Dabrafenib and trametinib administration in patients with BRAF V600E/R or non-V600 BRAF mutated advanced solid tumours (BELIEVE, NCCH1901): a multicentre, open-label, and single-arm phase II trial.

Background: BRAF V600 mutations are common in melanoma, thyroid, and non-small-cell lung cancers. Despite dabrafenib and trametinib being standard treatments for certain cancers, their efficacy across various solid tumours remains unelucidated. The BELIEVE trial assessed the efficacy of dabrafenib and trametinib in solid tumours with BRAF V600E/R or non-V600 BRAF mutations. Methods: Between October 1, 2019, and June 2022, at least 50 patients with measurable and seven without measurable diseases examined were enrolled in a subcohort of the BELIEVE trial (NCCH1901, jRCTs031190104). BRAF mutated solid tumour cases other than BRAF V600E mutated colorectal cancer, melanoma, and non-small cell lung cancer cases were included. Patients with solid tumours received dabrafenib (150 mg) twice daily and trametinib (2 mg) once daily until disease progression or intolerable toxicity was observed. The primary endpoint was overall response rate (ORR), and secondary endpoints included progression-free survival (PFS), 6-month PFS, and overall survival (OS). Bayesian analysis was performed using a prior distribution with a 30% expected response rate [Beta (0.6, 1.4)]. Findings: Fourty-seven patients with measurable disease, mainly with the BRAF V600E mutation (94%), and three others with non-V600E BRAF mutations (V600R, G466A, and N486_P490del) were enrolled. The primary sites included the thyroid gland, central nervous system, liver, bile ducts, colorectum, and pancreas. The confirmed ORR was 28.0%; the expected value of posterior distribution [Beta (14.6, 37.4)] was 28.1%, although the primary endpoint was achieved, not exceeding an unexpectedly high response rate of 60% obtained using Bayesian analysis. The disease control rate (DCR) was 84.0%. The median PFS was 6.5 months (95% confidence interval [CI]; 4.2-7.2 months, 87.8% at 6 months). Responses were observed across seven tumour types. Median OS was 9.7 months (95% CI, 7.5-12.2 months). Additional patients without measurable diseases had a median PFS of 4.5 months. Adverse events (AEs) were consistent with previous reports, with 45.6% of patients experiencing grade ≥3 AEs. Interpretation: This study reported promising efficacy against BRAF V600-mutant tumours. Dabrafenib and trametinib would offer a new therapeutic option for rare cancers, such as high-grade gliomas, biliary tract cancer, and thyroid cancer. Funding: This study was funded by the Japan Agency for Medical Research and Development (22ck0106622h0003) and a Health and Labour Sciences Research Grant (19EA1008).

Utility of allogeneic stem cell transplantation for adult Ph+ALL with complete molecular remission.

This study aimed to investigate the usefulness of allogeneic stem cell transplantation (allo-SCT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) in the first complete remission (CR1) with complete molecular remission (CMR). We compared the outcomes between Ph+ALL patients who did or did not undergo allo-SCT in CR1. We included patients enrolled in the prospective clinical studies in the tyrosine kinase inhibitor era conducted by the Japan Adult Leukemia Study Group, who achieved CMR within 3 months. A total of 147 patients (allo-SCT: 101; non-SCT: 46) were eligible for this analysis. In the multivariate analyses, allo-SCT was significantly associated with both superior overall survival (OS) (adjusted hazard ratio (aHR): 0.54; 95% CI: 0.30-0.97; p = .04) and relapse-free survival (RFS) (aHR: 0.21; 95% CI: 0.12-0.38; p < .001). The 5-year adjusted OS and RFS were 73% and 70% in the allo-SCT cohort, whereas they were 50% and 20% in the non-SCT cohort. Despite the higher non-relapse mortality (aHR: 3.49; 95% CI: 1.17-10.4; p = .03), allo-SCT was significantly associated with a lower relapse rate (aHR: 0.10; 95% CI: 0.05-0.20; p < .001). In addition, allo-SCT was also associated with superior graft-versus-host disease-free, relapse-free survival (aHR: 0.43; 95% CI: 0.25-0.74; p = .002). Propensity score-matched analyses confirmed the results of the multivariate analyses. In patients who achieved CMR within 3 months, allo-SCT in CR1 had superior survival and lower relapse compared with the non-SCT cohort.

Characteristics and prognosis of patients with COVID-19 and hematological diseases in Japan: a cross-sectional study.

The Japanese Society of Hematology performed an observational cross-sectional study to clarify the morbidity, prognosis, and prognostic factors in patients with COVID-19 with hematological diseases (HDs) in Japan. The study included patients with HDs who enrolled in our epidemiological survey and had a COVID-19 diagnosis and a verified outcome of up to 2 months. The primary endpoints were characteristics and short-term prognosis of COVID-19 in patients with HDs. A total of 367 patients from 68 institutes were enrolled over 1 year, and the collected data were analyzed. The median follow-up among survivors was 73 days (range, 1-639 days). The 60-day overall survival (OS) rate was 86.6%. In the multivariate analysis, albumin ≤ 3.3 g/dL and a need for oxygen were independently associated with inferior 60-day OS rates (hazard ratio [HR] 4.026, 95% confidence interval (CI) 1.954-8.294 and HR 14.55, 95% CI 3.378-62.64, respectively), whereas 60-day survival was significantly greater in patients with benign rather than malignant disease (HR 0.095, 95% CI 0.012-0.750). Together, these data suggest that intensive treatment may be necessary for patients with COVID-19 with malignant HDs who have low albumin levels and require oxygen at the time of diagnosis.

Reduced-intensity allogenic transplantation for children and adolescents with Philadelphia chromosome-positive acute lymphoblastic leukemia.

Survival rates of patients with Philadelphia chromosome-positive ALL (Ph+ALL) have improved considerably with the introduction of tyrosine kinase inhibitors (TKI); however, hematopoietic stem cell transplantation (HSCT) continues to play an important role. Reduced-intensity conditioning (RIC) regimens have been widely applied particularly for older patients, but their validity for children and adolescents with Ph+ALL has not been investigated. In this study, data from patients receiving HSCT for de novo Ph+ALL in first or second remission at ages younger than 25 years and with a history of pre-HSCT TKI therapy were retrospectively collected through the nationwide registry in Japan. In 265 patients who received myeloablative conditioning (MAC) and 33 patients receiving RIC, 5-year leukemia-free survival (LFS) rates were 67.3% and 79.8%, respectively (p = 0.142). Multivariate analysis of LFS, focusing on patients with good performance status, identified RIC as a significant prognostic factor for LFS (hazard ratio 0.32, p = 0.032), as well as older age, higher leukocyte count at diagnosis, and disease with additional chromosomal abnormalities. These trends were similar when we focused on patients who received prophylactic post-HSCT TKI treatment, as 5-year LFS was 81.0% for MAC and 84.4% for RIC (p = 0.748). In summary, HSCT with RIC regimen showed at least comparable LFS to HSCT with MAC regimen, and RIC was an independent favorable prognostic factor on multivariate analysis adjusting potential prognostic factors. While patient numbers were limited, our data suggest that RIC may be safely applied in this group, particularly combined with prophylactic post-HSCT TKI maintenance therapy.

Impact of MRD on clinical outcomes of unrelated hematopoietic stem cell transplantation in patients with Ph+ ALL: A retrospective nationwide study.

Measurable residual disease (MRD) status before transplantation has been shown to be a strong prognostic factor in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). However, the outcomes of unrelated hematopoietic stem cell transplantation based on the MRD status have not been fully investigated. In this retrospective study, we compared the outcomes of 715 consecutive adults with Ph+ ALL in complete remission who underwent unrelated cord blood transplantation (UCBT) (single-unit UCBT, n = 232 [4/6, 5/6, and 6/6 HLA match]), HLA-matched unrelated bone marrow transplantation (UBMT; n = 292 [8/8 HLA match]), or HLA-mismatched UBMT (n = 191 [7/8 HLA match]). In the MRD+ cohort, adjusted 3-year leukemia-free survival rates were 59.8%, 38.3%, and 55.5% after UCBT, HLA-matched UBMT, and HLA-mismatched UBMT, respectively. In the MRD- cohort, the corresponding rates were 65.3%, 70.4%, and 69.7%, respectively. The MRD+ HLA-matched UBMT group had a significantly higher risk of relapse than the MRD+ HLA-mismatched UBMT group (hazard ratio [HR] in the MRD+ HLA-mismatched UBMT group, 0.33; 95% confidence interval [CI] 0.15-0.74) and the MRD+ UCBT group (HR in the MRD+ UCBT group, 0.38; 95% CI 0.18-0.83). Furthermore, HLA-matched UBMT had a significant effect of MRD on death (HR 1.87; 95% CI 1.19-2.94), relapse or death (HR 2.24; 95% CI 1.50-3.34), and relapse (HR 3.12; 95% CI 1.75-5.57), while UCBT and HLA-mismatched UBMT did not. In conclusion, our data indicate Ph+ ALL patients with positive MRD may benefit from undergoing UCBT or HLA-mismatched UBMT instead of HLA-matched UBMT to reduce leukemic relapse.

Autologous peripheral blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia is safe but poses challenges for long-term maintenance of molecular remission: Results of the Auto-Ph17 study.

Autologous hematopoietic stem cell transplantation (SCT) is not a standard treatment option for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL); however, its position has been reassessed since the introduction of tyrosine kinase inhibitors (TKIs). We prospectively analyzed the efficacy and safety of autologous peripheral blood SCT (auto-PBSCT) for Ph+ALL patients aged between 55 and 70 years who had achieved complete molecular remission. Melphalan, cyclophosphamide, etoposide, and dexamethasone were used for conditioning. A total of 12 courses of maintenance therapy, including dasatinib, were performed. The required number of CD34+ cells was harvested in all five patients. No patient died within 100 days after auto-PBSCT, and no unexpected serious adverse events were observed. Although 1-year event-free survival was 100%, hematological relapse was observed in three patients at a median of 801 days (range, 389-1088 days) after auto-PBSCT. Molecular progressive disease was observed in the other two patients, although they maintained their first hematological remission at the last visit. Auto-PBSCT can be safely performed for Ph+ALL with TKIs. A limitation of auto-PBSCT was suggested, despite the increase in the intensity of a single treatment. The development of long-term therapeutic strategies by including new molecular targeted drugs is warranted to maintain long-term molecular remission.

Improvements in allogeneic hematopoietic cell transplantation outcomes for adults with ALL over the past 3 decades.

Allogeneic hematopoietic cell transplantation (allo-HCT) is a promising treatment for adult acute lymphoblastic leukemia (ALL), an intractable hematological malignancy. The trends in allo-HCT outcomes over the past 30 years were examined to verify the efficacy of evolving treatment methods and to identify further challenges. We analyzed data from a registry database that included 8467 adult ALL patients who underwent their first allo-HCT between 1990 and 2019. The period was divided into three 10-year intervals for analysis. Five-year overall survival improved from 48.2% to 70.2% in the first complete remission (CR1), from 25.6% to 44.1% in subsequent CR, and from 10.0% to 22.7% in non-CR. Nonrelapse mortality improved over the 3 decades in each disease stage. However, the relapse rate only improved in CR1 every decade (26.3% to 15.9% in CR1, 33.4% to 32.8% in subsequent CR, and 53.6% to 54.8% in non-CR). Although there were continual improvements in adjusted survival for Philadelphia chromosome (Ph)-positive patients, the improvement was inadequate for Ph- patients with t(4;11), t(8;14), t(14;18), or hypodiploidy. Allo-HCT outcomes for adults with ALL have improved over the past 30 years. Improved outcomes in the future will require more effective prevention of relapse in patients with ALL not in CR1 and in those with high-risk chromosomal abnormalities.

Dasatinib-based 2-step induction for adults with Philadelphia chromosome-positive acute lymphoblastic leukemia.

The standard treatment for adults with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in Japan is imatinib-based chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, ∼40% of patients cannot undergo HSCT in their first complete remission (CR1) because of chemotherapy-related toxicities or relapse before HSCT or older age. In this study, we evaluated dasatinib-based 2-step induction with the primary end point of 3-year event-free survival (EFS). The first induction (IND1) was dasatinib plus prednisolone to achieve CR, and IND2 was dasatinib plus intensive chemotherapy to achieve minimal residual disease (MRD) negativity. For patients who achieved CR and had an appropriate donor, HSCT during a consolidation phase later than the first consolidation, which included high-dose methotrexate, was recommended. Patients with pretransplantation MRD positivity were assigned to receive prophylactic dasatinib after HSCT. All 78 eligible patients achieved CR or incomplete CR after IND1, and 52.6% achieved MRD negativity after IND2. Nonrelapse mortality (NRM) was not reported. T315I mutation was detected in all 4 hematological relapses before HSCT. Fifty-eight patients (74.4%) underwent HSCT in CR1, and 44 (75.9%) had negative pretransplantation MRD. At a median follow-up of 4.0 years, 3-year EFS and overall survival were 66.2% (95% confidence interval [CI], 54.4-75.5) and 80.5% (95% CI, 69.7-87.7), respectively. The cumulative incidence of relapse and NRM at 3 years from enrollment were 26.1% and 7.8%, respectively. Dasatinib-based 2-step induction was demonstrated to improve 3-year EFS in Ph+ ALL. This study was registered in the UMIN Clinical Trial Registry as #UMIN000012173.

The differential effect of disease status at allogeneic hematopoietic cell transplantation on outcomes in acute myeloid and lymphoblastic leukemia.

This study aimed to compare the effect of disease status at the time of allogeneic hematopoietic cell transplantation (HCT) on post-transplant outcomes between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Japanese nationwide registry data for 6901 patients with AML and 2469 patients with ALL were analyzed. In this study, 2850 (41%), 937 (14%), 62 (1%), and 3052 (44%) AML patients and 1751 (71%), 265 (11%), 23 (1%), and 430 (17%) ALL patients underwent transplantation in first complete remission (CR1), second CR (CR2), third or subsequent CR (CR3 +), and non-CR, respectively. The probabilities of overall survival at 5 years for patients transplanted in CR1, CR2, CR3 + , and non-CR were 58%, 61%, 41%, and 26% for AML patients and 67%, 45%, 20%, and 21% for ALL patients, respectively. Multivariate analyses revealed that the risks of relapse and overall mortality were similar for AML patients transplanted in CR1 and CR2 (P = 0.672 and P = 0.703), whereas they were higher for ALL patients transplanted in CR2 than for those transplanted in CR1 (P < 0.001 for both). The risks of relapse and overall mortality for those transplanted in CR3 + and non-CR increased in a stepwise manner for both diseases, with the relevance being stronger for ALL than for AML patients. These results suggest a significant difference in the effect of disease status at HCT on post-transplant outcomes in AML and ALL. Further investigation to incorporate measurable residual disease data is warranted.

Optimal treatment for Philadelphia-negative acute lymphoblastic leukemia in first remission in the era of high-intensity chemotherapy.

The optimal treatment for Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1) has not been established in the high-intensity chemotherapy era. The outcomes of patients with Ph-negative ALL who underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a human leukocyte antigen-matched related or unrelated donor in CR1 (HSCT-MRD group and HSCT-MUD group) were obtained from a Japanese registry database. Patients aged 16-24 years and 25-65 years were analyzed separately, and their outcomes were compared to those of patients who continued high-intensity chemotherapy in CR1 in studies (202U group and 202O group) by the Japan Adult Leukemia Study Group (JALSG). In the HSCT-MRD group, patients younger than 25 years had lower overall survival (OS) than the 202U group, presumably due to the higher non-relapse mortality (NRM) in the HSCT-MRD group. Patients 25 years and older had similar OS to the 202O group. The lower relapse rate was counterbalanced by higher NRM in the HSCT-MRD group. In the HSCT-MUD group, patients in both age groups had similar OS to their corresponding groups in the JALSG studies. In conclusion, high-intensity chemotherapy may change the role of HSCT for Ph-negative ALL.

Newly proposed threshold and validation of white blood cell count at diagnosis for Philadelphia chromosome-positive acute lymphoblastic leukemia: risk assessment of relapse in patients with negative minimal residual disease at transplantation-a report from the Adult Acute Lymphoblastic Leukemia Working Group of the JSTCT.

White blood cell count (WBC) at diagnosis is the conventional prognostic factor in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Nevertheless, little is known about the impact of WBC at diagnosis considering the minimal residual disease (MRD) status at allogeneic hematopoietic cell transplantation (HCT). We evaluated adult patients with Ph+ ALL who achieved negative-MRD and received HCT in first complete remission between 2006 and 2018. The entire cohort was temporally divided into derivation (n = 258) and validation cohorts (n = 366). Using a threshold of 15,000/µL, which was determined by a receiver operating characteristic curve analysis in the derivation cohort, high WBC was associated with an increased risk of hematological relapse in both the derivation cohort (25.3% vs. 11.6% at 7 years, P = 0.004) and the validation cohort (16.2% vs. 8.5% at 3 years, P = 0.025). In multivariate analyses, high WBC was a strong predictor of hematological relapse in the derivation cohort (HR, 2.52, 95%CI 1.32-4.80, P = 0.005) and in the validation cohort (HR, 2.32, 95%CI, 1.18-4.55; P = 0.015). In conclusion, WBC at diagnosis with a new threshold of 15,000/µL should contribute to better risk stratification in patients with negative-MRD at HCT.

Minimal residual disease (MRD) positivity at allogeneic hematopoietic cell transplantation, not the quantity of MRD, is a risk factor for relapse of Philadelphia chromosome-positive acute lymphoblastic leukemia.

Minimal residual disease (MRD) monitoring by quantitative real-time reverse transcription PCR (qRT-PCR) is the standard of care in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL). We evaluated the impact of MRD status at hematopoietic cell transplantation (HCT) on relapse, as measured by a unified protocol at a central laboratory. Only patients with Ph-positive ALL who had minor transcripts (e1a2) and who underwent allogeneic HCT in first complete remission between 2008 and 2017 were included. First, patients with negative-MRD (n = 196) and positive-MRD (n = 61) at HCT were analyzed. As expected, MRD positivity at HCT was significantly associated with an increased risk of hematological relapse (hazard ratio [HR], 2.91; 95% CI 1.67-5.08; P < 0.001) in the multivariate analysis. Next, patients with positive-MRD were divided into low-MRD (n = 39) and high-MRD (n = 22) groups. In the multivariate analysis, high-MRD at HCT was not significantly associated with an increased risk of hematological relapse compared to the low-MRD group (HR 1.10; 95% CI 0.54-2.83; P = 0.620). These results indicate that the therapeutic decisions should be made based on MRD positivity, rather than on the MRD level, at HCT.

Machine learning-aided risk stratification in Philadelphia chromosome-positive acute lymphoblastic leukemia.

We used the eXtreme Gradient Boosting algorithm, an optimized gradient boosting machine learning library, and established a model to predict events in Philadelphia chromosome-positive acute lymphoblastic leukemia using a machine learning-aided method. A model was constructed using a training set (80%) and prediction was tested using a test set (20%). According to the feature importance score, BCR-ABL lineage, polymerase chain reaction value, age, and white blood cell count were identified as important features. These features were also confirmed by the permutation feature importance for the prediction using the test set. Both event-free survival and overall survival were clearly stratified according to risk groups categorized using these features: 80 and 100% in low risk (two or less factors), 42 and 47% in intermediate risk (three factors), and 0 and 10% in high risk (four factors) at 4 years. Machine learning-aided analysis was able to identify clinically useful prognostic factors using data from a relatively small number of patients.

Measurable residual disease affects allogeneic hematopoietic cell transplantation in Ph+ ALL during both CR1 and CR2.

Although measurable residual disease (MRD) at the time of allogeneic hematopoietic cell transplantation (allo-HCT) has been reported to be an important prognostic factor for Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) during first complete remission (CR1), the prognostic impact of MRD is unclear during second CR (CR2). To clarify the impact of MRD for both CR1 and CR2, we analyzed data from a registry database including 1625 adult patients with Ph+ ALL who underwent first allo-HCT during either CR1 or CR2 between 2002 and 2017. Adjusted overall and leukemia-free survival rates at 4 years were 71% and 64%, respectively, for patients undergoing allo-HCT during CR1 with MRD-, 55% and 43% during CR1 with MRD+, 51% and 49% during CR2 with MRD-, and 38% and 29% during CR2 with MRD+. Although survival rates were significantly better among patients with CR1 MRD- than among patients with CR2 MRD-, no significant difference was observed in survival rate between patients with CR1 MRD+ and CR2 MRD-. Relapse rates after 4 years were 16% in patients with CR1 MRD-, 29% in CR1 MRD+, 21% in patients with CR2 MRD-, and 46% in patients with CR2 MRD+. No significant difference was identified in relapse rate between patients with CR1 MRD- and CR2 MRD-. CR2 MRD- was not a significant risk factor for relapse in multivariate analysis (hazard ratio, 1.26; 95% confidence interval, 0.69-2.29; P = .45 vs CR1 MRD-). MRD at time of allo-HCT was an important risk factor in patients with Ph+ ALL during both CR1 and CR2.

COVID-19 Pandemic and Trends in Clinical Trials: A Multi-Region and Global Perspective.

To evaluate the effect of the COVID-19 pandemic on clinical development, the number of newly started clinical trials in each geographical region between January 2018 and December 2020 were calculated based on data from the ClinicalTrials.gov database. Data regarding new drug applications were obtained from European Medicines Agency monthly reports, pharmaceutical company press releases, and the archives of the Drugs.com database. The mean percentage change in newly started clinical trials for diseases other than COVID-19 between each month in 2019 and the corresponding month in 2020 was -7.5%, with the maximum of -57.3% observed between April 2019 and April 2020. Similarly, the mean percentage change of reported results for each month in 2019 and 2020 was -5.1%, with the maximum of -27.4% observed in July 2020. The activity of clinical trials was decreased as the number of COVID-19 patients was increased, and a statistically negative correlation was observed between the prevalence of COVID-19 and the percentage decrease in the number of clinical trials stared or reported results. As for new drug submissions, decreases were observed in the latter half of 2020 compared with the same period during the previous year, for each indicator. A considerable decline in non-COVID-19 activity for all indicators regarding clinical developments was suggested during the first wave of the COVID-19 pandemic. It is important to recognize the situation and continue to make efforts to conduct clinical trials for both COVID-19 and no-COVID-19 for new medical developments in the future.

Phase I clinical trial of intra-bone marrow cotransplantation of mesenchymal stem cells in cord blood transplantation.

Mesenchymal stem cells (MSCs) have immunomodulatory properties and support hematopoiesis in the bone marrow (BM). To develop a new strategy to not only prevent graft-vs-host disease (GVHD) but also to enhance engraftment, a phase I trial of cord blood transplantation (CBT) combined with intra-BM injection of MSCs (MSC-CBT) was designed. Third-party BM-derived MSCs were injected intra-BM on the day of CBT. The conditioning regimen varied according to patient characteristics. GVHD prophylaxis was tacrolimus and methotrexate. The primary endpoint was toxicity related to intra-BM injection of MSCs. Clinical outcomes were compared with those of six controls who received CBT alone. Five adult patients received MSC-CBT, and no adverse events related to intra-BM injection of MSCs were observed. All patients achieved neutrophil, reticulocyte, and platelet recoveries, with median times to recoveries of 21, 35, and 38 days, respectively, comparable with controls. Grade II-IV acute GVHD developed in three controls but not in MSC-CBT patients. No patients developed chronic GVHD in both groups. At 1 year after transplantation, all MSC-CBT patients survived without relapse. This study shows the safety of MSC-CBT, and the findings also suggest that cotransplantation of MSCs may prevent GVHD with no inhibition of engraftment. This trial was registered at the University Hospital Medical Information Network Clinical Trials Registry as number 000024291.

In vivo tracking of transplanted macrophages with near infrared fluorescent dye reveals temporal distribution and specific homing in the liver that can be perturbed by clodronate liposomes.

Macrophages play an indispensable role in both innate and acquired immunity, while the persistence of activated macrophages can sometimes be harmful to the host, resulting in multi-organ damage. Macrophages develop from monocytes in the circulation. However, little is known about the organ affinity of macrophages in the normal state. Using in vivo imaging with XenoLight DiR®, we observed that macrophages showed strong affinity for the liver, spleen and lung, and weak affinity for the gut and bone marrow, but little or no affinity for the kidney and skin. We also found that administered macrophages were still alive 168 hours after injection. On the other hand, treatment with clodronate liposomes, which are readily taken up by macrophages via phagocytosis, strongly reduced the number of macrophages in the liver, spleen and lung.

Multi-Lineage BCR-ABL Expression in Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Is Associated With Improved Prognosis but No Specific Molecular Features.

BACKGROUND: Recently, various blood cell lineages expressing the BCR-ABL fusion gene in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) have been reported. However, the biological and clinical significance of these BCR-ABL lineages has not been established; therefore, we aimed to clarify the impacts of these different BCR-ABL-expressing lineages. PATIENTS: Multi-lineage BCR-ABL expression (multi-Ph) was defined as BCR-ABL expression outside of the B-lineage compartment, as determined by fluorescence in situ hybridization (FISH) in peripheral blood neutrophils and bone marrow clots, and flow cytometry-sorted polymerase chain reaction (PCR). We analyzed IKZF1 deletion patterns by PCR, examined gene expression profiles using RNA sequencing, and compared treatment outcomes across different BCR-ABL-expressing lineages. RESULTS: Among the 21 multi-Ph patients in our 59-patient cohort (36%), BCR-ABL expression was detected at the multipotential progenitor level. However, no IKZF1 deletion patterns or gene expression profiles were identified that were specific for multi-Ph. However, multi-Ph patients were found to have better survival rates than patients with uni-lineage BCR-ABL expression [event-free survival (EFS): 74 vs. 33%, P = 0.01; overall survival (OS): 79 vs. 44% at 4 years, P = 0.01]. In multivariate analyses, multi-Ph was identified as a good prognostic factor for both EFS and OS. CONCLUSION: We confirmed that more than one-third of Ph+ALL patients could be classified as mutli-Ph. Although no specific molecular characteristics were identified for multi-Ph, this phenotype was associated with better treatment outcomes.

Gap between pediatric and adult approvals of molecular targeted drugs.

To clarify the approval status of molecular targeted antineoplastic drugs in the United States (U.S.), the European Union (E.U.), and Japan (JP), we checked the status of pediatric indications according to the package insert of each drug. A total of 103 drugs were approved for adult patients in at least one of the three regions whereas only 19 drugs were approved for pediatric patients. Sixty-six of 103 drugs (64.1%) had adult indications in the U.S., the E.U., and JP, whereas only three drugs had pediatric indications in all three regions. Abnormalities in six genes (NRAS, ABL1, JAK2, KIT, ALK and BRAF) were common in childhood cancers as well as adult cancers, for which at least one approved drug could be a potentially actionable drug. Although there were 16 candidate drugs that had adult indications for these abnormalities, only three drugs (18.8%) had pediatric indications. We confirmed that there were few molecular targeted antineoplastic drugs with pediatric indications in the U.S., the E.U., and JP compared with the number of approved drugs for adults. Drugs targeting genomic abnormalities which were common in both adult and pediatric cancers were considered to be good candidates for expansion of their indication for pediatric patients.