Gabapentin in Treating Hot Flashes in Patients With Prostate Cancer

OBJECTIVES:

- Determine the effectiveness of gabapentin in managing hot flashes in men with prostate
cancer.

- Determine the response of patients to this drug.

- Determine the toxicity of this drug in these patients.

- Determine the quality of life of patients treated with this drug.

OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients
are stratified according to the number of hot flashes per day (2-3 vs 4-9 vs 10 or more) and
duration of hot flash symptoms (less than 9 months vs 9 months or more). Patients are
randomized to one of four treatment arms.

All patients are observed for 7 days prior to drug administration in order to collect
baseline hot flash information.

- Arm I: Patients receive oral gabapentin once daily on days 1-28.

- Arm II: Patients receive oral gabapentin once daily on days 1-7 and twice daily on days
8-28.

- Arm III: Patients receive oral gabapentin once daily on days 1-7, twice daily on days
8-14, and three times daily on days 15-28.

- Arm IV: Patients receive oral placebo on one of three schedules corresponding to arms
I-III.

Patients in all arms may continue therapy with gabapentin for an additional 8 weeks.

Quality of life is assessed at baseline, day 28, and at the end of the additional 8 weeks.

Patients are followed at 6, 12, and 24 months.

PROJECTED ACCRUAL: A total of 220 patients (55 per treatment arm) will be accrued for this
study within 1 year.

Required characteristics:

1. Men with a history of prostate cancer who have received or are receiving androgen
ablation therapy.

2. Must be on a stable dose of hormone therapy for the past 4 weeks and must not be
planning on discontinuing hormone therapy throughout the duration of the randomized
phase (5 weeks).

3. Presence of hot flashes for ≥1 month prior to study entry.

4. Bothersome hot flashes (defined by their occurrence ≥14 times per week and of
sufficient severity to make the patient desire therapeutic intervention).

5. Life expectancy ≥ 6 months.

6. ECOG Performance Status (PS) 0 or 1.

7. ≥18 years of age

Contraindications:

1. History of renal insufficiency (defined as a creatinine ≥1.5 x UNL in the last two
years).

2. Any of the following current (≤ 4 weeks) or planned therapies:

- Antineoplastic chemotherapy

- Androgens

- Estrogens

- Progestational agents

3. History of allergic or other adverse reaction to gabapentin.

4. Prior use of gabapentin.

5. Antidepressants (use is allowed if patient has been on a stable dose for ≥1 month and
does not plan to modify this treatment during the next 5 weeks).