Effectiveness of Palifermin in Increasing CD4 Counts in Treatment-Experienced HIV Infected Adults

Antiretroviral therapy (ART) has dramatically improved the clinical outcome for HIV infected
adults; however, some people on potent ART experience poor recovery of CD4 counts despite
maximum suppression of viral load. Such uncontrolled HIV infection is associated with the
reduced ability by the human body to create new T cells (or thymopoiesis). HIV infected
adults experiencing reduced thymopoiesis are at increased risk of clinical disease
progression.

The thymus is the primary site for CD4 cell development; research suggests that keratinocyte
growth factor (KGF) may enhance thymus activity in individuals who exhibit reduced
thymopoiesis. Palifermin is a modified version of the naturally occurring KGF that is
approved to treat people with hematologic malignancies. The purpose of this study is to
evaluate the safety and efficacy of palifermin in increasing CD4 counts, through enhanced
thymopoiesis, in treatment-experienced HIV infected adults with suppressed viral loads but
low CD4 counts.

This study will last 24 weeks. Participants will be randomly assigned to one of four arms:

- Arm A participants will receive placebo

- Arm B participants will receive palifermin 20 mcg/kg

- Arm C participants will receive palifermin 40 mcg/kg

- Arm D participants will receive palifermin 60 mcg/kg

Participants will receive intravenous doses of their assigned intervention on Days 1, 2, and
3. All participants must remain on their current ART regimen for the duration of the study.
ART will not be provided by the study. There will be six study visits, and they will occur at
Weeks 1, 2, 4, 8, 12, and 24. All visits will include a targeted physical exam and blood and
urine collection.

Inclusion Criteria:

- HIV infected

- Receiving potent ART, defined as a combination of three or more antiretroviral drugs
for at least 6 months prior to study entry

- CD4 count of 200 cells/mm3 or less within 30 days prior to study entry

- Documented CD4 count obtained at study screening

- Documented current, persistent viral load less than or equal to 200 copies/ml for at
least 6 months prior to study entry

- Willing to use acceptable forms of contraception for the duration of the study

Exclusion Criteria:

- Active pancreatitis

- Androgens, Immunomodulators (e.g., growth factors, systemic corticosteroids, HIV
vaccines, immune globulin, interleukins, interferons), or investigational ART within
30 days prior to study entry

- Systemic cancer chemotherapy within 30 days prior to study entry, or history of
radiation therapy to the neck and chest regions at any time.

- Allergy or sensitivity to any component of palifermin

- Prior treatment with palifermin or other keratinocyte growth factors

- Current drug or alcohol use that, in the opinion of the investigator, may interfere
with study participation

- Serious illness or recent surgery that requires systemic treatment or hospitalization.
Participants who have completed therapy or are clinically stable on therapy for at
least 30 days prior to study entry are not excluded.

- Active cancer

- HIV-1 RNA levels >200 copies/mL within 6 months prior to study entry

- Pregnant or breastfeeding