Gilteritinib with or without venetoclax for relapsed/refractory FLT3-mutated acute myeloid leukaemia.

Patients with FLT3-mutated acute myeloid leukaemia (AML) that relapse or are refractory (R/R) to intensive induction have poor outcomes. Gilteritinib has recently become standard-of-care for patients with R/R FLT3-mutated AML. We investigated whether adding venetoclax to gilteritinib (gilt-ven) improves outcomes as compared with gilteritinib monotherapy. We included patients treated with gilteritinib (n = 19) and gilt-ven (n = 17) for R/R AML after intensive chemotherapy. Gilteritinib and gilt-ven groups did not differ in terms of mCRc rates (53% and 65%, p = 0.51) and realization of allogeneic haematopoietic stem-cell transplantation (HSCT, 47% and 35%, p = 0.5). Overall survival (OS) was comparable between groups, although a trend towards better OS was seen with gilt-ven (12-month OS 58.8% [95% CI 39.5%-87.6%]) versus gilteritinib (42.1% [95% CI 24.9%-71.3%] for gilteritinib). Early salvage with gilt-ven versus any other gilteritinib-based approach was associated with the best outcome (p = 0.031). Combination therapy was associated with increased haematological toxicity. In summary, gilt-ven did not improve remissions or HSCT-realization rates in patients with R/R FLT3-mutated AML as compared with gilteritinib and was associated with increased haematological toxicity. Although OS did not differ, a trend towards better survival was suggested with gilt-ven and a survival benefit was shown for gilt-ven approach when sequenced early for salvage.

Successful Treatment with Daratumumab of a Patient with Monoclonal Lambda Light Chain Disease Presenting as Nephrotic Syndrome and Crescentic Glomerulonephritis.

INTRODUCTION: Monoclonal immunoglobulin deposition diseases (MIDDs) are a group of systemic diseases, characterized by deposition of monoclonal immunoglobulin predominantly in the kidney. In the absence of overt hematologic disease, MIDDs are classified as a part of monoclonal gammopathy of renal significance. Patients with MIDD may present with a nephrotic syndrome and kidney function impairment. Treatment usually includes anti-plasma cell therapy. CASE PRESENTATION: We report a case of a 54-year-old female who presented with nephrotic syndrome related to light chain deposition disease of lambda type. Due to a complicated clinical course (including cardiac injury and thromboembolic stroke), plasma cell-targeted therapy was stopped. A few months later, the patient presented with severe acute kidney injury. Kidney biopsy revealed crescentic glomerulonephritis, and immunofluorescence staining was positive for lambda chain. Treatment with daratumumab was initiated resulting in stabilization of kidney function and partial nephrotic syndrome remission. CONCLUSION: This case highlights an uncommon histologic manifestation in a patient diagnosed with light chain deposition disease. Furthermore, it underscores the significance of plasma cell-targeted therapy and the favorable clinical and hematological response observed with daratumumab.

Real-world experience with belantamab mafodotin therapy for relapsed/refractory multiple myeloma: A multicentre retrospective study.

Belantamab mafodotin, an immuno-conjugate targeting B-cell maturation antigen, showed single-agent activity in phase 1 and 2 studies, and was recently approved for heavily pretreated relapsed/refractory multiple myeloma (RRMM) patients. Real-world data and long-term follow-up are scarce. We conducted a multisite retrospective study aimed to assess safety and efficacy of belantamab mafodotin monotherapy administered via the GSK expanded access compassionate care programme. One-hundred and six RRMM patients were treated with belantamab mafodotin between July 2019 and March 2021. The median age was 69.4 years. Patients were heavily pretreated with a median of six (range 2-11) prior therapy lines. Major adverse effects included ocular toxicity (keratopathy 68.4%, grade ≥3: 40.5%; blurred vision 36.8%, grade ≥3: 6.3%), thrombocytopenia (27.4%, grade ≥3: 17.9%) and infections (11.3%, grade ≥3: 7.5%). Median follow-up time was 11.9 [95% confidence interval (CI) 10.0-13.8] months. Overall response rate was 45.5%. Median progression-free survival was 4.7 (95% CI 3.5-5.9) months in the entire cohort and 8.8 (95% CI 6.6-10.9) months among responders. Median overall survival was 14.5 (95% CI 9.5-19.6) months, and not reached for responders. To conclude, in a real-world setting, belantamab mafodotin monotherapy showed efficacy comparable with the prospective clinical trials, with a tolerable toxicity profile.

Venetoclax-based salvage therapy for adult patients with relapsed/refractory acute lymphoblastic leukemia.

OBJECTIVES: Dysregulation of BCL-2 family members has been reported in acute lymphocytic leukemia (ALL), with various BH3-dependencies of the leukemic clone. We conducted a multicenter retrospective cohort of patients with relapsed/refractory B or T ALL, with ven-chemotherapy or ven-navitoclax combinations, to assess efficacy and safety. METHODS: Seventeen patients were included in the analysis, median age was 32 years, with 6 B-ALL and 11 T-ALL patients. Nine patients received venetoclax combined with chemotherapy, and 13 patients received venetoclax in combination with navitoclax, vincristine and asparaginase, of which 5 were already exposed to venetoclax in previous lines. RESULTS: ORR was 55% and 46% among the ven-chemotherapy and the ven-navitoclax-chemotherapy, respectively. Most of the responders proceeded to an allogenic bone marrow transplant in both cohorts. The most common adverse effects of the ven-navitoclax combination were infectious complications and hepatotoxicity. CONCLUSIONS: Our data demonstrated the possible efficacy of ven-chemotherapy and ven-navitoclax in r/r ALL with moderate toxicity.

Gilteritinib monotherapy for relapsed/refractory FLT3 mutated acute myeloid leukemia: a real-world, multi-center, matched analysis.

Patients with FLT3-mutated relapsed or refractory (R/R) acute myeloid leukemia (AML) have a dismal prognosis. Gilteritinib is a FLT3 tyrosine kinase inhibitor (TKI) recently approved for patients with R/R AML. We aimed to characterize real-world data regarding gilteritinib treatment in FLT3-mutated R/R AML and to compare outcomes with matched FLT3-mutated R/R AML patients treated with chemotherapy-based salvage regimens. Twenty-five patients from six academic centers were treated with gilteritinib for FLT3-mutated R/R AML. Eighty percent were treated with a prior intensive induction regimen and 40% of them received prior TKI therapy. Twelve patients (48%) achieved complete response (CR) with gilteritinib. The estimated median overall survival (OS) of the entire cohort was eight (CI 95% 0-16.2) months and was significantly higher in patients who achieved CR compared to those who did not (16.3 months, CI 95% 0-36.2 vs. 2.6 months, CI 95% 1.47-3.7; p value = 0.046). In a multivariate cox regression analysis, achievement of CR was the only predictor for longer OS (HR 0.33 95% CI 0.11-0.97, p = 0.044). Prior TKI exposure did not affect OS but was associated with better event-free survival (HR 0.15 95% CI 0.03-0.71, p = 0.016). An age and ELN-risk matched comparison between patients treated with gilteritinib and intensive salvage revealed similar response rates (50% in both groups); median OS was 9.6 months (CI 95% 2.3-16.8) vs. 7 months (CI 95% 5.1-8.9) in gilteritinib and matched controls, respectively (p = 0.869). In conclusion, in the real-world setting, gilteritinib is effective, including in heavily pre-treated, TKI exposed patients.

Midostaurin in combination with chemotherapy is most effective in patients with acute myeloid leukemia presenting with high FLT3-ITD allelic ratio who proceed to allogeneic stem cell transplantation while in first complete remission.

OBJECTIVES: Midostaurin, a multikinase and FLT3 inhibitor, is the first non-chemotherapy agent approved and widely adopted for the treatment of FLT3-ITD acute myeloid leukemia (AML). Yet, its role in improving survival of patients referred to allogeneic stem cell transplantation (allo-SCT) in first complete remission (CR1) needs to be defined. METHODS: This multicenter study retrospectively evaluated the outcome of 119 FLT3-ITD AML patients [59 (49.6%) males and 60 females] intensively treated between 2015 and 2019 at five Israeli centers. In our cohort, allo-SCT in CR1 was widely implemented (47%) and patient stratification was based on the current allelic ratio (AR) cutoff of 0.5. RESULTS: Ninety-eight patients (82.3%) achieved CR1/CR with incomplete count recovery (CRi). Death during induction was reported in 7 (5.9%) patients. In multivariate analysis, midostaurin use and allo-SCT in CR1 were the most significant factors affecting overall survival (OS). Midostaurin incorporation in chemotherapy regimens significantly improved CR + CRi rates (P = .002), reduced relapse rates (P = .02), and was remarkably advantageous for high-AR patients (2-year OS 82%). In low-AR patients, the midostaurin effect was much less prominent. CONCLUSIONS: Our results demonstrate benefits of midostaurin incorporation in intensive chemotherapy regimens, particularly for high-AR AML patients to whom it should be offered along with allo-SCT in CR1.

Venetoclax combinations induce high response rates in newly diagnosed acute myeloid leukemia patients ineligible for intensive chemotherapy in routine practice.

Combinations of the BCL-2 inhibitor, venetoclax, with either hypomethylating agents (HMA) or low dose cytarabine (LDAC), have shown promising results in clinical trials of AML patients unfit for intensive therapy. We report on the efficacy and safety of venetoclax combinations in AML patients treated outside of clinical trials. Complete remission (CR) + CR with incomplete count recovery (CRi) were achieved in 61% of patients, with similar CR+CRi rates in with secondary AML, and in patients who were previously treated with HMA (61% and 43%, respectively). Relapse occurred in 25% of patients, with a median event-free survival (EFS) of 11.7 months (95% CI, 10.09-13.35) in responding patients. At a median follow up of 8.7 months, the median overall survival (OS) was 9.8 months (95% CI 6.42-13.3) in the entire cohort. In multivariate analysis adverse karyotype was the only negative predictor of CR/CRi (p = .03), while both ECOG performance status (PS) and adverse karyotype were significantly associated with shorter OS (p = .023 and .038, respectively). Median OS was higher in patients achieving CR/CRi and in patients proceeding to allogeneic stem cell transplantation (allo-SCT). Treatment was well tolerated, with side effects similar to those described in the randomized clinical trials. Tumor lysis syndrome (TLS) occurred in 12% of patients. Our data support the efficacy and safety of venetoclax combinations in newly diagnosed AML patients not eligible for intensive therapy. According to our data, secondary AML patients could benefit from venetoclax combinations similarly to de-novo AML patients, and allo-SCT could be offered to selected patients achieving CR/CRi.

At three years, patients with acute lymphoblastic leukaemia are still at risk for relapse. Results of the international MRC UKALLXII/ECOG E2993 trial.

Late relapse [>3 years from complete remission (CR)] in acute lymphoblastic leukaemia (ALL), is unusual. Data from the MRC UKALLXII/ECOG E2993 trial are presented to evaluate the incidence and characteristics of late relapse in adult ALL. Of 1,909 patients, 1,752 (92%) achieved CR and among these 757 (43·2%) relapsed; 691 (91·3%) within three years and 66 (8·7%) beyond. Among these 66 patients, median time to relapse was 47 (37-144) months. Relapse beyond three years occurred in 3·8% of all who achieved CR. The cumulative risk of relapse was 40%, 43% and 45% at three, five and ten years respectively. Out of the 1 752 patients who achieved CR, 11·7% underwent autologous and 40·6% allogeneic transplant, while in CR1. Of the autologous patients, 43·2% relapsed early and 3·4% relapsed late. However, among the allogeneic patients, 13·2% relapsed early and only 1·3% late. The five-year overall survival from relapse was 5·8% and 20% in the early and late relapse patients respectively. In conclusion, late relapse in adults with ALL is not uncommon, and is associated with better outcome after relapse compared to early relapse.

Real-world data on incidence, clinical characteristics and outcome of patients with macrofocal multiple myeloma (MFMM) in the era of novel therapies: A study of the Greco-Israeli collaborative myeloma working group.

We investigated incidence, characteristics and outcome of patients with macrofocal multiple myeloma (MFMM) treated mainly with novel therapies. Based on definition (BMPCs <20% and lytic lesions/plasmacytomas, without anemia, renal insufficiency or hypercalcemia) we identified 140 patients with MFMM, among 4650 myeloma patients (3%). Twice the number of patients with typical myeloma were used as controls; 60% were <65 years and 70% had advanced bone disease. Plasmacytomas were more frequent in MFMM compared with standard myeloma (68% vs 15%, P < .05). Adverse prognostic parameters (high lactate dehydrogenase, advanced stage, high risk cytogenetics, immunoparesis) were less common in patients with MFMM compared with controls (P < .05); 90% received novel agents and 47% underwent autologous transplantation upfront; 90% achieved an objective response; 70% had at least very good partial response which was significantly higher compared with controls (P < .05). After a median follow-up of 52 months, 33 patients have died. Early death (<12 months) was infrequent in MFMM. Median progression-free survival and overall survival (OS) were 46 and 129 months respectively, both significantly longer compared with controls (P < .001). Proteasome inhibitor (PI)-based therapy was the only independent predictor for OS in the multivariate analysis (HR: 3.9; P < .001). In conclusion, MFMM is a distinct entity presented in young and elderly subjects, characterized by limited bone marrow infiltration, advanced bone disease and frequent presence of plasmacytomas; MFMM patients have less often adverse prognostic features and achieve excellent responses and prolonged OS especially when treated with PI-based therapies. Novel imaging will help in a more accurate classification of this entity.

The Predictive Value of Thromboelastogram in the Evaluation of Patients with Suspected Acute Venous Thromboembolism.

INTRODUCTION: The objective of this prospective study was to examine whether thromboelastogram (TEG) can predict the presence of venous thromboembolism (VTE) in patients who arrive at the emergency room with signs/symptoms that raise the suspicion of acute VTE. METHODS: Every patient was tested for D-dimer and all TEG parameters, including: reaction time, clot time formation, alpha-angle, maximal amplitude, clot viscoelasticity, coagulation index, and clot lysis at 30 min. For categorical variables, χ2 or the Fisher exact test were used, and for continuous variables the t test or other non-parametric tests were used. RESULTS: During 2016, a total of 109 patients were enrolled with a median age of 55.7 (21-89) years. Eighteen patients were diagnosed with VTE. Analyzing the different TEG parameters, both as continuous and categorical variables, did not reveal a statistically significant difference between VTE-positive and VTE-negative patients. Combining different TEG parameters or dividing the cohort according to gender, clinical suspicion of VTE (Well's criteria), or different levels of D-dimer did not change the results of the analysis. CONCLUSION: The current study could not demonstrate a significant value of any TEG parameter as a predictor of VTE among patients who came to the emergency room with signs/symptoms that raise the suspicion of VTE.

Newly diagnosed multiple myeloma patients carrying monoallelic deletion of the whole locus of immunoglobulin heavy chain gene have a better prognosis compared to those with t(4;14) and t(14;16).

The current study evaluated the prognostic significance of the monoallelic deletion of the whole locus of the immunoglobulin heavy-chain (w_del(IGH)) gene compared to translocations t(4;14) and t(14;16) among newly diagnosed multiple myeloma (MM) patients. We retrospectively analyzed clinical (age, gender, and staging) and laboratory data at diagnosis and the overall survival (OS) of 255 newly diagnosed MM patients carrying w_del(IGH) or translocations t(4;14) or t(14;16). Bone marrow samples were examined by morphological and sequential interphase fluorescense in situ hybridization analyses. Among 255 patients, 117 (45.8%) had w_del(IGH), 99 (38.8%) had t(4;14), and 39 (15.3%) had t(14;16). Mean age was 61.6 ± 11.6 years. Groups did not differ significantly in age, gender, or lactate dehydrogenase levels. Patients in the w_del(IGH) group presented more frequently at International Staging System stage I than at stage II/III. Patients in the w_del(IGH) group had significantly fewer additional chromosomal aberrations (1.58) than the other two groups (2.3 and 2.13 in the del(IGH), t(14;16) and t(4;14) groups, respectively, P < 0.0001). Furthermore, the w_del(IGH) group had significantly longer estimated median OS (9.47 years) compared to those with translocations t(14;16) (3.02 years, P = 0.002) or t(4;14) (4.18 years, P = 0.001), respectively. These findings suggest a potential prognostic significance of monoallelic deletion of IGH among these patients. Additional studies are needed to better understand the nature and mechanism of this prognostic factor.

Revisiting autologous transplantation in acute myeloid leukemia.

PURPOSE OF REVIEW: Autologous hematopoietic cell transplantation (auto-HCT) has been evaluated as a consolidation treatment for acute myeloid leukemia (AML) in the 1980s and 1990s. These prospective studies from large trials compared auto-HCT with chemotherapy. A comparison was made also with allogeneic hematopoietic cell transplantation (allo-HCT). These studies reported a lower relapse rate with auto-HCT compared with chemotherapy, but without impact on the overall survival. A high transplant-related mortality in that era confounded the relevance of these data. RECENT FINDINGS: Several prospective studies and a plethora of retrospective registry data have confirmed the potent antileukemic therapy of auto-HCT compared with chemotherapy and, in some instances, have even challenged the presumed superiority of allo-HCT as the definitive therapy for certain patients with AML. SUMMARY: The aggregate of recent data, prospective and retrospective, strongly suggests an important role for auto-HCT, at least as the most potent nonimmunologic antileukemia therapy. The transplant-related mortality in 2017 is close to that expected from standard consolidation therapy leading to the conclusion that the role of auto-HCT needs to be rigorously revisited, preferably in prospective studies, to establish its precise role in the current era.

Treatment patterns and clinical outcomes in high-risk newly diagnosed multiple myeloma patients carrying the 17p deletion: An observational multi-center retrospective study.

Del17p is a genomic imbalance occurring in ∼7%-10% of myeloma at diagnosis newly diagnosed myeloma patients (NDMM) and comprises a poor prognostic factor. The goal of this study is to analyze real world data and outcomes among NDMM patients carrying 17p deletion. We report an observational, retrospective, multicenter study. Sixty consecutive patients diagnosed with multiple myeloma in the 8 participating centers diagnosed between 1/2008 and 1/2016 proven to carry 17p deletion by means of fluorescence in situ hybridization (FISH) were identified. Most received a bortezomib-based induction, over half underwent autologous hematopoietic cell transplantation (HCT); 30% of the patients gained early access to new novel agents via clinical trials, access programs or private insurance. Overall response rate (ORR) after induction was 85%; 94% for transplant eligible (TE); and 75% for transplant ineligible (NTE), and declined in subsequent treatment lines, 64% achieved ≥ VGPR. Median overall survival (OS) was 43 months; median progression free survival (PFS) was 11 months, 19 months for TE and 7 for NTE. In multivariate analysis: higher M-Spike, presence of extramedullary disease, and >50% of cells baring del17p were associated with adverse PFS; Autologous HCT and higher hemoglobin were associated with longer PFS; OS was 59 months for patients with early access to newer agents. Older age and higher M-Spike levels were associated with adverse OS, Autologous HCT was associated with favorable OS, 59.7 vs 28.7 months for NTE patients. Despite the improvement achieved with autologous HCT and new novel agents, the prognosis of patients with 17p deletion is still inferior, emphasizing the need for novel approaches.

Very poor long-term survival in past and more recent studies for relapsed AML patients: The ECOG-ACRIN experience.

This study examines the long-term OS of relapsed AML patients who were enrolled to 9 successive ECOG-ACRIN trials for newly diagnosed AML, during 1984-2008. The objectives were to examine whether there is a trend of improvement in the survival of relapsed AML patients in the more recent studies and to search for prognostic factors that are associated with long-term OS after relapse. A total of 3012 patients were enrolled, 1779 (59.1%) achieved CR1 and of these, 58.9% relapsed. The median follow-up was 9.7 years. The median OS from relapse was 0.5 years and the 5-year OS was 10 (±1)%. These results were similar even for the most recent studies. A multivariate model showed that age, cytogenetics at diagnosis, duration of CR1 and undergoing allogeneic transplantation were significantly associated with OS from relapse. Even among patients who relapsed with better prognostic factors; age < 40 and CR1 > 12 months, there was no significant OS difference between the studies. In conclusion, this large cohort appears to confirm that the survival of AML patients postrelapse continues to be dismal and has not improved during the past quarter of a century.

Progressive refractory light chain amyloidosis and multiple myeloma patients are responsive to the addition of clarithromycin to IMiD based therapy.

Multiple myeloma (MM) and primary systemic light chain amyloidosis (AL) are both chronic plasma cell dyscrasias with different clinical expression but limited treatment options for relapsed refractory disease. We report the effect of the addition of clarithromycin on 31 MM and 17 AL with relapsed or refractory disease who had an insufficient response or disease progression while on an IMiD based therapy. In this high risk population, hematological response was reported in 48% of MM patients and 94% of AL patients. Responses were reported early in both groups (median 35 days) and were more sustained in AL patients. Adverse events were common and included mostly grade 1-2 fatigue, infections and abdominal discomfort. Cytopenias were common and cardiac complications were rare in both MM and AL patients. Clarithromycin-IMiD combination therapy appears to be both effective and safe in progressive MM and primarily in AL patients, although a prospective clinical trial is warranted to validate these results. Am. J. Hematol. 92:131-135, 2017. © 2016 Wiley Periodicals, Inc.

Translocation t(11;14) in newly diagnosed patients with multiple myeloma: Is it always favorable?

The most common translocation in multiple myeloma (MM) is t(11;14)(q13;q32). According to several studies, this translocation represents a unique subset of patients with relatively favorable outcomes. Using combined analyses of morphology and fluorescence in situ hybridization (I-FISH), we examined the co-occurrence rates of t(11;14) with seven chromosomal aberrations (CAs), del(13q), del(17p), del(1p), gain(1q), multiple gains(1q), del(16q), and del(IGH), and assessed the effect of the different combinations on patient outcomes, with overall survival (OS) as the main outcome measure. Bone marrow samples and clinical data from 212 patients with MM with t(11;14) were analyzed. At least two additional CAs were found in 35% (75/205) of patients and a strong correlation between specific CAs. The occurrence of three CAs [multiple gains of (1q) (HR = 6.94, P = 0.001), del(1p) (HR = 4.47, P = 0.008), and del(IGH) (HR = 2.38, P = 0.002)] exerted a profoundly deleterious effect on median OS when compared with patients with t(11;14) only. Del(17p) and del(13q) have also exerted a deleterious effect albeit to a lesser extent (HR = 2.05, P = 0.07 and HR = 1.81, P = 0.03, respectively). When compared with t(11;14) alone, the addition of certain CAs lead to worse outcomes. These findings may have important clinical and biological implications. Patients with coexisting adverse lesions and t(11;14) may be considered at high risk and managed accordingly. © 2016 Wiley Periodicals, Inc.

Efficacy and safety of salvage therapy using Carfilzomib for relapsed or refractory multiple myeloma patients: a multicentre retrospective observational study.

Carfilzomib has been established in previous years as a treatment for patients with relapsed and/or refractory multiple myeloma (RR-MM). A retrospective multicentre study to evaluate the clinical use of carfilzomib for RR-MM outside of a clinical trial setting was conducted by our group. One hundred and thirty-five patients were included. All patients had been previously exposed to bortezomib and 93% had also been treated with lenalidomide. The vast majority of patients received carfilzomib as part of a two- or three-drug combination. The overall response rate was 47·2%. Multivariate analysis revealed bortezomib resistance, lenalidomide resistance and albumin <35 g/l to negatively impact the likelihood of achieving response. The median duration of response was 8·4 months, and was significantly higher in patients receiving three-drug combination and patients presenting without extramedullary disease. The median progression-free survival and overall survival for the entire cohort was 4·9 months (95% confidence interval [CI] 3·8-6·4) and 12·2 months (95% CI 9-not reached), respectively. Toxicity was manageable, although treatment-related death was seen in 5% of patients. In the setting of progressive multiple myeloma, carfilzomib in a combination regimens yields effective results with a manageable toxicity.

Recurrent RAS and PIK3CA mutations in Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare histiocytic disorder that is challenging to diagnose and treat. We performed molecular analysis of BRAF in the largest cohort of ECD patients studied to date followed by N/KRAS, PIK3CA, and AKT1 mutational analysis in BRAF wild-type patients. Forty-six of 80 (57.5%) of patients were BRAFV600E-mutant. NRAS mutations were detected in 3 of 17 ECD BRAFV600E wild-type patients. PIK3CA mutations (p.E542K, p.E545K, p.A1046T, and p.H1047R) were detected in 7 of 55 patients, 4 of whom also had BRAF mutations. Mutant NRAS was present in peripheral blood CD14(+) cells, but not lymphoid cells, from an NRASQ61R mutant patient. Our results underscore the central role of RAS-RAF-MEK-ERK activation in ECD and identify an important role of activation of RAS-PI3K-AKT signaling in ECD. These results provide a rationale for targeting mutant RAS or PI3K/AKT/mTOR signaling in the subset of ECD patients with NRAS or PIK3CA mutations.