Irinotecan and temozolomide in combination with dasatinib and rapamycin versus irinotecan and temozolomide for patients with relapsed or refractory neuroblastoma (RIST-rNB-2011): a multicentre, open-label, randomised, controlled, phase 2 trial.

BACKGROUND: Neuroblastoma is the most common extracranial solid tumour in children. Relapsed or refractory neuroblastoma is associated with a poor outcome. We assessed the combination of irinotecan-temozolomide and dasatinib-rapamycin (RIST) in patients with relapsed or refractory neuroblastoma. METHODS: The multicentre, open-label, randomised, controlled, phase 2, RIST-rNB-2011 trial recruited from 40 paediatric oncology centres in Germany and Austria. Patients aged 1-25 years with high-risk relapsed (defined as recurrence of all stage IV and MYCN amplification stages, after response to treatment) or refractory (progressive disease during primary treatment) neuroblastoma, with Lansky and Karnofsky performance status at least 50%, were assigned (1:1) to RIST (RIST group) or irinotecan-temozolomide (control group) by block randomisation, stratified by MYCN status. We compared RIST (oral rapamycin [loading 3 mg/m2 on day 1, maintenance 1 mg/m2 on days 2-4] and oral dasatinib [2 mg/kg per day] for 4 days with 3 days off, followed by intravenous irinotecan [50 mg/m2 per day] and oral temozolomide [150 mg/m2 per day] for 5 days with 2 days off; one course each of rapamycin-dasatinib and irinotecan-temozolomide for four cycles over 8 weeks, then two courses of rapamycin-dasatinib followed by one course of irinotecan-temozolomide for 12 weeks) with irinotecan-temozolomide alone (with identical dosing as experimental group). The primary endpoint of progression-free survival was analysed in all eligible patients who received at least one course of therapy. The safety population consisted of all patients who received at least one course of therapy and had at least one post-baseline safety assessment. This trial is registered at ClinicalTrials.gov, NCT01467986, and is closed to accrual. FINDINGS: Between Aug 26, 2013, and Sept 21, 2020, 129 patients were randomly assigned to the RIST group (n=63) or control group (n=66). Median age was 5·4 years (IQR 3·7-8·1). 124 patients (78 [63%] male and 46 [37%] female) were included in the efficacy analysis. At a median follow-up of 72 months (IQR 31-88), the median progression-free survival was 11 months (95% CI 7-17) in the RIST group and 5 months (2-8) in the control group (hazard ratio 0·62, one-sided 90% CI 0·81; p=0·019). Median progression-free survival in patients with amplified MYCN (n=48) was 6 months (95% CI 4-24) in the RIST group versus 2 months (2-5) in the control group (HR 0·45 [95% CI 0·24-0·84], p=0·012); median progression-free survival in patients without amplified MYCN (n=76) was 14 months (95% CI 9-7) in the RIST group versus 8 months (4-15) in the control group (HR 0·84 [95% CI 0·51-1·38], p=0·49). The most common grade 3 or worse adverse events were neutropenia (54 [81%] of 67 patients given RIST vs 49 [82%] of 60 patients given control), thrombocytopenia (45 [67%] vs 41 [68%]), and anaemia (39 [58%] vs 38 [63%]). Nine serious treatment-related adverse events were reported (five patients given control and four patients given RIST). There were no treatment-related deaths in the control group and one in the RIST group (multiorgan failure). INTERPRETATION: RIST-rNB-2011 demonstrated that targeting of MYCN-amplified relapsed or refractory neuroblastoma with a pathway-directed metronomic combination of a multkinase inhibitor and an mTOR inhibitor can improve progression-free survival and overall survival. This exclusive efficacy in MYCN-amplified, relapsed neuroblastoma warrants further investigation in the first-line setting. FUNDING: Deutsche Krebshilfe.

An association between Dasatinib, elevated left atrial pressure and pleural effusion.

BACKGROUND: Tyrosine kinase inhibitors (TKI), such as Dasatinib, are effective in the treatment of chronic myeloid leukemia (CML) but associated with development of pleural effusions (PE). The relationship between haemodynamic parameters identified on transthoracic echocardiogram (TTE) such as elevated estimated left atrial pressure (LAP), and PE development is unknown. This study aims to describe associations between Dasatinib, elevated LAP and PE. METHODS: This was a retrospective study of 71 CML patients who underwent TTE during treatment with various TKIs. Descriptive analysis was performed to identify associations between TKI use, PE and elevated LAP on TTE. Multivariate logistic regression was performed to identify predictors of elevated LAP. RESULTS: There were 36 patients treated with Dasatinib, 15 Nilotinib, and 20 Imatinib. Those treated with Dasatinib had higher rates of elevated LAP (44% vs 7% Nilotinib vs 10% Imatinib, p < 0.01) and PE (39% vs 7% vs 0%, p < 0.01). In the 15 patients who developed PE, 14 (93%) patients were treated with Dasatinib. Patients with PE had higher rates of elevated LAP (67% vs 16%, p < 0.01). Nineteen (26.8%) patients in the entire cohort had elevated LAP. After multivariate adjustment, Dasatinib (OR 33.50, 95% CI = 4.99-224.73, p < 0.01) and age (OR 1.12, 95% CI = 1.04-1.20, p < 0.01) were associated with elevated LAP. CONCLUSIONS: Among patients with CML, there was an association between Dasatinib use, PE and elevated LAP on TTE. These findings are hypothesis generating and further studies are required to evaluate the utility of elevated LAP on TTE as a novel marker for prediction and surveillance of PE.

[The Effect and Safety of Flumatinib in Patients with Chronic Myelogenous Leukemia Failed First-and Second-line Treatment].

OBJECTIVE: To analyze the efficacy and safety of flumatinib, a second-generation tyrosine kinase inhibitor (TKI) independently developed in China, in patients with chronic myelogenous leukemia in chronic phase (CML-CP) who falied first-line and second-line treatment. METHODS: The clinical data of 30 CML-CP patients treated with flumatinib in Lianyungang First People's Hospital from January 2020 to September 2022 were collected retrospectively. Among them, 15 patients who received imatinib first-line treatment but failed treatment were included in the second-line group, and the other 15 patients who failed second-line treatment with nilotinib or dasatinib were included in the third-line group. The hematological and molecular responses of the patients in the two groups at 3, 6 and 12 months of treatment, and the event-free survival (EFS) and adverse reactions of patients at the end of follow-up were statistical analyzed. RESULTS: At 3, 6, and 12 months of treatment, 10, 11, and 12 patients in the second line group achieved major molecular response (MMR), which was higher than that of 3, 4, and 5 patients in the third line group (P =0.010, P =0.011, P =0.010). At 3 months of treatment, 12 and 13 patients achieved complete hematological response (CHR) and early molecular response (EMR) in the second-line group, which was higher than that of 9 and 13 patients in the third-line group, but the difference between the two groups was not statistically significant (P =0.232, P =1.000); At 6 and 12 months of treatment, 6 and 7 patients in the second-line group achieved MR4.5, which were higher than of 3 and 2 cases in the third-line group, but the difference was not statistically significant (P =0.427, P =0.713). The hematological adverse reactions of patients in the second-line group during treatment the period were mainly grade 1-2 thrombocytopenia and anemia, and no grade 3-4 of adverse reactions occurred. In the third-line group, there were 2 cases of grade 1-2 thrombocytopenia, grade 1-2 anemia and white blood cell 3 cases were reduced each, 1 case of grade 3-4 anemia, 2 cases of grade 3-4 neutropenia. The non-hematological adverse reactions in the second-line group were rash (2 cases), headache (1 case), diarrhea (1 case), fatigue (1 case), limb pain (1 case). There were 1 cases of diarrhea, 1 cases of nausea, and 1 cases of edema in the third-line group. There was no statistical significance in hematological and non-hematological adverse reactions between the two groups of patients (P >0.05). At the end of follow-up, the EFS rate of patients in the second-line group was higher than that in the third-line group (100% vs 93.3%), but the difference was not statistically significant (P =0.317). CONCLUSION: The second-generation TKI flumatinib independently developed in China, has good curative effect and safety for CML-CP patients who failed first-line and second-line treatment.

Incidence of pleural effusion with dasatinib and the effect of switching therapy to a different TKI in patients with chronic phase CML.

Dasatinib is one of the second generation tyrosine kinase inhibitors (TKI) which is approved for the treatment of patients with chronic phase CML (CP-CML) both in the front line and in the second line setting. Pleural effusion (PE) is a unique toxicity associated with dasatinib use. Our aim was to study the incidence of pleural effusion in our cohort of patients who were treated with dasatinib for CP-CML and the safety upon TKI switch. A total of 390 patients were treated with dasatinib during their course of treatment for CP-CML. A total of 69 patients (17.6%) developed any grade of PE. About 33 (48%) patients developed CTCAE grade 2 PE, 34 (49%) grade 3 and only 1 patient developed grade 4 PE. Recurrence of PE was observed in 34 (49%) patients. While only 12 patients (17.3%) continued using dasatinib after development of PE, dasatinib was discontinued in the other 57 patients. Therapy was switched to bosutinib in 13 patients out of which 6 (46%) patients re-developed PE. While only 12.5% patients developed re-accumulation of pleural fluid in patients switched to imatinib, none of the patients switched to nilotinib re-developed PE. A change in TKI to bosutinib was associated with a 46% risk of recurrence of PE in patients who develop PE on dasatinib for the treatment of CP-CML. The incidence of recurrent PE was markedly lower in patient switched to imatinib or nilotinib.

Drug-induced chylothorax as a rare pleural complication in dasatinib therapy for chronic myeloid leukaemia.

Chylothorax is a lymphatic chylous pleural effusion typically associated with traumatic (iatrogenic, non-iatrogenic) and non-traumatic (infections, malignancy, lymphatic disorders) aetiologies. Drug-induced chylothorax is uncommon and mostly reported in association with BCR-ABL tyrosine kinase inhibitor therapy.

Role of KCNK3 Dysfunction in Dasatinib-associated Pulmonary Arterial Hypertension and Endothelial Cell Dysfunction.

Pulmonary arterial (PA) hypertension (PAH) is a severe cardiopulmonary disease that may be triggered by exposure to drugs such as dasatinib or facilitated by genetic predispositions. The incidence of dasatinib-associated PAH is estimated at 0.45%, suggesting individual predispositions. The mechanisms of dasatinib-associated PAH are still incomplete. We discovered a KCNK3 gene (Potassium channel subfamily K member 3; coding for outward K+ channel) variant in a patient with dasatinib-associated PAH and investigated the impact of this variant on KCNK3 function. Additionally, we assessed the effects of dasatinib exposure on KCNK3 expression. In control human PA smooth muscle cells (hPASMCs) and human pulmonary endothelial cells (hPECs), we evaluated the consequences of KCNK3 knockdown on cell migration, mitochondrial membrane potential, ATP production, and in vitro tube formation. Using mass spectrometry, we determined the KCNK3 interactome. Patch-clamp experiments revealed that the KCNK3 variant represents a loss-of-function variant. Dasatinib contributed to PA constriction by decreasing KCNK3 function and expression. In control hPASMCs, KCNK3 knockdown promotes mitochondrial membrane depolarization and glycolytic shift. Dasatinib exposure or KCNK3 knockdown reduced the number of caveolae in hPECs. Moreover, KCNK3 knockdown in control hPECs reduced migration, proliferation, and in vitro tubulogenesis. Using proximity labeling and mass spectrometry, we identified the KCNK3 interactome, revealing that KCNK3 interacts with various proteins across different cellular compartments. We identified a novel pathogenic variant in KCNK3 and showed that dasatinib downregulates KCNK3, emphasizing the relationship between dasatinib-associated PAH and KCNK3 dysfunction. We demonstrated that a loss of KCNK3-dependent signaling contributes to endothelial dysfunction in PAH and glycolytic switch of hPASMCs.

Efficacy and safety of bosutinib in patients treated with prior imatinib and/or dasatinib and/or nilotinib: Subgroup analyses from the phase 4 BYOND study.

The BYOND study evaluated the efficacy and safety of bosutinib 500 mg once daily in patients with chronic myeloid leukemia (CML) resistant/intolerant to prior tyrosine kinase inhibitors (TKIs). These post-hoc analyses assessed the efficacy and safety of bosutinib by resistance or intolerance to prior TKIs (imatinib-resistant vs dasatinib/nilotinib-resistant vs TKI-intolerant), and cross-intolerance between bosutinib and prior TKIs (imatinib, dasatinib, nilotinib), in patients with Philadelphia chromosome-positive chronic phase CML. Data are reported after ≥3 years' follow-up. Of 156 patients with Philadelphia chromosome-positive chronic phase CML, 53 were imatinib-resistant, 29 dasatinib/nilotinib-resistant, and 74 intolerant to all prior TKIs; cumulative complete cytogenetic response rates at any time were 83.7%, 61.5%, and 86.8%, and cumulative major molecular response rates at any time were 72.9%, 40.7%, and 82.4%, respectively. Of 141, 95, and 79 patients who received prior imatinib, dasatinib, and nilotinib, 64 (45.4%), 71 (74.7%), and 60 (75.9%) discontinued the respective TKI due to intolerance; of these, 2 (3.1%), 5 (7.0%), and 0 had cross-intolerance with bosutinib. The response rates observed in TKI-resistant and TKI-intolerant patients, and low cross-intolerance between bosutinib and prior TKIs, further support bosutinib use for patients with Philadelphia chromosome-positive chronic phase CML resistant/intolerant to prior TKIs. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02228382.

Comparison of long-term outcomes between imatinib and dasatinib prophylaxis after allogeneic stem cell transplantation in patients with Philadelphia-positive acute lymphoblastic leukemia: A multicenter retrospective study.

BACKGROUND: Although the prognosis of Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) has improved with the introduction of tyrosine kinase inhibitors (TKIs) and stem cell transplantation, prevention of relapse after transplantation remains a concern. The aim of this study was to compare the impact of TKI prophylaxis with imatinib and dasatinib on long-term outcomes after transplantation. METHODS: Patients with Ph+ ALL who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1) and received TKI prophylaxis after allo-HSCT were included in this retrospective analysis. Two cohorts were established based on the choice of TKI prophylaxis: the imatinib (Ima) and dasatinib (Das) cohorts. The survival and safety outcomes of these cohorts were compared. RESULTS: Ninety-one patients in the Ima cohort and 50 in the Das cohort were included. After a median follow-up of 50.6 months, the 5-year cumulative incidence of relapse, nonrelapse mortality rate, and overall survival in the Ima and Das cohorts were 16.1% and 12.5%, 5.2% and 9.8%, and 86.5% and 77.6%, respectively, with no statistical differences. The cumulative incidence of mild chronic graft-versus-host disease was higher in the Das cohort. The most common adverse event was neutropenia (64.7% vs. 69.5%). The Das cohort had a higher incidence of gastrointestinal bleeding (25.5% vs. 2.3%) and gastrointestinal reaction (48.9% vs. 31.4%) than the Ima cohort. The proportion of patients treated on schedule was significantly lower in the Das cohort than in the Ima cohort, and drug intolerance was the main reason for protocol violation. CONCLUSIONS: For patients with Ph+ ALL undergoing allo-HSCT in CR1, imatinib prophylaxis achieved long-term outcomes similar to those of dasatinib.

Pharmacovigilance study of BCR-ABL1 tyrosine kinase inhibitors: a safety analysis of the FDA adverse event reporting system.

BACKGROUND: With the increased use of BCR-ABL1 tyrosine kinase inhibitors (TKIs) in cancer patients, adverse events (AEs) have garnered considerable interest. We conducted this pharmacovigilance study to evaluate the AEs of BCR-ABL1 TKIs in cancer patients using the Food and Drug Administration Adverse Event Reporting System (FAERS) database. METHODS: To query AE reports from the FAERS database, we used OpenVigil 2.1. Descriptive analysis was then employed to describe the characteristics of TKIs-associated AE reports. We also utilized the disproportionality analysis to detect safety signals by calculating the proportional reporting ratio (PRR) and reporting odds ratios (ROR). RESULTS: From the FAERS database, a total of 85,989 AE reports were retrieved, with 3,080 significant AE signals identified. Specifically, imatinib, nilotinib, dasatinib, bosutinib, and ponatinib had significant AE signals of 1,058, 813, 232, 186, and 791, respectively. These significant signals were further categorized into 26 system organ classes (SOCs). The AE signals of imatinib and ponatinib were primarily associated with general disorders and administration site conditions. On the other hand, nilotinib, dasatinib, and bosutinib were mainly linked to investigations, respiratory, thoracic and mediastinal disorders, and gastrointestinal disorders, respectively. Notably, new signals of 245, 278, 47, 55, and 253 were observed in imatinib, nilotinib, dasatinib, bosutinib, and ponatinib, respectively. CONCLUSIONS: The results of this study demonstrated that AE signals differ among the five BCR-ABL1 TKIs. Furthermore, each BCR-ABL1 TKI displayed several new signals. These findings provide valuable information for clinicians aiming to reduce the risk of AEs during BCR-ABL1 TKI treatment.

Treatment-free remission after a second TKI discontinuation attempt in patients with Chronic Myeloid Leukemia re-treated with dasatinib - interim results from the DAstop2 trial.

Tyrosine kinase inhibitor (TKI) discontinuation in chronic myeloid leukemia (CML) has become part of routine care for patients with a sustained deep molecular response (DMR). Approximately 50% experience a molecular relapse upon TKI cessation. Most of them quickly regain DMR upon TKI resumption. Whether these patients can achieve a second treatment-free remission (TFR) remains unclear. DAstop2 (ClinicalTrials.gov ID: NCT03573596) is a prospective study including patients with a failed first TFR attempt re-treated with any TKI for ≥ one year. Upon entering the study, patients received the TKI dasatinib for additional two years. Patients with sustained DMR for ≥1 year qualified for a second TKI stop. Ninety-four patients were included between Oct 2017-Dec 2021. At the time of data analysis, 62 patients had attempted a 2nd stop. After a median follow-up of 27 months from 2nd stop, TFR rates were 61, 56 and 46% at 6, 12 and 24 months respectively. No progression to advanced stage disease was seen and 87% had re-achieved MR4 within a median of 3 months from TKI re-initiation. In summary, we show that a 2nd TFR attempt after dasatinib treatment is safe, feasible and TFR rates seem in the range of those reported in trials of a first TKI stop.

Second Treatment-Free Remission Attempt in Patients with Chronic Myeloid Leukemia.

Long-term survival outcomes of patients with chronic myeloid leukemia in the chronic phase are now similar to those of the general population, following the introduction of ABL1 tyrosine kinase inhibitors (TKIs). Approximately 40% to 80% of patients with chronic myeloid leukemia successfully achieved treatment-free remission after the first attempt of TKI discontinuation (TFR1), after achieving a durable deep molecular response. However, the possibility of achieving treatment-free remission after a second attempt of TKI discontinuation (TFR2) remains unclear. Therefore, we reviewed current TFR2 studies to clarify the feasibility of achieving TFR2. We identified 5 TFR2 clinical trials and 2 real-world reports. TFR2 attempt may be feasible after retreatment with imatinib, nilotinib, or dasatinib. Patients who have achieved MR4.0 or deeper durable molecular remission are eligible to enter the TFR2 phase. Imatinib is well tolerated and can be administered for consolidative treatment before the TFR2 attempt, whereas drug-related adverse effects of nilotinib or dasatinib affect their tolerability and might lead to discontinuation. Late onset relapse (> 1 year or > 2 year) was often reported, thus careful monitoring is needed.

Effect of Tyrosine Kinase Inhibitor Therapy on Estimated Glomerular Filtration Rate in Patients with Chronic Myeloid Leukemia.

INTRODUCTION: The advent of tyrosine kinase inhibitors (TKIs) was revolutionary in the management of chronic myeloid leukemia (CML). Although TKIs were generally considered to be safe, they can be associated with renal injury. We evaluated the effect of TKIs on renal functions in a cohort of patients with long-term follow-up. MATERIAL AND METHODS: We retrospectively examined patients with chronic phase CML treated with TKIs. We analyzed the estimated glomerular filtration rate (eGFR) of patients from the initiation of TKI to the last follow-up. eGFR values of CML patients were compared to those of patients with stage 1 or 2 chronic kidney disease (CKD). RESULTS: A total of 195 patients with CML and 138 patients with CKD were examined. eGFR decline was 1.556 ml/min/1.73m2/year for patients with CML (P = .221). Patients receiving second-generation TKIs (2GTKI) were estimated to have 0.583 ml/min/1.73m2 higher eGFR value than that of the imatinib group, but it was not significant (P = .871). eGFR of patients who had used bosutinib had a downward trend. Duration of TKI therapy, age, and hypertension were found to be significant factors in eGFR decline for CML patients. Lower baseline GFR was associated with an increased risk of CKD development. CONCLUSION: Imatinib could result in a decline in eGFR which was clinically similar to early-stage CKD patients. We did not observe significant kidney function deterioration in patients receiving 2GTKIs including dasatinib and nilotinib. We recommend close renal function monitoring in patients receiving imatinib, especially for elderly patients with lower baseline eGFR and hypertension.

Long-Term Results of the Dasatinib-Blinatumomab Protocol for Adult Philadelphia-Positive ALL.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We report the long-term results of the frontline trial with dasatinib and blinatumomab in induction/consolidation (GIMEMA LAL2116, D-ALBA) for adult Philadelphia-positive ALL (Ph+ ALL), which enrolled 63 patients of all ages. At a median follow-up of 53 months, disease-free survival, overall survival, and event-free survival are 75.8%, 80.7%, and 74.6%, respectively. No events have occurred among early molecular responders. A significantly worse outcome was recorded for IKZF1plus patients. Twenty-nine patients-93.1% being in molecular response (ie, complete molecular response or positive nonquantifiable) after dasatinib/blinatumomab-never received chemotherapy/transplant and continued with a tyrosine kinase inhibitor only; 28 patients remain in long-term complete hematologic response (CHR). An allogeneic transplant was carried out in first CHR mainly in patients with persistent minimal residual disease; 83.3% of patients are in continuous CHR. The transplant-related mortality was 12.5% for patients transplanted in first CHR and 13.7% overall. Nine relapses and six deaths have occurred. ABL1 mutations were found in seven cases. The final analysis of the D-ALBA study shows that a chemotherapy-free induction/consolidation regimen on the basis of a targeted strategy (dasatinib) and immunotherapy (blinatumomab) is effective in inducing durable long-term hematologic and molecular responses in adult Ph+ ALL, paving the way for a new era in the management of these patients.

SOHO State of the Art Updates and Next Questions: Chronic Myeloid Leukemia and Pregnancy: "Per Aspera Ad Astra".

Chronic myeloid leukemia (CML) has evolved from an invariably fatal disease to a chronic disorder that can be treated with targeted drugs and allows survival expectations approaching age-matched controls. Thus, pregnancy and conception in CML should not be precluded anymore; however, to ensure the well-being of both the mother and the developing fetus careful planning and management are required. Tyrosine Kinase Inhibitors (TKIs) are not genotoxic or carcinogenic but can pose a risk to the developing fetus, due to their teratogenic potential. The risk depends on the TKI and the stage of fetal development during exposure. Teratogenic risk is high in the first trimester of pregnancy when the baby's organs and structures are forming (5-12 weeks). If a female patient is on therapy it is advisable to stop therapy at the first positive pregnancy test (3-5 weeks) to maximize the length of treatment-free, and ideally to not treat until delivery. If needed, the medication plan during pregnancy may be adjusted. Interferons can be used at any time, imatinib and nilotinib have a reduced placental crossing and could be carefully used after 16 weeks, whereas dasatinib crosses the placenta and can induce problems throughout the whole gestation. Management of pregnancy in CML is complex. This manuscript is an update of the state of the art allowing healthcare providers to be informed of the different situations that can occur and their governance.

The Role of Cellular Senescence in Cyclophosphamide-Induced Primary Ovarian Insufficiency.

Young female cancer patients can develop chemotherapy-induced primary ovarian insufficiency (POI). Cyclophosphamide (Cy) is one of the most widely used chemotherapies and has the highest risk of damaging the ovaries. Recent studies elucidated the pivotal roles of cellular senescence, which is characterized by permanent cell growth arrest, in the pathologies of various diseases. Moreover, several promising senolytics, including dasatinib and quercetin (DQ), which remove senescent cells, are being developed. In the present study, we investigated whether cellular senescence is involved in Cy-induced POI and whether DQ treatment rescues Cy-induced ovarian damage. Expression of the cellular senescence markers p16, p21, p53, and γH2AX was upregulated in granulosa cells of POI mice and in human granulosa cells treated with Cy, which was abrogated by DQ treatment. The administration of Cy decreased the numbers of primordial and primary follicles, with a concomitant increase in the ratio of growing to dormant follicles, which was partially rescued by DQ. Moreover, DQ treatment significantly improved the response to ovulation induction and fertility in POI mice by extending reproductive life. Thus, cellular senescence plays critical roles in Cy-induced POI, and targeting senescent cells with senolytics, such as DQ, might be a promising strategy to protect against Cy-induced ovarian damage.

Differential vascular endothelial cell toxicity of established and novel BCR-ABL tyrosine kinase inhibitors.

BCR-ABL tyrosine kinase inhibitors (TKIs) have dramatically improved survival in Philadelphia chromosome-positive leukemias. Newer BCR-ABL TKIs provide superior cancer outcomes but with increased risk of acute arterial thrombosis, which further increases in patients with cardiovascular comorbidities and mitigates survival benefits compared to imatinib. Recent studies implicate endothelial cell (EC) damage in this toxicity by unknown mechanisms with few side-by-side comparisons of multiple TKIs and with no available data on endothelial impact of recently approved TKIs or novels TKIs being tested in clinical trials. To characterize BCR-ABL TKI induced EC dysfunction we exposed primary human umbilical vein ECs in 2D and 3D culture to clinically relevant concentrations of seven BCR-ABL TKIs and quantified their impact on EC scratch-wound healing, viability, inflammation, and permeability mechanisms. Dasatinib, ponatinib, and nilotinib, the TKIs associated with thrombosis in patients, all significantly impaired EC wound healing, survival, and proliferation compared to imatinib, but only dasatinib and ponatinib impaired cell migration and only nilotinib enhanced EC necrosis. Dasatinib and ponatinib increased leukocyte adhesion to ECs with upregulation of adhesion molecule expression in ECs (ICAM1, VCAM1, and P-selectin) and leukocytes (PSGL1). Dasatinib increased permeability and impaired cell junctional integrity in human engineered microvessels, consistent with its unique association with pleural effusions. Of the new agents, bafetinib decreased EC viability and increased microvessel permeability while asciminib and radotinib did not impact any EC function tested. In summary, the vasculotoxic TKIs (dasatinib, ponatinib, nilotinib) cause EC toxicity but with mechanistic differences, supporting the potential need for drug-specific vasculoprotective strategies. Asciminib and radotinib do not induce EC toxicity at clinically relevant concentrations suggesting a better safety profile.

Phase I trial of Ganitumab plus Dasatinib to Cotarget the Insulin-Like Growth Factor 1 Receptor and Src Family Kinase YES in Rhabdomyosarcoma.

PURPOSE: Antibodies against insulin-like growth factor (IGF) type 1 receptor have shown meaningful but transient tumor responses in patients with rhabdomyosarcoma (RMS). The SRC family member YES has been shown to mediate IGF type 1 receptor (IGF-1R) antibody acquired resistance, and cotargeting IGF-1R and YES resulted in sustained responses in murine RMS models. We conducted a phase I trial of the anti-IGF-1R antibody ganitumab combined with dasatinib, a multi-kinase inhibitor targeting YES, in patients with RMS (NCT03041701). PATIENTS AND METHODS: Patients with relapsed/refractory alveolar or embryonal RMS and measurable disease were eligible. All patients received ganitumab 18 mg/kg intravenously every 2 weeks. Dasatinib dose was 60 mg/m2/dose (max 100 mg) oral once daily [dose level (DL)1] or 60 mg/m2/dose (max 70 mg) twice daily (DL2). A 3+3 dose escalation design was used, and maximum tolerated dose (MTD) was determined on the basis of cycle 1 dose-limiting toxicities (DLT). RESULTS: Thirteen eligible patients, median age 18 years (range 8-29) enrolled. Median number of prior systemic therapies was 3; all had received prior radiation. Of 11 toxicity-evaluable patients, 1/6 had a DLT at DL1 (diarrhea) and 2/5 had a DLT at DL2 (pneumonitis, hematuria) confirming DL1 as MTD. Of nine response-evaluable patients, one had a confirmed partial response for four cycles, and one had stable disease for six cycles. Genomic studies from cell-free DNA correlated with disease response. CONCLUSIONS: The combination of dasatinib 60 mg/m2/dose daily and ganitumab 18 mg/kg every 2 weeks was safe and tolerable. This combination had a disease control rate of 22% at 5 months.