The Impact of Pretransplant Use of Tyrosine Kinase Inhibitors on Allogeneic Stem Cell Transplantation in Patients with Chronic Myeloid Leukemia-A Single-institution Retrospective Study.

Objective Chronic myeloid leukemia (CML) is a malignant hematological disorder, and allogeneic stem cell transplantation (allo-SCT) was its only curative treatment until the introduction of tyrosine kinase inhibitors (TKIs). Allo-SCT is still considered for CML patients who are resistant to TKIs and in an advanced phase. Currently, second- and third-generation (2/3 G) TKIs are typically incorporated into the first-line treatment of CML. However, the impact of 2/3 G TKIs on subsequent allo-SCT remains unclear. We therefore evaluated the effect of 2/3 G TKIs on allo-SCT. Methods We retrospectively evaluated the effect of pretransplant therapy with TKIs on the outcome of allo-SCT for CML using clinical data at our institution. Patients or Materials Thirty-two CML patients who received their first allo-SCT procedure at our institute from 2001 to 2020 were included. We divided the patients into three subgroups based on TKI treatment before allo-SCT. Patients receiving no TKIs, only imatinib (IM), and 2/3 G TKIs were classified into the Non-TKI, IM, and 2/3 G TKI groups, respectively. Results In a univariate analysis, the pretransplant use of 2/3 G TKIs was significantly associated with a higher 5-year overall survival (91.7%) and relapse-free survival (75.0%) than the use of IM (37.5% and 12.5%) in patients presenting with or progressing to the advanced phase. In addition, pretransplant use of 2/3 G TKIs did not increase the incidence of graft-versus-host disease (GVHD). Conclusions We demonstrated that the pretransplant use of 2/3 G TKIs was safe and improved the outcome of CML patients who presented with or progressed to the advanced phase without increasing the frequency of GVHD.

Dose-finding trial of azacitidine as post-transplant maintenance for high-risk MDS: a KSGCT prospective study.

This 3+3 dose-escalation phase I multicenter study investigated the optimal dose of azacitidine (AZA) for post-hematopoietic stem cell transplantation (HSCT) maintenance, which remains unknown in Japan. Recipients of a first HSCT for high-risk myelodysplastic syndromes (MDS, n = 12) or acute myeloid leukemia (AML) with antecedent MDS (n = 3) received post-HSCT AZA maintenance in 2015-2019. The optimal AZA dose was defined as the dose at which 50-70% of patients can complete four cycles without dose-limiting toxicity (DLT). The initial dose level 1 was set as 30 mg/m2 for 5 days per 28-day cycle, and dose levels 0, 2, and 3 were set as 20, 40, and 50 mg/m2. DLT was defined as any grade 3 non-hematological or grade 4 hematological toxicity. The 15 evaluable patients were 55 (37-64) years old. The median observation of the post-HSCT survivors was 935 (493-1915) days. The median number of days post-HSCT to the start of AZA was 101 (59-176). In the first, second, and third cohorts, five of nine patients completed four cycles at dose level 1. In the final cohort, five of six additional patients completed at the same dose. In total, 10 (67%) patients tolerated AZA 30 mg/m2, which was determined as optimal. DLT occurred in five cases: grade 3 hepatotoxicity, pneumonia, enterocolitis, and grade 4 thrombocytopenia and neutropenia. The 2-year overall survival and disease-free survival rates post-HSCT were 77.0% and 73.3%. Post-HSCT AZA maintenance was well-tolerated and merits further evaluation for patients with MDS or AML with antecedent MDS. Trial registration: UMIN000018791.

Risk factor analysis for cytomegalovirus reactivation under prophylaxis with letermovir after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Letermovir has been approved as a novel cytomegalovirus (CMV) prophylactic agent after allogeneic hematopoietic stem cell transplantation (HSCT). However, there are still insufficient data to properly evaluate the real-world role of letermovir, and the risk factors for CMV reactivation under letermovir prophylaxis have not been clarified. METHODS: We performed a single-institution retrospective analysis of patients under prophylaxis with or without letermovir who underwent allogeneic HSCT between March 2012 and December 2019. In August 2018, letermovir was added to the clinical practice at our institution for the prophylaxis of CMV reactivation in allogeneic HSCT recipients. Patients who underwent HSCT without prophylactic letermovir from March 2012 until September 2018 served as a historical control. RESULTS: The cumulative incidence of clinically significant CMV infection (CS-CMVi) was significantly lower in the letermovir group than in the historical control group not receiving letermovir (30.2% vs. 71.6%, p < .05, at 100 days). In addition, the cumulative incidence of non-relapse mortality (NRM) at day 500 was significantly lower in the letermovir group (4.7% vs. 19.8%, p < .05). We then performed a risk factor analysis for developing CS-CMVi in the letermovir group. The only significant factor identified by this multivariable analysis was transplantation from a CMV seronegative donor to a seropositive recipient (Hazard ratio = 2.76, 95% confidence interval 1.14-6.68, p < .05). CONCLUSION: Our study showed that letermovir prophylaxis significantly reduced the incidence of CS-CMVi and NRM in a real-world setting and that the CMV serostatus of the donor remained as a risk factor for CS-CMVi even under letermovir prophylaxis.

Usefulness of the FilmArray Meningitis/Encephalitis Panel in diagnosis of central nervous system infection after allogeneic hematopoietic stem cell transplantation.

PURPOSE: The BioFire FilmArray® Meningitis/Encephalitis Panel (FAMEP) is designed to rapidly and accurately detect common multiple pathogens that cause central nervous system (CNS) infection, including viruses, bacteria, and yeast. The FAMEP's usefulness in the setting of allogeneic hematopoietic stem cell transplantation (HSCT) has not been fully evaluated. This retrospective study evaluated the usefulness of the FAMEP in the screening for CNS infection after allogeneic HSCT. METHODS: Cerebrospinal fluid (CSF) was obtained from 12 patients to evaluate the causes of CNS disorders after allogeneic HSCT, and the FAMEP was applied. RESULTS: The median day of the FAMEP evaluations was 27 days post-transplant (range, 0-390). Human herpesvirus 6 (HHV-6) was detected in three patients and cytomegalovirus was detected in one patient, leading to the diagnosis of encephalitis/myelitis. In three patients (HHV-6, n = 2; CMV, n = 1), the presence of the viruses was confirmed by conventional real-time polymerase chain reaction (PCR). However, in the remaining patient with HHV-6 detected by the AMEP, HHV-6 was not detected by real-time PCR at the onset but was detected 7 days later. The treatments for the detected viruses improved the clinical conditions in the four patients. CONCLUSIONS: Our results suggest that the FAMEP can be a useful sensitive assay in the screening and diagnosis of CNS viral infections after allogeneic HSCT.

Efficacy of ondansetron against emesis induced by a multiple-day cisplatin-based chemotherapy regimen for malignant lymphoma.

OBJECTIVES: This study aimed to evaluate the antiemetic efficacy of a 5-hydroxytryptamine-3 receptor antagonist (5-HT3RA), ondansetron, in patients with malignant lymphoma receiving multi-day cisplatin-based combination chemotherapy. METHODS: We conducted a single-institution retrospective analysis of patients receiving the first course of an ESHAP (etoposide, cisplatin, methylprednisolone, cytarabine) regimen including 4-day continuous infusion of cisplatin (25 mg/m2/day). All patients received ondansetron 4 mg intravenously during 5-day administration of ESHAP. The primary endpoint was complete response (CR) for emesis, which was defined as absence of both emesis and rescue medications. Total control (TC) was defined as an absence of emetic episodes, including nausea and emesis, and complete protection (CP) was defined as an absence of emesis with addition of rescue antiemetics. Nausea and vomiting were assessed and graded daily by medical staff. RESULTS: Eighty-two patients were analyzed. Nausea and vomiting were generally well controlled, with the CR rates of emesis being 79% in the overall phase, 82% in the early phase (days 1-6), and 89% in the delayed phase (days 7-10). TC and CP were achieved in 51 patients (62%) and 77 patients (94%) in the overall phase. DISCUSSION: Most of the chemotherapy regimens for lymphoid malignancies include high-dose corticosteroid which may be also effective as antiemetics. Although NK1 receptor antagonist (NK1RA) is generally recommended for cisplatin-containing chemotherapy, it can interact with variety drugs. CONCLUSION: Although NK1RA is generally recommended for cisplatin-containing regimen, our results suggest that ondansetron effectively controlled emesis in patients receiving ESHAP therapy which includes high-dose corticosteroid.

Adoptive cell therapy using tumor-infiltrating lymphocytes for melanoma refractory to immune-checkpoint inhibitors.

To evaluate the feasibility of adoptive cell therapy (ACT) using ex vivo-expanded tumor-infiltrating lymphocytes (TILs) in Japanese patients with melanoma who failed immune-checkpoint inhibitor therapy, an open-label, single-arm, pilot study was conducted. We investigated the immunological and genetic factors of the pretreatment tumor and expanded TILs that may be associated with the clinical response. The treatment protocol comprised preparation of TIL culture, lympho-depleting non-myeloablative preconditioning with cyclophosphamide and fludarabine, TIL infusion, and intravenous administration of low-dose IL-2. Three patients of clinical subtypes mucosal, superficial spreading, and acral melanoma underwent TIL-ACT. Most severe adverse events, including fever and leukopenia, were manageable with the supportive regimen specified in the protocol, suggesting that the TIL-ACT regimen is suitable for Japanese patients with melanoma. One patient showed a short-term partial response, one relatively long-stable disease, and one experienced disease progression. Whole-exome and transcriptional sequencing of isolated tumor cells and immunohistochemical analyses before TIL-ACT revealed various immunostimulatory factors, including a high tumor mutation burden and immune cell-recruiting chemokines, as well as various immunosuppressive factors including TGF-ß, VEGF, Wnt/ß-catenin, and MAPK signaling and epithelial-to-mesenchymal transition, which might influence the efficacy of TIL-ACT. Our results imply mechanisms for the antitumor effect of and resistance to TIL-ACT. Further studies of immune-resistant mechanisms of TIL-ACT are warranted. This study is registered with the UMIN Clinical Trial Registry (UMIN 000011431).

Impact of Specific Antibody Level on Human Herpesvirus 6 Reactivation after Allogeneic Stem Cell Transplantation.

The majority of adults are seropositive for human herpesvirus 6 (HHV-6). HHV-6 reactivation can occur after allogeneic hematopoietic stem cell transplantation (HSCT) and lead to life-threatening central nervous system disorders. In this prospective study, we evaluated the relationship between HHV-6 reactivation and anti-HHV-6 IgG antibody levels in recipients of allogeneic HSCT. The HHV-6 viral load in the plasma was quantitatively measured weekly after allogeneic HSCT by real-time polymerase chain reaction. The level of anti-HHV-6 IgG antibody was measured by enzyme-linked immunosorbent assay before and serially after transplantation. In 28 of the 56 evaluated patients (50%), HHV-6 reactivation was detected after transplantation. In a multivariate analysis, cord blood as the stem cell source was the only significant factor associated with HHV-6 reactivation (odds ratio, 8.6; 95% confidence interval, 2.3 to 32.6; P < .01). When evaluated in the recipients of cord blood transplantation (CBT), the anti-HHV-6 antibody level before transplantation was significantly lower in the patients with HHV-6 reactivation compared with those without (sample positivity index: median, 2.04 [range, 0.95 to 5.98] versus 4.15 [range, 3.93 to 5.65]; P < .05). The anti-HHV-6 antibody level was significantly decreased at 3 months post-transplantation compared with before transplantation (P < .01). Such differences were not observed in other stem cell sources. Our results demonstrate that the low anti-HHV-6 antibody level before transplantation was associated with the reactivation of HHV-6 after CBT, and that the anti-HHV-6 antibody level was significantly decreased specifically after CBT. These results suggest that HHV-6-specific humoral immunity plays a role in HHV-6 reactivation after CBT.

Phase 1 study of plerixafor in combination with total body irradiation-based myeloablative conditioning for allogeneic hematopoietic stem cell transplantation.

Plerixafor, a CXCR4 inhibitor, has the potential to mobilize leukemic cells, which may contribute to their chemosensitization. This phase 1 study evaluated the safety of myeloablative conditioning combined with plerixafor for allogeneic hematopoietic stem cell transplantation (HSCT). Patients with high-risk leukemia undergoing allogeneic HSCT after total body irradiation (TBI, 12 Gy)-based myeloablative conditioning were eligible; 9 patients were enrolled. The study was performed using a 3 + 3 design with an escalating total dose of plerixafor. Plerixafor was given subcutaneously 8 h before TBI and chemotherapeutic agents. Plerixafor was successfully escalated to the maximum dose (0.72 mg/kg) without dose-limiting toxicities. Underlying diseases were acute myelogenous and lymphoblastic leukemia, chronic myeloid leukemia, and myelodysplastic syndrome. As adverse events, plerixafor administration was associated with transient Grades 2-3 diarrhea (n = 7) and abdominal pain (n = 4). In 6 patients, leukemic cell mobilization into the peripheral blood by plerixafor was confirmed by a morphological or molecular method. All patients achieved neutrophil engraftment and 5 were alive in remission at a follow-up after 30-40 months. Plerixafor-combined myeloablative conditioning for allogeneic HSCT was well tolerated. Leukemic-cell mobilization into peripheral blood was observed in half of the patients. Further study is required to evaluate the efficacy and safety of this concept.

[Spontaneous remission of relapsed skin lesions of ALK-positive anaplastic large cell lymphoma after autologous stem cell transplantation].

A 44-year-old woman was diagnosed with anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) with clinical stage IVA (nodal and bladder involvement). Complete response (CR) was achieved after the CHOP chemotherapy; however, 12 months after the last course of chemotherapy, ALCL relapsed in the form of skin lesions without nodal involvement. After achieving a second CR with chemotherapy, autologous stem cell transplantation was performed. Two months after transplantation, the disease again relapsed as multiple skin lesions. Electron beam irradiation was performed; however, other skin lesions appeared thereafter and spontaneously disappeared. At present, 3.4 years after the transplantation, the patient is free from disease. ALK-positive ALCL relapsing as skin lesions may behave differently from the nodal relapse. An accumulation of cases is required to elucidate ALCL characteristics relapsing as skin lesions.

Cytomegalovirus retinitis after allogeneic hematopoietic stem cell transplantation under cytomegalovirus antigenemia-guided active screening.

Although cytomegalovirus (CMV) remains a leading cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT), the incidence of CMV retinitis is considered to be lower than the incidence of CMV infection in other organs following allogeneic HSCT. In this study, the incidence and characteristics of CMV retinitis were retrospectively evaluated in recipients of allogeneic HSCT. Ophthalmological screening was performed at the development of ocular symptoms or positive CMV infection using peripheral blood evaluated by pp65 antigenemia or polymerase chain reaction. Of the 514 patients, 13 patients developed CMV retinitis. The median onset of CMV retinitis was day 34 (range, 21-118) post transplant, and the cumulative incidence was 2.5% (95% CI, 1.6-4.2) at 6 months after transplantation. Five patients presented ocular symptoms at the onset. In the remaining eight asymptomatic patients, the diagnosis of CMV retinitis was made by the screening guided by positive CMV infection. All evaluable patients responded to antiviral treatment but three showed incomplete improvement with ocular sequela. Our results suggest that the incidence of CMV retinitis after allogeneic HSCT is not negligible and active ophthalmological screening based not only on symptoms but also positive CMV infection monitoring contributes to the early diagnosis of CMV retinitis.

Pharmacokinetics of intravenous busulfan as condition for hematopoietic stem cell transplantation: comparison between combinations with cyclophosphamide and fludarabine.

Busulfan (Bu) has been used in combination with fludarabine (Flu; BuFlu) or cyclophosphamide (Cy; BuCy) as conditioning for allogeneic hematopoietic stem cell transplantation (HSCT). This multi-institutional prospective study compared pharmacokinetic (PK) parameters of Bu between BuFlu and BuCy. Plasma Bu concentrations were measured by high-performance liquid chromatography at the first dose of the first and fourth days of intravenous Bu administrations (total of 16 doses of 0.8 mg/kg). Thirty-seven patients were evaluable (BuFlu, N = 18; BuCy, N = 19). The median age was significantly higher in BuFlu. In BuFlu, the median area under the blood concentration-time curve of Bu on the fourth day was 1183 µmol min/L (range 808-1509), which was significantly higher than that on the first day [1095 µmol min/L (range 822-1453), P < 0.01]. In contrast, such differences were not observed in BuCy. Consistently, there was a significant decrease in the clearance of Bu on the fourth day as compared with the first day in BuFlu. These results suggest that the PK of Bu was altered during the co-administration of Flu, which was not the case with Cy. A large-scale study is required to evaluate the significance of the differences in the PK of Bu between the conditionings on HSCT outcomes.

Toxoplasmosis after allogeneic hematopoietic stem cell transplantation: Impact of serostatus-based management.

Toxoplasmosis caused by Toxoplasma gondii (T. gondii) is a serious infectious complication after allogeneic hematopoietic stem cell transplantation (HSCT). The incidence of toxoplasmosis varies widely because of the variabilities of seroprevalence among patient populations. The incidence and the optimal management of toxoplasmosis after allogeneic HSCT in a patient population with a low seroprevalence have not been fully evaluated. We conducted a single-center retrospective study evaluating toxoplasmosis in Japanese patients who underwent allogeneic HSCT. Of the 728 evaluable patients, only 5 developed toxoplasmosis with a median onset of day 60 post-transplant (range, day 55-393). The cumulative incidence was 0.7% (95% CI: 0.3%-1.5%) at day 500 post-transplant. Four of the five patients succumbed due to toxoplasmosis. The more recently treated 220 patients (not the earlier 508 patients) were screened for the T. gondii serostatus, and prophylactic treatment with trimethoprim/sulfamethoxazole was applied. All five patients with toxoplasmosis were in the unscreened group, and there was no case of toxoplasmosis after the introduction of the screening and prophylactic treatment. Our results suggest that toxoplasmosis after allogeneic HST is rare but can develop as a life-threatening complication even in the populations with low seroprevalence, and that prophylactic treatment for seropositive patients could effectively prevent toxoplasmosis.

[Two serial events of delayed hemolytic transfusion reactions due to different primary immune response-induced irregular antibodies].

A 74-year-old woman with a history of pregnancies, but without previous transfusions, received a red blood cell transfusion for aplstic anemia. She lost consciousness due to severe anemia two weeks later and was transported by ambulance to our hospital. Delayed hemolytic transfusion reaction (DHTR) was diagnosed based on the detection of anti-E antibody and positive E antigen of the previously transfused product. A transfusion of E antigen-negative red cell products was performed. However, DHTR due to anti-c antibody developed 16 d after the transfusion of a c antigen-positive product. Based on the onset of ≥14 d after the transfusions and the detection of a causative IgM-type antibody, DHTR due to a primary immune response was diagnosed. Because the incidence of DHTR is low, physicians rarely experience it in clinical practice. However, in our case, DHTR due to a primary immune response, which is even rarer in DHTR cases, developed twice within a short period. A history of transfusion and pregnancy as well as preexisting irregular antibodies have been identified as risk factors for DHTR. Thus, more attention should be paid to the risk of DHTR redevelopment by repeated transfusions.

[Chronic active Epstein-Barr virus infection with multiple vascular lesions successfully treated by cord blood transplantation].

An 18-year-old woman presented with fever and liver dysfunction. Computed tomography showed lymphadenopathy, hepatosplenomegaly, and vascular lesions such as aneurysms and irregularities at multiple arteries, including coronary arteries. Based on the high copy number of Epstein-Barr virus (EBV)-DNA in the peripheral blood, EBV-infected CD4+T cells, and the proliferation of EBER-positive cells in the bone marrow, chronic active EBV infection (CAEBV) was diagnosed. Although the fever and liver dysfunction improved as a result of the initial immunosuppressive therapy and multiagent chemotherapy, EBV-DNA remained high. Moreover, she experienced repeated episodes of angina pectoris due to coronary arterial lesions. Therefore, cord blood transplantation was performed after reduced-intensity conditioning. EBV-DNA decreased quickly after initiating the conditioning and became undetectable at day 7 after the transplant. Vascular lesions did not progress after the transplant, and the patient's angina pectoris resolved. At 2.5 years after the transplant, she is alive without disease recurrence. The prognosis of CAEBV with vascular lesions is especially poor. Although the indication for allogeneic hematopoietic stem cell transplantation (HSCT) is difficult to determine in such cases, the clinical course of our case suggests that allogenic HSCT could be safely performed under appropriate management and could successfully control not only CAEBV but also vascular lesions.

[Efficacy of photocatalytic air purifiers in reducing dimethyl sulfide malodor following cryopreserved peripheral blood stem cell infusion].

Dimethyl sulfoxide (DMSO) is used as a cryoprotectant for peripheral blood stem cells (PBSC) preservation. Dimethyl sulfide (DMS) is a metabolite of DMSO secreted through patients' breath after PBSC infusion. It possesses malodor causing an unpleasant environment. We evaluated the efficacy of a photocatalyst environment purifier, which has the potential to lyse toxic substances, in reducing DMS malodor. High DMS concentration in the air after PBSC infusion rapidly decreased after operating the device. Our results suggest that photocatalytic reaction has the potential to reduce the DMS odor associated with PBSC infusion.