Multiparameter Phase I trials: a tool for model-based development of targeted agent combinations--example of EVESOR trial

Clinical results of the EVESOR trial, a multiparameter phase I trial of everolimus and sorafenib combination in solid tumors

PURPOSE

Everolimus (EVE) and sorafenib (SOR) combination was associated with synergistic activity in preclinical models. However, previous clinical studies were hampered by cumulative toxicities when both were given continuously. The academic EVESOR trial (NCT01932177) was designed to assess alternative doses and intermittent dosing schedules of EVE and SOR combination therapy to improve the benefit-risk ratio for patients with solid tumors.

METHODS

EVESOR is a multiparameter dose-escalation phase I trial investigating different doses and dosing schedules, with the final objective of generating data for modeling and simulation. Patients were allocated into continuous (A and B) or intermittent (C and D) schedules to determine the recommended phase II dose (RP2D). The clinical outcomes are presented here.

RESULTS

Forty-three patients were included from 2013 to 2019. Most of them had gynecological (25.6%), cholangiocarcinomas (23.2%), colorectal (14.0%), and breast cancers (11.6%). Dose-escalation up to EVE 10 mg QD and SOR 400 mg BID was possible on intermittent schedules. Five dose-limiting toxicities were observed, and dose reductions were required in 39.5% patients, stabilizing at EVE 5 mg and SOR 200 mg BID for 58.1% of them. The overall response rate was 6.3%, and disease control rate was 75.0%. The median progression-free survival (PFS) was 3.6 months. The longest median PFS were observed in cholangiocarcinomas (9.9 months), and gynecological adenocarcinomas (9.2 months).

CONCLUSION

Intermittent arms were associated with improved efficacy/toxicity profiles; and EVE 5 mg QD and SOR 200 mg BID was defined a clinically feasible dose. Strong signs of efficacy were found in cholangiocarcinomas and gynecologic carcinomas.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01932177.

From Fitting the Average to Fitting the Individual: A Cautionary Tale for Mathematical Modelers

An outstanding challenge in the clinical care of cancer is moving from a one-size-fits-all approach that relies on population-level statistics towards personalized therapeutic design. Mathematical modeling is a powerful tool in treatment personalization, as it allows for the incorporation of patient-specific data so that treatment can be tailor-designed to the individual. Herein, we work with a mathematical model of murine cancer immunotherapy that has been previously-validated against the average of an experimental dataset. We ask the question: what happens if we try to use this same model to perform personalized fits, and therefore make individualized treatment recommendations? Typically, this would be done by choosing a single fitting methodology, and a single cost function, identifying the individualized best-fit parameters, and extrapolating from there to make personalized treatment recommendations. Our analyses show the potentially problematic nature of this approach, as predicted personalized treatment response proved to be sensitive to the fitting methodology utilized. We also demonstrate how a small amount of the right additional experimental measurements could go a long way to improve consistency in personalized fits. Finally, we show how quantifying the robustness of the average response could also help improve confidence in personalized treatment recommendations.

EVESOR, a model-based, multiparameter, Phase I trial to optimize the benefit/toxicity ratio of everolimus and sorafenib

AIM

This novel multiparameter Phase I study aimed to optimize doses/dosing schedules of everolimus and sorafenib drug combination, based on modeling/simulation (NCT01932177).

PATIENTS & METHODS

About 26 patients with solid tumors were treated in four different dosing schedules. Everolimus once daily + sorafenib twice daily were given continuously in arms A and B, and intermittently in arms C (alternating every other week) and D (everolimus continuous and sorafenib 3 days on/4 days off).

RESULTS

Continuous schedules exhibited higher toxicity risks than intermittent schedules (64.1 vs 35.9%; p < 0.0001), and trends for lower disease control rates (80 vs 100%). No significant pharmacokinetic interaction was identified.

CONCLUSION

Feasibility of EVESOR trial is demonstrated. Intermittent schedules might provide better tolerance and efficacy than continuous schedules.