10536 Background: We previously developed a risk factor model in HR-NBL1/SIOPEN patients treated without DB including age, LDH and metastatic site index (MSI). We tested if this score (Morgenstern, PBC 2018) would provide meaningful information in DB treated HR-NBL1/SIOPEN patients. Methods: High-risk patients (stage 4 ≥1yr.; stage 4 < 1yr. with MYCN amplification (MNA); stage 2, 3, 0-21y with MNA) received intensive induction, surgery, high dose therapy (HDT) and local radiotherapy (21Gy). Patients with a ≤9 months intervall till HDT/SCT, ≥ partial response prior and no progression received up to 5 cycles of 100mg/m2 DB: as short-term (STI: 5 days) or long-term infusion (LTI: 10 days ) ± 6 (STI) or 3 (LTI) x 106 IU/m2 subcutaneous interleukin 2 (scIL2 over 2 x 5 days) followed by 2 weeks of 160mg/m2 oral isotretinoin. Results: DB was used in 1018 patients [512 males; 89% Stage, 1% Stage 4s, 10% loc. MNA; 2.8 yrs median age at diagnosis] in 18 countries. STI was used in 61% patients, LTI in 39% and DB without scIL2 in 62% patients. 2-yrs. event-free (EFS)/overall survival (OS) was 0.65±0.02/0.78±0.01 and 5-yrs. EFS/OS of 0.56±0.02/0.63±0.02. 891/1018 patients were evaluable for risk factor analysis. EFS multivariate analysis included age, MSI, LDH ≥1250U/L, HDT typ, response prior DB, DB schedule and use of scIL2: only age > 1.5yrs.(p = 0.002) and MSI > 1 (p = 0.002) had independent prognostic prediction. If restricted to stage 4 only, LDH ≥1250U/L was also an independent factor (p = 0.049). Points were allocated in proportion to the log-cumulative hazard ratio (cHR): cHR for LDH > 1250U/L was 1.33 (score of 1), cHR for age > 5 years and metastatic site involvement (MSI) > 1 were 1.79 and 1.86 (scores of 2). Using the score (0 to 5) relevant risk groups can be identified: 5-yrs. EFS/OS for scores 0&1 are 0.80±0.06&0.77±0.04, score 2/3 are 0.58±0.03&0.57±0.04 and for scores 4/5 are 0.50±0.06&0.43±0.08. Conclusions: The score adds value in DB treatment groups as it differentiates prognostic subgroups facilitating decision making for future DB add on treatments. Clinical trial information: NCT01704716.

BACKGROUND:Antimicrobial resistance (AMR) is being recognized as a priority by healthcare organizations across the world. However, many children are managed on IV antimicrobials in hospital with very little consideration of antimicrobial stewardship issues. OBJECTIVES:A nurse-led paediatric ambulatory outpatient parenteral antimicrobial therapy (OPAT) service, managing children with common infections being ambulated on short courses of IV antimicrobials, was introduced within Southampton Children's Hospital in January 2018. We evaluated the impact of this service in terms of the quality of antimicrobial prescribing and timing of ambulation in children presenting with common infections. METHODS:All cases managed within the service were reviewed in two separate 2 month time periods: prior to introduction of the service (September-October 2016) and then prospectively after its introduction (September-October 2018). RESULTS:A total of 96% of IV antibiotic management decisions at 48 h were deemed appropriate in 2018, compared with 75% in 2016. A total of 64% of patients were ambulated on IV antibiotics at some point during their treatment course in 2018, compared with 19% in 2016. However, a significant proportion of antimicrobial decisions made at the point of presentation to hospital remained suboptimal in 2018. CONCLUSIONS:Children are commonly managed with IV antibiotics in hospital. We demonstrate marked improvements in appropriate antimicrobial use through the introduction of a nurse-led ambulatory OPAT service. In addition, such a service can promote a greater proportion of children being ambulated from hospital, freeing up valuable inpatient beds and potentially delivering cost savings that can be used to fund such services.