said pharmaceutical
composition is for prophylactic use before the infection of leishmaniasis.

The Examiner relies on the following evidence:

Engel WO 99/37289 Jul. 29, 1999

T.K. Jha, Miltefosine, an Oral Agent, for the Treatment of Indian Visceral
Leishmaniasis, 341 THE NEW ENGLAND JOURNAL OF MEDICINE 1795-1800
(1999).

Steven G. Reed, Leishmaniasis Vaccination: Targeting the Source of
Infection, 194 J. EXP. MED. F7-F9 (2001).

Phillipe J. Guerin et al., Visceral Leishmaniasis: Current Status of Control,
Diagnosis, and Treatment, and a Proposed Research and Development
Agenda, 2 THE LANCET 494-501 (2002).

Clive R. Davies et al., Leishmaniasis: New Approaches to Disease Control,
326 BJM 377-382 (2003).

The Examiner rejected claims 1, 2, 6-10, and 12-16 under 35 U.S.C.
§ 112, first paragraph, as lacking enablement.
We reverse.

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ENABLEMENT
Issue
According to the Examiner, the Specification is enabling for treating
visceral leishmaniasis by administering miltefosin or perifosin, but isn’t
enabling for preventing visceral leishmaniasis using the same compounds
(Ans. 3-4).
The issue raised by this rejection is: Has the Examiner provided
sufficient reason to doubt the Specification’s assertions regarding prevention
of visceral leishmaniasis by prophylactic administration of miltefosin or
perifosin?
Findings of Fact
FF1 “Leishmaniasis is a name for various tropical diseases which
are caused by flagellates of the genus Leishmania and is transmitted by
various blood-sucking insects. The manifestations of leishmaniasis may be
visceral . . . , mucocutaneous . . . or cutaneous” (Engle 1: 12-15).
FF2 Orally administered miltefosine is an effective treatment for
visceral leishmaniasis. (Guerin 494, Abstract; Davies 377, col. 1; Jha 1795,
Abstract.)
FF3 The exact mechanism of miltefosine’s cytotoxicity with respect
to Leishmania, the protozoan parasite that causes Leishmaniasis, is
undetermined, but miltefosine is known to modify cell-signaling pathways
and membrane synthesis (Jha 1798, col. 1).
FF4 The claimed invention is directed to prevention of visceral
leishmaniasis by prophylactic administration of an alkyl phosphocholine,
specifically miltefosin or perifosin (claim 1).
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FF5 The Specification provides a prophylactic dosage plan “suitable
for the preventive treatment of leishmaniasis in man by oral administration”
of miltefosin (Spec. 4-5).
FF6 According to the Specification, the duration of “prophylactic
use” (Spec. 5) or “preventative administration ranges from 2 weeks to 6
months and, suitably, for the duration of the risk of infection” (id. at 6).
Principles of Law
A lack of enablement rejection is appropriate where the written
description fails to teach those in the art to make and use the invention as
broadly as claimed without undue experimentation. In re Cortright,
165 F.3d 1353, 1356 (Fed. Cir. 1999).
“[T]he PTO bears an initial burden of setting forth a reasonable
explanation as to why it believes that the scope of protection provided by
[the] claim[s] is not adequately enabled by the description of the invention
provided in the specification of the application; this includes, of course,
providing sufficient reasons for doubting any assertions in the specification
as to the scope of enablement.” In re Wright, 999 F.2d 1557, 1561 (Fed. Cir.
1993).
Analysis
The Examiner makes the following findings and/or observations in
support of the enablement rejection:
• “The invention is in a class of invention which the CAFC has
characterized as . . . unpredictable” (Ans. 5).

• “The instantly claimed process does not prevent exposure to the
disease” (Ans. 5), since “Appellant has not taught a way to prevent the
sand fly from biting” (id. at 9).

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• “[N]o vaccines or drugs for preventing a leishmaniasis infection are
available” (id. at 9).

• “There is no prior art that teaches alkyl phosphocholines are effective
in preventing visceral leishmaniasis” (id. at 6).

• “The instant specification fails to provide any experiments that show
that . . . administration [of alkyl phosphocholines] would be effective
in preventing visceral leishmaniasis” (id. at 7).

• “[P]ages 4-5 of the instant specification provide a regimen for
preventative treatment of leishmaniasis, however this disclosure is not
equivalent to guidance” (id.), thus “a skilled artisan would be required
to de novo locate, identify and characterize the claimed alkyl
phosphocholines” (id. at 8), and “would have to locate de novo steps
required for a process of preventing visceral leishmaniasis” (id. at 9).

None of these findings or observations provides a reasonable or
sufficient explanation as to why the claims are not enabled by the
Specification.
The Examiner has not explained why prevention of infection with a
Leishmania parasite requires prevention of exposure to the parasite.
Moreover, the Examiner has not explained why one skilled in the art would
have to “de novo locate, identify and characterize” miltefosin, or “locate de
novo steps” to administer it (Ans. 8, 9). The prior art teaches that miltefosin,
which modifies cell signaling and membrane synthesis (FF3), is effective in
treating already established visceral leishmaniasis (FF2), and the instant
Specification lays out a detailed regimen for administering this same drug
prophylactically (FF5, FF6). The Examiner has not explained why one
skilled in the art wouldn’t have expected prophylactic administration of
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miltefosin as directed - before and during the period of risk of infection - to
be similarly effective in preventing initial establishment of the infection.
Conclusions of Law
The Examiner has not provided sufficient reason to doubt the
Specification’s assertions regarding prevention of visceral leishmaniasis by
prophylactic administration of miltefosin or perifosin.
The rejection of claims 1, 2, 6-10, and 12-16 under 35 U.S.C. § 112,
first paragraph, as lacking enablement is reversed.

REVERSED

alw

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