Ph 2/3 Study in Subjects With MPM to Assess ADI-PEG 20 With Pemetrexed and Cisplatin

Response Rate

Objective Response Rate is calculated as the proportion of subjects whose best tumor response from all post-baseline tumor assessments is complete response (CR) or partial response (PR). The best tumor response is the best response recorded from the start of the treatment until the end of treatment taking into account any requirement for confirmation. To test Objective Response Rate significance, a Relative Risk Ratio (ADI-PEG 20 / Placebo) was calculated as the common relative risk of having a response (CR or PR) based on the Mantel-Haenszel estimator controlling for tumor histology (biphasic versus sarcomatoid).

Time frame: approximately 18 months

Overall Survival Phase 3 Interim Analysis

The primary analysis of OS Phase 3 was performed at the interim analysis. This was performed once 50% of the planned OS events for phase 3 have occurred (ie, 169 of the 338 planned OS events). This interim analysis will evaluate OS in the ITT population in an unblinded manner. The OS data at the second interim analysis will be analyzed to support the following decisions: Futility stopping: Terminate the study due to futility at the interim analysis. Sample size re-estimation: Increase the target number of OS events after the second interim analysis.. The treatment effect on OS will be evaluated using the stratified log-rank test (stratified by tumor histology).

Time frame: Approximately 18 months

Overall Survival

Overall survival is defined as the time from randomization until death. In the event that no death was documented prior to study termination or analysis cutoff, OS was censored at the last known date the subject was known to be alive, either through completion of on-study visits or through survival follow-up contact. The treatment effect on OS was evaluated using the stratified log-rank test (stratified by tumor histology). The Kaplan-Meier curves were also plotted. A Cox proportional hazard model with an adjustment for tumor histology (biphasic vs sarcomatoid) was used to compute the estimated hazard ratio and two-sided 95% CI. The treatment effect on OS was evaluated using the stratified log-rank test (stratified by tumor histology). The significance level to be used in the OS analysis at the final analysis was based on α = 0.04999 (two-sided).