Abstract PO4-11-07: Early response to Adaptive Nutrition and Exercise Weight loss (A-NEW) Study for Breast Cancer Survivors with Overweight or Obesity

Abstract BACKGROUND: Obesity is associated with inferior survival and increased risk of recurrence in breast cancer (BC) survivors. In the Look AHEAD trial, 45% of patients attained ≥5% weight loss at 2 months, and those who lost 3-6% of weight at 2 months had higher odds of 5% weight loss at 1 year. Behavioral weight loss (BWL) studies consistently demonstrate that only half of BC survivors lose 5% weight, emphasizing the need for new approaches to aid those not benefiting from BWL alone. We hypothesized that early weight loss could identify BC survivors with excess body weight who may not benefit from BWL alone, and my benefit from the addition of a FDA-approved anti-obesity pharmaceutical agent. METHODS: Women with stage 0-III BC and BMI 27 kg/m2 who completed recommended local therapy and chemotherapy were enrolled in a 6-month BWL program consisting of remote coaching, an online curriculum, and tracking of diet, activity and weight. Patients completed demographic surveys and were weighed in clinic at baseline and 2 months. We used an adaptive design utilizing weight loss at 2 months to identify those with greater likelihood of weight loss at 6 months with BWL alone. Patients with and without ≥5% weight loss at 2 months were stratified as FAST-BWL and SLOW-BWL, respectively. Those in FAST-BWL continued BWL alone for 4 months, while those in SLOW-BWL also receive anti-obesity medication (Contrave®) until end of study. We anticipate 55% of 55 subjects enrolled will be in the SLOW-BWL group, resulting in a sample size of approximately 30 SLOW-BWL women and 25 FAST-BWL women. Simon's two-stage minimax design was used for the SLOW-BWL group. The null hypothesis that the true rate of attaining ≥5% weight loss is 10.9%, which is chosen based on the rate of women attaining ≥5% weight loss in the self-directed arm in the previously conducted POWER-remote study. The null hypothesis will be rejected if 7 or more women are observed in the 30 patients who attain ≥5% weight loss. This design yields a power of 80% at type I error rate of 5% when the true rate of attaining ≥5% weight loss of the baseline weight for the SLOW-BWL women is 29%, a clinical meaningful rate for the SLOW-BWL women group. We performed a descriptive analysis and evaluated outcomes at 2 months. RESULTS: Total enrollment is complete, and at time of presentation, 54 of 55 participants will be at end of study. Mean age at enrollment was 56 30 -73, and majority were white (73%), postmenopausal (84%), had an ECOG of 0 (77%) and were employed (69%). The median time from diagnosis to enrollment was 3.9 years 0.6-10.0. Over half received chemotherapy (54%), radiation (73%), and current endocrine therapy (75%); only 13% received prior antiHER2 therapy. Mean baseline weight was 213 (SD 30) pounds and baseline BMI was 35.5 (4.7). Mean HbA1c, total cholesterol, LDL, and triglycerides were 5.6% (0.4), 203 (29), 120 (26), and 135 (64), respectively. After 2 months of the BWL intervention, 14 (27%) attained ≥5% weight loss (FAST-BWL) and 38 (73%) did not (SLOW-BWL). CONCLUSIONS: We have successfully enrolled to this novel adaptive design and will present full data at the conference. Understanding predictors of successful weight loss inform populations that may benefit from anti-obesity medication, and design future studies that allow more patients to achieve significant weight loss. Citation Format: Jennifer Sheng, Amanda Montanari, Jennifer Trost, Mengyang Lu, Justin Mahosky, Sheetal Parida, Amanda Blackford, Dipali Sharma, Marci Laudenslager, Kimberly Gudzune, Janelle Coughlin, Vered Stearns. Early response to Adaptive Nutrition and Exercise Weight loss (A-NEW) Study for Breast Cancer Survivors with Overweight or Obesity abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-11-07.