Start Your Search
MO09 - Mesothelioma I (ID 120)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Presentations: 1
- Moderators:K. Suzuki, S.G. Armato III
- Coordinates: 10/28/2013, 16:15 - 17:45, Bayside 204 A+B, Level 2
MO09.02 - A Randomised Phase II trial of Pegylated Arginine Deiminase in patients with Malignant Pleural Mesothelioma (ID 1355)
16:15 - 17:45 | Author(s): T. Szyszko
Preclinically, arginine deprivation has shown activity as a novel antimetabolite strategy for MPM patients who are deficient for the rate-limiting enzyme in arginine biosynthesis argininosuccinate synthetase (ASS1). Here, we examine the efficacy and safety of the arginine-lowering agent ADI-PEG20 (Polaris Group, San Diego, US) among patients with MPM.
We performed a multicentre randomised phase II clinical trial, based on patients with good performance status (0 or 1), non-resectable disease, ASS1-deficient MPM, and measurable disease. Patients were randomized 1:2 to receive best supportive care (BSC) or BSC+ADI-PEG20, stratified by: gender, histology (sarcomatoid versus non-sarcomatoid), prior treatment (chemonaive or previous platinum combination therapy), and centre. The primary endpoint, progression-free survival (PFS), is assessed by modified RECIST, and secondary endpoints include overall survival, tumor response rate, and toxicity. Translational endpoints included measurement of plasma arginine, citrulline and ADI-PEG20 antibody levels, assessment of metabolic response by [18F]Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and ASS1 methylation status using Illumina’s 450K DNA methylation array. The target sample size was estimated to detect a PFS hazard ratio of 0.60. [Trial funded by Cancer Research UK].
ASS1 deficiency was detected in 98 of 214 patients (46%) of which 68 were randomized on the trial (44 ADI-PEG20+BSC and 24 BSC alone). 66 patients have progressed so far (42 ADI-PEG20+BSC vs. 24 BSC alone), and 32 patients were alive (23 ADI-PEG20+BSC vs. 9 BSC alone). The hazard ratio for PFS was 0.53 (95%, CI 0.31 to 0.90, p=0.02) with a median PFS of 98 days for patients randomized to ADI-PEG20+BSC compared with 59 days for patients receiving BSC alone. ADI-PEG20 toxicity in patients with MPM has been consistent with previous trials of ADI-PEG20 in melanoma and liver cancer: commonly skin injection site reactions (grade 1-2), infrequent episodes of neutropenia (range: grade 1-4), anaphylactoid reactions (2 patients with grade 3 episodes) and serum sickness (1 patient). The best response by modified RECIST was stable disease. Metabolic responses (in 39 evaluable ADI-treated patients) were as follows: 46% with partial response (18/39), 31% with stable disease (12/39), 15% progressive metabolic disease (6/39) and 8% mixed metabolic response (3/39) by FDG-PET assessment. There was a significant difference between IHC assessed ASS1-negative and ASS1-positive patients and the methylation status of the ASS1 gene (p=0.025).
ADI-PEG20 is generally well tolerated and shows evidence of clinically significant activity in patients selected for arginine-dependent MPM demonstrating differential methylation of ASS1. Arginine deprivation may have a role in the future management of MPM either alone or in combination with selected therapies.
Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.