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.

ABSTRACT: 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 the response and resistance to InO. Pre- and post-InO-treated 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 and destabilization) and epitope alteration. Two CD22 mutant cases were post-InO hyper-mutators resulting from error-prone DNA damage repair (nonhomologous/alternative end-joining repair, or mismatch repair deficiency), suggesting that hypermutation drove escape from CD22-directed therapy. CD22-mutant relapses occurred after InO and subsequent hematopoietic stem cell transplantation (HSCT), suggesting that InO eliminated the 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 a compromise of the G1/S DNA damage checkpoint as a mechanism for evading InO-induced apoptosis. Genome-wide CRISPR/Cas9 screening of cell lines identified DNTT (terminal deoxynucleotidyl transferase) 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 before HSCT. The identified mechanisms of escape from CD22-targeted therapy extend beyond antigen loss and provide opportunities to improve therapeutic approaches and overcome resistance. These trials were registered at www.ClinicalTrials.gov as NCT01134575, NCT01371630, and NCT03441061.

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.

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.

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.

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.

Long-term follow-up of salvage therapy using a combination of inotuzumab ozogamicin and mini-hyper-CVD with or without blinatumomab in relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia.

BACKGROUND: The outcome of patients with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) is poor. The combination of inotuzumab with low-intensity mini-hyper-CVD (mini-hyper-CVD; cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 0.5 g/m2 × 4 doses) chemotherapy has shown encouraging results. The sequential addition of blinatumomab might improve outcome in patients with R/R ALL. METHODS: We used lower intensity chemotherapy, mini-hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 0.5 g/m2 x 4 doses) compared to conventional hyper-CVAD. RESULTS: Ninety-six patients with a median age of 37 years (range, 18-87 years) were treated. Overall, 77 patients (80%) responded, 55 (57%) of whom achieved complete response. The overall measurable residual disease negativity rate among responders was 83%. Forty-four (46%) patients underwent later allogeneic stem cell transplantation. Veno-occlusive disease of any grade occurred in 10 (10%) patients. The rates were 13% with the original schedule and 3% with the use of lower-dose inotuzumab and sequential blinatumomab. With a median follow-up of 36 months, the median overall survival (OS) was 13.4 months, with 3-year OS rates of 33%. The 3-year OS rate for patients with CD22 expression ≥70% and without adverse cytogenetics (KMT2A rearrangements, low hypodiploidy/near triploidy) was 55%. CONCLUSION: The combination of inotuzumab and low-intensity mini-hyper-CVD chemotherapy with or without blinatumomab shows sustained efficacy in patients with R/R ALL.

Discontinuation of Maintenance Tyrosine Kinase Inhibitors in Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia outside of Transplant.

BACKGROUND: The addition of tyrosine kinase inhibitors (TKIs) to chemotherapy has dramatically improved outcomes of patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). When allogeneic hematopoietic stem cell transplant (HSCT) is performed, maintenance TKI is generally given for a fixed duration. However, the optimal duration of TKI outside of HSCT remains unknown, and the common practice is to continue indefinitely. Here, we report characteristics and outcomes of 9 patients treated with chemotherapy + TKI without HSCT and later discontinued TKI. METHODS: Among 188 patients with Ph-positive ALL who did not undergo HSCT, 9 of them discontinued maintenance TKI mainly due to side effects. Patients were closely monitored with serial PCR testing for the BCR-ABL1 transcript. Major molecular response (MMR) was defined as BCR-ABL1 transcript ≤0.1% on the international scale for p210 transcripts and a 3-log reduction from baseline for p190 transcripts. Deep molecular remission (DMR) was defined as the absence of quantifiable BCR-ABL1 transcripts with a sensitivity of 0.01%. Molecular relapse was defined as loss of MMR. Treatment-free remission (TFR) was defined from time of TKI discontinuation to molecular relapse, last follow-up, or death from any cause. RESULTS: At the time of TKI discontinuation, transcript level was undetected in 6 patients, <0.01% in 2 patients, and 0.01% in another patient. Prior to discontinuation, the median duration of TKI therapy and of DMR was 70 and 47 months, respectively. No morphological relapse occurred. Three patients (33%) had molecular relapse at a median of 6 months. All 3 resumed TKI therapy, and 2 of them regained DMR after a median of 13 months. After a median follow-up of 49 months, the median TFR was not reached, and the 4-year TFR rate was 65%. The median duration of DMR in patients with and without molecular relapse was 22 and 58 months, respectively (p = 0.096). CONCLUSION: TKI discontinuation outside of HSCT in Ph-positive ALL in the setting of compelling toxicity may be safe only among a highly selected group of patients with deep and prolonged DMR undergoing close and frequent monitoring. Validation of these findings in prospective clinical trials is highly needed.

Phase 2 study of hyper-CMAD with liposomal vincristine for patients with newly diagnosed acute lymphoblastic leukemia.

Liposomal vincristine is designed to reduce neurotoxicity and increase dose intensity delivery, and has been approved as salvage therapy in relapsed/refractory acute lymphoblastic leukemia (ALL). Our aim was to evaluate the response rate, toxicities, and outcome of adults with newly diagnosed ALL who received liposomal vincristine, rather than regular vincristine in combination with intensive chemotherapy (Hyper-CMAD). In a single-center, phase 2 study, patients ≥18 years with newly-diagnosed B-cell ALL were eligible to receive hyper-CMAD alternating with high-dose methotrexate and cytarabine. Rituximab was administered in CD20 positive ALL. Tyrosine kinase inhibitors (imatinib or dasatinib) were added in Philadelphia chromosome-positive (Ph-positive) ALL. Thirty-one patients were enrolled, median follow-up of 59 months (0.3-70). Thirteen patients (42%) had CD20 positive ALL, and 21 (68%) had Ph-positive ALL. Thirty (97%) achieved complete remission (CR). All 26 patients with abnormal karyotype achieved complete cytogenetic response (CCyR), and 27/30 (90%) achieved negative minimal residual disease status by multicolor flow cytometry. Of 20 evaluable Ph-positive ALL patients, major molecular response (MMR) was achieved in 19 patients (95%); complete molecular response (CMR) in 14 (70%). Grade 3/4 peripheral neuropathy was observed in five (16%) with all grade peripheral neuropathy in 21 (68%). With a median follow-up of 59 months, 21 (68%) patients are alive. The 5-year CR duration and survival rates were 73% and 61%, respectively. Ten (32%) patients died: one, sepsis on C1D10; four, unknown; one, post-transplant complications; four, relapse. Hyper-CMAD with liposomal vincristine is safe and demonstrated high response and survival rates in newly diagnosed ALL.

The early achievement of measurable residual disease negativity in the treatment of adults with Philadelphia-negative B-cell acute lymphoblastic leukemia is a strong predictor for survival.

The minimal or measurable residual disease (MRD) status following induction/consolidation chemotherapy is an important prognostic endpoint in adult patients with newly diagnosed acute lymphoblastic leukemia (ALL). However, the optimal time-point (TP) of MRD assessment and its impact on outcome remains unclear. We analyzed 215 patients with newly diagnosed Philadelphia negative B-cell ALL who received intensive chemotherapy, and had available MRD assessment by multicolor flow cytometry at two separate TPs. The median time to first TP (1TP) and second TP (2TP) were 24 and 110 days, respectively. At 1TP, 148 patients (68%) were MRD negative and 67 (32%) were positive. Of the 148 patients with negative MRD at 1TP, 147 (99%) maintained it through 2TP. Patients who were MRD negative at both TPs, early MRD responders, had the 3-year event-free survival (EFS), and overall survival (OS) rates of 65% and 76%, respectively. Patients with improved MRD status from positive to negative, late MRD responders, had lower 3-year EFS and OS rates, 42% and 58%, respectively (P = .001). Multivariate analysis showed that KMT2A (MLL) rearrangement and MRD positivity at 1TP were the only factors correlated with worse OS. In conclusion, the earlier achievement of MRD negative remission is a stronger prognostic factor for survival.

Inotuzumab ozogamicin in combination with low-intensity chemotherapy (mini-HCVD) with or without blinatumomab versus standard intensive chemotherapy (HCVAD) as frontline therapy for older patients with Philadelphia chromosome-negative acute lymphoblastic leukemia: A propensity score analysis.

BACKGROUND: The outcome of older patients with newly diagnosed, Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) is poor. The combination of targeted therapy with low-intensity chemotherapy is safe and effective. The objective of the current analysis was to compare the outcome of patients who received a combination of inotuzumab ozogamicin plus low-intensity chemotherapy (mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone [mini-HCVD]) with or without blinatumomab versus the outcome of those who received the standard, intensive, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (HCVAD) regimen. METHODS: The authors analyzed 135 older patients with newly diagnosed, Ph-negative ALL who were treated prospectively with standard HCVAD (n = 77) or with the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab (n = 58). A propensity score analysis was conducted using 1:1 matching using the nearest neighbor matching method. RESULTS: Propensity score matching identified 38 patients in each cohort. The antibody plus low-intensity chemotherapy combination induced higher response rates (98% vs 88%), with lower rates of early death (0% vs 8%) and lower rates of death in complete remission (5% vs 17%). With propensity score matching, the 3-year event-free survival rates for patients who received HCVAD and those who received the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab were 34% and 64%, respectively (P = .003), and the 3-year overall survival rates were 34% and 63%, respectively (P = .004). By multivariate analysis, age (P = .019; hazard ratio, 1.045) and the combination of inotuzumab plus mini-HCVD with or without blinatumomab (P = .020; hazard ratio, 0.550) were identified as independent prognostic factors for survival. CONCLUSIONS: The combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab is safe and effective in older patients with newly diagnosed, Ph-negative ALL and confers a better outcome compared with standard HCVAD chemotherapy.

Philadelphia chromosome-positive acute lymphoblastic leukemia at first relapse in the era of tyrosine kinase inhibitors.

Despite the advances in the management of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) with the introduction of tyrosine kinase inhibitors (TKIs), relapses remain challenging. We reviewed clinical data from adult patients with Ph + ALL who received frontline hyperCVAD chemotherapy with a TKI to determine their outcomes after first relapse. Patients with first morphological relapse after prior complete remission were evaluated for predictors of response and survival. For 57 of 233 (25%) patients, there was morphological relapse after a median of 15.9 months from first remission [range: 5.3-94]. The choice of salvage treatments was at the discretion of the treating physician. So, 43 (75%) patients received a TKI in combination with their salvage treatment. Second remission was achieved in 41 of 49 (84%) evaluable patients. Median relapse free survival (RFS) was 10.5 months [range, 0.2-81]. The 1-year and 2-year overall survival (OS) were 41% and 20% respectively. On multivariate analysis, only elevated LDH (units/L), the use of first-generation or no TKI at the time of first relapse and the achievement of a major molecular response (MMR) had a significant effect on OS (HR: 2.82, 95% CI:1.11-7.16, P = .029; HR = 2.39, 95% CI: 1.07,5.39, P = .034; HR = 0.39, 95% CI: 0.16-0.94, P = .03, respectively). Whereas, only achievement of MMR was significantly prognostic for RFS with a HR of 0.48 (95% CI: 0.23-0.98, P = .04). The OS and RFS were comparable between recipients and non-recipients of allogeneic hematopoietic stem cell transplantation (alloHSCT) at second remission, due to a higher non-relapse mortality (53%) seen in patients who underwent alloHSCT.

Inotuzumab ozogamicin in combination with low-intensity chemotherapy for older patients with Philadelphia chromosome-negative acute lymphoblastic leukaemia: a single-arm, phase 2 study.

BACKGROUND: Inotuzumab ozogamicin, an anti-CD22 monoclonal antibody bound to a toxin, calicheamicin, has shown single-agent activity in relapsed or refractory acute lymphoblastic leukaemia. We aimed to assess the activity and safety of inotuzumab ozogamicin in combination with low-intensity chemotherapy in older patients with acute lymphoblastic leukaemia. METHODS: We did a single-arm, phase 2 study at the MD Anderson Cancer Center (Houston, TX, USA). Eligible patients were aged 60 years or older and had newly diagnosed, Philadelphia chromosome-negative, acute lymphoblastic leukaemia, and an Eastern Cooperative Oncology Group performance status of 3 or lower. The induction chemotherapy regimen used was mini-hyper-CVD (a lower intensity version of the conventional hyper-CVAD). Odd-numbered cycles (1,3, 5, and 7) comprised intravenous cyclophosphamide (150 mg/m2 every 12 h on days 1-3) and oral or intravenous dexamethasone (20 mg per day on days 1-4 and days 11-14); no anthracycline was administered. Intravenous vincristine (2 mg flat dose) was given on days 1 and 8. Even-numbered cycles comprised intravenous methotrexate (250 mg/m2 on day 1) and intravenous cytarabine (0·5 g/m2 given every 12 h on days 2 and 3). Intravenous inotuzumab ozogamicin was given on day 3 of the first four cycles at the dose of 1·3-1·8 mg/m2 at cycle 1, followed by 1·0 -1·3 mg/m2 in subsequent cycles. Maintenance therapy with dose-reduced POMP (purinethol [6-mercaptopurine], oncovin [vincristine sulfate], methotrexate, and prednisone) was given for 3 years. The primary endpoint of this study was progression-free survival at 2 years. Analyses were by intention to treat. The study is ongoing, recruiting patients for an approved expansion phase with a modified treatment plan by protocol amendment. The trial is registered with ClinicalTrials.gov, number NCT01371630. FINDINGS: Between Nov 12, 2011, and April 22, 2017, 52 patients with a median age of 68 years (IQR 64-72) were enrolled. With a median follow-up of 29 months (IQR 13-48), 2-year progression-free survival was 59% (95% CI 43-72). The most frequent grade 3-4 adverse events were prolonged thrombocytopenia (42 [81%] patients), infections during induction (27 [52%]) and consolidation chemotherapy (36 [69%]), hyperglycaemia (28 [54%]), hypokalaemia (16 [31%]), increased aminotransferases (ten [19%]), hyperbilirubinaemia (nine [17%]), and haemorrhage (seven [15%]). Veno-occlusive disease occurred in four (8%) patients. Six (12%) patients died from adverse events that were deemed treatment related (five [10%] from sepsis and one [2%] from veno-occlusive disease). INTERPRETATION: Inotuzumab ozogamicin plus mini-hyper-CVD chemotherapy is a safe and active first-line therapy option in older patients with newly diagnosed acute lymphoblastic leukaemia and could represent a new therapy for this population. Randomised, phase 3 trials to evaluate the efficacy of this combination compared with the current standard of care in this setting, combination chemotherapy without inotuzumab ozogamicin, are warranted. FUNDING: MD Anderson Cancer Center.

Chemoimmunotherapy with inotuzumab ozogamicin combined with mini-hyper-CVD, with or without blinatumomab, is highly effective in patients with Philadelphia chromosome-negative acute lymphoblastic leukemia in first salvage.

BACKGROUND: The outcomes of patients with relapsed or refractory (R-R) acute lymphoblastic leukemia (ALL) are poor. Inotuzumab ozogamicin and blinatumomab have single-agent activity in R-R ALL. Their addition to low-intensity chemotherapy may further improve the outcomes of patients with ALL in their first relapse. METHODS: The chemotherapy was lower in intensity than conventional hyperfractionated cyclophosphamide, vincristine, adriamycin, and dexamethasone and was called mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone (or mini-HCVD). Inotuzumab was given on day 3 of each of the first 4 cycles at 1.8 to 1.3 mg/m2 for cycle 1, and this was followed by 1.3 to 1.0 mg/m2 for subsequent cycles. From patient 39 onward, the inotuzumab dose was reduced and fractionated into weekly doses (0.6 and 0.3 mg/m2 during cycle 1 and 0.3 and 0.3 mg/m2 during subsequent cycles), and blinatumomab was administered for up to 4 cycles after inotuzumab therapy. RESULTS: Forty-eight patients with Philadelphia chromosome-negative ALL with a median age of 39 years were treated during their first relapse. Overall, 44 patients (92%) responded, with 35 of them (73%) achieving a complete response. The overall minimal residual disease negativity rate among the responders was 93%. Twenty-four patients (50%) underwent allogeneic stem cell transplantation (ASCT). Veno-occlusive disease of any grade occurred in 5 patients (10%). With a median follow-up of 31 months, the median progression-free survival (PFS) and the median overall survival (OS) were 11 and 25 months, respectively. The 2-year PFS and OS rates were 42% and 54%, respectively. Of the 24 patients (50%) who underwent ASCT, 14 patients were alive at the last follow-up (13 [54%] in remission). Of the remaining 20 responding patients who did not undergo subsequent ASCT, 6 (30%) remained in remission at the last follow-up. According to propensity score matching, the combination of mini-HCVD and inotuzumab with or without blinatumomab conferred better outcomes than intensive salvage chemotherapy or inotuzumab alone. CONCLUSIONS: The combination of inotuzumab and low-intensity mini-HCVD chemotherapy with or without blinatumomab shows encouraging results in patients with ALL in first salvage.

Impact of complete molecular response on survival in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia.

The impact of achieving complete molecular response (CMR) in Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) remains undefined. We evaluated the impact of CMR on outcomes among 85 patients with Ph(+) ALL who received first-line hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with methotrexate and high-dose cytarabine plus a tyrosine kinase inhibitor, had minimal residual disease (MRD) assessments for BCR-ABL1 by quantitative polymerase chain reaction at complete remission (CR) and at 3-month time points, and did not undergo allogeneic stem cell transplantation (SCT). MRD status at 3 months had better discrimination for overall survival (OS; P = .005) and relapse-free survival (RFS; P = .002) than did MRD status at CR (P = .11 and P = .04, respectively). At 3 months, achievement of CMR vs response less than CMR was associated with longer median OS (127 vs 38 months, respectively; P = .009) and RFS (126 vs 18 months, respectively; P = .007). By multivariate analysis, only CMR at 3 months was prognostic for OS (hazard ratio, 0.42; 95% confidence interval, 0.21-0.82; P = .01). Patients with Ph(+) ALL who achieve CMR at 3 months have superior survival compared with those with lesser molecular responses and have excellent long-term outcomes even without SCT.

Hyper-CVAD plus nelarabine in newly diagnosed adult T-cell acute lymphoblastic leukemia and T-lymphoblastic lymphoma.

Nelarabine, a water soluble prodrug of 9-ß-D-arabinofuranosylguanine (ara-G), is a T-cell specific purine nucleoside analogue. Given its activity in relapsed and refractory T acute lymphoblastic leukemia (T-ALL) and T lymphoblastic lymphoma (T-LBL), we sought to define its role in the frontline treatment of adult patients. Therefore, we conducted a single arm phase 2 study to determine the safety and efficacy of nelarabine in combination with hyper-CVAD in newly diagnosed patients. For induction/consolidation, patients received eight cycles of hyper-CVAD alternating with high-dose methotrexate and cytarabine plus two cycles of nelarabine given at a dose of 650 mg/m2 intravenously daily for 5 days. This was followed by thirty months of POMP maintenance chemotherapy with two additional cycles of nelarabine given instead of cycles 6 and 7 of POMP maintenance. Sixty-seven patients, including 40 with T-ALL and 26 with T-LBL, were enrolled. Complete response rates in both T-ALL and T-LBL were 87% and 100% respectively. Grade 3 to 4 neurotoxic adverse events were reported in 5 patients. There were 21 relapses (31%) including 2 after allogeneic stem cell transplantation. Median duration of follow-up was 42.5 months. The 3-year complete remission duration (CRD) and overall survival (OS) rates were 66% and 65%, respectively. Compared to our historic hyper-CVAD data, there was no survival benefit with the addition of nelarabine. In conclusion, hyper-CVAD plus nelarabine was well tolerated and active in the frontline treatment of adult T-ALL/LBL patients.

Differential impact of minimal residual disease negativity according to the salvage status in patients with relapsed/refractory B-cell acute lymphoblastic leukemia.

BACKGROUND: Minimal residual disease (MRD) assessment predicts survival for patients with newly diagnosed acute lymphoblastic leukemia (ALL). Its significance in relapsed/refractory ALL is less clear. METHODS: This study identified 78 patients with relapsed/refractory B-cell ALL who achieved a morphologic response with inotuzumab ozogamicin (n = 41), blinatumomab (n = 11), or mini-hyperfractionated cyclophosphamide, vincristine, and doxorubicin plus inotuzumab (n = 26) during either salvage 1 (S1; n = 46) or salvage 2 (S2; n = 32) and had undergone an MRD assessment by multiparameter flow cytometry at the time of remission. RESULTS: MRD negativity was achieved in 41 patients overall (53%). The MRD negativity rate was 57% in S1 and 47% in S2. Among patients in S1, achieving MRD negativity was associated with longer event-free survival (EFS; median, 18 vs 7 months; 2-year EFS rate, 46% vs 17%; P = .06) and overall survival (OS; median, 27 vs 9 months; 2-year OS, 52% vs 36%; P = .15). EFS and OS were similar in S2, regardless of the MRD response. Among MRD-negative patients who underwent allogeneic stem cell transplantation (SCT), EFS and OS were superior for those who underwent SCT in S1 rather than S2 (P = .003 and P = .04, respectively). Patients in S1 who achieved MRD negativity and subsequently underwent SCT had the best outcomes with a 2-year OS rate of 65%. CONCLUSIONS: Patients with relapsed/refractory ALL who achieve MRD negativity in S1 can have long-term survival. Patients in S2 generally have poor outcomes, regardless of their MRD status. Cancer 2017;123:294-302. © 2016 American Cancer Society.

TP53 mutation does not confer a poor outcome in adult patients with acute lymphoblastic leukemia who are treated with frontline hyper-CVAD-based regimens.

BACKGROUND: Tumor protein 53 (TP53) mutations are uncommon in adult patients with acute lymphoblastic leukemia (ALL) and predict a poor outcome. METHODS: TP53 mutation analysis was performed in 164 newly diagnosed adult patients with ALL using a combination of targeted amplicon-based next-generation sequencing and Sanger sequencing. RESULTS: TP53 mutations were detected in 25 patients (15%), with a median allelic frequency of 42.2% (range, 5.6%-93.8%). The majority of mutations were single-nucleotide variants of missense type and involved the DNA-binding domain. TP53-mutated (TP53mut ) ALL was found to be significantly associated with older age, lower median white blood cell and platelet counts, lower frequency of Philadelphia chromosome and a higher frequency of low hypodiploid karyotype compared with ALL with wild-type TP53 (TP53wt ). To evaluate the prognostic effect of TP53 mutations, the authors selected 146 patients with B-cell immunophenotype ALL (24 with TP53mut and 122 with TP53wt ) who were uniformly treated with frontline hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD)-based regimens; >90% of these individuals also received a monoclonal antibody. Over a median follow-up duration of 15 months, there was no significant difference in the median overall survival, event-free survival, and duration of complete remission noted between patients with TP53mut ALL and those with TP53wt ALL. CONCLUSIONS: Hyper-CVAD-based regimens appear to negate the poor prognostic impact of TP53 mutations in patients with adult B-cell immunophenotype ALL. Cancer 2017;123:3717-24. © 2017 American Cancer Society.