| 1. |
- Dreisig, Karin, et al.
(författare)
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TPMT polymorphisms and minimal residual disease after 6-mercaptopurine post-remission consolidation therapy of childhood acute lymphoblastic leukaemia
- 2021
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Ingår i: Pediatric Hematology and Oncology. - : Informa UK Limited. - 0888-0018 .- 1521-0669. ; 38:3, s. 227-238
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Tidskriftsartikel (refereegranskat)abstract
- © 2020 Taylor & Francis Group, LLC. Bone marrow minimal residual disease (MRD) is the strongest predictor of relapse in children with acute lymphoblastic leukemia (ALL). 6-mercaptopurine (6MP) in ALL therapy has wide inter-individual variation in disposition and is strongly influenced by polymorphisms in the thiopurine methyltransferase (TPMT) gene. In 952 patients treated according to the NOPHO ALL2008 protocol, we explored the association between thiopurine disposition, TPMT genotypes and MRD levels after consolidation therapy with 6MP, high-dose methotrexate (HD-MTX), asparaginase, and vincristine. The levels of the cytotoxic DNA-incorporated thioguanine were significantly higher on day 70-79 in G460A/A719G TPMT heterozygous (TPMT HZ) compared to TPMT wild type (TPMT WT) patients (mean: 230.7 vs. 149.7 fmol/µg DNA, p = 0.002). In contrast, TPMT genotype did not associate with the end of consolidation MRD levels irrespective of randomization of the patients to fixed dose (25 mg/m2/day) or 6MP escalation (up to 50 or 75 mg/m2/day) during consolidation therapy.
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| 2. |
- Gottschalk Højfeldt, Sofie, et al.
(författare)
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Relapse risk following truncation of PEG-asparaginase in childhood acute lymphoblastic leukemia.
- 2021
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 137:17, s. 2373-2382
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Tidskriftsartikel (refereegranskat)abstract
- Truncation of asparaginase treatment due to asparaginase related toxicities or silent inactivation (SI) is common and may increase relapse risk in acute lymphoblastic leukemia (ALL). We investigated relapse risk following suboptimal asparaginase exposure among 1401 children aged 1-17 years, diagnosed with ALL between July 2008 and February 2016, and treated according to the NOPHO ALL2008 protocol including extended asparaginase exposure (1,000 IU/m2 intramuscularly weeks 5 to 33). Patients were included with delayed entry at their last administered asparaginase treatment or detection of SI and followed until relapse, death, secondary malignancy, or end of follow-up (median: 5.71 years, interquartile range: 4.02-7.64). In a multiple Cox model comparing patients with (n=358) and without (n=1043) truncated asparaginase treatment due to clinical toxicity, the adjusted relapse-specific hazard ratio (aHR) was 1.33 (95% confidence interval [CI]: 0.86-2.06, P=0.20). In a substudy including only patients with information on enzyme activity (n=1115), the 7-year cumulative incidence of relapse for the 301 patients with truncation of asparaginase treatment or SI (157 hypersensitivity, 53 pancreatitis, 14 thrombosis, 31 other, 46 SI) was 11.1% (95% CI: 6.9-15.4) versus 6.7% (95% CI: 4.7-8.6) for the 814 remaining patients. The relapse-specific aHR was 1.69 (95% CI: 1.05-2.74, P=0.03). The unadjusted bone-marrow relapse-specific HR was 1.83 (95% CI: 1.07-3.14, P=0.03) and 1.86 (95% CI: 0.90- 3.87, P=0.095) for any CNS relapse. These results emphasize the importance of therapeutic drug monitoring and appropriate adjustment of asparaginase therapy when feasible.
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| 3. |
- Toksvang, Linea Natalie, et al.
(författare)
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Maintenance therapy and risk of osteonecrosis in children and young adults with acute lymphoblastic leukemia : a NOPHO ALL2008 sub-study
- 2021
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Ingår i: Cancer Chemotherapy and Pharmacology. - : Springer. - 0344-5704 .- 1432-0843. ; 88:5, s. 911-917
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Osteonecrosis is a burdensome treatment-related toxicity that is mostly diagnosed during or soon after 6-mercaptopurine (6MP)/methotrexate (MTX) maintenance therapy for acute lymphoblastic leukemia (ALL), possibly indicating a pathogenic role of these drugs. Methods We prospectively registered symptomatic osteonecrosis during treatment of 1234 patients aged 1.0-45.9 years treated according to the Nordic Society of Hematology and Oncology (NOPHO) ALL2008 protocol. MTX/6MP metabolites were measured as part of the NOPHO ALL2008 maintenance therapy study. Results After a median follow-up of 5.6 years [interquartile range (IQR) 3.6-7.5], 68 patients had been diagnosed with symptomatic osteonecrosis. The cumulative incidence was 2.7% [95% confidence interval (CI) 1.6-3.8%] for patients aged < 10 years, 14.9% (95% CI 9.7-20.2%) for patients aged 10.0-17.9 years, and 14.4% (95% CI 8.0-20.8%) for patients aged >= 18 years. The median time from diagnosis of ALL to diagnosis of osteonecrosis in these age groups was 1.0 year (IQR 0.7-2.0), 2.0 years (IQR 1.1-2.4), and 2.2 years (IQR 1.8-2.8), respectively (p = 0.001). With 17,854 blood samples available for MTX and 6MP metabolite analysis, neither erythrocyte levels of 6-thioguanine (TG) nucleotides (p > 0.99), methylated 6MP metabolites (p = 0.37), MTX polyglutamates (p = 0.98) nor DNA-TG (p = 0.53) were significantly associated with the hazard of osteonecrosis in Cox models stratified by the three age groups and adjusted for sex. Conclusion Maintenance therapy intensity determined by 6MP and MTX metabolites was not associated with the risk of developing osteonecrosis in the NOPHO ALL2008 cohort.
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