Gabapentin in Treating Peripheral Neuropathy in Cancer Patients Undergoing Chemotherapy

OBJECTIVES:

- Determine whether gabapentin improves the pain and other symptoms in cancer patients
with chemotherapy-induced peripheral neuropathy.

- Determine the effect of this drug on symptom distress, mood states, functional
abilities, and overall quality of life in these patients.

- Determine the toxic effects of this drug in these patients.

OUTLINE: This is a randomized, double-blind, placebo-controlled, multicenter study. Patients
are stratified according to neurotoxic chemotherapy (active vs nonactive and discontinued vs
completed) and neurotoxic chemotherapeutic agents (vinca alkaloids vs taxanes vs
platinum-based compounds vs combination of two or more of the above agents). Patients are
randomized to 1 of 2 treatment arms.

- Arm I: Patients receive titrating doses of oral gabapentin twice daily and then three
times daily for 3 weeks. Patients then receive a fixed dose of oral gabapentin three
times daily for 3 weeks. Patients cross-over to therapy as in arm II at week 8.

- Arm II: Patients receive titrating doses of oral placebo and then a fixed dose of oral
placebo as in arm I. Patients cross-over to therapy as in arm I at week 8.

Quality of life is assessed at baseline and then at the end of weeks 6, 8, and 14.

PROJECTED ACCRUAL: A total of 100 patients (50 per treatment arm) will be accrued for this
study.

DISEASE CHARACTERISTICS:

- Has received or is currently receiving neurotoxic chemotherapy, including taxanes
(e.g., paclitaxel or docetaxel), platinum-based compounds (e.g., carboplatin,
cisplatin, or oxaliplatin), or vinca alkaloids (e.g., vincristine or vinblastine)

- Pain or symptoms of peripheral neuropathy of at least 1 month duration attributed to
chemotherapy-induced peripheral neuropathy

- Average daily pain rating of at least 4 out of 10 using the pain numerical
rating scale (where 0 is no pain and 10 is the worst pain possible) OR

- Evidence of peripheral neuropathy of at least grade 1 out of 3 by ECOG Common

- Toxicity Criteria for sensory neuropathy

- No other identified causes of painful paresthesia existing prior to chemotherapy

- No radiotherapy-induced or malignant plexopathy

- No lumbar or cervical radiculopathy

- No pre-existing peripheral neuropathy of another etiology, including:

- B12 deficiency

- AIDS

- Monoclonal gammopathy

- Diabetes

- Heavy metal poisoning

- Amyloidosis

- Syphilis

- Hyperthyroidism or hypothyroidism

- Inherited neuropathy

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Life expectancy:

- At least 6 months

Renal:

- Creatinine no greater than 1.5 times upper limit of normal

Other:

- No prior allergic reaction or intolerance to gabapentin

- No significant psychiatric illness (e.g., mania, psychosis, or schizophrenia) that
would preclude study compliance

- No extreme difficulty swallowing pills

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

Other:

- More than 30 days since prior investigational agent for pain control

- Concurrent selective serotonin reuptake inhibitors allowed

- Concurrent nonsteroidal anti-inflammatory drugs allowed

- No concurrent tricyclic antidepressant (e.g., amitriptyline, nortriptyline, or
desipramine)*

- No concurrent monoamine oxidase inhibitor*

- No concurrent opioid analgesic*

- No other concurrent adjuvant analgesic (e.g., anticonvulsant, clonazepam, or
mexiletine)*

- No concurrent topical analgesics (e.g., lidocaine gel or lidocaine patch)*

- No concurrent amifostine

- No concurrent investigational agent for pain control NOTE: * For pain or symptoms due
to chemotherapy-induced peripheral neuropathy