High-dose individualized antithymocyte globulin with therapeutic drug monitoring in high-risk cord blood transplant

BACKGROUND

Graft-versus-host disease (GvHD) and rejection are main limitations of cord blood transplantation (CBT), more so in patients with severe inflammation or previous rejections. While rigorous T-cell depletion with antithymocyte globulin (ATG) is needed to prevent GvHD and rejection, overexposure to ATG leads to slow T-cell recovery after transplantation, especially in CBT.

OBJECTIVE

To evaluate high-dose, upfront ATG with individualized dosing and therapeutic drug monitoring (TDM) in pediatric CBT for patients at high risk for GvHD and rejection.

STUDY DESIGN

Heavily inflamed patients and patients with a recent history of rejection were eligible for individualized high-dose ATG with real-time TDM. The ATG dosing scheme was adjusted to target a post-CBT exposure of <10 AU*day/mL, while achieving a pre-CBT exposure of 60-120 AU*day/mL; exposure levels previously defined for optimal efficacy and safety in terms of reduced GvHD and rejection, respectively. Main outcomes of interest included efficacy (target exposure attainment) and safety (incidence of GvHD and rejection). Other outcomes of interest included T-cell recovery and survival.

RESULTS

Twenty-one patients were included ranging from 2 months to 18 years old, receiving an actual median cumulative dose of ATG of 13.3 mg/kg (range 6-30 mg/kg) starting at a median 15 days (range 12-17) prior to CBT. Dosing was adjusted in 14 patients (increased in 3 and decreased in 11 patients). Eighteen (86%) and 19 (91%) patients reached the target pre-CBT and post-CBT exposure, respectively. Cumulative incidence for acute GvHD was 34% (95% CI 23-45) and 5% (95% CI 0-10%) for grade 2-4 and grade 3-4, respectively; cumulative incidence of rejection was 9% (95% CI 2-16%). Overall survival was 75% (95% CI 65-85%).

CONCLUSION

Individualized high-dose ATG with TDM is feasible and safe for patients with hyperinflammation in a CBT setting. We observe high target ATG exposure attainment, good immune reconstitution (despite very high doses of ATG) and acceptable rates of GvHD and rejection.

Frailty and sarcopenia within the earliest national Dutch childhood cancer survivor cohort (DCCSS-LATER): a cross-sectional study

BACKGROUND

Childhood cancer survivors appear to be at increased risk of frailty and sarcopenia, but evidence on the occurrence of and high-risk groups for these aging phenotypes is scarce, especially in European survivors. The aim of this cross-sectional study was to assess the prevalence of and explore risk factors for pre-frailty, frailty, and sarcopenia in a national cohort of Dutch childhood cancer survivors diagnosed between 1963 and 2001.

METHODS

Eligible individuals (alive at the time of study, living in the Netherlands, age 18-45 years, and had not previously declined to participate in a late-effects study) from the Dutch Childhood Cancer Survivor Study (DCCSS-LATER) cohort were invited to take part in this cross-sectional study. We defined pre-frailty and frailty according to modified Fried criteria, and sarcopenia according to the European Working Group on Sarcopenia in Older People 2 definition. Associations between these conditions and demographic and treatment-related as well as endocrine and lifestyle-related factors were estimated with two separate multivariable logistic regression models in survivors with any frailty measurement or complete sarcopenia measurements.

FINDINGS

3996 adult survivors of the DCCSS-LATER cohort were invited to participate in this cross-sectional study. 1993 non-participants were excluded due to lack of response or a decline to participate and 2003 (50·1%) childhood cancer survivors aged 18-45 years were included. 1114 (55·6%) participants had complete frailty measurements and 1472 (73·5%) participants had complete sarcopenia measurements. Mean age at participation was 33·1 years (SD  7·2). 1037 (51·8%) participants were male, 966 (48·2%) were female, and none were transgender. In survivors with complete frailty measurements or complete sarcopenia measurements, the percentage of pre-frailty was 20·3% (95% CI 18·0-22·7), frailty was 7·4% (6·0-9·0), and sarcopenia was 4·4% (3·5-5·6). In the models for pre-frailty, underweight (odds ratio [OR] 3·38 [95% CI 1·92-5·95]) and obesity (OR 1·67 [1·14-2·43]), cranial irradiation (OR 2·07 [1·47-2·93]), total body irradiation (OR 3·17 [1·77-5·70]), cisplatin dose of at least 600 mg/m² (OR 3·75 [1·82-7·74]), growth hormone deficiency (OR 2·25 [1·23-4·09]), hyperthyroidism (OR 3·72 [1·63-8·47]), bone mineral density (Z score ≤-1 and >-2, OR 1·80 [95% CI 1·31-2·47]; Z score ≤-2, OR 3·37 [2·20-5·15]), and folic acid deficiency (OR 1·87 [1·31-2·68]) were considered significant. For frailty, associated factors included age at diagnosis between 10-18 years (OR 1·94 [95% CI 1·19-3·16]), underweight (OR 3·09 [1·42-6·69]), cranial irradiation (OR 2·65 [1·59-4·34]), total body irradiation (OR 3·28 [1·48-7·28]), cisplatin dose of at least 600 mg/m² (OR 3·93 [1·45-10·67]), higher carboplatin doses (per g/m²; OR 1·15 [1·02-1·31]), cyclophosphamide equivalent dose of at least 20 g/m² (OR 3·90 [1·65-9·24]), hyperthyroidism (OR 2·87 [1·06-7·76]), bone mineral density Z score ≤-2 (OR 2·85 [1·54-5·29]), and folic acid deficiency (OR 2·04 [1·20-3·46]). Male sex (OR 4·56 [95%CI 2·26-9·17]), lower BMI (continuous, OR 0·52 [0·45-0·60]), cranial irradiation (OR 3·87 [1·80-8·31]), total body irradiation (OR 4·52 [1·67-12·20]), hypogonadism (OR 3·96 [1·40-11·18]), growth hormone deficiency (OR 4·66 [1·44-15·15]), and vitamin B12 deficiency (OR 6·26 [2·17-1·81]) were significantly associated with sarcopenia.

INTERPRETATION

Our findings show that frailty and sarcopenia occur already at a mean age of 33 years in childhood cancer survivors. Early recognition and interventions for endocrine disorders and dietary deficiencies could be important in minimising the risk of pre-frailty, frailty, and sarcopenia in this population.

FUNDING

Children Cancer-free Foundation, KiKaRoW, Dutch Cancer Society, ODAS Foundation.

Risk and determinants of low and very low bone mineral density and fractures in a national cohort of Dutch adult childhood cancer survivors (DCCSS-LATER): a cross-sectional study

BACKGROUND

Childhood cancer survivors are at risk of developing skeletal comorbidities later in life. We aimed to assess risk factors for low and very low bone mineral density (BMD), and the risk of and risk factors for any fractures and vertebral fractures in a national cohort of Dutch adult childhood cancer survivors.

METHODS

In this cross-sectional study, we used data from the DCCSS LATER cohort, which comprised individuals who were alive for at least 5 years after diagnosis of childhood cancer (ie, histologically confirmed malignancies or Langerhans cell histiocytosis), were diagnosed before the age of 19 years, and who had been treated at one of seven Dutch paediatric oncology centres between 1963 and 2002 (hereafter referred to as survivors). For this study, we invited survivors aged 18-45 years, who were alive as of Oct 10, 2016, living in the Netherlands, and who were deemed eligible by their treating physician to participate. We assessed BMD using dual-energy x-ray absorptiometry (DXA). Self-reported fractures that occurred at least 5 years after cancer diagnosis were assessed using available medical history and compared with population-level data from the Swedish national registry. We assessed vertebral fractures in a subset of participants using a vertebral fracture assessment. We assessed associations between the occurrence of low (Z-score of ≤-1) or very low (Z-score of ≤-2) BMD, fractures, and vertebral fractures and demographic, treatment-related, endocrine, and lifestyle-related factors using logistic regression analysis.

FINDINGS

Between April 29, 2016, and Jan 22, 2020, 3996 (64·8%) of 6165 individuals from the DCCSS LATER cohort were invited to participate, of whom 2003 (50·1%) were enrolled (mean age at participation was 33·1 years [SD 7·2], 966 [48·2%] were female, and 1037 [51·8%] were male [data on ethnicity and race were not available due to national policies]). 1548 (77·3%) had evaluable DXA scans for assessment of BMD, 1892 (94·5%) provided medical history of fractures, and 249 (12·4%) were assessed for vertebral fractures. 559 (36·1%) of 1548 had low BMD at any site, and 149 (9·6%) had very low BMD at any site. The standardised incidence ratio of any first fracture was 3·53 (95% CI 3·06-4·06) for male participants and 5·35 (4·46-6·52) for female participants. 33 (13·3%) of 249 participants had vertebral fractures. Male sex, underweight, high carboplatin dose, any dose of cranial radiotherapy, hypogonadism, hyperthyroidism, low physical activity, and severe vitamin D deficiency were associated with low BMD at any site and male sex, underweight, cranial radiotherapy, growth hormone deficiency, and severe vitamin D deficiency were associated with very low BMD at any site. Additionally, male sex, former and current smoking, and very low lumbar spine BMD were associated with any fractures, whereas older age at follow-up, previous treatment with platinum compounds, growth hormone deficiency, and low physical activity were specifically associated with vertebral fractures.

INTERPRETATION

Survivors of childhood cancer are at increased risk of any first fracture. Very low lumbar spine BMD was associated with fractures, highlighting the importance of active BMD surveillance in high-risk survivors (ie, those treated with cranial, craniospinal, or total body irradiation). Moreover, our results indicate that intensive surveillance and timely interventions for endocrine disorders and vitamin deficiencies might improve bone health in childhood cancer survivors, but this needs to be assessed in future studies.

FUNDING

Children Cancer-free Foundation (KiKa), KiKaRoW, and ODAS foundation.

Improved survival for children and young adolescents with acute myeloid leukemia: a Dutch study on incidence, survival and mortality

Variation in survival of pediatric acute myeloid leukemia (pAML) over time and between Western European countries exists. The aim of the current study is to assess the progress made for the Dutch pAML population (0-17 years) during 1990-2015, based on trends in incidence, survival and mortality. Data from the population-based Netherlands Cancer Registry were merged with leukemia-related characteristics and treatment specifics from the Dutch Childhood Leukemia Study Group (Dutch Childhood Oncology Group (DCOG) from 2002 onwards). Mortality data (1980-2016) were obtained from the cause of death registry of Statistics Netherlands. Trend analyses were performed over time and by treatment protocol. Between 1990 and 2015, a total of 635 children aged 0-17 years were diagnosed with AML for an average of 25 patients (range 18-36) per year. There was a slight increase in the incidence at age 1-4 years (average annual percentage change (AAPC) of +2.2% per year (95% CI 0.8-3.5, p < 0.01)). Overall, the 5-year survival significantly improved over the past 26 years and nearly doubled from 40% in the early 1990s to 74% in 2010-2015. Multivariable analysis showed a 49% reduction in risk of death for pAML patients treated according to the latest DB-AML 01 protocol (p = 0.03). The continuing decrease of mortality (AAPC -2.8% per year (95% CI -4.1 to -1.5)) supports the conclusion of true progress against pAML in the Netherlands.

Constitutional mismatch repair deficiency in a healthy child: On the spot diagnosis?

Constitutional mismatch repair deficiency (CMMRD) is a rare, recessively inherited childhood cancer predisposition syndrome caused by biallelic germline mutations in one of the mismatch repair genes. The CMMRD phenotype overlaps with that of neurofibromatosis type 1 (NF1), since many patients have multiple café-au-lait macules (CALM) and other NF1 signs, but no germline NF1 mutations. We report of a case of a healthy 6-year-old girl who fulfilled the diagnostic criteria of NF1 with >6 CALM and freckling. Since molecular genetic testing was unable to confirm the diagnosis of NF1 or Legius syndrome and the patient was a child of consanguineous parents, we suspected CMMRD and found a homozygous PMS2 mutation that impairs MMR function. Current guidelines advise testing for CMMRD only in cancer patients. However, this case illustrates that including CMMRD in the differential diagnosis in suspected sporadic NF1 without causative NF1 or SPRED1 mutations may facilitate identification of CMMRD prior to cancer development. We discuss the advantages and potential risks of this CMMRD testing scenario.

Iron refractory iron deficiency anemia: a heterogeneous disease that is not always iron refractory

TMPRSS6 variants that affect protein function result in impaired matriptase‐2 function and consequently uninhibited hepcidin production, leading to iron refractory iron deficiency anemia (IRIDA). This disease is characterized by microcytic, hypochromic anemia and serum hepcidin values that are inappropriately high for body iron levels. Much is still unknown about its pathophysiology, genotype–phenotype correlation, and optimal clinical management. We describe 14 different TMPRSS6 variants, of which 9 are novel, in 21 phenotypically affected IRIDA patients from 20 families living in the Netherlands; 16 out of 21 patients were female. In 7 out of 21 cases DNA sequencing and multiplex ligation dependent probe amplification demonstrated only heterozygous TMPRSS6 variants. The age at presentation, disease severity, and response to iron supplementation were highly variable, even for patients and relatives with similar TMPRSS6 genotypes. Mono‐allelic IRIDA patients had a milder phenotype with respect to hemoglobin and MCV and presented significantly later in life with anemia than bi‐allelic patients. Transferrin saturation (TSAT)/hepcidin ratios were lower in IRIDA probands than in healthy relatives. Most patients required parenteral iron. Genotype alone was not predictive for the response to oral iron. We conclude that IRIDA is a genotypically and phenotypically heterogeneous disease. The high proportion of female patients and the discrepancy between phenotypes of probands and relatives with the same genotype, suggest a complex interplay between genetic and acquired factors in the pathogenesis of IRIDA. In the absence of inflammation, the TSAT/hepcidin ratio is a promising diagnostic tool, even after iron supplementation has been given. Am. J. Hematol. 91:E482–E490, 2016. © 2016 Wiley Periodicals, Inc.

Sufficient Immunosuppression with Thymoglobulin Is Essential for a Successful Haplo-Myeloid Bridge in Haploidentical-Cord Blood Transplantation

In haploidentical (haplo)-cord blood (CB) transplantations, early haplo donor engraftment serves as a myeloid bridge to sustainable CB engraftment and is associated with early neutrophil recovery. The conditioning regimens as published for haplo-cord protocols usually contain serotherapy, such as rabbit antithymocyte globulin (ATG) (Thymoglobulin, Genzyme, Cambridge, MA). However, reducing or omitting serotherapy is an important strategy to improve early immune reconstitution after transplantation. The need for serotherapy in successful haplo-cord transplantation, defined as having a haplo-derived myeloid bridge to CB engraftment, has not been investigated before. Two consecutive cohorts of patients underwent transplantation with haplo-CB. The first group underwent transplantation with haplo-CB for active infection and/or an underlying condition with expected difficult engraftment without a conventional donor available. They received a single unit (s) CB and haplo donor cells (CD34(+) selected, 5 × 10(6) CD34(+)/kg). The second cohort included patients with poor-risk malignancies, not eligible for other treatment protocols. They received a sCB and haplo donor cells (CD19/αβTCR-depleted; 5 × 10(6) CD34(+)/kg). Retrospectively in both cohorts, active ATG (Thymoglobulin) levels were measured and post-hematopoietic cell transplantation area under the curve (AUC) was calculated. The influence of ATG exposure for having a successful haplo-myeloid bridge (early haplo donor engraftment before CB engraftment and no secondary neutropenia) and transplantation-related mortality (TRM) were analyzed as primary endpoints. Twenty patients were included (16 in the first cohort and 4 in the second cohort). In 58% of evaluable patients, there was no successful haplo-derived myeloid bridge to CB engraftment, for which a low post-transplantation ATG exposure appeared to be a predictor (P <.001). TRM in the unsuccessful haplo-bridge group was 70% ± 16% versus 12% ± 12% in the successful haplo-bridge group (P = .012). In conclusion, sufficient in vivo T depletion with ATG is required for a successful haplo-myeloid bridge to CB engraftment.