A Phase 1 Safety Study of Evexomostat (SDX-7320) in Patients with Late-Stage Cancer: An Antiangiogenic, Insulin-Sensitizing Drug Conjugate Targeting METAP2.

Abstract

Purpose: To investigate the safety and tolerability of evexomostat (SDX-7320) in patients with late-stage cancer.

Patients and methods: This phase 1 dose-escalation safety study used an accelerated titration followed by a 3 + 3 design on 7- or 14-day administration, with dose expansion at the recommended phase 2 dose in 32 patients with late-stage, solid tumors. Measurements included standard assessments of safety, tolerability, target engagement in whole blood, plasma levels of protein biomarkers, and drug exposure. Tumor response was measured using RECIST v.1.1.

Results: Thirty-two patients were dosed with evexomostat (SDX-7320), starting at 1.7 mg/m2 once per week and escalated to 65 mg/m2 (once every 2 weeks, 28 days/cycle). Dose escalation and expansion confirmed the maximum tolerated dose at 49 mg/m2 once every 2 weeks with reversible thrombocytopenia as the dose-limiting toxicity. Most treatment-emergent adverse events were of grade 1 or 2 in severity and nonserious, with no grade 5 adverse events. Eighty percent of patients (n = 20/25 evaluable) had stable disease, and the average treatment duration was 87 days (3.1 cycles). Key angiogenic biomarkers VEGF-C and bFGF (FGF2) improved in response to evexomostat. Patients with baseline insulin resistance (i.e., fasting insulin >20 µU/mL; n = 11) exhibited significant decreased fasting insulin after treatment. Decreases in leptin were observed in 27/31 patients (87%), whereas adiponectin increased in 28/31 patients (90%). Plasma lipid profiles showed increased high-density lipoprotein (HDL) and decreased low-density lipoprotein (LDL) cholesterol.

Conclusions: Evexomostat (SDX-7320) was well-tolerated with prolonged stable disease and metastatic control in an open-label, phase I safety study. Improvements were observed in angiogenic and metabolic biomarkers.

Significance: Obesity and insulin resistance are known to promote tumor growth and accelerate the mortality of patients with cancer. Evexomostat is a novel antiangiogenic and antimetastatic drug candidate which also has insulin-sensitizing and antiobesity properties that is being developed for use in combination with standard-of-care therapies for obese patients with cancer.