Infliximab Is Not Associated With Increased Risk of Malignancy or Hemophagocytic Lymphohistiocytosis in Pediatric Patients With Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Immunosuppressive therapy for inflammatory bowel disease (IBD) in pediatric patients is thought to increase the risk of malignancy and lymphoproliferative disorders, including hemophagocytic lymphohistiocytosis (HLH). We compared unadjusted incidence rates of malignancy and HLH in pediatric patients with IBD exposed to infliximab (IFX) with patients not exposed to biologics and calculated standardized incidence ratios (SIRs). METHODS: We collected and analyzed data from 5766 participants in a prospective study of long-term outcomes of pediatric patients with IBD (NCT00606346), from May 31, 2007 through June 30, 2016. Patients were 17 years old or younger and had Crohn's disease, ulcerative colitis, or IBD-unclassified with 24,543.0 patient-years of follow-up. We estimated incidence rates for malignancy and HLH as events/1000 patient-years of follow-up. We calculated age-, sex-, and race-adjusted SIRs, with 95% confidence intervals (CIs), using the Surveillance, Epidemiology, and End Results Program (SEER) database. RESULTS: Thirteen of the 15 patients who developed a malignancy and all 5 of the patients who developed HLH had been exposed to thiopurines; 10 patients with malignancy had also been exposed to a biologic agent. Unadjusted incidence rates showed no increased risk of malignancy (0.46/1000 patient-years) or HLH (0.0/1000 patient-years) in patients exposed to IFX as the only biologic vs those unexposed to biologics (malignancy: 1.12/1000 patient-years; HLH: 0.56/1000 patient-years). SIRs did not demonstrate an increased risk of malignancy among patients exposed to IFX (SIR, 1.69; 95% CI, 0.46-4.32) vs patients not exposed to a biologic agent (SIR, 2.17; 95% CI, 0.59-5.56), even when patients were stratified by thiopurine exposure. CONCLUSIONS: In determination of age-, sex-, and race-adjusted SIRs using data from a large clinical study and the SEER database, we found that IFX exposure did not associate with increased risk of malignancy or HLH in pediatric patients with IBD. Thiopurine exposure is an important precedent event for the development of malignancy or HLH in pediatric patients with IBD.

Increases in Sex Hormones during Anti-Tumor Necrosis Factor α Therapy in Adolescents with Crohn's Disease.

OBJECTIVE: To evaluate children with Crohn's disease for inverse relationships between systemic inflammatory cytokines and sex hormone regulation in the context of anti-tumor necrosis factor α (TNF-α) therapy. STUDY DESIGN: An observational study design was used to assess sex hormone and gonadotropin levels at the time of initiation of anti-TNF-α therapy and 10 weeks and 12 months later in 72 adolescents (Tanner stage 2-5) with Crohn's disease. Mixed-model linear regression was used to evaluate relationships between hormone levels, systemic inflammation, and dual-energy x-ray absorptiometry whole-body fat mass Z scores over the study interval. RESULTS: Sex hormone Z scores increased significantly during the 10-week induction interval: testosterone Z scores in male patients increased from a median of -0.36 to 0.40 (P < .05) and estradiol Z scores in females increased from -0.35 to -0.02 (P < .01). In mixed model regression, the pediatric Crohn's disease activity index score, cytokine levels, and measures of inflammation were significantly and negatively associated with sex hormone Z scores and with luteinizing hormone and follicle-stimulating hormone levels, adjusted for sex and Tanner stage. Sex hormone and gonadotropin levels were not associated with body mass index or fat mass Z-scores. CONCLUSIONS: Crohn's disease is associated with delayed maturation, and initiation of anti-TNF-α therapy was associated with significant and rapid increases in sex hormone and gonadotropin levels, in association with improvements in disease activity and measures of inflammation. These data are consistent with preclinical studies of the effects of inflammation on sex hormone regulation.

Determination and Confirmation of Recommended Ph2 Dose of Amivantamab in Epidermal Growth Factor Receptor Exon 20 Insertion Non-Small Cell Lung Cancer.

Amivantamab has demonstrated durable responses with a tolerable safety profile in non-small cell lung cancer with EGFR exon 20 insertions (Ex20ins) who progressed after prior platinum chemotherapy. Data supporting the amivantamab recommended phase II dose (RP2D) in this patient population are presented. Pharmacokinetic (PK) analysis and population PK (PopPK) modeling were conducted using serum concentration data obtained following amivantamab intravenous administration (140-1,750 mg). Pharmacodynamics (PDs) were evaluated using depletion of soluble EGFR and MET. Exposure-response (E-R) analyses were performed using the primary efficacy end point of objective response rate in patients with EGFR Ex20ins. The E-R relationship for safety was explored for adverse events of clinical interest. Amivantamab exhibited linear PKs at 350-1,750 mg dose levels following administration, with no maximum tolerated dose identified. A two-compartment PopPK model with linear clearance adequately described the observed PKs. Body weight was a covariate of clearance and volume of distribution in the central compartment. PopPK modeling showed that a weight-based, 2-tier (< 80 and ≥ 80 kg) dosing strategy reduces PK variability and provides comparable exposure across 2 weight groups, with 87% of patients achieving exposures above the target threshold. The final confirmed RP2D of amivantamab was 1,050 mg for < 80 kg (1,400 mg for ≥ 80 kg) weekly in cycle 1 (28 days) and every 2 weeks thereafter. No significant exposure-efficacy or safety correlation was observed. In conclusion, the amivantamab RP2D is supported by PK, PD, safety, and efficacy analyses. E-R analyses confirmed that the current regimen provides durable efficacy with tolerable safety.

Management of infusion-related reactions (IRRs) in patients receiving amivantamab in the CHRYSALIS study.

BACKGROUND: Amivantamab, a fully humanized EGFR-MET bispecific antibody, has antitumor activity in diverse EGFR- and MET-driven non-small cell lung cancer (NSCLC) and a safety profile consistent with associated on-target activities. Infusion-related reaction(s) (IRR[s]) are reported commonly with amivantamab. We review IRR and subsequent management in amivantamab-treated patients. METHODS: Patients treated with the approved dose of intravenous amivantamab (1050 mg, <80 kg; 1400 mg, ≥80 kg) in CHRYSALIS-an ongoing, phase 1 study in advanced EGFR-mutated NSCLC-were included in this analysis. IRR mitigations included split first dose (350 mg, day 1 [D1]; remainder, D2), reduced initial infusion rates with proactive infusion interruption, and steroid premedication before initial dose. For all doses, pre-infusion antihistamines and antipyretics were required. Steroids were optional after the initial dose. RESULTS: As of 3/30/2021, 380 patients received amivantamab. IRRs were reported in 256 (67%) patients. Signs/symptoms of IRR included chills, dyspnea, flushing, nausea, chest discomfort, and vomiting. Most of the 279 IRRs were grade 1 or 2; grade 3 and 4 IRR occurred in 7 and 1 patients, respectively. Most (90%) IRRs occurred on cycle 1, D1 (C1D1); median time-to-first-IRR onset during C1D1 was 60 min; and first-infusion IRRs did not compromise subsequent infusions. Per protocol, IRR was mitigated on C1D1 with holding of infusion (56% [214/380]), reinitiating at reduced rate (53% [202/380]), and aborting infusion (14% [53/380]). C1D2 infusions were completed in 85% (45/53) of patients who had C1D1 infusions aborted. Four patients (1% [4/380]) discontinued treatment due to IRR. In studies aimed at elucidating the underlying mechanism(s) of IRR, no pattern was observed between patients with versus without IRR. CONCLUSION: IRRs with amivantamab were predominantly low grade and limited to first infusion, and rarely occurred with subsequent dosing. Close monitoring for IRR with the initial amivantamab dose and early intervention at first IRR signs/symptoms should be part of routine amivantamab administration.

Amivantamab plus lazertinib in osimertinib-relapsed EGFR-mutant advanced non-small cell lung cancer: a phase 1 trial.

Patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) often develop resistance to current standard third-generation EGFR tyrosine kinase inhibitors (TKIs); no targeted treatments are approved in the osimertinib-relapsed setting. In this open-label, dose-escalation and dose-expansion phase 1 trial, the potential for improved anti-tumor activity by combining amivantamab, an EGFR-MET bispecific antibody, with lazertinib, a third-generation EGFR TKI, was evaluated in patients with EGFR-mutant NSCLC whose disease progressed on third-generation TKI monotherapy but were chemotherapy naive (CHRYSALIS cohort E). In the dose-escalation phase, the recommended phase 2 combination dose was established; in the dose-expansion phase, the primary endpoints were safety and overall response rate, and key secondary endpoints included progression-free survival and overall survival. The safety profile of amivantamab and lazertinib was generally consistent with previous experience of each agent alone, with 4% experiencing grade ≥3 events; no new safety signals were identified. In an exploratory cohort of 45 patients who were enrolled without biomarker selection, the primary endpoint of investigator-assessed overall response rate was 36% (95% confidence interval, 22-51). The median duration of response was 9.6 months, and the median progression-free survival was 4.9 months. Next-generation sequencing and immunohistochemistry analyses identified high EGFR and/or MET expression as potential predictive biomarkers of response, which will need to be validated with prospective assessment. ClinicalTrials.gov identifier: NCT02609776 .

Body composition abnormalities in long-term survivors of pediatric hematopoietic stem cell transplantation.

OBJECTIVE: To quantify lean mass (LM) and fat mass (FM) in survivors of childhood allogeneic hematopoietic stem-cell transplantation (alloHSCT) compared with healthy reference participants and identify risk factors for body composition abnormalities. STUDY DESIGN: Whole body LM and FM were measured with dual energy x-ray absorptiometry in 54 survivors (ages 5-25 years) and 894 healthy reference participants in a cross-sectional study. Multivariate regression models were used to compare sex- and race-specific Z-scores for LM for height (LM-Ht) and FM for height (FM-Ht) in survivors and reference participants and to identify correlates of LM-Ht and FM-Ht Z-scores in alloHSCT. RESULTS: Height Z-scores were significantly lower in alloHSCT survivors (P < .001) compared with reference participants; body mass index Z-scores did not differ (P = .13). Survivors had significantly lower mean LM-Ht Z-scores (-0.72; 95% CI, -1.02--0.42; P < .001) and greater FM-Ht Z-scores (1.10; 95% CI, 0.84-1.39; P < .001) compared with reference participants. LM-Ht Z-score deficits in alloHSCT survivors were larger (-1.26; 95% CI, -1.53--0.99; P < .001) after adjustment for FM-Ht Z-scores. Endocrinopathies and alloHSCT characteristics were not associated with LM-Ht or FM-Ht Z-scores. CONCLUSION: Survivors of childhood alloHSCT have significant LM deficits and FM excess. Future studies should identify the mechanism and consequences of these abnormalities.

Association of chronic kidney disease with muscle deficits in children.

The effect of chronic kidney disease (CKD) on muscle mass in children, independent of poor growth and delayed maturation, is not well understood. We sought to characterize whole body and regional lean mass (LM) and fat mass (FM) in children and adolescents with CKD and to identify correlates of LM deficits in CKD. We estimated LM and FM from dual energy x-ray absorptiometry scans in 143 children with CKD and 958 controls at two pediatric centers. We expressed whole body, trunk, and leg values of LM and FM as Z-scores relative to height, sitting height, and leg length, respectively, using the controls as the reference. We used multivariable regression models to compare Z-scores in CKD and controls, adjusted for age and maturation, and to identify correlates of LM Z-scores in CKD. Greater CKD severity associated with greater leg LM deficits. Compared with controls, leg LM Z-scores were similar in CKD stages 2 to 3 (difference: 0.02 [95% CI: -0.20, 0.24]; P = 0.8), but were lower in CKD stages 4 to 5 (-0.41 [-0.66, -0.15]; P = 0.002) and dialysis (-1.03 [-1.33, -0.74]; P < 0.0001). Among CKD participants, growth hormone therapy associated with greater leg LM Z-score (0.58 [0.03, 1.13]; P = 0.04), adjusted for CKD severity. Serum albumin, bicarbonate, and markers of inflammation did not associate with LM Z-scores. CKD associated with greater trunk LM and FM, variable whole body LM, and normal leg FM, compared with controls. In conclusion, advanced CKD associates with significant deficits in leg lean mass, indicating skeletal muscle wasting. These data call for prospective studies of interventions to improve muscle mass among children with CKD.

Determinants of changes in linear growth and body composition in incident pediatric Crohn's disease.

BACKGROUND & AIMS: Pediatric Crohn's disease (CD) is associated with growth, lean mass (LM), and fat mass (FM) deficits. This study assessed and identified determinants of changes in height and body composition in children with CD following. METHODS: Whole-body LM and FM were assessed using dual-energy x-ray absorptiometry in 78 CD subjects at diagnosis, 6, 12, and a median of 43 months (range, 24-63) later. Race- and sex-specific Z scores for lean mass (LM-ht-Z) and fat mass (FM-ht-Z) relative to height were derived using reference data in >900 controls. Serum cytokines and growth factors were measured, and quasi-least squares regression was used to identify determinants of changes in height and body composition. RESULTS: LM-ht-Z and FM-ht-Z (both P<.005) improved significantly after diagnosis; however, female patients had persistent LM deficits vs controls (-0.50+/-1.02, P<.05). Serum interleukin-6, tumor necrosis factor-alpha, and lipopolysaccharide binding protein decreased significantly (all P<.001). Greater increases in LM-ht-Z were associated with infliximab therapy (P<.05), increases in albumin (P<.001) and decreases in erythrocyte sedimentation rate (P<.05), interleukin-6 (P<.005), and lipopolysaccharide binding protein (P<.05). Greater increases in FM-ht-Z were associated with glucocorticoid, methotrexate, and infliximab therapy, and increases in albumin (P<.05) and growth hormone binding protein (P<.05). Overall, height-Z did not improve; however, greater increases in insulin-like growth factor-1 (P<.05) and decreases in tumor necrosis factor-alpha (P<.05), interleukin-6 (P<.05), and lipopolysaccharide binding protein (P<.05) levels were associated with increases in height-Z. CONCLUSIONS: Immune-mediated mechanisms contribute to growth and body composition deficits in CD. Therapies should target these deficits.

Skeletal health of children and adolescents with inflammatory bowel disease.

Current evidence points to suboptimal bone health in children and adolescents with inflammatory bowel disease (IBD) when compared with their healthy peers. This compromise is evident from diagnosis. The clinical consequences and long-term outcome of this finding are still unknown. The mechanism of suboptimal bone health in children and adolescents with IBD lays mainly in reduced bone formation, but also reduced bone resorption, processes necessary for bone growth. Factors contributing to this derangement are inflammation, delayed growth and puberty, lean mass deficits, and use of glucocorticoids. We recognize that evidence is sparse on the topic of bone health in children and adolescents with IBD. In this clinical guideline, based on current evidence, we provide recommendations on screening and monitoring bone health in children and adolescents with IBD, including modalities to achieve this and their limitations; monitoring of parameters of growth, pubertal development, and reasons for concern; evaluation of vitamin D status and vitamin D and calcium intake; exercise; and nutritional support. We also report on the current evidence of the effect of biologics on bone health in children and adolescents with IBD, as well as the role of bone active medications such as bisphosphonates. Finally, we summarize the existing numerous gaps in knowledge and potential subjects for future research endeavors.

Circulating microRNA is a biomarker of pediatric Crohn disease.

OBJECTIVE: The gold standard for the diagnosis and evaluation of Crohn disease (CD) is endoscopy/colonoscopy, although this is invasive, costly, and associated with risks to the patient. Recently, circulating microRNAs (miRNAs) have emerged as promising noninvasive biomarkers. Here, we examined the utility of serum miRNAs as biomarkers of CD in children. PATIENTS AND METHODS: Studies were conducted using sera samples from patients with pediatric CD, healthy controls, and a comparison group of patients with pediatric celiac disease. Serum miRNA levels were explored initially using a microfluidic quantitative reverse transcription-polymerase chain reaction array platform. Findings were subsequently validated using quantitative reverse transcription-polymerase chain reaction in larger validation sample sets. The diagnostic utility of CD-associated serum miRNA was examined using receiver operating characteristic analysis. RESULTS: A survey of miRNA levels in the sera of control and patients with CD detected significant elevation of 24 miRNAs, 11 of which were chosen for further validation. All of the candidate biomarker miRNAs were confirmed in an independent CD sample set (n = 46). To explore the specificity of the CD-associated miRNAs, they were measured in the sera of patients with celiac disease (n = 12); none were changed compared with healthy controls. Receiver operating characteristic analyses revealed that serum miRNAs have promising diagnostic utility, with sensitivities for CD above 80%. Significant decreases in serum miRNAs were observed in 24 incident patients with pediatric CD after 6 months of treatment. CONCLUSIONS: The present study identifies 11 CD-associated serum miRNA with encouraging diagnostic potential. Our findings suggest serum miRNAs may prove useful as noninvasive biomarkers in CD.

Daratumumab Plus Atezolizumab in Previously Treated Advanced or Metastatic NSCLC: Brief Report on a Randomized, Open-Label, Phase 1b/2 Study (LUC2001 JNJ-54767414).

INTRODUCTION: The programmed death-ligand 1 inhibitor atezolizumab improves progression-free survival (PFS) and overall survival (OS) for patients with previously treated advanced NSCLC. Preclinical studies indicate that targeting CD38-positive cells with daratumumab may synergistically enhance atezolizumab's antitumor activity by increasing the effector T-cell activity. METHODS: This phase 1b-2 study included a safety run-in (one cycle of daratumumab plus atezolizumab) and randomized phases (daratumumab plus atezolizumab versus atezolizumab alone). The primary objective of the randomized phase was to compare overall response rates. The secondary objectives included evaluations of safety, clinical benefit rate (stable disease or better), PFS, OS, and pharmacokinetics. RESULTS: In total, 99 patients were enrolled (safety run-in, n = 7; randomized, n = 46 per arm). In the randomized phase, the overall response rate was 4.3% for daratumumab plus atezolizumab and 13.0% for atezolizumab alone (OR: 0.30; 95% confidence interval: 0.03-1.92). The respective clinical benefit rates were 52.2% and 43.5%. No improvements were observed in the median PFS or median OS for combination therapy. The study was terminated because of the limited efficacy of daratumumab plus atezolizumab. CONCLUSIONS: Daratumumab plus atezolizumab therapy did not improve efficacy versus atezolizumab monotherapy for patients with previously treated advanced NSCLC.

Amivantamab in EGFR Exon 20 Insertion-Mutated Non-Small-Cell Lung Cancer Progressing on Platinum Chemotherapy: Initial Results From the CHRYSALIS Phase I Study.

PURPOSE: Non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertion (Exon20ins) mutations exhibits inherent resistance to approved tyrosine kinase inhibitors. Amivantamab, an EGFR-MET bispecific antibody with immune cell-directing activity, binds to each receptor's extracellular domain, bypassing resistance at the tyrosine kinase inhibitor binding site. METHODS: CHRYSALIS is a phase I, open-label, dose-escalation, and dose-expansion study, which included a population with EGFR Exon20ins NSCLC. The primary end points were dose-limiting toxicity and overall response rate. We report findings from the postplatinum EGFR Exon20ins NSCLC population treated at the recommended phase II dose of 1,050 mg amivantamab (1,400 mg, ≥ 80 kg) given once weekly for the first 4 weeks and then once every 2 weeks starting at week 5. RESULTS: In the efficacy population (n = 81), the median age was 62 years (range, 42-84 years); 40 patients (49%) were Asian, and the median number of previous lines of therapy was two (range, 1-7). The overall response rate was 40% (95% CI, 29 to 51), including three complete responses, with a median duration of response of 11.1 months (95% CI, 6.9 to not reached). The median progression-free survival was 8.3 months (95% CI, 6.5 to 10.9). In the safety population (n = 114), the most common adverse events were rash in 98 patients (86%), infusion-related reactions in 75 (66%), and paronychia in 51 (45%). The most common grade 3-4 adverse events were hypokalemia in six patients (5%) and rash, pulmonary embolism, diarrhea, and neutropenia in four (4%) each. Treatment-related dose reductions and discontinuations were reported in 13% and 4% of patients, respectively. CONCLUSION: Amivantamab, via its novel mechanism of action, yielded robust and durable responses with tolerable safety in patients with EGFR Exon20ins mutations after progression on platinum-based chemotherapy.

Longitudinal assessment of bone density and structure in an incident cohort of children with Crohn's disease.

BACKGROUND & AIMS: The impact of childhood Crohn's disease (CD) on volumetric bone mineral density (vBMD), bone structure, and muscle mass have not been established. The objective of this longitudinal study was to assess musculoskeletal outcomes in an incident cohort of children with CD using peripheral quantitative computed tomography (pQCT). METHODS: Tibia pQCT was performed in 78 CD subjects (ages, 5-18 years) at diagnosis and in 67 over the subsequent year. pQCT outcomes were converted to sex- and race-specific z scores based on reference data in over 650 controls. Multivariable linear regression models identified factors associated with changes in bone outcomes. RESULTS: At diagnosis, CD subjects had significant deficits in trabecular vBMD (z score, -1.32+/-1.32; P< .001), cortical section modulus (a measure of bone geometry and strength) (z score, -0.44+/-1.11; P< .01), and muscle (z score, -0.96+/-1.02; P< .001) compared with controls. Over the first 6 months, trabecular vBMD and muscle z scores improved significantly (both, P< .001); however, section modulus worsened (P= .0001), and all 3 parameters remained low after 1 year. Increases in muscle z scores were associated with less severe declines in cortical section modulus z scores. Improvements in trabecular vBMD z scores were greater in prepubertal subjects. Glucocorticoids were associated with increases in cortical vBMD. CONCLUSIONS: Substantial deficits in trabecular vBMD, cortical bone geometry, and muscle were observed at CD diagnosis. Trabecular vBMD improved incompletely; however, cortical deficits progressed despite improvements in muscle. Glucocorticoids were not associated with bone loss. Therapies to improve bone accrual in childhood CD are needed.

Antitumor Activity of Amivantamab (JNJ-61186372), an EGFR-MET Bispecific Antibody, in Diverse Models of EGFR Exon 20 Insertion-Driven NSCLC.

EGFR exon 20 insertion driver mutations (Exon20ins) in non-small cell lung cancer (NSCLC) are insensitive to EGFR tyrosine kinase inhibitors (TKI). Amivantamab (JNJ-61186372), a bispecific antibody targeting EGFR-MET, has shown preclinical activity in TKI-sensitive EGFR-mutated NSCLC models and in an ongoing first-in-human study in patients with advanced NSCLC. However, the activity of amivantamab in Exon20ins-driven tumors has not yet been described. Ba/F3 cells and patient-derived cells/organoids/xenograft models harboring diverse Exon20ins were used to characterize the antitumor mechanism of amivantamab. Amivantamab inhibited proliferation by effectively downmodulating EGFR-MET levels and inducing immune-directed antitumor activity with increased IFNγ secretion in various models. Importantly, in vivo efficacy of amivantamab was superior to cetuximab or poziotinib, an experimental Exon20ins-targeted TKI. Amivantamab produced robust tumor responses in two Exon20ins patients, highlighting the important translational nature of this preclinical work. These findings provide mechanistic insight into the activity of amivantamab and support its continued clinical development in Exon20ins patients, an area of high unmet medical need. SIGNIFICANCE: Currently, there are no approved targeted therapies for EGFR Exon20ins-driven NSCLC. Preclinical data shown here, together with promising clinical activity in an ongoing phase I study, strongly support further clinical investigation of amivantamab in EGFR Exon20ins-driven NSCLC.This article is highlighted in the In This Issue feature, p. 1079.

Improvement in biomarkers of bone formation during infliximab therapy in pediatric Crohn's disease: results of the REACH study.

BACKGROUND & AIMS: Crohn's disease (CD) is associated with altered bone metabolism. This study examined changes in bone formation and resorption after infliximab induction and associations between bone biomarkers, linear growth, and disease activity (Pediatric Crohn's Disease Activity Index [PCDAI]) after 54 weeks of infliximab therapy. METHODS: One hundred twelve subjects ages 6-17 years with moderate to severe CD received infliximab induction (5 mg/kg/dose) at weeks 0, 2, and 6; week-10 responders were randomized to infliximab every 8 or every 12 weeks maintenance therapy. Serum bone-specific alkaline phosphatase (BSAP), N-terminal propeptide of type 1 collagen (P1NP), urine C-telopeptide of collagen cross-links (CTX-1), and deoxypyrodinoline (DPD) were collected at baseline and 10 weeks. PCDAI and height z-scores were assessed at baseline and at 10 and 54 weeks. RESULTS: Models were adjusted for bone age, gender, height, and steroid use. Baseline BSAP and P1NP levels were negatively associated with PCDAI (both P = .01). BSAP and P1NP increased during induction (both P < .001) and were associated with 54-week increases in height z-score (P < .05 and P < .001, respectively). Improvements in P1NP were associated with 54-week decreases in PCDAI (P = .01). CTX-1 and DPD also increased during induction (P < .001 and P = .01, respectively) but were not associated with changes in PCDAI. Changes in CTX-1 were associated with improvements in height z-score (P < .002). CONCLUSIONS: Infliximab therapy is associated with dramatic increases in BSAP and P1NP, consistent with inhibition of tumor necrosis factor-alpha effects on osteoblasts. The increases in CTX-1 and DPD likely reflect coupling of bone formation and resorption and increases in linear growth.

Interpretation of biomarkers of bone metabolism in children: impact of growth velocity and body size in healthy children and chronic disease.

OBJECTIVES: To determine the effects of growth, maturation, and whole body bone mineral content (WB-BMC) accrual on biomarkers of bone formation (bone-specific alkaline phosphatase [BSAP]) and resorption (urine deoxypyridinoline/creatinine [DPD]) in healthy children and children with Crohn's disease. STUDY DESIGN: BSAP and DPD were measured at baseline, with growth and dual energy x-ray absorptiometry (DXA) WB-BMC measured at baseline and 6 months in 202 control subjects and 110 subjects with Crohn's disease, ages 5 to 21 years. Multivariable linear regression identified determinants of biomarkers in control subjects and subjects with Crohn's disease. RESULTS: In control subjects, BSAP and DPD were significantly and independently associated with sex, Tanner stage, WB-BMC, height velocity, and WB-BMC accrual rates; these covariates explained 77% to 80% of the variability in the bone biomarkers, respectively. Subjects with Crohn's disease had lower height-for-age (P < .001) and WB-BMC-for-height (P <.05) than control subjects. Crohn's disease was associated with lower BSAP (P < .001) and greater DPD (P < .001), independent of growth, maturation, baseline WB-BMC, and WB-BMC accrual, compared with control subjects. CONCLUSIONS: These data illustrate the potential confounding effects of growth and WB-BMC on bone metabolism biomarkers in children. After adjustment for these effects, Crohn's disease was associated with lower biomarkers of bone formation and greater bone resorption.

Increases in IGF-1 After Anti-TNF-α Therapy Are Associated With Bone and Muscle Accrual in Pediatric Crohn Disease.

Context: Low levels of insulinlike growth factor 1 (IGF-1) in pediatric and adolescent Crohn disease (CD) likely contribute to bone and muscle deficits. Objective: Assess changes in IGF-1 levels and associations with bone and muscle accrual following initiation of anti-tumor necrosis factor α (TNF-α) therapy in pediatric and adolescent CD. Design and Participants: Participants (n = 75, age 5 to 21 years) with CD were enrolled in a prospective cohort study; 63 completed the 12-month visit. Main Outcome Measures: IGF-1 levels at baseline and 10 weeks, as well as dual-energy x-ray absorptiometry (DXA) and tibia peripheral quantitative computed tomography (pQCT) measures of bone and muscle at baseline and 12 months after initiation of anti-TNF-α therapy. Outcomes were expressed as sex-specific z scores. Results: IGF-1 z scores increased from a median (interquartile range) of -1.0 (-1.58 to -0.17) to -0.36 (-1.04 to 0.36) over 10 weeks (P < 0.001). Lesser disease severity and systemic inflammation, as well as greater estradiol z scores (in girls), was significantly associated with greater IGF-1 z scores over time. DXA whole-body bone mineral content, leg lean mass, and total hip and femoral neck bone mineral density (BMD) z scores were low at baseline (P < 0.0001 vs reference data) and increased significantly (P < 0.001) over 12 months. Greater increases in IGF-1 z scores over 10 weeks predicted improvement in DXA bone and muscle outcomes and pQCT trabecular BMD and cortical area. Adjustment for changes in muscle mass markedly attenuated the associations between IGF-1 levels and bone outcomes. Conclusions: Short-term improvements in IGF-1 z scores predicted recovery of bone and muscle outcomes following initiation of anti-TNF-α therapy in pediatric CD. These data suggest that disease effects on growth hormone metabolism contribute to musculoskeletal deficits in CD.

Gender differences in body composition deficits at diagnosis in children and adolescents with Crohn's disease.

BACKGROUND: Childhood Crohn's disease (CD) is associated with poor growth and decreased body mass index (BMI); however, lean mass (LM) and fat mass (FM) deficits prior to therapy have not been characterized. OBJECTIVES: To quantify LM and FM in incident pediatric CD subjects and controls, and to identify determinants of LM and FM deficits. METHODS: Whole body LM and FM were assessed using DXA in 78 CD subjects and 669 healthy controls, ages 5-21 yr. Gender specific z-scores for LM (LM-Ht) and FM (FM-Ht) relative to height were derived using log linear regression models in the controls. Multivariate linear regression models adjusted for potential confounders. RESULTS: CD was associated with significantly lower height and BMI for age. Within CD subjects, FM-Ht and LM-Ht were significantly lower in females compared with males (FM-Ht z: -0.66+/-0.83 vs. -0.08+/-0.95, p<0.01; LM-Ht z: -1.12+/-1.12 vs. -0.57+/-0.99, p<0.05). In females, CD was associated with significantly lower LM-Ht (p<0.001) and FM-Ht (p=0.001), adjusted for age, race and Tanner stage, compared with controls. LM and FM deficits were significantly greater in older females with CD; 47% of adolescent females had LM-Ht

Serum Infliximab, Antidrug Antibodies, and Tumor Necrosis Factor Predict Sustained Response in Pediatric Crohn's Disease.

BACKGROUND: Serum infliximab (s-IFX) levels, antibodies to IFX (ATI), and inflammatory markers are important in predicting clinical outcomes in adults, but their roles in pediatric Crohn's disease (CD) require further study. The primary aim of this study was to determine the association between serologic parameters during induction and ongoing IFX therapy at 12 months in pediatric CD. METHODS: S-IFX, ATI, serum tumor necrosis factor alpha (s-TNF-α), and C-reactive protein were measured at IFX initiation, 10 weeks, 6 months, and 12 months in a prospective cohort study of children with CD at a single tertiary care center. RESULTS: At 12 months, 60 of 77 participants (78%) remained on IFX. Participants who completed 12 months of IFX had higher 10-week median s-IFX levels (20.40 µg/mL; interquartile range [IQR], 11.20-35.00] versus 8.70 µg/mL; IQR 0.90-16.90; P = 0.01), a greater proportion with undetectable 10-week ATI (P = 0.008), and a greater median change in s-TNF-α between baseline and week 10 (-5.96 pg/mL; IQR, -8.73 to -4.17 versus -1.76 pg/mL; IQR, -5.60 to 0.30; P = 0.006). Receiver operating characteristic analysis to predict ongoing IFX at 12 months showed area under the curve (95% confidence interval) for 10-week s-IFX and change in s-TNF-α from baseline to 10 weeks to be 0.71 (0.54-0.88) and 0.74 (0.58-0.91), respectively. C-reactive protein was not associated with ongoing therapy. CONCLUSIONS: ATI, s-IFX, and s-TNF-α during IFX induction are associated with 12-month clinical outcomes in pediatric CD. Future studies are needed to further define the clinical role of s-TNF-α measurement and to compare the clinical utility of 10 and 14-week ATI and s-IFX levels.

Improvements in Bone Density and Structure during Anti-TNF-α Therapy in Pediatric Crohn's Disease.

CONTEXT: Pediatric Crohn's Disease (CD) is associated with deficits in trabecular bone mineral density (BMD) and cortical structure, potentially related to TNF-α effects to decrease bone formation and promote bone resorption. OBJECTIVE: This study aimed to examine changes in bone density and structure in children and adolescents with CD following initiation of anti-TNF-α therapy. DESIGN AND PARTICIPANTS: Participants (n = 74; age 5-21 years) with CD completed a 12-month prospective cohort study. MAIN OUTCOME MEASURES: Tibia peripheral quantitative computed tomography scans were obtained at initiation of anti-TNF-α therapy and 12 months later. Musculoskeletal outcomes were expressed as sex-and race-specific z scores relative to age, based on >650 reference participants. RESULTS: At baseline, CD participants had lower height, trabecular BMD, cortical area (due to smaller periosteal and larger endocortical circumferences), and muscle area z scores, compared with reference participants (all P < .01). Pediatric CD activity index decreased during the 10-week induction (P < .001), in association with subsequent gains in height, trabecular BMD, cortical area (due to recovery of endocortical bone), and muscle area z scores over 12 months (height P < .05; others P < .001). Bone-specific alkaline phosphatase levels, a biomarker of bone formation, increased a median of 75% (P < .001) during induction with associated 12-month improvements in trabecular BMD and cortical area z scores (both P < .001). Younger age was associated with greater increases in trabecular BMD z scores (P < .001) and greater linear growth with greater recovery of cortical area (P < .001). CONCLUSIONS: Anti-TNF-α therapy was associated with improvements in trabecular BMD and cortical structure. Improvements were greater in younger and growing participants, suggesting a window of opportunity for treatment of bone deficits.