Impact of sex on outcomes in patients with hairy cell leukemia (HCL): An HCL Patient Data Registry (PDR) analysis

7577

Background: HCL is a rare indolent leukemia that is more common in men, with a 4:1 male predominance. To date, no studies have characterized the potential difference in outcomes of HCL between male and female patients. Hence, we sought to evaluate the outcomes of female HCL patients using the HCL-PDR. Methods: The HCL Foundation sponsored the development of HCL-PDR to characterize the clinical features and outcomes of this rare leukemia. HCL-PDR is an international multicenter PDR that includes patient, disease and treatment information abstracted from medical records. Adult patients enrolled in the HCL-PDR were included in the study. Female patients with HCL were the study population, with males as the comparator. The primary endpoint was the time to next treatment (TTNT) in females compared to males. Secondary endpoints included response rates (RR) and predictors of TTNT. Responses were categorized as: complete response (CR) including CR/CRu (CR unconfirmed)/HR (hematologic response), and partial response (PR), which included PR/PRu (PR unconfirmed)/pHR (partial HR). CRu was defined as no disease in bone marrow (BM) without available blood counts and HR as blood counts meeting criteria for HR, but no available BM. Cox proportional hazard models were used to estimate the hazard ratios for TTNT risk. Results: 357 patients were included: 265 males and 92 females. Table shows baseline characteristics stratified by sex. Among the patients who had disease status assessed after first treatment (n=224, males 169 and females 55), there was no significant difference in RR. However, females had significantly longer median TTNT (17.6 years) relative to males (8 years, HR 0.54, 95% CI 0.32-0.91, p=0.02) that remained significant after adjusting for other variables (RR and BRAF mutation) in multivariable analysis (HR 0.32, 95% CI 0.11-0.97, p=0.04). Factors predictive of longer TTNT include female sex and CR (HR.0.26, 95% CI 0.11-0.57, p=0.001). Conclusions: This is the first study to date reporting the clinical characteristics and outcomes in female HCL patients. The significantly longer TTNT in females compared to males may be related to factors such as underlying molecular features or hormonal influences. This finding needs to be explored further. [Table: see text]

Effect of induction intensity on survival in patients with acute myeloid leukemia

e19004

Background: Acute Myeloid Leukemia (AML) has traditionally been treated frontline with intensive induction chemotherapy in patients fit enough for this treatment. The FDA has approved several oral targeted therapies for AML in recent years. The survival impact of these agents vs induction chemotherapy is unknown. Methods: In this single-center, retrospective study, patients diagnosed with AML from 2015-2020 were included if they received treatment with either high intensity chemotherapy (HiC) or lower intensity targeted therapy (LITT). HiC was defined as a regimen containing cytarabine + anthracycline given on a “7+3” based schedule. Patients treated with liposomal cytarabine-daunorubicin were excluded. LITT was defined as venetoclax, gilteritinib, enasidenib, or ivosidenib alone or in combination with a hypomethylating agent. Patients fell into four groups: HiC only, LITT only, HiC followed by LITT, and LITT followed by HiC with assignment censored at transplant. Overall survival (OS) was estimated using Kaplan-Meier method and patients receiving any HiC vs LITT only were compared using log-rank test. Results: A total of 332 patients were included: 177 received HiC only, 116 LITT only, 32 HiC before LITT, and 7 LITT before HiC. Baseline characteristics and OS data are outlined in the table. The any HiC group had a lower median age and more patients with WBC >10 K/µL at diagnosis, as well as more patients receiving allogeneic hematopoietic cell transplant (HCT). OS was superior in the any HiC group vs LITT only group. Receipt of any HiC remained predictive of OS after adjusting for age (HR 0.65, 95% CI 0.44-0.96, p = 0.03); however, was no longer predictive of OS after adjusting for age and receipt of HCT. Conclusions: While HiC was associated with superior OS compared to LITT only treatment in univariable analysis, the survival benefit was no longer apparent after adjusting for age and receipt of HCT. The results suggest that intensity of AML treatment is less impactful on prognosis than ability to receive HCT. Differences in age were likely confounded by clinical trial eligibility and prescribing information specifically affecting patients receiving LITT. In the era of LITT, prospective randomized studies of intensity of AML therapy, particularly in non-favorable risk disease, are imperative to striking a balance between toxicity and cure for patients of all ages.[Table: see text]

Type of prior genotoxic insult determines the genomic characteristics of therapy-related acute myeloid leukemia

7515

Background: Therapy-related AML (tAML) is a long-term complication of cytotoxic cancer therapy. It is characterized by adverse genetics and inferior survival outcomes when compared to de novo AML. A proposed mechanism in tAML pathogenesis includes treatment-induced selection of clones harboring pre-existing mutations (i.e. clonal hematopoiesis, CH). We hypothesize that genotoxic therapies used to treat prior malignancy drive leukemogenesis through different mechanisms leading to unique clonal compositions. Methods: AML patients (pts) treated at The Ohio State University between 2015-2018 were included. Genetic profiling was performed using Miseq Illumina platform with a 49-gene targeted sequencing panel at our clinical laboratory. Results: We studied 337 AML pts (Table), of whom 53% had smoking history. Mutations involving ASXL1 were more common in smokers vs non-smokers (14% vs 5.8%, p= .001), while JAK2 mutations were more common in non-smokers (8% vs 1.2%, p= .003). Regarding specific genotoxic therapies and mutations in tAML, we investigated common CH-associated mutations including DNMT3A, TET2, and ASXL1 (DTA mutations). In tAML pts, those exposed to radiotherapy experienced a higher frequency of DTA (52% vs 27%, p= .05), NPM1 (21% vs 0%, p= .002), and SRSF2 (15% vs 0%, p= .01) mutations, and conversely, a lower incidence of TP53 mutations (21% vs 46%, p= .04). Pts with history of cytotoxic chemotherapy had a lower incidence of DTA mutations, including those who received platinum agents (8% vs 49%, p= .005) and taxanes (7% vs 52%, p< .001), but had a higher incidence of TP53 mutations (75% vs 25%, p< .001 for platinum; 53% vs 25%, p= .04 for taxanes). Similarly, alkylators and anthracyclines were associated with lower incidence of DNMT3A (0% vs 20%, p= .009) and ASXL1 (0% vs 12.5%, p= .04) mutations. Conclusions: Different genotoxic agents demonstrate unique effects in leukemia development. Our data suggest that CH clones with DTA mutations may be enriched with smoking and radiotherapy, while cytotoxic chemotherapy may confer a higher incidence of TP53 mutations. Given the adverse prognosis of TP53 mutated AML, identification of pre-existing CH clones might influence treatment selection in solid tumor pts receiving anticancer therapy. [Table: see text]

Diagnostic utility of bronchoscopy in newly diagnosed acute leukemia patients

e19510

Background: Over 40% of newly diagnosed acute leukemia patients receiving induction therapy develop acute respiratory failure. Bronchoscopy is a valuable tool for evaluating airway disease, but its diagnostic yield in this setting has not been fully explored. Methods: We performed a retrospective chart review of 75 newly diagnosed acute leukemia patients who had bronchoscopies. Data recorded prior to bronchoscopy included age, diagnosis, induction treatment regimen, chest imaging, assisted ventilation, duration of neutropenia and antibiotic therapy and microbiological studies. Bronchoalveolar lavage (BAL) cultures were sorted by organism, as well as by other pathologic findings. The primary outcome was antibiotic change supported by culture data. Results: The study population is summarized in the table. Induction regimen backbones included 7+3 (51), 7+4+ATRA (2), decitabine (12), hyperCVAD (2), AYA (3), other (1) and none (4); 18 patients were treated on clinical trial. Average days of neutropenia was 10.92 and average days of antibiotic therapy was 10.57. Thirty-eight patients had chest infiltrates, 11 received NIPPV, and 17 were mechanically ventilated. We identified 24 patients with +BAL studies. Of these, 37.5% (9) had + blood, urine or sputum studies before bronchoscopy, but only 3 had cultures positive for the same organism as the BAL. Of 51 patients with –BAL studies, 33.3% (17) had prior negative cultures. Infections were most commonly bacterial (15, 62.5%), followed by viral (5, 20.8%) and fungal (4, 16.7%). The most common organisms were rhinovirus, vancomycin sensitive Enterococcus (4, 16.7% each) followed by VRE, Candida albicans and MRSA (2, 8.3% each). Five patients (6.7%) had alveolar hemorrhage. Of the 24 patients with +BAL cultures, bronchoscopy findings supported changing antibiotics in 18. In contrast, antibiotics were changed in 16 patients without +BAL cultures. Conclusions: We investigated the utility of bronchoscopy on AL patients during their initial admission. BAL cultures were positive in 32% of newly diagnosed AL patients undergoing bronchoscopy. However, +BAL cultures identified a new organism in 87.5% and guided antibiotic therapy in 75% of these patients. Further studies will be needed to establish predictors of bronchoscopy findings in this patient population. [Table: see text]

Acalabrutinib with obinutuzumab (Ob) in treatment-naive (TN) and relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL): Three-year follow-up

7500

Background: Acalabrutinib is a highly selective, potent, covalent Bruton tyrosine kinase inhibitor. This Phase 1b/2 trial evaluated acalabrutinib with the CD20 antibody Ob in TN and R/R CLL. Methods: Patient (pts) with TN and R/R (≥1 prior therapy) CLL were eligible. In 28-day cycles, acalabrutinib was given at 100 mg BID or 200 mg QD PO (n=15; all switched to 100 mg BID) until progressive disease (PD); Ob was given in standard fashion for 6 cycles starting with Cycle 2. The primary endpoints were overall response rate (ORR) and safety. Minimal residual disease (MRD) was assessed using flow cytometry (sensitivity 10-4). Results: 19 TN and 26 R/R pts were treated; median age of all pts was 61 y (range 42-76). Pt characteristics, disposition, efficacy and MRD are in the Table. Common adverse events (AEs; any grade) were upper respiratory tract infection (71%), increased weight (71%), maculopapular rash (67%), cough (64%), diarrhea (62%), headache (56%), nausea (53%), arthralgia (51%) and dizziness (47%). Common Gr 3/4 AEs were decreased neutrophil count (24%), syncope (11%), decreased platelet count, increased weight and cellulitis (9% each). There were 2 (4%) Gr 3 bleeding events (hematuria, muscle hemorrhage) and 1 (2%) Gr 3 atrial fibrillation event. Conclusions: Acalabrutinib plus Ob was well tolerated and yielded high response rates that were durable and deepened over time in TN and R/R CLL patients. Clinical trial information: NCT02296918. [Table: see text]

Incidence, characteristics, and risk factors of venous thromboembolism in adolescent and young adult acute lymphoblastic leukemia patients receiving peg-asparaginase

e18520

Background: Venous thromboembolism (VTE) is common in acute lymphoblastic leukemia (ALL) patients (pts) receiving peg-asparaginase (ASNase) however there is limited data regarding the incidence of VTE and risk factors for VTE in adolescent and young adults (AYA) treated with ASNase. Methods: This is a single institutional retrospective analysis of AYA pts with ALL who received ASNase from January 2013 to December 2018. Time to VTE was calculated from date of starting treatment to onset of VTE or censored at last assessment date, treating death as a competing risk. The cumulative incidence of VTE was estimated and the Fine and Gray regression models accounting for competing risks were used to examine the association between risk factors and VTE. Results: Forty-six AYA ALL patients were included. Pt characteristics are shown in the Table. Twenty pts had a VTE following ASNase with the cumulative incidence rate of 35% (95% CI: 22-48%) at 100 days. The most common VTE sites were cerebral (n=6) and upper extremity (n=6). Nine pts (43%) had at least one recurrent VTE. After initial VTE, ASNase was continued in 13 pts (62%), stopped in 6 pts (29%), and dose reduced in 2 pts (10%). Nine pts (45%) of those who developed VTE received antithrombin. Out of the 6 pts with VTE who had ASNase discontinued or dose reduced, 2 (33%) had progression of ALL. The hazard ratios (HR) for risk of VTE from univariable regression models are listed in Table 1. Male sex was associated with increased VTE risk, with HR=3.33 (95% CI: 1.13-9.77). Conclusions: Our study estimated the incidence of VTE in the AYA cohort. Only male sex was identified as a risk factor for VTE. Additional studies are needed to assess VTE risk factors in AYA pts with ALL. Pt characteristics and hazard ratios for risk of VTE. [Table: see text]

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations. EGR2 mutations were detected in 91/2403 (3.8%) investigated cases, and associated with younger age at diagnosis, advanced clinical stage, high CD38 expression and unmutated IGHV genes. EGR2-mutated patients frequently carried ATM lesions (42%), TP53 aberrations (18%) and NOTCH1/FBXW7 mutations (16%). EGR2 mutations independently predicted shorter time-to-first-treatment (TTFT) and overall survival (OS) in the screening cohort; they were confirmed associated with reduced TTFT and OS in the CRC cohort and independently predicted short OS from randomization in the UK CLL4 cohort. A particularly dismal outcome was observed among EGR2-mutated patients who also carried TP53 aberrations. In summary, EGR2 mutations were independently associated with an unfavorable prognosis, comparable to CLL patients carrying TP53 aberrations, suggesting that EGR2-mutated patients represent a new patient subgroup with very poor outcome.

Erlotinib in African Americans with advanced non-small cell lung cancer: a prospective randomized study with genetic and pharmacokinetic analyses

Prospective studies on epidermal growth factor receptor (EGFR) inhibitors in African Americans with non-small cell lung cancer (NSCLC) have not previously been performed. In this phase II randomized study, 55 African Americans with NSCLC received 150 mg/day erlotinib or a body weight-adjusted dose with subsequent escalations to the maximum-allowable dose, 200 mg/day, to achieve rash. Erlotinib and OSI-420 exposures were lower than those observed in previous studies, consistent with CYP3A pharmacogenetics implying higher metabolic activity. Tumor genetics showed only two EGFR mutations, EGFR amplification in 17/47 samples, eight KRAS mutations, and five EML4-ALK translocations. Although absence of rash was associated with shorter time to progression (TTP), disease-control rate, TTP, and 1-year survival were not different between the two dose groups, indicating the dose-to-rash strategy failed to increase clinical benefit. Low incidence of toxicity and low erlotinib exposure suggest standardized and maximum-allowable dosing may be suboptimal in African Americans.