Increased platelet to red blood cell transfusion ratio associated with acute kidney injury in children with life-threatening bleeding

INTRODUCTION

Transfusion may increase the risk of organ failure through immunomodulatory effects. The primary objective of this study was to assess for patient or transfusion-related factors that are independently associated with the risk of acute kidney injury (AKI) and acute respiratory distress syndrome (ARDS) in a cohort of children with life-threatening bleeding from all etiologies.

METHODS

In a secondary analysis of the prospective observational massive transfusion in children (MATIC) study, multivariable logistic regression was performed in an adjusted analysis to determine if blood product ratios or deficits were independently associated with AKI or ARDS in children with life-threatening bleeding.

RESULTS

There were 449 children included with a median (interquartile range, IQR) age of 7.3 years (1.7-14.7). Within 5 days of the life-threatening bleeding event, AKI occurred in 18.5% and ARDS occurred in 20.3% of the subjects. Every 10% increase in the platelet to red blood cell transfusion ratio is independently associated with a 12.7% increase in the odds of AKI (adjusted odds ratio 1.127; 95% confidence interval 1.025-1.239; p-value .013). Subjects with operative or medical etiologies were independently associated with an increased risk of AKI compared to those with traumatic injury. No transfusion-related variables were independently associated with the risk of developing ARDS.

CONCLUSION

The use of increased platelet to red blood cell transfusion ratios in children with life-threatening bleeding of any etiology may increase the risk of AKI but not ARDS. Prospective trials are needed to determine if increased platelet use in this cohort increases the risk of AKI to examine possible mechanisms.

Indoximod-based chemo-immunotherapy for pediatric brain tumors: A first-in-children phase I trial

BACKGROUND

Recurrent brain tumors are the leading cause of cancer death in children. Indoleamine 2,3-dioxygenase (IDO) is a targetable metabolic checkpoint that, in preclinical models, inhibits anti-tumor immunity following chemotherapy.

METHODS

We conducted a phase I trial (NCT02502708) of the oral IDO-pathway inhibitor indoximod in children with recurrent brain tumors or newly diagnosed diffuse intrinsic pontine glioma (DIPG). Separate dose-finding arms were performed for indoximod in combination with oral temozolomide (200 mg/m2/day x 5 days in 28-day cycles), or with palliative conformal radiation. Blood samples were collected at baseline and monthly for single-cell RNA-sequencing with paired single-cell T cell receptor sequencing.

RESULTS

Eighty-one patients were treated with indoximod-based combination therapy. Median follow-up was 52 months (range 39-77 months). Maximum tolerated dose was not reached, and the pediatric dose of indoximod was determined as 19.2 mg/kg/dose, twice daily. Median overall survival was 13.3 months (n = 68, range 0.2-62.7) for all patients with recurrent disease and 14.4 months (n = 13, range 4.7-29.7) for DIPG. The subset of n = 26 patients who showed evidence of objective response (even a partial or mixed response) had over 3-fold longer median OS (25.2 months, range 5.4-61.9, p = 0.006) compared to n = 37 nonresponders (7.3 months, range 0.2-62.7). Four patients remain free of active disease longer than 36 months. Single-cell sequencing confirmed emergence of new circulating CD8 T cell clonotypes with late effector phenotype.

CONCLUSIONS

Indoximod was well tolerated and could be safely combined with chemotherapy and radiation. Encouraging preliminary evidence of efficacy supports advancing to Phase II/III trials for pediatric brain tumors.

CTIM-32. FIRST-IN-CHILDREN PHASE 1 TRIAL OF INDOXIMOD-BASED CHEMO-IMMUNOTHERAPY FOR PATIENTS WITH PEDIATRIC BRAIN TUMORS: ANALYSIS OF SAFETY, TOLERABILITY, AND 5-YEAR OUTCOME

BACKGROUND

Recurrent brain tumors are the leading cause of cancer death in children. We conducted a first-in-children, two-institution, Phase 1 open-label dose-confirmation study using a 3 + 3 design, with expansion cohorts, to determine the recommended pediatric dose of the IDO pathway-inhibitor indoximod (NCT02502708). DESIGN/

METHODS

Eligible patients were 3-22 years old with either recurrent malignant brain tumor or newly-diagnosed diffuse intrinsic pontine glioma (DIPG). Palliative radiation, surgery or dexamethasone were allowed as needed for patient management. Separate dose-finding arms were performed for indoximod plus temozolomide (200 mg/m2/day orally for 5 days of each 28-day cycle) and for indoximod plus conformal radiation (in patients for whom re-irradiation was planned as standard-of-care). At progression, patients who were otherwise clinically stable were offered crossover to indoximod plus a second-line chemotherapy regimen (cyclophosphamide 2.5 mg/kg/day orally and etoposide 50 mg/m2/day orally for 21 days of each 28-day cycle).

RESULTS

Between December 2015 and January 2019, the study enrolled 81 brain tumor patients, including newly-diagnosed DIPG (n = 13) or recurrent ependymoma (n = 27), glioblastoma/high-grade glioma (n = 19), medulloblastoma (n = 13), or other CNS tumors ( n= 9). Median follow-up was 52 months (range 39-77 months). No dose-limiting toxicities were observed, and the pediatric indoximod dose was determined (19.2 mg/kg/dose, given twice daily). Indoximod was well tolerated and did not affect the ability to deliver chemotherapy or radiation as planned. Median overall survival was 13.6 months (n = 81). Median overall survival was 34.7 months for the subset of patients who continued indoximod with second-line chemotherapy after progression on indoximod plus temozolomide (n = 18).

CONCLUSIONS

Indoximod was well tolerated and could be combined with a variety of standard treatments for pediatric brain tumors. Preliminary anti-tumor activity and overall survival suggest that indoximod with standard therapy should be further evaluated in pediatric brain tumors, and potentially other pediatric solid tumors.

IMMU-04. FIRST-IN-CHILDREN PHASE 1B STUDY USING THE IDO PATHWAY INHIBITOR INDOXIMOD IN COMBINATION WITH RADIATION AND CHEMOTHERAPY FOR CHILDREN WITH NEWLY DIAGNOSED DIPG (NCT02502708, NLG2105)

Background

Diffuse intrinsic pontine glioma (DIPG) is a uniformly fatal brain tumor with no available cure. Indoximod blocks the IDO (indoleamine 2,3-dioxygenase) pathway, thereby reversing IDO-mediated immune suppression in the tumor microenvironment.

Methods

Patients aged 3 to 21 years with treatment-naive DIPG were eligible for this phase 1b dose-confirmation study of indoximod. The treatment regimen comprised continuous oral indoximod (38.4 mg/kg/day divided twice daily) with conformal photon radiation (54 Gy in 30 fractions), followed by cycles of indoximod with temozolomide (200 mg/m2/day, days 1–5 in 28-day cycles).

Results

Thirteen patients (median age 9 years, range 5 to 20 years) with DIPG were treated. Median OS was 14.5 months (follow-up ranged 4.8 to 29.3 months), 12-month OS was 61.5% (8/13), and 18-month OS was 30.8% (4/13), with 1 patient remaining in follow-up at the data cutoff. This compared favorably to expected median OS of approximately 10.8 months, 12-month OS of 45.3%, and 18-month OS of 16.2% taken from published historical data from the Pediatric Brain Tumor Consortium. Two patients showed near-complete responses lasting until relapsing after 7.6 months and 13.3 months of study therapy, respectively. Many patients had increased circulating non-classical monocytes (nc-Monos, CD16+, CD14neg, CD33+, HLA-DR+) within the first 3 treatment cycles, and elevation of this early pharmacodynamic marker was predictive of subsequent OS. Patients with nc-Monos >10% (n=7) had median OS of 19 months, whereas patients with nc-Monos below 10% (n=5) had median OS of 7 months (p=0.0047). No patients stopped therapy for toxicity. The most common indoximod-attributed adverse events were thrombocytopenia, neutropenia, nausea, vomiting, dizziness, and fatigue.

Conclusions

Adding indoximod immunotherapy to conventional radiation and chemotherapy for front-line treatment of pediatric patients with DIPG was well-tolerated. Improved outcomes were observed in patients having evidence of pharmacodynamic response. A follow-on phase 2 study is in progress (NCT04049669).

What does it mean to be a physician? Exploring social imaginaries of first-year medical students

OBJECTIVES

To explore if community embedded discussions with local community members reshape the social imaginary of medicine among students and contribute positively to their professional identity.

METHODS

This explorative, qualitative study involved 35 first-year medical students who volunteered to attend a 2-hour forum at a local church to ask community members about their experiences with doctors and healthcare systems.  Student participants were asked to reflect on five structured questions. The written reflections were submitted for analysis, de-identified, and analyzed using Glaser's classic grounded theory, constant comparative analysis, and Taylor's model of modern social imaginaries as an analytical lens.

RESULTS

The results indicate that student participants identified seven main themes regarding what community members expect from their doctors, including active listening (n=22), physical touch (n=18), and compassion (n=16). Responses also indicated that only 5.6% of the students felt that the preclinical curriculum was adequately preparing them for what local community members identified as important to patient care. However, students recognized that two aspects of the curriculum, Physical Diagnosis (n=12) and volunteering/community engagement (n=9), were congruent with the expectations of future patients.

CONCLUSIONS

The results suggest that students identified educational experiences that were congruent with the social imaginary of patients. However, patient expectations were discordant to some aspects of the medical imaginary of medical students. The experience and subsequent reflections may be salient to contributing to each student's professional identity and provide a model for other medical schools to explore how the curriculum is fulfilling the community's perception of ideal patient care.