Parker, Beverly

271 Background: Many studies have shown that fatigue is associated with poor outcomes such as quality of life and physical function in breast cancer survivors.Early treatment of symptoms that result in persistent fatigue may be a strategy to mitigate long-term fatigue.As a result, we studied symptoms and developed risk estimates for patients that are most likely to develop fatigue by pre-surgery and follow up among patients treated on the I-SPY 2 neoadjuvant trial. I-SPY 2 is a phase-II adaptive trial for high-risk early-stage breast cancer patients. Methods: In this retrospective cohort study of 306 women undergoing neoadjuvant chemotherapy +/- targeted therapy, patients complete electronic surveys of symptoms via 34 PRO-CTCAE items and QOL via 9 PROMIS instruments. Fatigue is collected as part of the PROMIS survey and scored using Health Measures. Study timepoints are screening (SC), weekly study treatment (ST), 12 weeks (12w), pre-surgery (PS) and at 1, 6, 12 and 24 months (FU1-FU4) following surgery. Correlation between symptoms and fatigue at equal timepoints was quantified using spearman correlations and BH-adjusted p-values. For symptom odds analysis, symptoms were binarized such that those that had an average grade of mild or above (severity), rarely or above (frequency) or a little bit or above (interference) between ST weeks 1-6 were considered present. Clinically significant (CS) increase in fatigue was defined as an increase >=0.5 standard deviation (SD) in mean from baseline. Logistic regression was used to determine odds ratios of factors associated with fatigue. Results: Baseline PROMIS fatigue mean score was 47.14 (SD 9.31) with a median of 47.45. A CS increase in fatigue from baseline was seen in 55% of patients at 12w, and 61% of patients pre-surgery. Of the patients that had a CS increase in fatigue at any point prior to surgery, 45.7% had persistent fatigue through FU1-4. Symptoms associated with Fatigue at 12w were shortness of breath, headache, and nausea (P< 0.03). At PS, fatigue was significantly correlated with GI symptoms, neuropathy, and shortness of breath (P< 0.03). Risk estimates for patients that filled out symptom surveys at early timepoints (weeks 1-6) and also had fatigue were evaluated. Patients with early GU (genitourinary) symptoms had higher risk of fatigue at IR (OR=9.33, p=0.02, 88.9% in cases vs 33.3% in controls). Patients with early GI symptoms at PS (OR=8.56, p=0.03, 90.1% vs 50%), or FU2-4 (OR= 5.88 and 7.36, p= 0.04 and 0.02, 80% vs 39.1% and 81.8% vs 36.3%) also had a higher risk of developing fatigue. Conclusions: A CS increase in fatigue during treatment and follow up is seen in the majority of patients and is associated with a large number of persistent symptoms.

369 Background: Patient-reported outcomes (PROs) are a valuable component to understand treatment tolerability and toxicity. We have implemented an electronic system for monitoring PROs and quality of life (QOL) for patients enrolled in the I-SPY2 trial, a phase II trial evaluating the effect of novel neoadjuvant therapies for breast cancer. We associated patient demographic factors with symptoms, decline in physical function (PF), and tolerability to treatment. Methods: Study population for this analysis includes 259 enrolled patients receiving combinations of experimental immunotherapy and chemotherapy. Patients completed PRO-CTCAE/PROMIS/FACT surveys reflecting symptom severity, symptom frequency, tolerability of drug, and physical function at baseline through follow up (12 months). CTCAE 5.0 was collected weekly at these timepoints to assess adverse events (AE). Odds ratio and regularized multi-variate regression was used to evaluate early symptoms predictive of a clinically significant decline in PF from baseline to post-treatment follow-up. Results: Of 259 patients, 160 (58%) were White, 13 (5%) were Asian, 26 (10%) were African American (AA), and 25 (9.3%) were Hispanic. 25% of all patients had a clinically significant decline in PF between baseline and pre-surgery/follow-up. Symptom predictors of decline included high frequency of diarrhea and severity of joint pain. African American (AA) patients had higher severity of joint pain than White patients (OR = 14.9, P < 0.05). Within the first 12 weeks of treatment, AA patients and non-white (NW) patients were more likely to report severe vomiting than White patients (OR =13.22 and 12.72, P< 0.05 and P< 0.03 respectively). Overall, patients that reported lower tolerance to therapy had higher grade of AE. While patients with low-grade adverse events were less bothered by their side effects at follow-up, higher grade adverse events such as hypothyroidism impacted distress levels by more than double. Conclusions: Among I-SPY2 participants, when higher grade of symptoms is persistent through follow up, it impacts physical function and tolerability even after end of therapy. Our study can allow physicians to be more diligent in active and post treatment monitoring. Clinical trial information: NCT01042379 .

LBA520 Background: I-SPY 2 is a multicenter trial using response-adaptive randomization within biomarker subtypes including MammaPrint (MP) risk to evaluate novel neoadjuvant agents in high-risk breast cancer. Oral paclitaxel and encequidar (OPE) is an oral combination of paclitaxel (P) with a p-glycoprotein pump inhibitor, encequidar, to enhance gastrointestinal (GI) absorption. Dostarlimab (D) is an anti-PD-1 monoclonal antibody. Methods: Women with tumors ≥ 2.5cm and MP high-risk cancers were screened and treated starting Oct 5, 2020. Treatment included Oral Paclitaxel 205mg/m2 and encequidar 12.9 mg on days 1-3, Carboplatin (Cb) AUC 1.5 on day 1 weekly x 12, and Dostarlimab (D) 500 mg every 3 weeks x 4, followed by doxorubicin/ cyclophosphamide (AC) every 2-3 weeks x 4. The control arm was IV P weekly x 12 followed by AC every 2-3 weeks x 4. For patients with HER2+ disease, weekly Trastuzumab (T) was administered during the first 12 weeks. The arm was eligible for graduation [> 85% chance of success in a 300-person phase 3 neoadjuvant trial with a pathologic complete response (pCR) endpoint] in 10 predefined signatures. Results: 106 patients (44 HR+HER2-, 56 HR-HER2- (TN), 6 HER2+) received OPE/Cb/D ± T. The control arm included 388 historical controls (201 HR+HER2-, 156 TN, 31 HER2+). 22 patients (20 HR+, 2 HR-) in OPE/Cb/D were MP1 (MP high) and 84 patients (29 HR+, 55 HR-) were MP2 (MP ultra-high). OPE/Cb/D graduated in the TN signature and accrual was stopped. Conclusions: OPE/Cb/D graduated in the TN signature with a higher predicted pCR rate compared to control. OPE and D have been, individually, shown to have efficacy in other settings. The lower-than-expected pCR rate and lower irAEs with triplet therapy (taxane, platinum, immune checkpoint inhibitor [ICI]) in TN compared to prior IV chemo + ICI arms on I-SPY 2 suggests a possible interference of OPE with ICI. Changes in gut microbiome is being investigated as an explanation. Clinical trial information: NCT01042379 . [Table: see text]