A Phase III randomized study comparing the effects of oxandrolone (Ox) and megestrol acetate (Meg) on weight (wt), lean body mass (LBM) and quality of life (QOL) in solid tumor patients (pts) receiving chemotherapy (chemo)

18546 Background: Involuntary wt loss is a significant problem in pts with cancer and may lead to a decline in QOL, limit treatment options and reduce survival. Wt loss in these pts disproportionately represents a loss of muscle mass. Meg, a synthetic progesterone derivative, promotes wt gain mostly through an increase in adipose tissue rather than in LBM. Ox is a potent oral anabolic steroid with minimal androgenic activity which promotes wt gain primarily through increased LBM. Methods: Prospective, randomized phase III trial comparing the effects of Ox and Meg on wt, body composition and QOL in pts with solid tumors and wt loss receiving chemo. Body composition was serially assessed by Bioelectrical Impedance Analysis. QOL was evaluated with the FACT-G and the Anorexia/Cachexia subscale (FAACT). Eligibility: age ≥18; PS: 0–2; life expectancy ≥6 mos; near normal organ function; and progressive wt loss on chemo. Ineligibility: full dose anticoagulation; hormonally responsive or hematologic malignancies; and ongoing or planned treatment with corticosteroids (antiemetic use allowed), estrogens or progestins. The primary endpoint was LBM after 12 wks of drug therapy. Study design allowed 90% power for detecting a 1.5 kg difference between treatment groups using a 5% two-sided level of significance. A max of 155 pts were to be accrued. An interim analysis was planned after 62 pts had completed 12 wks on study. Results: As of 12/05, 74 pts have been accrued (72 eligible): median age 64 yrs, 42% females and 62% stage 4 disease. 25 pts (arm 1:8, arm 2:17) have completed 12 wks of therapy and 20 remain on study. 76 Grade 3/4 toxicities (arm 1:23, arm 2:53) and 1 grade 5 arrhythmia (arm 2) have been recorded. Accrual is ongoing and differing trends in wt gain and body composition between arms are emerging. Conclusions: This is the first and only trial comparing these two commonly utilized therapies for cancer-related anorexia/cachexia. Differences in efficacy, particularly effects on LBM, QOL and toxicity which emerge from this trial are likely to influence symptom management standards of care in the oncology community. Supported by Savient Pharmaceuticals and NCI grant 1 U10 CA81851. No significant financial relationships to disclose.