Summary
Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or ...secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically‐mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs.
Idiopathic pure red cell aplasia (PRCA) and secondary PRCA associated with thymoma and large granular lymphocyte leukemia are generally considered to be immune-mediated. The PRCA2004/2006 study ...showed that poor responses to immunosuppression and anemia relapse were associated with death. PRCA may represent the prodrome to MDS. Thus, clonal hematopoiesis may be responsible for treatment failure. We investigated gene mutations in myeloid neoplasm-associated genes in acquired PRCA. We identified 21 mutations affecting amino acid sequences in 11 of the 38 adult PRCA patients (28.9%) using stringent filtering of the error-prone sequences and SNPs. Four PRCA patients showed 7 driver mutations in TET2, DNMT3A and KDM6A, and 2 PRCA patients carried multiple mutations in TET2. Five PRCA patients had mutations with high VAFs exceeding 0.3. These results suggest that clonal hematopoiesis by stem/progenitor cells might be related to the pathophysiology of chronic PRCA in certain adult patients.
Imatinib mesylate (IM) trough concentration varies among IM-treated chronic myeloid leukemia (CML) patients. Although IM pharmacokinetics is influenced by several enzymes and transporters, little is ...known about the role of pharmacogenetic variation in IM metabolism. In this study, associations between IM trough concentration, clinical response and 11 single-nucleotide polymorphisms in genes involved in IM pharmacokinetics (ABCB1, ABCC2, ABCG2 CYP3A5, SLC22A1 and SLCO1B3) were investigated among 67 Japanese chronic phase CML patients. IM trough concentration was significantly higher in patients with a major molecular response than in those without one (P=0.010). No significant correlations between IM trough concentration and age, weight, body mass index or biochemical data were observed. However, the dose-adjusted IM trough concentration was significantly higher in patients with ABCG2 421A than in those with 421C/C (P=0.015). By multivariate regression analysis, only ABCG2 421A was independently predictive of a higher dose-adjusted IM trough concentration (P=0.015). Moreover, previous studies have shown that the ABCG2 421C>A (p.Q141K) variant is prevalent among Japanese and Han Chinese individuals and less common among Africans and Caucasians. Together, these data indicate that plasma IM concentration monitoring and prospective ABCG2 421C>A genotyping may improve the efficacy of IM therapy, particularly among Asian CML patients.
An optimal pretransplant conditioning regimen for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in older adults has not been established. Three prospective multicenter phase II ...studies were conducted, in which 142 patients older than 54 years (median age, 61 years; range 55–70 years) with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) received a myeloablative dose of intravenous busulfan (ivBu, 12.8 mg/kg) along with fludarabine (180 mg/m
2
) ± low dose total body irradiation for allo-HSCT between September 2009 and February 2013. A total of 103 AML and 39 MDS patients including 21 related bone marrow (BM) or peripheral blood (PB), 50 unrelated BM, and 71 unrelated cord blood (UCB) transplantation were enrolled. Grade 3 or greater toxicities were observed in 105 patients. Neutrophil engraftment was achieved in 70 out of the 71 related PB/BM or unrelated BM recipients, and 61 out of the 71 UCB recipients. The cumulative incidence rates of relapse and non-relapse mortality after 2 years were 24.0 and 24.1%, respectively. The overall and event-free survival rates at 2 years were 53.3 and 47.4%, respectively. The myeloablative dose of ivBu was well tolerated without increased toxicity-related mortality in older adults who underwent allo-HSCT with any donor source.
Background
Tacrolimus is metabolized by cytochrome P450 (CYP) 3A4 and 3A5. We investigated the influence of
CYP3A5
polymorphism and concurrent use of azole antifungal agents (AZ) on the ...pharmacokinetics of a once-daily modified-release tacrolimus formulation (Tac-QD) in patients after hematopoietic stem cell transplantation (HSCT).
Design and methods
Twenty-four patients receiving allogeneic HSCT were enrolled. Genotyping for
CYP3A5*3
was done by a PCR-restriction fragment length polymorphism method. Trough blood concentrations (C
0
) of tacrolimus were measured by chemiluminescence magnetic microparticle immunoassay. Continuous infusion of tacrolimus was administered from the day before transplantation and was switched to Tac-QD after adequate oral intake.
Results
Thirteen patients had a
CYP3A5*3/*3
genotype, and 11 patients had a
CYP3A5*1/*1
or
*1/*3
genotype. No significant difference was observed in daily dosages and the C
0
of tacrolimus between the two genotype groups without AZ. However, in patients who were co-administered AZ, the C
0
values of tacrolimus were higher in patients with the
CYP3A5*3/*3
allele than with the
CYP3A5*1
allele (
P
= 0.034), although daily doses of Tac-QD in patients with
CYP3A5*3/*3
were significantly lower than those with the
CYP3A5*1
allele (
P
= 0.041). The cumulative incidence of acute kidney injury was higher in patients with the
CYP3A5*3/*3
than with the
CYP3A5*1
allele when AZ was co-administered. The decrement for daily dosage of Tac-QD was significantly greater in patients expressing the
CYP3A5*3/*3
than the
CYP3A5*1
allele.
Conclusions
CYP3A5
genotyping may be useful for safe and effective immunosuppressive therapy with Tac-QD in HSCT patients in whom the use of AZ is anticipated.
Inotuzumab ozogamicin (InO) is a targeted treatment for adults with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL). InO was previously studied in INO-VATE, an international, ...open-label, randomized phase 3 trial comparing InO against standard of care (SoC). In the present subgroup analysis, we evaluated outcomes in the 55 Asian patients who were randomized in INO-VATE (31 InO and 24 SoC). Complete remission (CR) or CR with incomplete hematologic recovery (CRi) was achieved in 22/31 patients treated with InO versus 5/24 treated with SoC. In the InO arm, more of the patients achieving CR/CRi were minimal residual disease (MRD)-negative (17/22 versus 1/5), and more patients proceeded directly to hematopoietic stem cell transplantation (15/31 versus 3/24). Median overall survival for the respective arms was 5.8 versus 3.9 months (hazard ratio 0.67; 97.5% CI 0.28, 1.62). In the safety analysis (
n
= 51), the most common adverse events were hematologic. Sinusoidal obstruction syndrome was reported in five InO patients and one SoC patient. In conclusion, Asian patients with relapsed or refractory B-cell ALL experienced improved efficacy with InO versus SoC, with an efficacy and safety profile consistent with results of the overall INO-VATE population.
Clinical trial registration:
ClinicalTrials.gov identifier: NCT01564784.
Patients with acute myeloid leukemia who are treated with conventional chemotherapy still have a substantial risk of relapse; the prognostic factors and optimal treatments after relapse have not been ...fully established. We, therefore, retrospectively analyzed data from patients with acute myeloid leukemia who had achieved first complete remission to assess their prognosis after first relapse.
Clinical data were collected from 70 institutions across the country on adult patients who were diagnosed with acute myeloid leukemia and who had achieved a first complete remission after one or two courses of induction chemotherapy.
Among the 1,535 patients who were treated with chemotherapy alone, 1,015 relapsed. Half of them subsequently achieved a second complete remission. The overall survival was 30% at 3 years after relapse. Multivariate analysis showed that achievement of second complete remission, salvage allogeneic hematopoietic cell transplantation, and a relapse-free interval of 1 year or longer were independent prognostic factors. The outcome after allogeneic transplantation in second complete remission was comparable to that after transplantation in first complete remission. Patients with acute myeloid leukemia and cytogenetic risk factors other than inv(16) or t(8;21) had a significantly worse outcome when they did not undergo salvage transplantation even when they achieved second complete remission.
We found that both the achievement of second complete remission and the application of salvage transplantation were crucial for improving the prognosis of patients with acute myeloid leukemia in first relapse. Our results indicate that the optimal treatment strategy after first relapse may differ according to the cytogenetic risk.
The efficacy and safety of lenalidomide (LEN) consolidation therapy and subsequent LEN maintenance therapy after high-dose therapy with autologous peripheral blood stem cell transplantation ...(auto-PBSCT) were evaluated in patients with newly diagnosed symptomatic multiple myeloma (MM). Forty-one patients were enrolled and received high-dose dexamethasone (DEX) therapy as an initial induction. The patients who did not respond to the DEX therapy were further treated with four cycles of bortezomib plus DEX (BD) induction therapy. For patients who responded to BD, PBSC harvesting was scheduled following high-dose cyclophosphamide and filgrastim administration. After PBSC harvesting, high-dose chemotherapy of melphalan with auto-PBSCT was performed. One hundred days after auto-PBSCT, patients received consolidation therapy consisting two cycles of LEN plus low-dose DEX (Ld) and LEN maintenance therapy. Only one death occurred during mobilization therapy, but the protocol developed in this study was considered generally safe to provide. Overall response rates after consolidation and maintenance therapies were 73.7% and 81.6%, respectively. Two-year progression-free survival and overall survival were 76.3% and 92.1%, respectively. These observations suggest that LEN consolidation and maintenance therapy are effective and safe, and provide favorable response rates in patients with MM.
Nilotinib potently inhibits human uridine diphosphate-glucuronosyltransferase (UGT1A1) activity, causing hyperbilirubinemia. We investigated the influence of UGT1A1 polymorphisms and nilotinib plasma ...trough concentrations (C0) on nilotinib-induced hyperbilirubinemia in 34 Japanese patients with chronic myeloid leukemia (CML). The proportion of patients with hyperbilirubinemia was significantly higher among patients with the UGT1A1 *6/*6 and *6/*28 genotypes (poor metabolizers) than among those with other genotypes (p=0.004). The median time to elevation of bilirubin levels in UGT1A1 poor metabolizers was 2.0 weeks (hazard ratio, 6.11). The median time to reduction in nilotinib dose in UGT1A1 poor metabolizers was 4.0 weeks (hazard ratio, 7.52; p=0.002). Consequently, in the maintenance phase 3 months following the initiation of nilotinib therapy, the median daily dose and C0 of nilotinib were 350 mg/day and 372ng/mL, respectively, in UGT1A1 poor metabolizers, and 600mg/day and 804ng/mL, respectively, in the other patients. Patients at increased hyperbilirubinemia risk could be identified by prospective UGT1A1 genotyping prior to nilotinib therapy. To avoid an interruption of CML treatment due to nilotinib-induced hyperbilirubinemia, it may be beneficial to reduce the initial nilotinib dose to 300400 mg/day for UGT1A1 poor metabolizers.
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