Preclinical models have shown that blocking PD-1/PD-L1 pathways enhances antileukemic responses. Azacitidine upregulates PD-1 and IFNγ signaling. We therefore conducted this single-arm trial, in ...which patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) were treated with azacitidine 75 mg/m
days 1 to 7 intravenously or subcutaneously with nivolumab 3 mg/kg intravenously on days 1 and 14, every 4 to 6 weeks. For the seventy patients who were treated, the median age was 70 years (range, 22-90) and the median number of prior therapies received was 2 (range, 1-7). The overall response rate (ORR) was 33%, including 15 (22%) complete remission/complete remission with insufficient recovery of counts, 1 partial response, and 7 patients with hematologic improvement maintained >6 months. Six patients (9%) had stable disease >6 months. The ORR was 58% and 22%, in hypomethylating agent (HMA)-naïve (
= 25) and HMA-pretreated (
= 45) patients, respectively. Grade 3 to 4 immune-related adverse events occurred in 8 (11%) patients. Pretherapy bone marrow and peripheral blood CD3 and CD8 were significantly predictive for response on flow cytometry. CTLA4 was significantly upregulated on CD4
Teff in nonresponders after 2 and 4 doses of nivolumab. Azacitidine and nivolumab therapy produced an encouraging response rate and overall survival in patients with R/R AML, particularly in HMA-naïve and salvage 1 patients. Pretherapy bone marrow aspirate and peripheral blood CD3 percentage may be biomarkers for patient selection. SIGNIFICANCE: Azacitidine in combination with nivolumab appeared to be a safe and effective therapy in patients with AML who were salvage 1, prior hypomethylator-naïve, or had increased pretherapy CD3
bone marrow infiltrate by flow cytometry or IHC. Bone marrow CD3 and CD8 are relatively simple assays that should be incorporated to select patients in future trials.
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Outcome in acute myeloid leukemia (AML) worsens with age, at least in part because of higher treatment-related mortality (TRM) in older patients. Eligibility for intensive AML treatment protocols is ...therefore typically based on age as the implied principal predictor of TRM, although other health- and disease-related factors modulate this age effect.
We empirically defined TRM using estimated weekly hazard rates in 3,365 adults of all ages administered intensive chemotherapy for newly diagnosed AML. We used the area under the receiver operator characteristic curve (AUC) to quantify the relative effects of age and other covariates on TRM in a subset of 2,238 patients. In this approach, an AUC of 1.0 denotes perfect prediction, whereas an AUC of 0.5 is analogous to a coin flip.
Regardless of age, risk of death declined once 4 weeks had elapsed from treatment start, suggesting that patients who die during this time comprise a qualitatively distinct group. Performance status (PS) and age were the most important individual predictors of TRM (AUCs of 0.75 and 0.65, respectively). However, multicomponent models were significantly more accurate in predicting TRM (AUC of 0.83) than PS or age alone. Elimination of age from such multicomponent models only minimally affected their predictive accuracy (AUC of 0.82).
These data suggest that age is primarily a surrogate for other covariates, which themselves add significantly to predictive accuracy, thus challenging the wisdom of using age as primary or sole basis for assignment of intensive, curative intent treatment in AML.
Kupffer cells form a large intravascular macrophage bed in the liver sinusoids. The differentiation history and diversity of Kupffer cells is disputed; some studies argue that they are derived from ...blood monocytes, whereas others support a local origin from intrahepatic precursor cells. In the present study, we used both flow cytometry and immunohistochemistry to distinguish 2 subsets of Kupffer cells that were revealed in the context both of bone marrow transplantation and of orthotopic liver transplantation. One subset was radiosensitive and rapidly replaced from hematogenous precursors, whereas the other was relatively radioresistant and long-lived. Both were phagocytic but only the former population was recruited into inflammatory foci in response to CD8+ T-cell activation. We propose the name “sessile” for the radioresistant Kupffer cells that do not participate in immunoinflammatory reactions. However, we found no evidence that these sessile Kupffer cells arise from immature intrahepatic precursors. Our conclusions resolve a long-standing controversy and explain how different experimental approaches may reveal one or both of these subsets.
Mold-active primary antifungal prophylaxis (PAP) is routinely recommended in neutropenic patients with newly diagnosed acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) ...undergoing remission-induction chemotherapy (RIC). Isavuconazole (ISAV) is an extended spectrum mold-active triazole and has superior tolerability and fewer significant drug-drug interactions compared with other triazoles.
In our investigator-initiated, phase 2 trial, treatment-naive adult patients with AML or MDS starting RIC received ISAV per the dosing recommendations in the US label until neutrophil recovery (absolute neutrophil count ANC ≥ 0.5 × 109/L) and attainment of complete remission, occurrence of invasive fungal infection (IFI), or for a maximum of 12 weeks. The primary endpoint was the incidence of proven/probable IFI during ISAV PAP and up to 30 days after the last dose.
Sixty-five of 75 enrolled patients received ISAV PAP (median age, 67 years, median ANC at enrollment, 0.72 × 109/L). Thirty-two patients (49%) received oral targeted leukemia treatments (venetoclax, FTL3 inhibitors). Including the 30-day follow-up period, probable/proven and possible IFIs were encountered in 4 (6%) and 8 patients (12%), respectively. ISAV trough serum concentrations were consistently > 1 µg/mL, showed low intraindividual variation, and were not significantly influenced by chemotherapy regimen. Tolerability of ISAV was excellent, with only 3 cases (5%) of mild to moderate elevations of liver function tests and no QTc prolongations.
ISAV is a safe and effective alternative for PAP in patients with newly diagnosed AML/MDS undergoing RIC in the era of recently approved or emerging small-molecule antileukemia therapies.
NCT03019939.
Mature B-cell neoplasms and immature or precursor B-cell neoplasms need to be distinguished because these patients usually require different therapeutic approaches. B-cell neoplasms that express TdT ...without unequivocal other features of immaturity may therefore present a diagnostic challenge. We describe 13 patients with TdT-positive aggressive B-cell lymphoma. The clinicopathologic features of these patients were highly heterogeneous, but for the purpose of this study we grouped these cases as follows: (1) de novo high-grade B-cell lymphoma with MYC, BCL2, and/or BCL6 rearrangements (double-hit or triple-hit lymphoma) with TdT expression. In this group we included two cases of de novo composite lymphoma in which there were components of diffuse large B-cell lymphoma and TdT-positive blastic B-cell lymphoma; (2) TdT-positive aggressive B-cell lymphoma arising in patients who previously had follicular lymphoma; (3) initial relapse of TdT-negative aggressive B-cell lymphoma in patients who previously had follicular lymphoma, followed by relapses in which the neoplasm acquired TdT expression; and (4) mature B-cell lymphomas that acquired TdT expression at relapse. This group included one case of EBV-positive diffuse large B-cell lymphoma and one case of pleomorphic variant mantle cell lymphoma. All patients in this study had an aggressive clinical course and a dismal outcome despite appropriate therapy. Rather than "squeezing" these cases into current World Health Organization classification categories, we suggest the use of a descriptive term such as high-grade B-cell lymphoma with TdT expression. In these tumors, the cytogenetic findings and poor prognosis of this patient subgroup suggest that these neoplasms need to be distinguished from B-lymphoblastic leukemia/lymphoma. Segregation of these neoplasms also may foster additional research on these neoplasms.
It is known that complete remission (CR) prolongs survival in acute myeloid leukemia (AML). In 2003, less stringent response categories were introduced, most notably CR with incomplete platelet ...recovery (CRp). Although the significance of CRp for survival remains unclear, reports of AML trials frequently combine CR with CRp rather than considering CR as a separate entity.
This practice led us to retrospectively examine the effect of CR on outcome in newly diagnosed AML, by using data from 6,283 patients treated on Eastern Cooperative Oncology Group (ECOG) and Southwest Oncology Group (SWOG) protocols or at M. D. Anderson Cancer Center. This effect was then contrasted with the effect of CRp in the M. D. Anderson Cancer Center cohort.
At least 94% of patients receiving cytarabine-based therapy and surviving for more than 3 or 5 years achieved a CR with either initial or salvage therapy; limited data suggest the same for patients receiving initial therapies that did not contain cytarabine. Patients with CR were more likely to live beyond 3 or 5 years than patients with CRp. The likelihood of achieving a CR rather than CRp was greater for patients with AML who had better prognosis. After adjustment for covariates, the relapse-free survival of patients achieving CR was longer than that of patients achieving CRp, whereas patients with CRp survived longer than those with resistant disease.
Our data indicate that CR is of unique clinical significance and should be reported as separate response in trials of newly diagnosed AML. Nonetheless, our findings validate CRp as a clinically meaningful response.
Venetoclax combined with hypomethylating agents is a new standard of care for newly diagnosed patients with acute myeloid leukaemia (AML) who are 75 years or older, or unfit for intensive ...chemotherapy. Pharmacodynamic studies have suggested superiority of the longer 10-day regimen of decitabine that has shown promising results in patients with high-risk AML in phase 2 trials. We hypothesised that venetoclax with 10-day decitabine could have improved activity in patients with newly diagnosed AML and those with relapsed or refractory AML, particularly in high-risk subgroups.
This single centre, phase 2 trial was done at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). The study enrolled older patients (aged >60 years) with newly diagnosed AML, not eligible for intensive chemotherapy; secondary AML (progressed after myelodysplastic syndrome or chronic myelomonocytic leukaemia); and relapsed or refractory AML. Patients were required to have an Eastern Cooperative Oncology Group (ECOG) performance status of 3 or less, white blood cell count less than 10 × 10
per L, and adequate end-organ function. Patients with favourable-risk cytogenetics (eg, t15;17 or core-binding factor AML) or who had received previous BCL2-inhibitor therapy were excluded. Patients received decitabine 20 mg/m
intravenously for 10 days with oral venetoclax 400 mg daily for induction, followed by decitabine for 5 days with daily venetoclax for consolidation. The primary endpoint was overall response rate. The secondary endpoints analysed within this report include safety, overall survival, and duration of response, in keeping with recommendations of European LeukemiaNet 2017 guidelines. All patients who received at least one dose of treatment were eligible for safety and response assessments. The trial was registered on ClinicalTrials.gov (NCT03404193) and continues to accrue patients.
Between Jan 19, 2018, and Dec 16, 2019, we enrolled 168 patients; 70 (42%) had newly diagnosed AML, 15 (9%) had untreated secondary AML, 28 (17%) had treated secondary AML, and 55 (33%) had relapsed or refractory AML. The median age was 71 years (IQR 65-76) and 30% of patients had ECOG performance status of 2 or higher. The median follow-up for all patients was 16 months (95% CI 12-18; actual follow-up 6·5 months; IQR 3·4-12·4). The overall response rate was 74% (125 of 168 patients; 95% CI 67-80) and in disease subgroups were: 89% in newly diagnosed AML (62 of 70 patients; 79-94), 80% in untreated secondary AML (12 of 15 patients; 55-93), 61% in treated secondary AML (17 of 28 patients; 42-76), and 62% in relapsed or refractory AML (34 of 55 patients; 49-74). The most common treatment-emergent adverse events included infections with grades 3 or 4 neutropenia (n=79, 47%) and febrile neutropenia (n=49, 29%). 139 (83%) of 168 patients had serious adverse events, most frequently neutropenic fever (n=63, 38%), followed by pneumonia (n=17, 10%) and sepsis (n=16, 10%). The 30-day mortality for all patients was 3·6% (n=6, 95% CI 1·7-7·8). The median overall survival was 18·1 months (95% CI 10·0-not reached) in newly diagnosed AML, 7·8 months (2·9-10·7) in untreated secondary AML, 6·0 months (3·4-13·7) in treated secondary AML, and 7·8 months (5·4-13·3) relapsed or refractory AML. The median duration of response was not reached (95% CI 9·0-not reached) in newly diagnosed AML, 5·1 months (95% CI 0·9-not reached) in untreated secondary AML, not reached (95% CI 2·5-not reached) in previously treated secondary AML, and 16·8 months (95% CI 6·6-not reached) in relapsed or refractory AML.
Venetoclax with 10-day decitabine has a manageable safety profile and showed high activity in newly diagnosed AML and molecularly defined subsets of relapsed or refractory AML. Future larger and randomised studies are needed to clarify activity in high-risk subsets.
US National Institutes of Health and National Cancer Institute.
Background
Patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) have limited treatment options. In preclinical models of AML, inhibition of the PD‐1/PD‐L1 axis demonstrated ...antileukemic activity. Avelumab is an anti–PD‐L1 immune checkpoint inhibitor (ICI) approved in multiple solid tumors. The authors conducted a phase 1b/2 clinical trial to assess the safety and efficacy of azacitidine with avelumab in patients with R/R AML.
Methods
Patients aged ≥18 years who had R/R AML received azacitidine 75 mg/m2 on days 1 through 7 and avelumab on days 1 and 14 of 28‐day cycles.
Results
Nineteen patients were treated. The median age was 66 years (range, 22‐83 years), 100% had European LeukemiaNet 2017 adverse‐risk disease, and 63% had prior exposure to a hypomethylating agent. Avelumab was dosed at 3 mg/kg for the first 7 patients and at 10 mg/kg for the subsequent 12 patients. The most common grade ≥3 treatment‐related adverse events were neutropenia and anemia in 2 patients each. Two patients experienced immune‐related adverse events of grade 2 and grade 3 pneumonitis, respectively. The overall complete remission rate was 10.5%, and both were complete remission with residual thrombocytopenia. The median overall survival was 4.8 months. Bone marrow blasts were analyzed for immune‐related markers by mass cytometry and demonstrated significantly higher expression of PD‐L2 compared with PD‐L1 both pretherapy and at all time points during therapy, with increasing PD‐L2 expression on therapy.
Conclusions
Although the combination of azacitidine and avelumab was well tolerated, clinical activity was limited. High expression of PD‐L2 on bone marrow blasts may be an important mechanism of resistance to anti–PD‐L1 therapy in AML.
Lay Summary
This report describes the results of a phase 1b/2 study of azacitidine with the anti–PD‐L1 immune checkpoint inhibitor avelumab for patients with relapsed/refractory acute myeloid leukemia (AML).
The clinical activity of the combination therapy was modest, with an overall response rate of 10.5%.
However, mass cytometry analysis revealed significantly higher expression of PD‐L2 compared with PD‐L1 on AML blasts from all patients who were analyzed at all time points.
These data suggest a novel potential role for PD‐L2 as a means of AML immune escape.
Azacitidine combined with the anti–PD‐L1 immune checkpoint inhibitor avelumab does not produce significant clinical efficacy for patients with relapsed/refractory acute myeloid leukemia (AML). However, an analysis of AML blasts reveals PD‐L2 surface expression as a novel mechanism of immune escape.
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