ABSTRACT
Background: The hypomethylating agents (HMAs) are an important therapeutic option for older patients (pts) with AML and have become the backbone for combination regimens (eg, with Venetoclax). However, there are very limited real-life prospective studies regarding clinical outcome of these pts, including infectious complications and infection related mortality (IRM) during treatment. Aims: To investigate the infectious complications and clinical outcome in AML patients treated with HMAs± Venetoclax (V) outside of clinical trials. Methods: The recruitment of this prospective multicentric study (CE-Id-study:2908) has been completed on December 31, 2020. We enrolled 230 AML pts with a median age of 75 years (range 25-94);157 pts (68%) had >2 relevant comorbidities. Of the 230 cases, 132 (57%) received a first-line therapy with a combination of HMAs+V while 98 (43%) were treated with HMAs monotherapy (azacitidine or decitabine). A total of 1550 cycles of HMAs have been administered (680/1550 with HMAs+V). Results: The best response achieved, with HMAs treatment, was: CR in 44% of cases (57,6% with HMAs+V and 25,5% with HMAs alone, P=0,0001), PR in 17% and SD in 14% of cases (ORR 61%;72% in HMAS+V and 46% in HMAs alone, P=0,0007). The microbiological or radiological proven infectious complications (almost one) occurred in 160/230 (70%) of pts, mainly pneumonia (in 42% of pts) and/or bacteremia/sepsis (one or more events in 29% of pts). Febrile neutropenia (one or more episodes) occurred in 38% of pts and 14 cases of Covid-19 (6%) were reported. After a median follow-up of 9 months (1-24) from the start of HMAs therapy, 144 (63%) pts died and 86 (37%) were alive. The 1 yr OS probability was 46% with a median OS of 10,3 months (11 months in HMAs+V and 9 months in HMAs alone;P=ns). The primary causes of death were: progression of AML (42%), Infection (26%-37/144), Infection+AML (24%), other causes (8%). The IRM was 26% and 19/144 (13%) pts died of infectious complication while in CR/PR (16 in HMAs+V group and only 3 in HMAs group;P=0,005). Data on antibiotic prophylaxis, hospitalization, drugdoses modulation, are available and analyzed in this study. Summary/Conclusion: The results of this real-life, multicentric, prospective study, confirm a higher CR rate in pts treated with HMAs+V compared to HMAs alone (P=0,0001). However, we found a high rate of infectious complications and IRM (26%) with a higher infection related deaths in patients in CR/PR who were treated with HMAs+V (P=0,005). Findings from this study highlight the critical relevance of infection prevention in reducing infectious mortality, which adversely impacts the OS of this frail AML population.
ABSTRACT
Genetic and Clinical Background: The clinical outcome of Core Binding Factor Leukemia (CBFL) seems influenced by the mutational status of KIT. In fact, several retrospective studies, in addition to our own, as well as a systematic review, indicate that KIT mutations have a negative prognostic impact in AML with t(8;21) or, to a lesser extent, with inv(16)/t(16;16). In addition, gene expression studies found KIT to be highly expressed in CBFL regardless of its mutational status. Furthermore, recent studies have identified novel recurrent somatic mutations co-occurring with KITmut. In-vitro studies revealed that Midostaurin (Mido) is effective in inhibiting both wild type (WT) and a range of KIT mutants. In addition, it is proven to be effective in KIT-positive malignancies such as Aggressive Systemic Mastocytosis (ASM), Mast Cell Leukemia (MCL), and SM with Associated Hematological Neoplasm (SM-AHN). With this background, we designed a Phase II trial to evaluate the safety and efficacy of Mido in association with Intensive Chemotherapy (IC), in CBFL regardless of KIT mutational status. Methods: The inclusion criteria were the following: age 18 to 60 years, diagnosis of de-novo CBFL, adequate organ function, signed informed consent. The exclusion criteria were: central nervous system involvement, uncontrolled infections, other active malignancies, a Qtc value greater than 470 ms (according to Bazett formula) at the electrocardiogram, significant uncontrolled or active cardiovascular diseases. Patients received standard induction therapy with an anthracycline containing regimen (“7+3”-like) + Mido, three cycles of post-remission consolidation chemotherapy with high-dose cytarabine + Mido, and 12 months of Mido as Maintenance. The Mido dosage was: 50 mg orally twice a day, on days 8-21, in association with IC, and 50 mg orally twice a day as single agent maintenance. In order to attain a reduction in 2 years Relapse Incidence (RI), from the historical value of 48% to 28% (Primary Objective of the Study), we plan to enrol 39 patients (power 82%, alpha error 4,6%). At diagnosis all patients were studied by a comprehensive NGS panel targeting 40 DNA genes and 29 RNA fusion driver genes. MRD status was assessed by qPCR and high-resolution multicolor flow cytometry at established check-points during consolidation and maintenance therapy. Results: 17 patients were enrolled between December 2018 to April 2020 (table1). Overall, the CR rate was 94.2%. At a median follow-up of 9 months (range 3-19 months), we recorded a RI of 12.5%, an OS of 93.7%, and a DFS of 81.2%. 16 patients continue on study and 14 patients are in 1st CR, MRD-negative by flow cytometry and qPCR. Six patients (35.2 %) experienced 12 Treatment Emergent Adverse Event (TEAE), 10 out of whom were infections, with grade 3-4 neutropenia (Table 2). We only recorded one death from SARS-Cov2 infection (Interstitial Pneumonia) in a patient in MRD-negative complete remission. There were no treatment-related deaths. Conclusion: In patients with CBFL, the regimen consisting of intensive chemotherapy and consolidation chemotherapy in association with Mido, followed by Mido maintenance, had an acceptable safety profile and excellent response rates with a significant proportion of patients in MRD-negative complete remission. Trial is continuing to accrue (EudraCT Number 2017-002094-18;ClinicalTrials ID: NCT 03686345). This work was supported by a grant from Fondazione Regionale per la Ricerca Biomedica (FRRB 2015). [Formula presented] Disclosures: Krampera: Janssen: Membership on an entity's Board of Directors or advisory committees;Novartis: Membership on an entity's Board of Directors or advisory committees. Todisco: Jannsen, Abbvie, Jazz: Membership on an entity's Board of Directors or advisory committees. Veronese: Novartis: Other: Travel Expenses;Bayer: Honoraria;AstraZeneca: Other: Travel Expenses;Janssen Cilag: Honoraria. OffLabel Disclosure: Midostaurin for treatment of Core Binding Factor Leukemia. The drug has been used as KIT inhibitor.