Masaya Okada

Discontinuation of dasatinib in patients with chronic myeloid leukaemia who have maintained deep molecular response for longer than 1 year (DADI trial): a multicentre phase 2 trial

BACKGROUND First-line imatinib treatment can be successfully discontinued in patients with chronic myeloid leukaemia after deep molecular response has been sustained for at least 2 years. We investigated the safety and efficacy of discontinuing second-line or subsequent dasatinib after at least 1 year of deep molecular response. METHODS The Dasatinib Discontinuation trial was a prospective multicentre trial done in Japan. Eligible patients taking dasatinib and with confirmed stable deep molecular response were enrolled between April 1, 2011, and March 31, 2012. All patients received dasatinib consolidation therapy for at least 1 year. In those with sustained deep molecular response, dasatinib was discontinued. Patients were followed up every month in year 1 (clinical cutoff), every 3 months in year 2, and every 6 months in year 3 for deep molecular response and immunological profiles. The primary endpoint was the proportion of patients with treatment-free remission at 6 months after discontinuation. Molecular relapse was defined as loss of deep molecular response at any assessment. This study is registered, number UMIN000005130. FINDINGS 88 patients were enrolled in the consolidation phase, 24 were excluded from the discontinuation phase due to fluctuations in BCR-ABL1 transcript levels. One patient was excluded because of positive expression of major and minor BCR-ABL1 transcripts in chronic myeloid leukaemia cells and the detection of minor BCR-ABL1 transcripts during consolidation. Thus, 63 patients discontinued dasatinib treatment. The 25 patients who were excluded from discontinuation continued to receive dasatinib and none showed disease progression. Median follow-up was 20.0 months (IQR 16.5-24.0). Of the 63 patients who discontinued and were not excluded, 30 patients maintained deep molecular response while 33 patients had molecular relapses, all within the first 7 months after discontinuation. The estimated overall treatment-free remission was 49% (95% CI 36-61) at 6 months. No severe treatment-related toxic effects were seen. Treatment was restarted in the 33 patients with relapse; rapid molecular responses were seen in all 33 patients, of whom 29 (88%) regained deep molecular response within 3 months, as did the remaining four by 6 months. INTERPRETATION Dasatinib discontinuation after sustained deep molecular response for more than 1 year is feasible. FUNDING Epidemiological and Clinical Research Information Network (ECRIN).

Risk and prevention of graft failure in patients with preexisting donor-specific HLA antibodies undergoing unmanipulated haploidentical SCT.

A role of donor-specific HLA antibodies (DSA) in graft failure after SCT has been suggested, but the relevance of DSA in unmanipulated haploidentical SCT (haplo-SCT) remains unknown. We prospectively examined HLA antibodies using the Luminex-based single Ag assay for 79 adult patients undergoing unmanipulated haplo-SCT. Among them, 16 (20.2%) were HLA Ab-positive, including five patients with antibodies not corresponding to donor HLA Ags and 11 DSA-positive patients. Of the 11 DSA-positive patients, five received treatments to decrease DSA levels, including two, who received plasma exchange and rituximab, two who received platelet transfusions from healthy-related donors having DSA-corresponding HLA Ags and one who received bortezomib. Platelet transfusion was the most simple and effective treatment option for class I DSA. The cumulative incidence of neutrophil recovery was significantly lower in pretransplant (post-treatment) DSA-positive patients than in DSA-negative patients (61.9 vs 94.4%, P=0.026). Notably, three of five patients with high levels of DSA had graft failure. Donors should be selected on the basis of an evaluation of HLA antibodies. If haplo-SCT from donors with HLA Ags that correspond to high levels of DSA must be performed, then recipients should be treated for DSA to improve the chances of successful donor engraftment.

Severe hemorrhagic complications during remission induction therapy for acute promyelocytic leukemia: incidence, risk factors, and influence on outcome

Background: Even after the introduction of all‐trans retinoic acid (ATRA), early hemorrhagic death remains a major cause of remission induction failure for acute promyelocytic leukemia (APL). Methods: To investigate severe hemorrhagic complications during remission induction therapy with respect to incidence, risk factors, and influence on outcome. Results were analyzed for 279 patients enrolled in the APL97 study conducted by the Japan Adult Leukemia Study Group (JALSG). Results: Severe hemorrhage occurred in 18 patients (6.5%). Although most of them were receiving frequent transfusions, the targeted levels of platelet counts (30 × 109/L) and plasma fibrinogen (1.5 g/L) for this study were reached at the day of bleeding in only 71% and 40%, respectively. Nine of them succumbed to an early death, while the remaining nine patients eventually achieved complete remission (CR). The 5‐yr event‐free survival rate was 68.1% for those who did not suffer severe hemorrhage, and 31.1% for those who did (P < 0.0001). For patients who achieved CR, on the other hand, there was no difference in disease‐free survival between patients with and without severe hemorrhage (P = 0.6043). Risk factor analysis identified three pretreatment variables associated with severe hemorrhage: initial fibrinogen level, white blood cell count, and performance status. Additionally, patients with severe hemorrhage were more easily prone to develop retinoic acid syndrome or pneumonia than patients without hemorrhage. Conclusions: These results indicate that fatal hemorrhage represents a major obstacle in curing APL, and that patients with such high‐risk features may benefit from more aggressive supportive care.

Endothelial damage caused by cytomegalovirus and human herpesvirus-6

Summary:Infection with cytomegalovirus (CMV) or human herpesvirus-6 (HHV-6) may have a role in vascular endothelial damage after bone marrow transplantation (BMT). In total, 41 patients who underwent BMT were classified into four groups (12, 10, 7, and 12 patients who were infected with both CMV and HHV-6, CMV alone, HHV-6, and neither virus, respectively). Levels of thrombomodulin, plasminogen activator inhibitor-1, and cyclic GMP were 7.5±1.7 FU/ml, 76.4±24.1 ng/ml, and 9.51±1.1 pmol/ml, respectively, in the patients with both viruses, while the respective values were 2.9±0.67 FU/ml, 33.8±8.09 ng/ml, and 2.90±1.4 pmol/ml in patients infected with CMV alone, 4.8±0.96 FU/ml, 47.7±9.21 ng/ml, and 5.48±0.55 pmol/ml in patients with HHV-6 alone, and 1.6±0.39, 17.5±7.88 ng/ml, and 0.45±0.3 in those with neither virus. All three markers were significantly higher in the three groups with at least one virus than in the uninfected patients (P<0.05), and were also higher in patients with HHV-6 alone than in those with CMV alone (P<0.05). These results suggest that infection by CMV or HHV-6 causes vascular endothelial injury, with HHV-6 having a stronger effect than CMV, and combined infection having a stronger effect than either virus alone. Such viral infection may be a cause of thrombotic microangiopathy after BMT.

Predicting the severity of graft-versus-host disease from interleukin-10 levels after bone marrow transplantation.

Acute graft-versus-host disease (GVHD) is the most important complication of allogeneic bone marrow transplantation. We investigated the possibility of predicting severe acute GVHD using plasma interleukin-10 levels in 31 patients who underwent allogeneic bone marrow transplantation. In patients with acute GVHD, the interleukin-10 (IL-10) level increased significantly from the aplastic phase through the leukocyte recovery phase after transplantation (P < 0.05, paired t-test). The ratio of the IL-10 level in the aplastic phase to that in the leukocyte recovery phase was significantly correlated with the severity of acute GVHD (P < 0.05, t-test), and the incidence of grade III or IV disease was significantly increased (P < 0.0001). since il-10 antagonizes various other cytokines that induce acute gvhd, determination of the il-10 level is equivalent to assessing the total production of cytokines promoting gvhd. the ratio of the il-10 level in the aplastic phase to that in the recovery phase seems to be useful for predicting the subsequent risk of acute gvhd.

Effects of total body irradiation on the vascular endothelium

Takatsuka H, Wakae T, Mori A, Okada M, Okamoto T, Kakishita E. Effects of total body irradiation on the vascular endothelium. Clin Transplant 2002: 16: .

A Phase I/II study of nilotinib in Japanese patients with imatinib-resistant or -intolerant Ph+ CML or relapsed/refractory Ph+ ALL

Nilotinib is a second-generation BCR-ABL kinase inhibitor with improved potency and selectivity compared to imatinib. A Phase I/II dose-escalation study was designed to evaluate the efficacy, safety, and pharmacokinetics of nilotinib in Japanese patients with imatinib-resistant or -intolerant Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) or relapsed/refractory Ph+ acute lymphoblastic leukemia (ALL). A total of 34 patients were evaluated in this analysis and had a median duration of drug exposure of 293 (range 13–615) days. All 6 CML-CP patients without complete hematologic response (CHR) at baseline rapidly achieved CHR. A major cytogenetic response was achieved in 94% of patients with CML-CP, including a complete cytogenetic response in 69%. A major molecular response was achieved by 56%. These responses were also observed in patients with CML in advanced stages and Ph+ ALL. Non-hematologic adverse events were mostly mild to moderate. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 50 and 28% of patients, respectively. Overall, the results of this study suggest that nilotinib induced significant responses in imatinib-resistant or -intolerant patients with CML-CP and CML in advanced stages and Ph+ ALL. The results of this study confirmed the efficacy and safety of nilotinib in Japanese patients.

Evaluation of CMV/human herpes virus-6 positivity in bronchoalveolar lavage fluids as early detection of acute GVHD following BMT: evidence of a significant relationship

We evaluated the relationship between CMV and human herpes virus-6 (HHV-6) reactivation and the incidence of grades 2 to 4 acute GVHD post BMT. Bronchoalveolar lavage fluid (BALF) samples extracted from 54 BMT recipients on post-BMT day 35 were analyzed by PCR for detection of CMV DNA, HHV-6 DNA and CMV plus HHV-6 DNA. CMV DNA was detected in 26 patients and 13 (50%) developed grades 2 to 4 acute GVHD. Of the 28 who were CMV negative, only six (21.4%) developed grades 2 to 4 acute GVHD. HHV-6 was detected in 18 patients, and 11 (61.1%) developed grades 2 to 4 acute GVHD. Of the 36 who were HHV-6 negative, only eight (22.2%) developed grades 2 to 4 acute GVHD. CMV and HHV-6 were detected in 13 patients, and eight (61.5%) developed grades 2 to 4 acute GVHD. Of the 23 who were negative for both CMV and HHV-6, only three (13%) developed grades 2 to 4 acute GVHD. In all experiments, the difference between the groups was significant (P < 0.05, P < 0.05 and P < 0.01, respectively). we conclude that herpes virus infection, in particular cmv concurrent with hhv-6 reactivation, is predictive of moderate to severe acute gvhd. Bone Marrow Transplantation (2000) 26, 77–81.

Reduced-Intensity Conditioning Followed by Unrelated Umbilical Cord Blood Transplantation for Advanced Hematologic Malignancies: Rapid Engraftment in Bone Marrow

Reduced-intensity (RI) conditioning followed by cord blood transplantation (CBT) is a new treatment modality, but failure to engraft is a major concern. We describe 12 patients with advanced hematologic malignancies who underwent RI conditioning and CBT with a conditioning regimen consisting of 200 mg/m2 fludarabine (Flu), 50 mg/kg cyclophosphamide (CY), and 3 Gy total body irradiation (TBI). Cyclosporin A and/or methotrexate were used for graft-versus-host disease prophylaxis. Cord blood grafts were not mismatched for more than 2 serologically defined HLA alleles but were later found by high-resolution DNA typing to be mismatched for 2 to 4 alleles in most cases. Short tandem repeat analysis of bone marrow cells at day 14 showed complete donor chimerism in 6 of the patients and mixed chimerism in 5, indicating rapid engraftment in the bone marrow, whereas the remaining patient experienced graft rejection. Neutrophil recovery was achieved at a median of day 17 (range, days 11-24) in 10 of the 11 patients with marrow chimerism at day 14. Of these 10 patients, however, transplantation-related mortality within 100 days occurred in 4 patients who showed failed platelet recovery and a lack of durable engraftment. Overall survival and disease-free survival rates were 41.7% and 33.3%, respectively.These results show that CB mismatched at 2 to 4 HLA alleles and transplanted with the Flu/CY/3 Gy TBI regimen is able to engraft in the bone marrow as early as day 14.

Thrombotic microangiopathy following allogeneic bone marrow transplantation

Thrombotic microangiopathy is one of the complications of bone marrow transplantation and is related to other complications such as graft-versus-host disease, veno-occlusive disease, diffuse alveolar hemorrhage, and cytomegalovirus infection. Thrombotic microangiopathy occurred in three out of 12 patients who underwent allogeneic bone marrow transplantation over the past 1 year at our department. We compared the changes in cytokines and other molecules between patients with and without microangiopathy from before conditioning to the early post-transplantation period. All three patients with microangiopathy showed a significant increase of interleukin-12 at the time of leukocyte recovery after transplantation (two-way layout analysis of variance; P < 0.05), while none of the patients without microangiopathy showed an increase of interleukin-12. no significant differences were found between the two groups with respect to the other cytokines and molecules that were tested. these findings suggested that thrombotic microangiopathy might be predicted at an early stage after bone marrow transplantation by detecting an increase of interleukin-12 at the time of leukocyte recovery. the possibility that thrombotic microangiopathy is related to inflammation or autoimmunity was also suggested.