Genomic determinants of response and resistance to inotuzumab ozogamicin in B-cell ALL.

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate that delivers calicheamicin to CD22-expressing cells. In a retrospective cohort of InO-treated patients with B-cell acute lymphoblastic leukemia, we sought to understand the genomic determinants of response and resistance to InO. Pre- and post-InO patient samples were analyzed by whole genome, exome, and/or transcriptome sequencing. Acquired CD22 mutations were observed in 11% (3/27) of post-InO relapsed tumor samples, but not in refractory samples (0/16). There were multiple CD22 mutations per sample and the mechanisms of CD22 escape included epitope loss (protein truncation, protein destabilization) and epitope alteration. Two CD22 mutant cases were post-InO hypermutators resulting from error-prone DNA damage repair (non-homologous/alternative end joining, mismatch repair deficiency), suggesting hypermutation drove escape from CD22-directed therapy. CD22-mutant relapses occurred after InO and subsequent hematopoietic stem cell transplantation (HSCT), suggesting InO eliminated predominant clones, leaving subclones with acquired CD22 mutations that conferred resistance to InO and subsequently expanded. Acquired loss-of-function mutations in TP53, ATM and CDKN2A were observed, consistent with compromise of the G1/S DNA damage checkpoint as a mechanism of evading InO-induced apoptosis. Genome wide CRISPR/Cas9 screening in cell lines identified DNTT (TdT) loss as a marker of InO resistance. In conclusion, genetic alterations modulating CD22 expression and DNA damage response influence InO efficacy. Our findings highlight the importance of defining the basis of CD22 escape, and eradication of residual disease prior to HSCT. The identified mechanisms of escape from CD22-targeted therapy extend beyond antigen loss, and provide opportunities to improve therapeutic approaches and overcome resistance.

A phase 1/2 study of mini-hyper-CVD plus venetoclax in patients with relapsed/refractory acute lymphoblastic leukemia.

ABSTRACT: Preclinical studies suggest that Bcl-2 inhibition with venetoclax has antileukemic activity in acute lymphoblastic leukemia (ALL) and may synergize with conventional chemotherapy. We designed a phase 1/2 clinical trial to evaluate the safety and efficacy of low-intensity chemotherapy in combination with venetoclax in adults with relapsed or refractory ALL. Patients received the mini-hyper-CVD regimen (dose-attenuated hyperfractionated cyclophosphamide, vincristine, and dexamethasone alternating with methotrexate and cytarabine) in combination with venetoclax (200 mg or 400 mg daily) on days 1 to 14 in cycle 1 and on days 1 to 7 in consolidation cycles. Twenty-two patients were treated. The median number of prior therapies was 2 (range, 1-6). Thirteen patients (59%) had undergone prior allogeneic stem cell transplant (allo-SCT), and 7 of 18 patients (39%) with B-cell ALL had previously received both inotuzumab ozogamicin and blinatumomab. The recommended phase 2 dose of venetoclax in the combination regimen was 400 mg daily. The composite complete remission (CR) and CR with incomplete hematologic recovery (CRi) rate was 57% (CR, 43%; CRi, 14%), and 45% of responders achieved measurable residual disease negativity by multiparameter flow cytometry. Four patients proceeded to allo-SCT. The median duration of response was 6.3 months. The median overall survival was 7.1 months, and the 1-year overall survival rate was 29%. The most common grade ≥3 nonhematologic adverse events were infection in 17 patients (77%) and febrile neutropenia in 4 patients (18%). Overall, the combination of mini-hyper-CVD plus venetoclax was active in heavily pretreated relapsed/refractory ALL. Further development of venetoclax-based combinations in ALL is warranted. This trial is registered at www.clinicaltrials.gov as #NCT03808610.

Dose-Dense Mini-Hyper-CVD, Inotuzumab Ozogamicin and Blinatumomab Achieves Rapid MRD-Negativity in Philadelphia Chromosome-Negative B-cell Acute Lymphoblastic Leukemia.

BACKGROUND: The combination of low-intensity chemotherapy and inotuzumab ozogamicin (INO), with sequential blinatumomab, is highly effective in older adults with newly diagnosed B-cell acute lymphoblastic leukemia (ALL) and in relapsed or refractory B-cell ALL. Earlier, "dose-dense" administration of blinatumomab could lead to earlier and deeper measurable residual disease (MRD) responses and better outcomes. PATIENTS AND METHODS: We performed a retrospective analysis of the safety and efficacy of a dose-dense regimen of mini-hyper-CVD (mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone alternating with mini-methotrexate and cytarabine), INO, and blinatumomab in patients with B-cell ALL. RESULTS: Twenty-one patients were treated (frontline, n = 9; MRD consolidation, n = 4; relapsed/refractory, n = 8). In the frontline cohort, all patients achieved CR/CRi and MRD negativity by flow cytometry at the end of cycle 1. Across the frontline and MRD consolidation cohorts, 10/11 patients (91%) achieved next-generation sequencing MRD negativity at a sensitivity of 10-6, including 6/10 evaluable patients (60%) who achieved next-generation sequencing MRD negativity after cycle 1. The CR/CRi rate in the relapsed/refractory cohort was 63%, and all responders achieved MRD negativity by flow cytometry at the end of cycle 1. The 1-year overall survival rate for the combined cohort of the frontline and MRD-positive patients was 83%. No new safety signals were observed with the dose-dense mini-hyper-CVD, INO, and blinatumomab regimen. CONCLUSION: Dose-dense delivery of mini-hyper-CVD, INO, and blinatumomab was safe and resulted in rapid and deep MRD negativity in patients with B-cell ALL. This regimen is now being prospectively evaluated in both the frontline and relapsed/refractory settings.

Phase 2 study of inotuzumab ozogamicin for measurable residual disease in acute lymphoblastic leukemia in remission.

ABSTRACT: The detection of measurable residual disease (MRD) is the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). Using inotuzumab ozogamicin in the setting of MRD may improve outcomes. Patients with ALL in first complete remission (CR1) or beyond (CR2+) with MRD ≥ 1 × 10-4 were enrolled in this phase 2 trial. Inotuzumab was administered at 0.6 mg/m2 on day 1 and 0.3 mg/m2 on day 8 of cycle 1, then at 0.3 mg/m2 on days 1 and 8 of cycles 2-6. Twenty-six consecutive patients with a median age of 46 years (range, 19-70 years) were treated. Nineteen (73%) were in CR1 and seven (27%) in CR2+; 16 (62%) had Philadelphia chromosome-positive ALL. Fifteen (58%) had baseline MRD ≥ 1 × 10-3. A median of 3 cycles (range, 1-6) were administered. Eighteen (69%) patients responded and achieved MRD negativity. After a median follow-up of 24 months (range, 9-43), the 2-year relapse-free survival rate was 54% and the 2-year overall survival rate was 60% in the entire cohort. Most adverse events were low grade; sinusoidal obstruction syndrome was noted in 2 patients (8%). In summary, inotuzumab ozogamicin resulted in favorable survival, MRD negativity rates, and safety profiles for patients with ALL and MRD-positive status. This study was registered at www.ClinicalTrials.gov as #NCT03441061.

Genomic determinants of response and resistance to inotuzumab ozogamicin in B-cell ALL.

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate that delivers calicheamicin to CD22-expressing cells. In a retrospective cohort of InO treated patients with B-cell acute lymphoblastic leukemia, we sought to understand the genomic determinants of response to InO. Acquired CD22 mutations were observed in 11% (3/27) of post-InO relapsed tumor samples. There were multiple CD22 mutations per sample and the mechanisms of CD22 escape included protein truncation, protein destabilization, and epitope alteration. Hypermutation by error-prone DNA damage repair (alternative end-joining, mismatch repair deficiency) drove CD22 escape. Acquired loss-of-function mutations in TP53 , ATM and CDKN2A were observed, suggesting compromise of the G1/S DNA damage checkpoint as a mechanism of evading InO-induced apoptosis. In conclusion, genetic alterations modulating CD22 expression and DNA damage response influence InO efficacy. The escape strategies within and beyond antigen loss to CD22-targeted therapy elucidated in this study provide insights into improving therapeutic approaches and overcoming resistance. KEY POINTS: We identified multiple mechanisms of CD22 antigen escape from inotuzumab ozogamicin, including protein truncation, protein destabilization, and epitope alteration.Hypermutation caused by error-prone DNA damage repair was a driver of CD22 mutation and escape.

Mini-hyper-CVD plus inotuzumab ozogamicin, with or without blinatumomab, in the subgroup of older patients with newly diagnosed Philadelphia chromosome-negative B-cell acute lymphocytic leukaemia: long-term results of an open-label phase 2 trial.

BACKGROUND: The outcome of older patients with B-cell acute lymphocytic leukaemia is inferior to that in younger patients due to the adverse disease biology and their inability to tolerate intensive therapy. We aimed to study the long-term outcomes of inotuzumab ozogamicin with or without blinatumomab in combination with low-intensity chemotherapy in these patients. METHODS: For this open-label phase 2 trial, patients aged 60 years or older with newly diagnosed, Philadelphia-chromosome negative, B-cell acute lymphocytic leukaemia, and an ECOG performance status of 3 or lower were eligible. This study was conducted at the University of Texas MD Anderson Cancer Center. The induction chemotherapy consisted of mini-hyper-CVD and has been published before; inotuzumab ozogamicin was administered intravenously on day 3 of the first four cycles at a dose of 1·3-1·8 mg/m2 in cycle 1, followed by 1·0-1·3 mg/m2 in subsequent cycles (cycles 2-4). Maintenance therapy with dose-reduced POMP (6-mercaptopurine, vincristine, methotrexate, and prednisone) was given for 3 years. From patient 50 onwards, the study protocol was amended to fractionate inotuzumab ozogamicin to a maximum cumulative dose of 2·7 mg/m2 (0·9 mg/m2 during cycle 1 fractionated into 0·6 mg/m2 on day 2 and 0·3 mg/m2 on day 8 of cycle 1, and 0·6 mg/m2 in cycles 2-4 fractionated into 0·3 mg/m2 on day 2 and 0·3 mg/m2 on day 8) followed by blinatumomab for four cycles (cycles 5-8). POMP maintenance was shortened to 12 cycles with one cycle of blinatumomab administered by continuous infusion after every three cycles of POMP. The primary endpoint was progression-free survival and was analysed on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov (NCT01371630) and the present data is from the newly diagnosed, older subgroup of patients treated on the phase 2 portion of this trial; the trial is still enrolling patients. RESULTS: Between Nov 11, 2011, and March 31, 2022, 80 patients were enrolled and treated (32 female and 48 male patients; median age 68 years [IQR 63-72]), 31 of whom were treated after the protocol amendment. With a median follow-up of 92·8 months (IQR 8·8-67·4), the 2-year progression-free survival was 58·2% (95% CI 46·7-68·2) and 5-year progression-free survival was 44·0% (31·2-54·3). At a median follow-up of 104·4 months (IQR 6·6-89·2) for the patients treated before the protocol amendment and 29·7 months (8·8-41·0) for those treated after the protocol amendment, median progression-free survival did not differ significantly between the two groups (34·7 months [95% CI 15·0-68·3] vs 56·4 months [11·3-69·7]; p=0·77). The most common grade 3-4 events were thrombocytopenia in 62 (78%) patients and febrile neutropenia in 26 (32%) patients. Six (8%) patients developed hepatic sinusoidal obstruction syndrome. There were eight (10%) deaths due to infectious complications, nine (11%) from complications related to secondary myeloid malignancy, and four (5%) from sinusoidal obstruction syndrome. INTERPRETATION: Inotuzumab ozogamicin with or without blinatumomab added to low-intensity chemotherapy showed promising activity in terms of progression-free survival in older patients with B-cell acute lymphocytic leukaemia. Further attenuation of the chemotherapy regimen might improve tolerability while maintaining efficacy in older patients. FUNDING: Pfizer and Amgen.

Ultrasensitive NGS MRD assessment in Ph+ ALL: Prognostic impact and correlation with RT-PCR for BCR::ABL1.

Reverse transcription polymerase chain reaction (RT-PCR) for BCR::ABL1 is the most common and widely accepted method of measurable residual disease (MRD) assessment in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL); however, RT-PCR may not be an optimal measure of MRD in many cases of Ph+ ALL. We evaluated the clinical impact of a highly sensitive next-generation sequencing (NGS) MRD assay (sensitivity of 10-6 ) and its correlation with RT-PCR for BCR::ABL1 in patients with Ph+ ALL. Overall, 32% of patients had a discordance between MRD assessment by RT-PCR and NGS, and 31% of patients who achieved NGS MRD negativity were PCR+ at the same timepoint. Among eight patients with long-term detectable BCR::ABL1 by PCR, six were PCR+/NGS-. These patients generally had stable PCR levels that persisted despite therapeutic interventions, and none subsequently relapsed; in contrast, patients who were PCR+/NGS+ had more variable PCR values that responded to therapeutic intervention. In a separate cohort of prospectively collected clinical samples, 11 of 65 patients (17%) with Ph+ ALL who achieved NGS MRD negativity had detectable BCR::ABL1 by PCR, and none of these patients relapsed. Relapse-free survival and overall survival were similar in patients who were PCR+/NGS- and PCR-/NGS-, suggesting that PCR for BCR::ABL1 did not provide additional prognostic information in patients who achieved NGS MRD negativity. NGS-based assessment of MRD is prognostic in Ph+ ALL and identifies patients with low-level detectable BCR::ABL1 who are unlikely to relapse nor to benefit from therapeutic interventions.

Results of salvage therapy with mini-hyper-CVD and inotuzumab ozogamicin with or without blinatumomab in pre-B acute lymphoblastic leukemia.

BACKGROUND: Historically, adults with relapsed-refractory acute lymphoblastic leukemia (ALL) experienced poor outcomes with intensive chemotherapy. This mature analysis explores the benefit of the addition of sequential blinatumomab to low-intensity mini-Hyper-CVD chemotherapy with inotuzumab ozogamicin in this setting. METHODS: Mini-Hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 83% dose reduction) was combined with inotuzumab during the first 4 courses. From Patient #68 and onwards, inotuzumab was given in reduced and fractionated doses, and blinatumomab was added sequentially for 4 courses. Maintenance therapy with prednisone, vincristine, 6-mercaptopurine and methotrexate was given for 12 courses, and blinatumomab for 4 additional courses. RESULTS: Among 110 patients (median age, 37 years) treated, 91 (83%) responded (complete response, 69 patients, 63%). Measurable residual disease negativity was documented in 75 patients (82% of responders). Fifty-three patients (48%) received allogeneic stem cell transplantation (SCT). Hepatic sinusoidal obstruction syndrome occurred in 9/67 patients (13%) on the original inotuzumab schedule and in 1/43 (2%) on the modified schedule. With a median follow-up of 48 months, the median overall survival (OS) was 17 months, and the 3 year OS was 40%. The 3 year OS was 34% with mini-Hyper-CVD plus inotuzumab and 52% with additional blinatumomab (P = 0.16). By landmark analysis at 4 months, the 3 year OS was 54%, similar between patients who did or did not receive allogeneic SCT. CONCLUSION: Low-intensity mini-Hyper-CVD plus inotuzumab with or without blinatumomab showed efficacy in patients with relapsed-refractory ALL, with better survival after the addition of blinatumomab. Trial registration The trial was registered on clinicaltrials.gov with the identifier NCT01371630.

Frontline combination of ponatinib and hyper-CVAD in Philadelphia chromosome-positive acute lymphoblastic leukemia: 80-months follow-up results.

The combination of ponatinib, a third-generation BCR::ABL1 tyrosine kinase inhibitor, with hyper-CVAD chemotherapy resulted in high rates of complete molecular remissions and survival, without the need for stem cell transplantation (SCT) in most patients with Philadelphia chromosome(Ph)-positive acute lymphocytic leukemia (ALL). Confirming these results in a large cohort of patients with longer follow-up would establish this regimen as a new standard of care. Adults with newly diagnosed Ph-positive ALL were treated with the hyper-CVAD regimen. Ponatinib was added as 45 mg daily × 14 during induction, then 45 mg daily continuously (first 37 patients) or 30 mg daily continuously, with dose reduction to 15 mg daily upon achievement of a complete molecular response (CMR; absence of a detectable BCR::ABL1 transcript by quantitative reverse transcription polymerase-chain reaction at a sensitivity of 0.01%). Maintenance therapy consisted of daily ponatinib and vincristine-prednisone monthly for 2 years, followed by daily ponatinib indefinitely. Twelve intrathecal injections of cytarabine alternating with methotrexate were given as central nervous system prophylaxis. The trial is registered on clinicaltrials.gov with the identifier NCT01424982. Eighty-six patients were treated. Their median age was 46 years (range, 21-80). All 68 patients with active disease at the initiation of therapy achieved complete response (CR) The cumulative CMR rate was 86%. Twenty- patients (23%) underwent allogeneic SCT. With a median follow-up of 80 months (range, 16-129 months), the estimated 6-year event-free survival rate was 65% and the overall survival rate was 75%. There was no difference in outcome by performance of allogeneic SCT in first CR. Common grade 3-5 adverse events included infection (n = 80, 93%), increased liver transaminases (n = 26, 31%) and total bilirubin (n = 13, 15%), hypertension (n = 15, 17%), pancreatitis (n = 13, 15%), hemorrhage (n = 12, 13%), and skin rash (n = 9, 10%). Two ponatinib-related deaths from myocardial infarction (3%; at months 2.6 and 4.3, respectively; both in CR) in the first 37 patients treated led to the ponatinib dose-modifications mentioned earlier, with no further ponatinib-related deaths observed. The long-term results of ponatinib and hyper-CVAD continue to demonstrate excellent outcome results and acceptable safety data, indicating that this strategy is another standard of care approach in frontline Ph-positive ALL.

Ponatinib and blinatumomab for Philadelphia chromosome-positive acute lymphoblastic leukaemia: a US, single-centre, single-arm, phase 2 trial.

BACKGROUND: Ponatinib and blinatumomab are effective therapies in patients with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia, and their combination might be a promising treatment option. In this study, we aimed to evaluate this chemotherapy-free strategy. METHODS: We did a single-centre, single-arm, phase 2 study at the University of Texas MD Anderson Cancer Center, Houston, TX, USA, in patients aged 18 years or older with newly diagnosed or relapsed or refractory Ph-positive acute lymphoblastic leukaemia or chronic myeloid leukaemia in lymphoid blast phase. Patients with an ECOG performance status of 2 or less who had a total bilirubin concentration two-times the upper limit of normal (ULN) or less (≤2·4 mg/dL), alanine aminotransferase and aspartate aminotransferase concentration no more than three-times the ULN, and serum lipase and amylase concentrations no more than three-times the ULN were eligible for inclusion. Ponatinib 30 mg orally and continuous intravenous blinatumomab 28 µg over 24 h (for 28 days each cycle) were given in combination for up to five 42-day cycles, followed by ponatinib monotherapy. Patients received 12 doses of intrathecal chemotherapy as CNS prophylaxis. The primary endpoints were complete molecular response (defined as absence of a detectable BCR-ABL1 transcript by PCR at a sensitivity of 0·01%) in patients with newly diagnosed disease and overall response in patients with relapsed or refractory disease or chronic myeloid leukaemia in lymphoid blast phase. All assessments were done according to the intention-to-treat principle. The trial completed its original target accrual and was amended on March 23, 2022, to enrol an additional 30 patients, thus increasing the sample size to 90 patients. The trial is registered with ClinicalTrials.gov, NCT03263572, and it is ongoing. FINDINGS: Between Feb 6, 2018, to May 6, 2022, 60 (83%) of 72 patients assessed were enrolled and received ponatinib and blinatumomab (40 [67%] patients had newly diagnosed Ph-positive acute lymphoblastic leukaemia, 14 [23%] had relapsed or refractory Ph-positive acute lymphoblastic leukaemia, and six [10%] had chronic myeloid leukaemia in lymphoid blast phase). 32 (53%) patients were men and 28 (47%) were women; 51 (85%) patients were White or Hispanic; and the median age of participants was 51 years (IQR 36-68). The median duration of follow-up for the entire cohort was 16 months (IQR 11-24). Of patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia, 33 (87%) of 38 evaluable patients had a complete molecular response. 12 (92%) of 13 evaluable patients with relapsed or refractory Ph-positive acute lymphoblastic leukaemia had an overall response. 11 (79%) had a complete molecular response. Five (83%) of six patients with chronic myeloid leukaemia in lymphoid blast phase had an overall response. Two (33%) had a complete molecular response. The most common grade 3-4 adverse events that occurred in more than 5% of patients were infection (22 [37%] patients), increased amylase or lipase concentration (five [8%] patients), increased alanine aminotransferase or aspartate aminotransferase concentration (four [7%] patients), pain (four [7%] patients), and hypertension (four [7%] patients). One (2%) patient discontinued blinatumomab due to tremor. Three (5%) patients discontinued ponatinib secondary to cerebrovascular ischaemia, portal vein thrombosis, and coronary artery stenosis in one patient each. No treatment-related deaths were observed. INTERPRETATION: The chemotherapy-free combination of ponatinib and blinatumomab resulted in high rates of complete molecular response in patients with newly diagnosed and relapsed or refractory Ph-positive acute lymphoblastic leukaemia. Patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia could be spared the toxicities associated with chemotherapy and the need for allogeneic haematopoietic stem-cell transplantation in first response. FUNDING: Takeda Oncology and Amgen.

Hyper-CVAD and sequential blinatumomab for newly diagnosed Philadelphia chromosome-negative B-cell acute lymphocytic leukaemia: a single-arm, single-centre, phase 2 trial.

BACKGROUND: Blinatumomab is effective in relapsed or refractory B-cell acute lymphocytic leukaemia and results in high rates of minimal residual disease negativity. We aimed to establish whether the incorporation of blinatumomab into front-line therapy for acute lymphocytic leukaemia could improve outcomes. METHODS: We conducted a single-arm, phase 2 trial at The University of Texas MD Anderson Cancer Center (Houston, TX, USA). Patients aged 14 years or older with confirmed, newly diagnosed Philadelphia chromosome (Ph)-negative B-cell acute lymphocytic leukaemia were eligible, including patients who had received up to one course of chemotherapy before enrolment. Patients received four cycles of intensive chemotherapy (hyper-CVAD [hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone] alternating with high-dose methotrexate and cytarabine), followed by four cycles of blinatumomab consolidation (up to 28 µg/day by continuous intravenous infusion for 28 days, given every 42 days). Maintenance consisted of 15 cycles of alternating blocks of three cycles of POMP (6-mercaptopurine, vincristine, methotrexate, and prednisone) chemotherapy and one of blinatumomab. The primary endpoint was relapse-free survival evaluated in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, NCT02877303, and is still enrolling patients. FINDINGS: Between Nov 14, 2016, and Aug 27, 2020, 38 patients with newly diagnosed B-cell acute lymphocytic leukaemia were treated (median age 37 years [IQR 29-45]; 26 [68%] male; 21 [55%] White, non-Hispanic). With a median follow-up of 37 months (IQR 28-49), estimated 3-year relapse-free survival was 73% (95% CI 56-85). No patients relapsed more than 2 years after the start of therapy. One (3%) patient developed transient grade 3 cytokine release syndrome, and four (11%) patients had a grade 3 blinatumomab-related neurological event. The most common non-haematological grade 3-4 adverse events were infections, which occurred in 14 (37%) of 38 patients during induction and in 27 (71%) of 38 patients during consolidation chemotherapy cycles. One (3%) patient discontinued therapy because of treatment-related neurotoxicity. There were two deaths-one due to infection and one due to respiratory failure-which were not considered treatment-related. INTERPRETATION: Front-line sequential chemotherapy with blinatumomab resulted in encouraging long-term survival. Future randomised studies should evaluate the routine incorporation of blinatumomab in the treatment of patients with Ph-negative B-cell acute lymphocytic leukaemia. FUNDING: Amgen.

Blinatumomab is associated with favorable outcomes in patients with B-cell lineage acute lymphoblastic leukemia and positive measurable residual disease at a threshold of 10-4 and higher.

The presence of measurable residual disease (MRD) is the strongest predictor of relapse in acute lymphoblastic leukemia (ALL). We conducted a prospective, single-arm, phase II study in adults with B-cell ALL with MRD ≥1 × 10-4 after ≥3 months from the start of frontline therapy or one month from any salvage therapy. Blinatumomab was administered at a standard dosing of 28 micrograms daily as a continuous infusion for up to five cycles and up to four additional maintenance cycles. Thirty-seven patients with a median age of 43 years (range, 22-84 years) were treated. Twenty-seven patients (73%) were treated in first complete remission (CR) and 10 patients (27%) in second CR and beyond. Eighteen patients (49%) had Philadelphia-chromosome positive ALL and received concomitant tyrosine kinase inhibitor therapy. Twenty-three patients (62%) had a baseline MRD ≥10-3 . A median of three cycles (range, 1-9 cycles) were administered. Overall, 27 patients (73%) achieved MRD-negative remission. With a median follow-up of 31 months (range, 5-70 months), the estimated 3-year relapse-free survival (RFS) rate was 63% (95% confidence interval [CI], 43%-77%) and overall survival (OS) rate 67% (95% CI, 46%-81%). These rates were 51% (95% CI, 27%-70%) and 61% (95% CI, 36%-78%) in patients with baseline MRD ≥1 × 10-3 , and 83% (95% CI, 45%-95%) and 77% (95% CI, 32%-95%) in patients with baseline MRD <10-3 respectively. The rates of adverse events were consistent with previous studies of blinatumomab. In summary, blinatumomab induced MRD negativity in most patients and resulted in high rates of RFS and OS. This study is registered at www.clinicaltrials.gov as #NCT02458014. Funding was provided by Amgen Inc.

High-sensitivity next-generation sequencing MRD assessment in ALL identifies patients at very low risk of relapse.

Measurable residual disease (MRD) is highly prognostic for relapse and overall survival (OS) in acute lymphoblastic leukemia (ALL), although many patients with apparent "MRD negativity" by standard assays still relapse. We evaluated the clinical impact of a highly sensitive next-generation sequencing (NGS) MRD assay in 74 adults with ALL undergoing frontline therapy. Among remission samples that were MRD negative by multiparameter flow cytometry (MFC), 46% were MRD+ by the NGS assay. After 1 cycle of induction chemotherapy, MRD negativity by MFC at a sensitivity of 1 × 10-4 and NGS at a sensitivity of 1 × 10-6 was achieved in 66% and 23% of patients, respectively. The 5-year cumulative incidence of relapse (CIR) among patients who achieved MRD negativity by MFC at complete remission (CR) was 29%; in contrast, no patients who achieved early MRD negativity by NGS relapsed, and their 5-year OS was 90%. NGS MRD negativity at CR was associated with significantly decreased risk of relapse compared with MRD positivity (5-year CIR, 0% vs 45%, respectively; P = .04). Among patients who were MRD negative by MFC, detection of low levels of MRD by NGS identified patients who still had a significant risk of relapse (5-year CIR, 39%). Early assessment of MRD using a highly sensitive NGS assay adds clinically relevant prognostic information to standard MFC-based approaches and can identify patients with ALL undergoing frontline therapy who have a very low risk of relapse and excellent long-term survival.

Genetic correlates in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia treated with Hyper-CVAD plus dasatinib or ponatinib.

Recurring genetic abnormalities have been identified in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). Among them, IKZF1 deletion was associated with poor prognosis in patients treated with imatinib-based or dasatinib-based regimens. However, the molecular determinants for clinical outcomes in ponatinib-treated patients remain unknown. We systematically analyzed genetic alterations in adults with Ph-positive ALL uniformly treated in clinical trials with dasatinib-based regimens or a ponatinib-based regimen and investigated the molecular determinants for treatment outcomes using pretreatment specimens collected from adults with Ph-positive ALL treated with Hyper-CVAD plus dasatinib or ponatinib. DNA sequencing and SNP microarray were performed and recurrent genetic abnormalities were found in 84% of the patients, among whom IKZF1 deletion was most frequently detected (60%). IKZF1 deletion frequently co-occurred with other copy-number abnormalities (IKZF1plus, 46%) and was significantly associated with unfavorable overall survival (OS) (false discovery rate < 0.1) and increased cumulative incidence of relapse (p = 0.01). In a multivariate analysis, dasatinib therapy, lack of achievement of 3-month complete molecular response, and the presence of IKZF1plus status were significantly associated with poor OS. The differential impact of IKZF1plus was largely restricted to patients given Hyper-CVAD plus ponatinib; dasatinib-based regimens had unfavorable outcomes regardless of the molecular abnormalities.

Outcomes of acute lymphoblastic leukemia with KMT2A (MLL) rearrangement: the MD Anderson experience.

Acute lymphoblastic leukemia (ALL) with t(4;11)(q21;q23)-KMT2A-AFF1 is associated with a poor prognosis. The impact of KMT2A rearrangements other than t(4;11) is uncertain, and the benefit of allogeneic stem cell transplantation (HSCT) is unclear. We reviewed adult patients with ALL treated at our institution from 1984 to 2019 and identified 50 out of 1102 (5%) with KMT2A rearrangement, including 42 (84%) with t(4;11)/KMT2A-AFF1 and 8 (16%) with other gene partners. The median age was 45 years (range, 18-78 years); median white blood cell count was 109.0 3 109/L (range, 0.5-1573.0). The complete remission (CR) rate was 88%, and the rate of measurable residual disease negativity by flow cytometry at CR was 41% (76% overall during follow-up). At the last follow-up, 14 patients were alive. The 5-year overall survival (OS) rate was 18% (95% confidence interval [CI], 9% to 35%), with no difference between t(4;11) and other KMT2A rearrangements (P 5 .87). In a 4-month landmark analysis, the 5-year OS rate was 32% (95% CI, 14% to 70%) in patients who underwent HSCT vs 11% (95% CI, 3-39) in others (P 5 .10). Our study confirms the poor prognosis of ALL with any KMT2A rearrangement and the role of HSCT in these patients.

Hyper-CVAD plus ofatumumab versus hyper-CVAD plus rituximab as frontline therapy in adults with Philadelphia chromosome-negative acute lymphoblastic leukemia: A propensity score analysis.

BACKGROUND: The outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper-CVAD + ofatumumab (hyper-CVAD + ofatumumab) has not been compared with the outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper-CVAD plus rituximab (hyper-CVAD + Rituximab) in Philadelphia chromosome-negative acute lymphoblastic leukemia (ALL) in a randomized clinical trial. METHODS: The authors compared the outcomes of 69 patients treated with hyper-CVAD + ofatumumab and 95 historical-control patients treated with hyper-CVAD + Rituximab. Historical-control patients were treated with hyper-CVAD + Rituximab if they had CD20 expression ≥ 20%. Ofatumumab (day 1 of course 1, 300 mg intravenously; subsequent doses, 2000 mg intravenously) was administered on days 1 and 11 of courses 1 and 3 and on days 1 and 8 of courses 2 and 4 for a total of 8 doses. A propensity score analysis with inverse probability of treatment weighting (IPTW) was performed to adjust for baseline covariates between groups. RESULTS: The median event-free survival with stem cell transplantation (SCT) censoring was 33 and 65 months with hyper-CVAD + Rituximab and hyper-CVAD + ofatumumab, respectively (crude P = .064; IPTW P = .054). The median overall survival with SCT censoring was 52 months and not reached, respectively (crude P = .087; IPTW P = .097). CONCLUSIONS: Hyper-CVAD + ofatumumab was associated with better outcomes than hyper-CVAD + Rituximab among patients with newly diagnosed Philadelphia chromosome-negative ALL.

Prognostic factors for progression in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia in complete molecular response within 3 months of therapy with tyrosine kinase inhibitors.

BACKGROUND: The achievement of a 3-month complete molecular response (CMR) is a major prognostic factor for survival in patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). However, 25% of patients relapse during therapy with tyrosine kinase inhibitors (TKIs). METHODS: The authors reviewed 204 patients with Ph-positive ALL who were treated between January 2001 and December 2018 using the combination of hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone) plus a TKI (imatinib, 44 patients [22%]; dasatinib, 88 patients [43%]; or ponatinib, 72 patients [35%]). Progression-free survival (PFS) was defined as the time from the start date of therapy to the date of relapse, death, or last follow-up. Overall survival (OS) was defined as the time from the start date of therapy to the date of death or last follow-up. RESULTS: Overall, a 3-month CMR was observed in 57% of patients, including 32% of those who received imatinib, 52% of those who received dasatinib, and 74% of those who received ponatinib. The median follow-up was 74 months (imatinib, 180 months; dasatinib, 106 months; ponatinib, 43 months). Among 84 patients in 3-month CMR, 17 (20%) proceeded to undergo allogeneic stem cell transplantation (ASCT). The 5-year PFS and OS rates were 68% and 72%, respectively. By multivariate analysis, ponatinib therapy was the only significant favorable independent factor predicting for progression (P = .028; hazard ratio, 0.388; 95% CI, 0.166-0.904) and death (P = .042; hazard ratio, 0.379; 95% CI, 0.149-0.966). ASCT was not a prognostic factor for PFS and OS by univariate analysis. CONCLUSIONS: In patients with Ph-positive ALL, ponatinib is superior to other types of TKIs in inducing and maintaining a CMR, thus preventing disease progression. ASCT does not improve outcome once a 3-month CMR is achieved.