Gemtuzumab ozogamicin plus midostaurin in combination with standard '7 + 3' induction therapy in newly diagnosed AML: Results from the SAL-MODULE phase I study.

We conducted a phase I trial in newly diagnosed acute myeloid leukaemia (AML) to investigate the combination of two novel targeted agents, gemtuzumab ozogamicin (GO) and midostaurin, with intensive chemotherapy in FLT3-mutated AML and CBF leukaemia. Three dose levels of midostaurin and one to three sequential doses of 3 mg/m2 GO in combination with '7 + 3' induction were evaluated. Based on safety findings in 12 patients, our results show that 3 mg/m2 GO on Days 1 + 4 and 100 mg midostaurin on Days 8-21 can be safely combined with IC in newly diagnosed AML.

Pyruvate kinase M2 regulates mitochondrial homeostasis in cisplatin-induced acute kidney injury.

An important pathophysiological process of acute kidney injury (AKI) is mitochondrial fragmentation in renal tubular epithelial cells, which leads to cell death. Pyruvate kinase M2 (PKM2) is an active protein with various biological functions that participates in regulating glycolysis and plays a key role in regulating cell survival. However, the role and mechanism of PKM2 in regulating cell survival during AKI remain unclear. Here, we found that the phosphorylation of PKM2 contributed to the formation of the PKM2 dimer and translocation of PKM2 into the mitochondria after treatment with staurosporine or cisplatin. Mitochondrial PKM2 binds myosin heavy chain 9 (MYH9) to promote dynamin-related protein 1 (DRP1)-mediated mitochondrial fragmentation. Both in vivo and in vitro, PKM2-specific loss or regulation PKM2 activity partially limits mitochondrial fragmentation, alleviating renal tubular injury and cell death, including apoptosis, necroptosis, and ferroptosis. Moreover, staurosporine or cisplatin-induced mitochondrial fragmentation and cell death were reversed in cultured cells by inhibiting MYH9 activity. Taken together, our results indicate that the regulation of PKM2 abundance and activity to inhibit mitochondrial translocation may maintain mitochondrial integrity and provide a new therapeutic strategy for treating AKI.

Midostaurin plus daunorubicin or idarubicin for young and older adults with FLT3-mutated AML: a phase 3b trial.

The pivotal RATIFY study demonstrated midostaurin (50 mg twice daily) with standard chemotherapy significantly reduced mortality in adult patients (<60 years) with newly diagnosed (ND) FLT3mut acute myeloid leukemia (AML). Considering that AML often present in older patients who show poor response to chemotherapy, this open-label, multicenter phase 3b trial was designed to further assess safety and efficacy of midostaurin plus chemotherapy in induction, consolidation, and maintenance monotherapy in young (≤60 years) and older (>60 years) patients with FLT3mut ND-AML. Compared with RATIFY, this study extended midostaurin treatment from 14 days to 21 days, substituted anthracyclines (idarubicin or daunorubicin), and introduced variation in standard combination chemotherapy dosing ("7+3" or "5+2" in more fragile patients). Total 301 patients (47.2% >60 years and 82.7% with FLT3-ITDmut) of median age 59 years entered induction phase. Overall, 295 patients (98.0%) had at least 1 adverse event (AE), including 254 patients (84.4%) with grade ≥3 AE. The grade ≥3 serious AEs occurred in 134 patients. No difference was seen in AE frequency between age groups, but grade ≥3AE frequency was higher in older patients. Overall, complete remission (CR) rate including incomplete hematologic recovery (CR + CRi) (80.7% [95% confidence interval, 75.74-84.98]) was comparable between age groups (≤60 years [83.5%]; >60 to ≤70 years [82.5%]; in patients >70 years [64.1%]) and the type of anthracycline used in induction. CR + CRi rate was lower in males (76.4%) than females (84.4%). Overall, the safety and efficacy of midostaurin remains consistent with previous findings, regardless of age, sex, or induction regimen. The trial is registered at www.clinicaltrials.gov as #NCT03379727.

Treatment with midostaurin and other FLT3 targeting inhibitors is associated with an increased risk of cardiovascular adverse events in patients who underwent allogeneic hematopoietic stem cell transplantation with FLT3-mutated AML.

The addition of midostaurin to standard chemotherapy has improved survival in patients with FLT3-mutated AML. However, the impact of midostaurin and other FLT3 inhibitors (FLT3i) on cardiovascular adverse events (CAEs) has not been studied in patients who underwent allogeneic hematopoietic stem cell transplantation in a real-world setting. We reviewed 132 patients with AML who were treated with intensive induction therapy and consecutive allogeneic stem cell transplantation at our institution (42 FLT3-mutated AML and 90 with FLT3 wildtype). We identified treatment with midostaurin and/or FLT3i as an independent risk factor for CAEs not resulting in higher non-relapse mortality (NRM) or impaired overall survival (OS). Hence, close monitoring for CAEs is warranted for these patients.

Evaluation of drug-drug interactions between midostaurin and strong CYP3A4 inhibitors in patients with FLT-3-mutated acute myeloid leukemia (AML).

PURPOSE: Midostaurin, approved for the treatment of newly diagnosed, FLT3-mutated acute myeloid leukemia (AML), is metabolized by cytochrome P450 3A4 (CYP3A4). Midostaurin with concomitant strong CYP3A4 inhibitors use (e.g., antifungal azoles) may result in drug-drug interactions. This post hoc analysis of RATIFY phase 3 study data evaluated effects of strong CYP3A4 inhibitor use on the exposure and safety of midostaurin. METHODS: Trough concentrations were used to assess midostaurin and metabolite exposure in the presence and absence of strong CYP3A4 inhibitors. Adverse event (AE) frequency was assessed in patients who received concomitant strong CYP3A4 inhibitors vs those who did not. Time to first clinically notable AE (CNAE) was also assessed in patients with high midostaurin plasma exposure vs those of matched placebo controls. RESULTS: Use of concomitant strong CYP3A4 inhibitors was most frequent during the induction phase (60.8%). A 1.44-fold increase in midostaurin plasma exposure was observed in patients with concomitant strong CYP3A4 inhibitor use vs those without. Midostaurin-treated patients who received concomitant strong CYP3A4 inhibitors experienced grade 3/4 infection-related AEs more frequently vs those who did not. Patients with high levels of midostaurin exposure had a shorter median time to first grade 3/4 CNAE vs placebo controls (36 vs 41 days, respectively; P = .012). CONCLUSION: Although concomitantly administered strong CYP3A4 inhibitors increased midostaurin exposure 1.44-fold, no clinically relevant differences in safety were noted. Midostaurin dose adjustment is not necessary with concomitant strong CYP3A4 inhibitors in patients with FLT3-mutated AML; however, caution is advised, and patients should be closely monitored.

Midostaurin plus intensive chemotherapy for younger and older patients with AML and FLT3 internal tandem duplications.

We conducted a single-arm, phase 2 trial (German-Austrian Acute Myeloid Leukemia Study Group [AMLSG] 16-10) to evaluate midostaurin with intensive chemotherapy followed by allogeneic hematopoietic-cell transplantation (HCT) and a 1-year midosta urin maintenance therapy in adult patients with acute myeloid leukemia (AML) and fms-related tyrosine kinase 3 (FLT3) internal tandem duplication (ITD). Patients 18 to 70 years of age with newly diagnosed FLT3-ITD-positive AML were eligible. Primary and key secondary endpoints were event-free survival (EFS) and overall survival (OS). Results were compared with a historical cohort of 415 patients treated on 5 prior AMLSG trials; statistical analysis was performed using a double-robust adjustment with propensity score weighting and covariate adjustment. Results were also compared with patients (18-59 years) treated on the placebo arm of the Cancer and Leukemia Group B (CALGB) 10603/RATIFY trial. The trial accrued 440 patients (18-60 years, n = 312; 61-70 years, n = 128). In multivariate analysis, EFS was significantly in favor of patients treated within the AMLSG 16-10 trial compared with the AMLSG control (hazard ratio [HR], 0.55; P < .001); both in younger (HR, 0.59; P < .001) and older patients (HR, 0.42; P < .001). Multivariate analysis also showed a significant beneficial effect on OS compared with the AMLSG control (HR, 0.57; P < .001) as well as to the CALGB 10603/RATIFY trial (HR, 0.71; P = .005). The treatment effect of midostaurin remained significant in sensitivity analysis including allogeneic HCT as a time-dependent covariate. Addition of midostaurin to chemotherapy was safe in younger and older patients. In comparison with historical controls, the addition of midostaurin to intensive therapy led to a significant improvement in outcome in younger and older patients with AML and FLT3-ITD. This trial is registered at clinicaltrialsregistry.eu as Eudra-CT number 2011-003168-63 and at clinicaltrials.gov as NCT01477606.

Superior Efficacy of Midostaurin Over Cladribine in Advanced Systemic Mastocytosis: A Registry-Based Analysis.

PURPOSE: On the basis of data from the German Registry on Disorders of Eosinophils and Mast Cells, we compared the efficacy of midostaurin and cladribine in patients with advanced systemic mastocytosis (AdvSM). PATIENTS AND METHODS: Patients with AdvSM (n = 139) were treated with midostaurin only (n = 63, 45%), cladribine only (n = 23, 17%), or sequentially (midostaurin-cladribine, n = 30, 57%; cladribine-midostaurin, n = 23, 43%). Prognosis was assessed through the Mutation-Adjusted Risk Score (MARS). Besides the comparison of efficacy between midostaurin and cladribine on response (eg, organ dysfunction, bone marrow mast cell [MC] infiltration, and tryptase), overall survival (OS), and leukemia-free survival, we focused on the impact of treatment on involved non-MC lineages, for example, monocytes or eosinophils, and the KIT D816V expressed allele burden. RESULTS: Midostaurin only was superior to cladribine only with effects from responses on MC and non-MC lineages conferring on a significantly improved OS (median 4.2 v 1.9 years, P = .033) and leukemia-free survival (2.7 v 1.3 years, P = .044) on the basis of a propensity score-weighted analysis of parameters included in MARS. Midostaurin compensated the inferior efficacy of cladribine in first- and second-line treatment. On midostaurin in any line, response of eosinophilia did not improve its baseline adverse prognostic impact, whereas response of monocytosis proved to be a positive on-treatment parameter. Multivariable analysis allowed to establish three risk categories (low/intermediate/high) through the combination of MARS and the reduction of the KIT D816V expressed allele burden of ≥ 25% at month 6 (median OS not reached v 3.0 years v 1.0 year; P < .001). CONCLUSION: In this registry-based analysis, midostaurin revealed superior efficacy over cladribine in patients with AdvSM. In midostaurin-treated patients, the combination of baseline MARS and molecular response provided a compelling three-tier risk categorization (MARSv2.0) for OS.

Midostaurin therapy for advanced systemic mastocytosis: Mayo Clinic experience in 33 consecutive cases.

We retrospectively examined our experience with midostaurin therapy in 33 consecutive patients (median age 68 years; 58% females) with advanced systemic mastocytosis (adv-SM): aggressive SM (ASM; n = 17), SM associated with another hematologic neoplasm (SM-AHN; n = 14) and mast cell leukemia (MCL; n = 2). KITD816V mutation was detected in 84% of the patients and C findings in 91%. Eleven (33%) patients were previously treated with other cytoreductive drugs, including cladribine (n = 4) and imatinib (n = 3). Median time from diagnosis to initiation of midostaurin therapy was 2.2 months (range 0.3-41). Using modified valent criteria, overall response was 42% (53% ASM, 29% SM-AHN, 50% MCL; p = .22), all classified as being major. Responses included ≥50% reduction in bone marrow mast cells in 40% and normalization of serum tryptase in 29%, of evaluated cases. After a median follow-up of 14.6 months from initiation of midostaurin therapy, 7 (21%) deaths, 1 (3%) leukemic progression, and 18 (55%) treatment discontinuations were documented; median duration of midostaurin treatment was 7.9 months (range 0.5-123) and response duration 21.5 months (range 2.9-123). Most frequent side effect was gastrointestinal (51%) while grade 3/4 neutropenia or thrombocytopenia occurred in 12% of patients. Response to treatment was not predicted by KIT mutation (p = .67) or exposure to prior cytoreductive therapy (p = .44). Median survival was longer in midostaurin responders but not significantly (median 26.5 vs. 16 months; p = .15). Findings from the current study are broadly consistent with previously published clinical trial observations.

Use of midostaurin in mixed phenotype acute leukemia with FLT3 mutation: A case series.

Mixed phenotype acute leukemia (MPAL) is a rare type of acute leukemia where blasts present phenotypes from more than one lineage. A poor prognostic has been associated with this disease, and limited data are currently available to guide the choice of therapy. Regarding FLT3-positive MPAL, only one case treated with midostaurin has been published to date. Here, we report the successful use of midostaurin to treat three FLT3-positive MPAL T/myeloid and B/myeloid patients. Midostaurin was successfully added to intensive induction (two patients) and consolidation chemotherapy (three patients) without significant adverse events requiring a dose adjustment or discontinuation. The therapy received resulted in complete remission for two patients and complete remission with an incomplete hematologic recovery for the third. All patients proceeded to HSCT and stayed in remission after an extended follow-up respectively at 28, 31, and 11 months later. These results suggest that the addition of midostaurin during induction and consolidation therapy may represent a treatment option for FLT3-positive MPAL.

Midostaurin-induced Sweet syndrome in a patient with FLT3-ITD-positive AML.

Sweet syndrome (SS), also referred as acute febrile neutrophilic dermatosis, is an inflammatory process characterised by the abrupt appearance of erythematous papules or nodules with predominant neutrophilic infiltration in the dermis. Fever and neutrophilia are common presenting features. However, extracellular manifestations, including ocular and musculoskeletal, may occur. SS is divided into three subtypes: classical (or idiopathic), malignancy associated and drug induced. Medication-induced subtype accounts for up to 26% of cases. In recent years, emerging evidence has showed that SS may also occur in neutropenic patients who underwent induction for acute myeloid leukemia (AML). The identification of FMS-like tyrosine kinase 3 (FLT3) gene mutation in approximately 30% of patients with AML has promoted the targeted therapy with FLT3-internal tandem duplication (ITD) inhibitors. Midostaurin, a recently Food and Drug Administration-approved medication for FLT3-ITD-positive AML, was reported once as cause for SS. We report a midostaurin-induced SS with neutropenia in a patient following induction chemotherapy of AML.

D-dopachrome tautomerase contributes to lung epithelial repair via atypical chemokine receptor 3-dependent Akt signaling.

BACKGROUND: Emphysematous COPD is characterized by aberrant alveolar repair. Macrophage migration inhibitory factor (MIF) contributes to alveolar repair, but for its structural and functional homolog D-dopachrome tautomerase (DDT) this is unknown. MIF mediates its effects through CD74 and/or C-X-C chemokine receptors 2 (CXCR2), 4(CXCR4), and possibly 7 (ACKR3). DDT can also signal through CD74, but interactions with other receptors have not been described yet. We therefore aimed at investigating if and how DDT contributes to epithelial repair in COPD. METHODS: We studied effects of recombinant DDT on cell proliferation and survival by clonogenic assay and annexin V-PI staining respectively. DDT-induced signaling was investigated by Western blot. Effects on epithelial growth and differentiation was studied using lung organoid cultures with primary murine or human epithelial cells and incubating with DDT or an ACKR3-blocking nanobody. DDT-ACKR3 interactions were identified by ELISA and co-immunoprecipitation. FINDINGS: We found that DDT promoted proliferation of and prevented staurosporine-induced apoptosis in A549 lung epithelial cells. Importantly, DDT also stimulated growth of primary alveolar epithelial cells as DDT treatment resulted in significantly more and larger murine and human alveolar organoids compared to untreated controls. The anti-apoptotic effect of DDT and DDT-induced organoid growth were inhibited in the presence of an ACKR3-blocking nanobody. Furthermore, ELISA assay and co-immunoprecipitation suggested DDT complexes with ACKR3. DDT could activate the PI3K-Akt pathway and this activation was enhanced in ACKR3-overexpressing cells. INTERPRETATION: In conclusion, DDT contributes to alveolar epithelial repair via ACKR3 and may thus augment lung epithelial repair in COPD. FUNDING: As stated in the Acknowledgments.

The safety profile of FLT3 inhibitors in the treatment of newly diagnosed or relapsed/refractory acute myeloid leukemia.

INTRODUCTION: FLT3 inhibitors are important drugs in the therapy of FLT3 positive acute myeloid leukemia (AML). Midostaurin was registered in combination with chemotherapy to treat newly diagnosed AML. Gilteritinib and quizartinib demonstrate effectiveness in a randomized trial in relapsed/refractory AML. Several promising FLT3 inhibitors are being evaluated in clinical research. AREAS COVERED: This review will report the safety of FLT3 inhibitors that are registered for acute myeloid leukemia induction and rescue therapy. EXPERT OPINION: In the near future, it is possible that all the FLT3 positive non M3-AML patients will receive a FLT3 inhibitor. Therapy adherence and strategies to mitigate adverse events must be pursued. The treatment with FLT3 inhibitors may be optimized in terms of toxicities with a rational evaluation of antifungal prophylaxis and concomitant therapy, cardiology monitoring, and keeping in mind rare adverse events. Future studies on unfit patients, special populations, and maintenance settings are warranted, together with post-market studies and real-life experiences. Whenever new FLT3 inhibitors will come to the clinic, we could face a scenario in which profound knowledge of effectiveness, toxicities, and off-target effects will be relevant to choose the best drug for each patient.

Choosing Antifungals for the Midostaurin-Treated Patient: Does CYP3A4 Outweigh Recommendations? A Brief Insight from Real Life.

INTRODUCTION: Patients treated with midostaurin and chemotherapy are at risk of invasive fungal disease. Prophylactic posaconazole is recommended for these patients, but posaconazole strongly inhibits the CYP3A4 isozyme that metabolizes midostaurin. Posaconazole therefore introduces a risk of patient's overexposure to midostaurin. METHODS: Blood samples were obtained from 4 patients treated with midostaurin for newly diagnosed FLT3-mutAML. Patients had received a concomitant treatment with posaconazole, isavuconazole, or micafungin, respectively. All blood samples were drawn before daily dose administration of midostaurin. RESULTS: Posaconazole caused a ≥8-fold increase of midostaurin plasma levels at through, which was accompanied by a decreased plasma exposure to O-demethylated or hydroxylated midostaurin metabolites. We also show that hematologists react to risk perception by replacing posaco-nazole with antifungals like micafungin or isavuconazole, which lack a strong inhibition of CYP3A4 and fail to modify midostaurin pharmacokinetics but are not formally recommended in these settings. DISCUSSION: In real-life scenarios, concerns about CYP3A4 inhibition may outweigh compliance with recommendations. Large studies are needed to survey the risk:benefit of hematologist's decision to replace posaconazole with other antifungals.

Practical management of adverse events in patients with advanced systemic mastocytosis receiving midostaurin.

INTRODUCTION: Systemic mastocytosis (SM) is characterized by the overproduction and accumulation of neoplastic mast cells (MCs) in the bone marrow, skin, and visceral organs. The KIT D816V mutation is found in approximately 90% of cases. In advanced SM (advSM), inferior survival often relates to MC-induced organ damage that may impact multiple organ systems. In addition, mediator symptoms related to MC activation can severely impact the quality of life. The oral multikinase/KIT inhibitor midostaurin was approved by the US Food and Drug Administration and the European Medicines Agency as monotherapy for advSM based on data from phase 2 clinical studies. AREAS COVERED: This review discusses the management of common adverse events (AEs) in patients with advSM who participated in phase 2 clinical studies that led to the approval of midostaurin. EXPERT OPINION: In the advSM population undergoing treatment with midostaurin, treatment-related AEs are often difficult to distinguish from disease-related symptoms, which can lead to premature discontinuation and improper dose reduction of midostaurin therapy in patients who might have benefitted from continued therapy. Here we present strategies to help optimize AE management and maximize the potential benefits of midostaurin in advSM.

Drug-drug interactions of newly approved small molecule inhibitors for acute myeloid leukemia.

Several small molecule inhibitors (SMIs) have been recently approved for AML patients. These targeted therapies could be more tolerable than classical antineoplastics, but potential drug-drug interactions (DDI) are relatively frequent. Underestimation or lack of appropriate awareness and management of DDIs with SMIs can jeopardize therapeutic success in AML patients, which often require multiple concomitant medications in the context of prior comorbidities or for the prevention and treatment of infectious and other complications. In this systematic review, we analyze DDIs of glasdegib, venetoclax, midostaurin, quizartinib, gilteritinib, enasidenib, and ivosidenib. CYP3A4 is the main enzyme responsible for SMIs metabolism, and strong CYP3A4 inhibitors, such azoles, could increase drug exposure and toxicity; therefore dose adjustments (venetoclax, quizartinib, and ivosidenib) or alternative therapies or close monitoring (glasdegib, midostaurin, and gilteritinib) are recommended. Besides, coadministration of strong CYP3A4 inducers with SMIs should be avoided due to potential decrease of efficacy. Regarding tolerability, QTc prolongation is frequently observed for most of approved SMIs, and drugs with a potential to prolong the QTc interval and CYP3A4 inhibitors should be avoided and replaced by alternative treatments. In this study, we critically assess the DDIs of SMIs, and we summarize best management options for these new drugs and concomitant medications.

Bax and Bak jointly control survival and dampen the early unfolded protein response in pancreatic ß-cells under glucolipotoxic stress.

ER stress and apoptosis contribute to the loss of pancreatic ß-cells under pro-diabetic conditions of glucolipotoxicity. Although activation of canonical intrinsic apoptosis is known to require pro-apoptotic Bcl-2 family proteins Bax and Bak, their individual and combined involvement in glucolipotoxic ß-cell death are not known. It has also remained an open question if Bax and Bak in ß-cells have non-apoptotic roles in mitochondrial function and ER stress signaling, as suggested in other cell types. Using mice with individual or combined ß-cell deletion of Bax and Bak, we demonstrated that glucolipotoxic ß-cell death in vitro occurs by both non-apoptotic and apoptotic mechanisms, and the apoptosis could be triggered by either Bax or Bak alone. In contrast, they had non-redundant roles in mediating staurosporine-induced apoptosis. We further established that Bax and Bak do not affect normal glucose-stimulated ß-cell Ca2+ responses, insulin secretion, or in vivo glucose tolerance. Finally, our experiments revealed that combined deletion of Bax and Bak amplified the unfolded protein response in islets during the early stages of chemical- or glucolipotoxicity-induced ER stress. These findings shed new light on roles of the core apoptosis machinery in ß-cell survival and stress signals of importance for the pathobiology of diabetes.

Cost-effectiveness of midostaurin in the treatment of newly diagnosed FLT3-mutated acute myeloid leukemia in France.

BACKGROUND: Midostaurin (MIDO) combined with standard chemotherapy was approved by the European Medicines Agency in 2017 for the treatment of adults with newly diagnosed FLT3-mutated acute myeloid leukemia (AML) based on results from the RATIFY trial. METHODS: A cost-effectiveness model was developed to compare MIDO and standard-of-care (SOC) to SOC alone in France. Per Haute Autorité de Santé (HAS) guidelines, a partitioned survival model with eight health states was used: diagnosis/induction, complete remission, relapse, hematopoietic stem cell transplantation (HSCT), HSCT recovery, post-HSCT recovery (stabilized after HSCT recovery), post-HSCT relapse, and mortality. A lifetime horizon was used beginning at diagnosis with a "cure model,", which assumed natural mortality after trial cut-off. Utility values were obtained from a systematic literature review and included disutilities. Resource utilization was based on HAS clinical guidelines and a survey of French physicians and included drugs and administration, adverse events, routine medical care, HSCT, and end-of-life care costs. RESULTS: In RATIFY and after extrapolation, MIDO improved survival compared to SOC, translating into MIDO-treated patients gaining 1.12 life years (LYs) and 1.23 quality-adjusted life years (QALYs) versus SOC. The incremental cost-effectiveness ratio (ICER) for MIDO versus SOC was €68,781 per LY and €62,305 per QALY. Sensitivity analyses showed consistency with base case findings. CONCLUSIONS: MIDO represents a clinically significant advancement in the management of newly diagnosed FLT3-mutated AML. In this analysis, MIDO add-on therapy showed gains in LYs and QALYs versus SOC alone and was found to be a cost-effective option at a €100,000 per QALY threshold for end-of-life treatment.

Unique case of ANCA-negative pauci-immune necrotizing glomerulonephritis with diffuse alveolar hemorrhage, potentially associated with midostaurin.

We present a 61-year-old male with FLT3-mutated acute myeloid leukemia treated with midostaurin who developed acute kidney injury requiring hemodialysis and pulmonary renal syndrome. Antibodies to proteinase-3, myeloperoxidase, and glomerular basement membrane were negative. Renal biopsy confirmed acute pauci-immune focal necrotizing glomerulonephritis (GN) with fibrin crescents indicating rapidly progressing glomerulonephritis. He improved with pulse methylprednisolone, intravenous cyclophosphamide, and plasma exchange with resolution of hemoptysis. This case highlights the importance of prompt renal biopsy to guide early initiation of life-saving therapies. To our knowledge, this is the first reported case of ANCA-negative pauci-immune necrotizing GN likely secondary to midostaurin.