BACKGROUND: Inotuzumab ozogamicin (InO) is an antibody-drug conjugate used for adults with relapsed/refractory B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). The INotuzumab Ozogamicin trial to inVestigAte Tolerability and Efficacy (INO-VATE) previously reported improved outcomes with InO versus standard-of-care (SoC) chemotherapy. This article reports the final INO-VATE results (≥2 years of follow-up) and additional analyses of patient characteristics associated with improved outcomes. METHODS: Between August 27, 2012, and January 4, 2015, this multicenter, parallel, open-label, phase 3 trial randomized 326 adults with relapsed/refractory ALL to InO (n = 164) or SoC (n = 162); 307 received 1 or more doses of the study drug (164 in the InO arm and 143 in the SoC arm). RESULTS: The complete remission (CR)/complete remission with incomplete hematologic recovery (CRi) rate was higher with InO versus SoC (73.8% vs 30.9%; 1-sided P < .0001), with consistent CR/CRi rates across patient subgroups. The median overall survival (OS) was 7.7 months with InO and 6.2 months with SoC, with 2-year OS rates of 22.8% and 10.0%, respectively (overall hazard ratio, 0.75; 97.5% confidence interval [CI], 0.57-0.99; 1-sided P = .0105). The predictors of OS with InO were the best minimal residual disease status, baseline platelet count, duration of first remission, achievement of CR/CRi, and follow-up hematopoietic stem cell transplantation (HSCT; all 2-sided P values < .05). More InO arm patients proceeded directly to HSCT after achieving CR/CRi before any follow-up induction therapy (39.6% [95% CI, 32.1%-47.6%] vs 10.5% [6.2%-16.3%]; 1-sided P < .0001). The most frequent all-grade and grade 3 or higher adverse events in both arms were hematologic. Veno-occlusive disease (VOD)/sinusoidal obstruction syndrome (SOS) was more frequent with InO (23 of 164 [14.0%] vs 3 of 143 [2.1%]). CONCLUSIONS: In patients with relapsed/refractory BCP ALL in INO-VATE, InO was associated with a greater likelihood of CR/CRi across key patient subgroups, and it served as a bridge to HSCT. Potential VOD/SOS risk factors must be considered when InO treatment decisions are being made.

Adults with relapsed/refractory acute lymphoblastic leukemia (R/R ALL) have a poor prognosis, especially if disease burden is high. This post hoc analysis of the phase 3 INO-VATE trial examined the efficacy and safety of inotuzumab ozogamicin (InO) vs. standard of care chemotherapy (SC) among R/R ALL patients with low, moderate, or high disease burden, respectively, defined as bone marrow blasts (BMB) < 50% (n = 53 vs. 48), 50-90% (n = 79 vs. 83), and >90% (n = 30 vs. 30). Patients in the InO vs. SC arm with low, moderate, and high BMB%, respectively, had improved rates of complete remission/complete remission with incomplete hematologic recovery (74% vs. 46% [p = 0.0022], 75 vs. 27% [p < 0.0001], and 70 vs. 17% [p < 0.0001]), and improved overall survival (hazard ratio: 0.64 [p = 0.0260], 0.81 [p = 0.1109], and 0.60 [p = 0.0335]). Irrespective of BMB%, cytopenias were the most common treatment-emergent adverse events, and post-transplant veno-occlusive disease was more common with InO vs. SC. Patients with extramedullary disease or lymphoblastic lymphoma showed similar efficacy and safety outcomes. This favorable benefit-to-risk ratio of InO treatment irrespective of disease burden supports its use in challenging and high disease burden subpopulations. INO-VATE is registered at www.clinicaltrials.gov : #NCT01564784.

CC-90002 is an anti-CD47 antibody that inhibits CD47-SIRPα interaction and enables macrophage-mediated killing of tumor cells in hematological cancer cell lines. In this first clinical, phase 1, dose-escalation and -expansion study (CC-90002-AML-001; NCT02641002), we evaluated CC-90002 in patients with relapsed/refractory acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes (MDS). CC-90002 was administered in escalating doses of 0.1-4.0 mg/kg, using a modified 3 + 3 design. Primary endpoints included dose-limiting toxicities (DLTs), non-tolerated dose (NTD), maximum tolerated dose (MTD), and recommended phase 2 dose. Secondary endpoints included preliminary efficacy, pharmacokinetics, and presence/frequency of anti-drug antibodies (ADAs). Between March 2016 and July 2018, 28 patients were enrolled (24 with AML and 4 with MDS) at 6 sites across the USA. As of July 18, 2018, all patients had discontinued, mainly due to death or progressive disease. The most common treatment-emergent adverse events were diarrhea (46.4%), thrombocytopenia (39.3%), febrile neutropenia (35.7%), and aspartate aminotransferase increase (35.7%). Four patients experienced DLTs (1 patient had grade 4 disseminated intravascular coagulation and grade 5 cerebral hemorrhage, 1 had grade 3 purpura, 1 had grade 4 congestive cardiac failure and grade 5 acute respiratory failure, and another had grade 5 sepsis). The NTD and MTD were not reached. No objective responses occurred. CC-90002 serum exposure was dose-dependent. ADAs were present across all doses, and the proportion of ADA-positive patients in cycle 1 increased over time. Despite no unexpected safety findings, the CC-90002-AML-001 study was discontinued in dose escalation for lack of monotherapy activity and evidence of ADAs. However, as other anti-CD47 agents in clinical trials are showing promising early results for AML and MDS, understanding preclinical and clinical differences between individual agents in this class will be of high importance.

Background

Patients with relapsed/refractory (R/R) Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) have a poor prognosis and limited treatment options.

Methods

The efficacy of inotuzumab ozogamicin (InO), a humanized anti-CD22 monoclonal antibody conjugated to the cytotoxic antibiotic calicheamicin, was evaluated in R/R ALL patients in the phase 1/2 study 1010 (NCT01363297) and open-label, randomized, phase 3 study 1022 (INO-VATE; NCT01564784). This analysis focused specifically on Ph+ R/R ALL patients. In study 1022, Ph+ patients were randomly assigned 1:1 to InO (n = 22) or standard intensive chemotherapy (SC) (n = 27) and 16 Ph+ patients in study 1010 received InO.

Results

In study 1022, rates of complete remission/complete remission with incomplete hematologic recovery (CR/CRi) and minimal residual disease (MRD) negativity (patients achieving CR/CRi) were higher with InO (CR/CRi = 73%; MRD = 81%) versus SC (CR/CRi = 56%; MRD = 33%). The corresponding rates in study 1010 were 56% (CR/CRi) and 100% (MRD). The hematopoietic stem cell transplantation (HSCT) rate in study 1022 was 41% versus 19% for InO versus SC; however, there was no benefit in overall survival (median OS: 8.7 vs 8.4 months; hazard ratio, 1.17 [95% CI, 0.64-2.14]). The probability of being event-free (progression-free survival) at 12 months was greater with InO versus SC (20.1% vs 4.8%).

Conclusion

Given the substantial improvement in responses and rates of HSCT, InO is an important treatment option for patients with R/R Ph+ ALL. Future studies need to consider better characterization of disease characteristics, more sensitive MRD measurements, MRD-directed therapy before HSCT, and potentially combination therapies, including tyrosine kinase inhibitors.

Background

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate used for adults with relapsed/refractory B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). The INotuzumab Ozogamicin trial to inVestigAte Tolerability and Efficacy (INO-VATE) previously reported improved outcomes with InO versus standard-of-care (SoC) chemotherapy. This article reports the final INO-VATE results (≥2 years of follow-up) and additional analyses of patient characteristics associated with improved outcomes.

Methods

Between August 27, 2012, and January 4, 2015, this multicenter, parallel, open-label, phase 3 trial randomized 326 adults with relapsed/refractory ALL to InO (n = 164) or SoC (n = 162); 307 received 1 or more doses of the study drug (164 in the InO arm and 143 in the SoC arm).

Results

The complete remission (CR)/complete remission with incomplete hematologic recovery (CRi) rate was higher with InO versus SoC (73.8% vs 30.9%; 1-sided P < .0001), with consistent CR/CRi rates across patient subgroups. The median overall survival (OS) was 7.7 months with InO and 6.2 months with SoC, with 2-year OS rates of 22.8% and 10.0%, respectively (overall hazard ratio, 0.75; 97.5% confidence interval [CI], 0.57-0.99; 1-sided P = .0105). The predictors of OS with InO were the best minimal residual disease status, baseline platelet count, duration of first remission, achievement of CR/CRi, and follow-up hematopoietic stem cell transplantation (HSCT; all 2-sided P values < .05). More InO arm patients proceeded directly to HSCT after achieving CR/CRi before any follow-up induction therapy (39.6% [95% CI, 32.1%-47.6%] vs 10.5% [6.2%-16.3%]; 1-sided P < .0001). The most frequent all-grade and grade 3 or higher adverse events in both arms were hematologic. Veno-occlusive disease (VOD)/sinusoidal obstruction syndrome (SOS) was more frequent with InO (23 of 164 [14.0%] vs 3 of 143 [2.1%]).

Conclusions

In patients with relapsed/refractory BCP ALL in INO-VATE, InO was associated with a greater likelihood of CR/CRi across key patient subgroups, and it served as a bridge to HSCT. Potential VOD/SOS risk factors must be considered when InO treatment decisions are being made.

Background

The prognosis for adults with relapsed acute lymphoblastic leukemia is poor. We sought to determine whether inotuzumab ozogamicin, an anti-CD22 antibody conjugated to calicheamicin, results in better outcomes in patients with relapsed or refractory acute lymphoblastic leukemia than does standard therapy.

Methods

In this phase 3 trial, we randomly assigned adults with relapsed or refractory acute lymphoblastic leukemia to receive either inotuzumab ozogamicin (inotuzumab ozogamicin group) or standard intensive chemotherapy (standard-therapy group). The primary end points were complete remission (including complete remission with incomplete hematologic recovery) and overall survival.

Results

Of the 326 patients who underwent randomization, the first 218 (109 in each group) were included in the primary intention-to-treat analysis of complete remission. The rate of complete remission was significantly higher in the inotuzumab ozogamicin group than in the standard-therapy group (80.7% [95% confidence interval {CI}, 72.1 to 87.7] vs. 29.4% [95% CI, 21.0 to 38.8], P<0.001). Among the patients who had complete remission, a higher percentage in the inotuzumab ozogamicin group had results below the threshold for minimal residual disease (0.01% marrow blasts) (78.4% vs. 28.1%, P<0.001); the duration of remission was longer in the inotuzumab ozogamicin group (median, 4.6 months [95% CI, 3.9 to 5.4] vs. 3.1 months [95% CI, 1.4 to 4.9]; hazard ratio, 0.55 [95% CI, 0.31 to 0.96]; P=0.03). In the survival analysis, which included all 326 patients, progression-free survival was significantly longer in the inotuzumab ozogamicin group (median, 5.0 months [95% CI, 3.7 to 5.6] vs. 1.8 months [95% CI, 1.5 to 2.2]; hazard ratio, 0.45 [97.5% CI, 0.34 to 0.61]; P<0.001); the median overall survival was 7.7 months (95% CI, 6.0 to 9.2) versus 6.7 months (95% CI, 4.9 to 8.3), and the hazard ratio was 0.77 (97.5% CI, 0.58 to 1.03) (P=0.04). In the safety population, the most frequent grade 3 or higher nonhematologic adverse events with inotuzumab ozogamicin were liver-related. Veno-occlusive liver disease of any grade occurred in 15 patients (11%) who received inotuzumab ozogamicin and in 1 patient (1%) who received standard therapy.

Conclusions

The rate of complete remission was higher with inotuzumab ozogamicin than with standard therapy, and a higher percentage of patients in the inotuzumab ozogamicin group had results below the threshold for minimal residual disease. Both progression-free and overall survival were longer with inotuzumab ozogamicin. Veno-occlusive liver disease was a major adverse event associated with inotuzumab ozogamicin. (Funded by Pfizer; INO-VATE ALL ClinicalTrials.gov number, NCT01564784.).

The phase 3 INO-VATE trial demonstrated higher rates of remission, measurable residual disease negativity, and improved overall survival for patients with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) who received inotuzumab ozogamicin (InO) vs standard-of-care chemotherapy (SC). Here, we examined associations between genomic alterations and the efficacy of InO. Of 326 randomized patients, 91 (InO, n = 43; SC, n = 48) had samples evaluable for genomic analysis. The spectrum of gene fusions and other genomic alterations observed was comparable with prior studies of adult ALL. Responses to InO were observed in all leukemic subtypes, genomic alterations, and risk groups. Significantly higher rates of complete remission (CR)/CR with incomplete count recovery were observed with InO vs SC in patients with BCR::ABL1-like ALL (85.7% [6/7] vs 0% [0/5]; P = .0076), with TP53 alterations (100% [5/5] vs 12.5% [1/8]; P = .0047), and in the high-risk BCR::ABL1- (BCR::ABL1-like, low-hypodiploid, KMT2A-rearranged) group (83.3% [10/12] vs 10.5% [2/19]; P < .0001). This retrospective, exploratory analysis of the INO-VATE trial demonstrated potential for benefit with InO for patients with R/R ALL across leukemic subtypes, including BCR::ABL1-like ALL, and for those bearing diverse genomic alterations. Further confirmation of the efficacy of InO in patients with R/R ALL exhibiting the BCR::ABL1-like subtype or harboring TP53 alterations is warranted. This trial was registered at www.ClinicalTrials.gov as #NCT01564784.

Ponatinib, the only approved all known-BCR::ABL1 inhibitor, is a third-generation tyrosine-kinase inhibitor (TKI) designed to inhibit BCR::ABL1 with or without any single resistance mutation, including T315I, and induced robust and durable responses at 45 mg/day in patients with CP-CML resistant to second-generation TKIs in the PACE trial. However, cardiovascular toxicities, including arterial occlusive events (AOEs), have emerged as treatment-related AEs within this class of TKIs. The OPTIC trial evaluated the efficacy and safety of ponatinib using a novel, response-based, dose-reduction strategy in patients with CP-CML whose disease is resistant to ≥2 TKIs or who harbor T315I. To assess the dose-response relationship and the effect on the safety of ponatinib, we examined the outcomes of patients with CP-CML enrolled in PACE and OPTIC who received 45 mg/day of ponatinib. A propensity score analysis was used to evaluate AOEs across both trials. Survival rates and median time to achieve ≤1% BCR::ABL1IS in OPTIC were similar or better than in PACE. The outcomes of patients with T315I mutations were robust in both trials. Patients in OPTIC had a lower exposure-adjusted incidence of AOEs compared with those in PACE. This analysis demonstrates that response-based dosing for ponatinib improves treatment tolerance and mitigates cardiovascular risk.