A phase 1 study of OSI-930 in combination with erlotinib in patients with advanced solid tumours

Aim: To determine the maximum tolerated dose (MTD) of OSI-930 that can be combined with erlotinib, and establish recommended phase 2 doses when both agents are administered daily in patients with advanced solid tumours. Patients and methods: Eligible patients with advanced solid tumours were enrolled into this standard “three + three” dose escalation study. Study treatment commenced on day 1 with OSI-930, and erlotinib was introduced on day 8. PK profiles of OSI-930, erlotinib and its active metabolite, OSI-420, were determined. Changes in sVEGFR2 as a pharmacodynamic biomarker of OSI-930 activity were assessed. Results: Twenty one patients were enrolled to 1 of 3 cohorts: 200 mg OSI-930 BID + 100 mg erlotinib QD; 200 mg OSI-930 BID + 150 mg erlotinib QD; 300 mg OSI-930 BID + 150 mg erlotinib QD. The most common adverse events were anorexia (85%), diarrhoea (75%), rash (70%) and lethargy (65%). The MTD was not reached but the onset of cumulative toxicity necessitating dose modification after the 28-d DLT assessment period was common at the highest dose level. A PK interaction was identified with co-administration of both agents resulting in a two-fold increase in OSI-930 exposure. Pharmacodynamic activity was observed with a decline in sVEGFR levels detected in all patients. Ten patients had disease stabilization (median duration 119 d). Conclusions: 200 mg OSI-930 BID + 150 mg erlotinib QD were the recommended doses for further evaluation of this combination