Conway, Olivia J.

TPS589 Background: In patients (pts) with metastatic unresectable urothelial cancer, platinum-based chemotherapy remains the standard of care for first-line treatment followed by switch maintenance avelumab if disease control is achieved with chemotherapy. Outside of this setting, single agent immunotherapy is often used in pts that have recurrence after platinum-based chemotherapy or are platinum ineligible. Atezolizumab is a PD-L1 inhibitor currently approved for pts that have urothelial cancers expressing positive PD-L1 or pts ineligible for receiving platinum-based chemotherapy. Tumor-targeted radiotherapy can generate immune-stimulating effects without immune suppression as was previously thought. Moreover, it has become clear that radiotherapy can induce profound effects on tumor cells and the tumor microenvironment that can enhance or trigger an anticancer immune response. While numerous trials have investigated the abscopal effect, this trial will have specific parameters regarding drug type, radiation dose and administration. Methods: A032002 is a phase 2 trial addressing pts that are platinum ineligible or refractory to platinum-based chemotherapy. 144 pts will be randomized to receive either atezolizumab or atezolizumab and single site radiation therapy. The atezolizumab regimen is 1200 mg every 3 weeks. Administration of radiotherapy will occur to one non-target site (8 Gy x 3) for pts randomized to the atezolizumab + radiotherapy arm. All pts will undergo centralized PD-L1 testing (SP142 monoclonal primary antibody), which can be performed on archival tissue; a new biopsy is only required if no archival tissue is available. Key eligibility criteria include age ≥ 18 years, ECOG performance status 0-2, histologically confirmed metastatic urothelial cancer, having at least one measurable site per RECIST 1.1 to monitor for abscopal response, one site targetable for radiation, and tissue available for PD-L1 testing. The primary endpoint is tumor response within 6 months of randomization. Tumor response is defined as a complete response (CR) or partial response (PR) as assessed by the treating physician using RECIST 1.1 criteria. For a one-sided log rank test with a type 1 error rateof 0.10, the study has 90% power to detect a 20% increase in response rate. Key secondary endpoints include tumor response using iRECIST, progression-free survival and overall survival. Quality of life assessments include EORTC QLQ-C30, QLQ-BLM30 and PROMIS-Fatigue. Tissue, urine and blood samples will be collected and biobanked for future correlative science. Enrollment to ART began in December 2021. The study is available for participation at all US NCTN sites with a projected enrollment of 3 years. Support: U10CA180821, U10CA180882. Clinical trial information: NCT04936230 .

12040 Background: Novel strategies are needed to assess frailty in the context of therapy decisions for older adults with acute myeloid leukemia (AML). Our objectives were to describe pre-treatment DAFI scores for older AML patients treated on clinical trials and explore their relationship with treatment outcomes. Methods: We conducted a exploratory analysis utilizing data from two clinical trials of adults aged ≥60 years with newly diagnosed AML (Alliance/CALGB 11001 [intensive therapy] and Alliance/CALGB 11002 [non-intensive therapy]). We included the subset of patients in each trial enrolled on geriatric assessment companion studies (Alliance/CALGB 361006, 361101). A DAFI score was calculated for each patient using 51 variables including demographic, geriatric assessment, and laboratory data derived from the geriatric assessment. Individuals with ≥90% items were included (consistent with other studies); DAFI scores ranged from 0 to 1 and were evaluated using established categories (0- <.2 [robust]; 0.2-<.35 [pre-frail]; 0.35+ [frail]) and as a continuous score. Associations between DAFI scores and toxicity and overall survival (OS) were evaluated with Fisher’s exact-testing and Kaplan Meier/cox proportional hazards, respectively. Results: The median age was 68 years (range 61, 82) and 72 years (range 61, 92) for those getting intensive (N=31) and less intensive therapy (N= 75), respectively. Individuals in the intensive study had a median pre-treatment DAFI score of 0.15 (range 0.05, 0.31) and were all categorized as robust (75%) or pre-frail (25%). There was no significant difference in median OS (14.6 vs. 14.7 months) or non-hematological grade 3+ adverse events (AEs; 85% vs. 89%) between robust vs. pre-frail individuals in this trial, respectively. However, pre-frail adults experienced a trend towards greater grade 4 non-hematological toxicity than robust individuals (67% vs 26%, p=0.05). In the non-intensive trial, the median DAFI score was 0.24 (range 0.04, 0.48) and most individuals were pre-frail (49.3%) or frail (17.3%). Non-hematologic grade 3+ AEs did not vary by DAFI group, 88% robust, 95% pre-frail, and 77% frail (p=0.15). Median OS was 7.4, 10.8, and 6.3 months for robust, pre-frail, and frail respectively (p=0.17). Adjusting for age, each 0.1 increase in DAFI score was associated with increased mortality hazard (HR 1.8, 95% CI 1.0-3.2). Conclusions: DAFI score calculation provides a potential novel strategy for categorization of frailty in AML. In our assessment, higher DAFI scores were associated with toxicity during intensive induction and mortality in the less intensive setting. This method should be studied in larger samples randomized by treatment intensity. Support: UG1CA189823; Bayer Healthcare/Berlex (CALGB 11001); NCT01253070 (CALGB 11001). Clinical trial information: NCT01253070, NCT01420926.