Background: Treatment of older patients with myelodysplastic syndrome (MDS) is based on disease biology and performance status. Performance status, however, does not reflect increasing co-morbidities, functional dependence or psychosocial issues in older patients. Patients and Methods: This prospective study evaluated the burden of geriatric related health issues, assessed feasibility of "tailored" Comprehensive Geriatric Assessment (CGA), and compared treatment duration and survival in older patients with MDS and oligoblastic acute myeloid leukemia with and without deficits in CGA domains (n = 98). Results: Although only 27 (28%) patients had an Eastern Cooperative Oncology Group score ≥2, 78% (n = 77) patients had deficits in at least one CGA domain. Deficits were spread across all CGA domains, including dependence for instrumental activity of daily living (iADL; n = 33, 34%). Importantly, patients who were dependent for iADL (3.7 ± 2.6 vs 12.1 ± 7.9; p = .009), had cognitive impairment (3.5 ± 2.1 vs. 10.9 ± 7.9; p = .034) or impaired mobility (3.8 ± 2.5 vs. 13.2 ± 7.6; p = .001) completed significantly less azacitidine cycles as compared to those without these deficits. Cox-proportional regression showed that iADL dependency (hazard ratio 3.37; p = .008) and higher comorbidities (hazard ratio 4.7; p b .001) were associated with poor prognosis independent of disease related factors. Poor survival of iADL dependent patients was seen in both azacitidine (6 vs 19 months; p b .001) and supportive care cohorts (26 vs 48 months; p = .01). Conclusion: CGA detected geriatric related health issues, predicted poor survival and identified patients less likely to continue and benefit from azacitidine. Hence, CGA should be included in the treatment decision algorithm of older patients with MDS.

Background: The management of older patients with Myelodysplastic syndrome (MDS) and Acute Myeloid Leukaemia (AML) is currently based on disease biology and performance status despite the heterogeneity of ageing and the increasingly complex care needs of frail and multi-morbid patients. Performance status scores fail to capture deficits across all the domains of ageing therefore patients that are pre-frail or vulnerable fail to be identified early in their journey. Geriatric assessments have been firmly established in the management of oncological patients but not as yet in haematological malignancies. Aims and Methods: This prospective interventional study was conducted at the Royal Adelaide Hospital. The aim was to determine if deficits in ageing were associated with therapy completion rates and survival. After the treatment decision had been made by the haematologists, consented patients had nurse-led geriatric assessments followed by Geriatrician review in participants with abnormal assessments subjective concerns with interventions implemented. Results: A total of 108 patients were enrolled into the study over a 4 year period. Although only 29 (27%) patients had an Eastern Cooperative Oncology Group score ≥2, 86 (79%) patients had deficits in at least one domain of ageing. Deficits were spread across all domains, including dependence for instrumental activity of daily living (iADL) (n=32, 29%). Patients who were iADL-dependent (3.2±5 vs. 10.8±15; p=0.004), were cognitively impaired (2.8±4 vs. 9.9±15; p=0.010) or had impaired mobility measured by the timed-up and got test (3.3±5 vs. 11.±15; p=0.002), completed significantly less cycles of azacitidine therapy than patients without deficits in these domains (Fig 1A-C). The patients who ceased therapy prematurely (less than 6 cycles) also had significantly poorer overall survival (OS) of patients compared to patients completing at least six cycles of azacitidine. (Fig 1D). Other domains predictive of poorer survival were iADL dependence (HR 4.91; p=0.003) and increased comorbidities (HR 4.41; p=0.004) independent of age and disease factors (n=108) (Fig 2A). Additionally iADL dependence was associated with shortened survival regardless of therapy choice reflecting the frailty of this group of patients - azacitidine (6 vs. 19 months, p=0.002) and supportive care cohorts (28 months vs. not reached, p=0.04; Fig 2B-C). Seventy patients were reviewed by the Geriatrician which led to the identification of a significant degree of multimorbidity (87%) and polypharmacy (73%), which have been shown to negatively impact on morbidity. Interventions and recommendations included changes in medications (57%), investigations for further evaluation of non-oncologic conditions (61%), social support referral including Aged Care Assessment (34%), nutritional support by counselling or referral to dietician (37%), formal cognitive evaluation and management (60%), physical therapy program referral or counselling (39%), referral or shared care with other specialists besides haematology and the primary care provider (26%), and psychologist referral (16%). Conclusion: This study demonstrates that geriatric assessment is feasible and instrumental in identifying geriatric related health issues in a significant proportion of patients compared to the use of performance scores. Deficits associated with ageing are associated with premature cessation of therapy and poorer survival. Geriatric assessments should form part of the assessment of older persons with the aim of reducing adverse outcomes and maintaining quality of life. Disclosures Ross: Celgene: Research Funding; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria. Hiwase:Novartis: Research Funding; Celgene: Research Funding.

Background Epetraborole (EBO) — an orally available bacterial leucyl transfer RNA synthetase inhibitor with potent activity against nontuberculous mycobacteria — is under clinical development for treatment of MAC lung disease. We conducted a Phase 1b dose-ranging study of EBO tablets in healthy adult volunteers, to inform dose selection in the treatment of MAC lung disease. Methods In this double-blind, placebo-controlled trial, EBO or placebo tablets were administered (n=8/cohort, 3:1 randomization) at dosages of 250-1000 mg q24h or 500 mg or 1000 mg q48h for up to 28 days. Standard Ph1 clinical and laboratory evaluations and treatment-emergent adverse events (TEAEs) were assessed. Based on prior human studies using significantly higher EBO daily doses, gastrointestinal (GI) events and anemia were predetermined AEs of special interest (AESIs). Plasma concentrations of EBO were measured by validated LC-MS/MS methods. Plasma PK parameters were determined using non-compartmental methods. Results A total of 43 subjects were enrolled; the 1000 mg q24h cohort was terminated early due to local COVID restrictions. Overall, 80.6% EBO subjects and 83.3% placebo subjects experienced ≥1 TEAE, none of which was serious or severe (Table). Most TEAEs were mild in severity (90%), and the remainder were moderate (10%). No TEAE leading to withdrawal from study was reported. The most frequent types of TEAEs were GI events (48.4% EBO, 41.7% placebo subjects), the most common being mild nausea. Two subjects had premature discontinuation of EBO due to a TEAE (asymptomatic liver enzyme elevations in a 250 mg q24h subject and mild nausea in a 1000 mg q48h subject). One 1000mg q24h subject had a TEAE of anemia. No clinically significant findings or TEAEs were observed for physical examinations, ECGs, or urine laboratory tests. Plasma Cmax and AUC0-∞ of EBO increased in a linear, dose-proportional manner across cohorts. Tmax was observed at ∼1 h post dose; mean t1/2 ranged from 7.63 to 11.1 h. Conclusion Oral EBO administered for 28-day dosing was generally well tolerated at the predicted therapeutic dose (500mg q24h) Predictable PK characteristics facilitate its use in MAC lung disease Further evaluation in a Phase 2/3 treatment-refractory MAC lung disease study is planned Disclosures Paul B. Eckburg, MD, Paratek Pharmaceuticals, Inc.: Safety Review Board|Spero Therapeutics, Inc.: Advisor/Consultant Sanjay Chanda, PhD, AN2 Therapeutics: Stocks/Bonds George Talbot, MD, AN2 Therapeutics, Inc.: Advisor/Consultant|AN2 Therapeutics, Inc.: Co-founder Christopher M. Rubino, PharmD, Adagio Therapeutics: Grant/Research Support|Amplyx Pharmaceuticals, Inc: Grant/Research Support|AN2 Therapeutics: Grant/Research Support|Antabio SAS: Grant/Research Support|Arcutis Biotherapeutics, Inc: Grant/Research Support|B. Braun Medical Inc.: Grant/Research Support|Basilea Pharmaceutica: Grant/Research Support|Boston Pharmaceuticals: Grant/Research Support|Bravos Biosciences: Ownership Interest|Celdara Medical LLC: Grant/Research Support|Cidara Therapeutics Inc: Grant/Research Support|Cipla USA: Grant/Research Support|Crestone Inc: Grant/Research Support|CXC: Grant/Research Support|Debiopharm International SA: Grant/Research Support|Entasis Therapeutics: Grant/Research Support|Evopoint Biosciences Co.: Grant/Research Support|Fedora Pharmaceuticals: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Hoffmann-La Roche: Grant/Research Support|ICPD: Ownership Interest|ICPD Biosciences, LLC.: Ownership Interest|Insmed Inc.: Grant/Research Support|Iterum Therapeutics Limited: Grant/Research Support|Kaizen Bioscience, Co.: Grant/Research Support|KBP Biosciences USA: Grant/Research Support|Lassen Therapeutics: Grant/Research Support|Matinas Biopharma: Grant/Research Support|Meiji Seika Pharma Co., Ltd.: Grant/Research Support|Melinta Therapeutics: Grant/Research Support|Menarini Ricerche S.p.A: Grant/Research Support|Mutabilis: Grant/Research Support|Nabriva Therapeutics AG: Grant/Research Support|Novartis Pharmaceuticals Corp.: Grant/Research Support|Paratek Pharmaceuticals, Inc.: Grant/Research Support|PureTech Health: Grant/Research Support|Sfunga Therapeutics: Grant/Research Support|Spero Therapeutics,: Grant/Research Support|Suzhou Sinovent Pharmaceuticals Co.: Grant/Research Support|TauRx Therapeutics: Grant/Research Support|Tetraphase Pharmaceuticals: Grant/Research Support|tranScrip Partners: Grant/Research Support|Utility Therapeutics: Grant/Research Support|Valanbio Therapeutics, Inc.: Grant/Research Support|VenatoRx: Grant/Research Support|Wockhardt Bio AG: Grant/Research Support.

Rearranged during transfection (RET), a neuronal growth factor receptor tyrosine kinase, regulates the development of sympathetic, parasympathetic, motor, and sensory neurons in the enteric nervous system. The intended site of action for GSK3352589 is intestinal tissues. GSK3352589 is an RET kinase inhibitor that was administered in double‐blind, randomized, placebo‐controlled single‐dose (SD) and repeat‐dose (RD) studies in healthy subjects to investigate its safety/tolerability and pharmacokinetics. In the SD study (n = 28), GSK3352589 was dosed from 2 to 400 mg, including a food effect arm (25 mg). In the RD study (n = 40), GSK3352589 was dosed for 14 days with food twice daily from 5 to 200 mg. With single (fed and fasted) and repeat (fed) doses, bioavailability was low and less than dose‐proportional. There was a food effect with 25 mg once daily but may not be clinically relevant. Elimination half‐life was ≥17 hours at SD ≥ 15 mg. Accumulation ratios for Cmax, AUCt, AUCtau, and AUC24 after twice‐daily dosing to steady state ranged from 1.2 to 1.8 for all doses except the 200‐mg dose, which had ratios between 1.9 and 2.7. Administration of GSK3352589 after SD and RD was well tolerated with no safety concerns in healthy subjects.