Asparaginase encapsulated in erythrocytes as second-line treatment in hypersensitive patients with acute lymphoblastic leukaemia

Asparaginase is essential in treating acute lymphoblastic leukaemia (ALL). Asparaginase-related hypersensitivity causes treatment discontinuation, which is associated with decreased event-free survival. To continue asparaginase treatment after hypersensitivity, a formulation of asparaginase encapsulated in erythrocytes (eryaspase) was developed. In NOR-GRASPALL 2016 (NCT03267030) the safety and efficacy of eryaspase was evaluated in 55 patients (aged 1-45 years; median: 6.1 years) with non-high-risk ALL and hypersensitivity to asparaginase conjugated with polyethylene glycol (PEG-asparaginase). Eryaspase (150 u/kg) was scheduled to complete the intended course of asparaginase (1-7 doses) in two Nordic/Baltic treatment protocols. Forty-nine (96.1%) patients had asparaginase enzyme activity (AEA) ≥100 iu/l 14 ± 2 days after the first eryaspase infusion [median AEA 511 iu/l; interquartile range (IQR), 291-780], whereas six of nine (66.7%) patients had AEA ≥100 iu/l 14 ± 2 days after the fourth infusion (median AEA 932 iu/l; IQR, 496-163). The mean terminal half-life of eryaspase following the first infusion was 15.3 ± 15.5 days. Few asparaginase-related adverse events were reported; five patients (9.1%) developed clinical allergy associated with enzyme inactivation. Replacement therapy was successfully completed in 50 patients (90.9%). Eryaspase was well tolerated, and most patients had AEA levels above the therapeutic target after the first infusion. The half-life of eryaspase confirmed that a 2-week schedule is appropriate.

Circulating Tumor DNA is Prognostic and Potentially Predictive of Eryaspase Efficacy in Second-line in Patients with Advanced Pancreatic Adenocarcinoma

PURPOSE

Eryaspase is composed of l-asparaginase encapsulated in erythrocytes and has demonstrated significant efficacy in a randomized phase II trial. We assessed the prognostic and predictive value of circulating tumor DNA (ctDNA) in patients, plasma included in this trial.

EXPERIMENTAL DESIGN

Samples prospectively collected pretreatment were centrally analyzed by next-generation sequencing. Prognostic values of baseline ctDNA and ctDNA early changes between day 0 and 28 were assessed in both arms combined on objective response rate (ORR), progression-free survival (PFS), and overall survival (OS); three groups were defined: negative ctDNA (Neg), ctDNA responders (Resp), and ctDNA nonresponders (NResp). Predictive value of ctDNA for eryaspase efficacy was investigated.

RESULTS

ctDNA was positive at baseline in 77 patients of the 113 tested patients (68%). Detectable ctDNA was an independent negative prognostic factor for OS (4.6 vs. 8.8 months; P = 0.0025) and PFS (1.6 vs. 3.3 months; P = 0.00043). Early change in ctDNA levels was correlated with ORR (20%, 26%, 0%; P < 0.04), PFS (3.7, 3.4, 1.6 months; P < 0.0001), and OS (11.7, 6.5, 4.3 months; P < 0.0001) according to the three defined groups (Neg, Res, NResp, respectively). In patients with ctDNA detectable at baseline, eryaspase was associated with better PFS [HR = 0.53; 95% confidence interval (CI): 0.3-0.94)] and OS (HR = 0.52; 95% CI: 0.29-0.91).

CONCLUSIONS

We confirm from a prospective randomized trial that: (i) the presence of ctDNA at baseline is a major prognostic factor, (ii) the early change of ctDNA correlates with treatment outcome, and (iii) the ctDNA could be a predictive biomarker of eryaspase efficacy.

Circulating tumor DNA is prognostic and potentially predictive of eryaspase efficacy in patients with advanced pancreatic adenocarcinoma

4617

Background: Eryaspase is composed of L-asparaginase encapsulated in erythrocytes. It has demonstrated significant efficacy in combination with chemotherapy in a randomized phase 2 trial in second-line in patients with advanced pancreatic adenocarcinoma. We assessed, in this study, the prognostic and predictive value of circulating tumor DNA (ctDNA) in plasma samples of patients included in the eryaspase phase 2 trial. Methods: Samples prospectively collected pre-treatment at each 28-day cycle were centrally analyzed by next-generation sequencing (BPER method). Prognostic values of baseline ctDNA and ctDNA early changes between day 0 and 28 were assessed in both arms combined on objective response rate (ORR), progression free survival (PFS) and overall survival (OS). We conducted interaction test between ctDNA positivity and treatment arm, and the predictive value of ctDNA for eryaspase efficacy was investigated. Results: Patients with at least one available plasma sample have been included (n = 122/141). The presence of ctDNA at baseline was identified in 68% (77/113) of patients and was an independent negative prognostic factor for OS (4.6 vs 8.8 months; p = 0.0025) and PFS (1.6 vs 3.3 months; p = 0.00043). Early change in ctDNA levels was assessed by separating patients into three categories (one without detectable ctDNA, and two according to radio median value between day 0 and day 28) that were significantly correlated with ORR, PFS and OS. A significant interaction was observed between the presence of ctDNA and eryaspase efficacy. In patients with ctDNA detectable at baseline, eryaspase was associated with better PFS (HR = 0.53; 95% CI: 0.3-0.94) and OS (HR = 0.52; 95% CI: 0.29-0.91). Conclusions: We confirm from a prospective randomized trial that 1/ the presence of ctDNA at baseline is a major prognostic factor, 2/ the early change of ctDNA correlates with treatment outcome and 3/ the ctDNA could be a predictive biomarker of eryaspase efficacy. Clinical trial information: NCT02195180 .

Erythrocyte-encapsulated asparaginase (eryaspase) combined with chemotherapy in second-line treatment of advanced pancreatic cancer: An open-label, randomized Phase IIb trial

PURPOSE

This Phase IIb (NCT02195180) open-label study evaluated erythrocyte-encapsulated asparaginase (eryaspase) in combination with chemotherapy in second-line advanced pancreatic adenocarcinoma.

METHODS

Eligible patients were randomized 2:1 to either eryaspase in combination with gemcitabine or mFOLFOX6 (eryaspase arm), or to gemcitabine or mFOLFOX6 alone (control arm). Co-primary endpoints were overall survival (OS) and progression-free survival (PFS) in patients with low asparagine synthetase (ASNS) expression. Secondary endpoints included OS and PFS in the entire population.

RESULTS

141 patients were randomized (eryaspase arm, n = 95; control arm, n = 46). Median OS and PFS in patients with low ASNS expression were 6.2 months (95% CI, 5.1-8.8) in the eryaspase arm versus 4.9 months (3.1-7.1) in the control arm (HR, 0.63; 95% CI, 0.39-1.01; P = 0.056) and 2.0 months (95% CI, 1.8-3.4) in the eryaspase arm versus 1.8 months (1.4-3.8) in the control arm (HR, 0.67; 95% CI, 0.40-1.12; P = 0.127), respectively. In the entire population, median OS and PFS for the eryaspase arm versus control were 6.0 months versus 4.4 months (HR, 0.60; P = 0.008) and 2.0 months versus 1.6 months (HR, 0.56; 95% CI, 0.37-0.84; P = 0.005), respectively. The combination of eryaspase and chemotherapy was well tolerated. The most frequent Grade 3/4 adverse events in the eryaspase arm (n = 93) were gamma-glutamyltransferase increase (16 [17.2%]), neutropenia (12 [12.9%]), and physical health deterioration (12 [12.9%]).

CONCLUSION

Eryaspase in combination with chemotherapy is associated with improvements in OS and PFS, irrespective of ASNS expression in second-line advanced pancreatic adenocarcinoma. A Phase III trial is underway.

The ENCHANT-1 trial (NCT01677455): An open label multicenter phase II proof of concept study evaluating first-line ganetespib monotherapy in women with metastatic HER2-positive or triple-negative breast cancer (TNBC)

TPS1136

Background: Hsp90 is a molecular chaperone protein required for the stabilization and activation of many proteins, referred to as Hsp90 ‘clients’, including those commonly implicated in breast tumorigenesis such as HER2, EGFR, ER, PI3K, AKT, P53 and VEGFR. Ganetespib is a novel triazolone inhibitor of Hsp90 being studied in over 20 clinical trials, with over 700 patients treated to date. Ganetespib is ~50x more potent than 1st-generation Hsp90 inhibitors, and has been well tolerated in clinical trials with a favorable safety profile. Mild to moderate, transient diarrhea is the most common adverse event associated with ganetespib infusion and is manageable with appropriate supportive care. Ganetespib has shown activity in preclinical models of HER2+, ER+/PR+ and triple negative breast cancer (TNBC). In a phase I trial, ganetespib demonstrated single-agent clinical activity in HER2+ disease with an objective response rate (ORR) of 15% and a disease stabilization rate of 46% in heavily pretreated patients. This efficacy-screening study is designed to provide further evidence of ganetespib activity and identify potentially predictive biomarkers in metastatic breast cancer. Methods: The ENCHANT-1 trial is an international, first-line Phase II study in two cohorts of breast cancer patients: Cohort A, HER2 amplified (n=35), and Cohort B, TNBC (n=35). HER2+ patients must have received prior anti-HER2 therapy in the adjuvant setting. Patients are treated with ganetespib at 150 mg/m2 twice weekly on a three out of four-week regimen. Primary endpoint: ORR assessed using RECIST1.1 criteria. Key secondary endpoints include metabolic effects as assessed by PET/CT at week 3. Tumor genetic signature and proteomic profiling are performed on patient’s tumors in an effort to develop biomarkers of response. At the time of submission 6 patients have been enrolled into this study. Clinical trial information: NCT01677455.