Phase I study of FOLFIRI plus pimasertib as second-line treatment for KRAS-mutated metastatic colorectal cancer.

BACKGROUND: The mitogen-activated protein kinase (MAPK) pathway has been implicated in the molecular pathogenesis of human cancers, including metastatic colorectal cancer (mCRC). This provides a rationale for the development of MAPK-targeted agents such as pimasertib. METHODS: Patients with KRAS mutant mCRC were treated in the second-line setting with FOLFIRI (5-fluorouracil/folinic acid/irinotecan) plus pimasertib. The primary objective of the safety run-in phase was to determine the maximum-tolerated dose (MTD) and the recommended phase II dose of pimasertib combined with FOLFIRI. RESULTS: Sixteen patients were enrolled in the trial. Ten and six patients were treated daily with 45 and 60 mg of pimasertib plus FOLFIRI, respectively. The MTD was considered to be 45 mg per day. The most common treatment-emergent adverse events were diarrhoea, nausea, vomiting, asthenia and skin/rash event. Of the 15 patients in the efficacy analysis group, two patients had partial response, nine patients had stable disease, three patients had progressive disease as their best overall response and one patient could not be evaluated. CONCLUSIONS: Dose escalation of pimasertib in combination with FOLFIRI was limited by toxicity. At the MTD of 45 mg per day, pimasertib was adequately tolerated in patients with mCRC and no unexpected or new safety signals or concerns were identified.

A phase I schedule dependency study of the aurora kinase inhibitor MSC1992371A in combination with gemcitabine in patients with solid tumors.

INTRODUCTION: MSC1992371A is an aurora kinase inhibitor with potential antitumor activity. METHODS: This trial established the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of oral MSC1992371A given before or after gemcitabine (1,000 mg/m(2)) in a 21-day cycle in patients with advanced malignancies. In schedule 1 (n = 31), gemcitabine was administered on days 1 and 8 followed by escalating doses of MSC1992371A on days 2 and 9. In schedule 2 (n = 35), MSC1992371A was given on days 1 and 8 followed by gemcitabine on days 2 and 9. Patients had a range of solid tumors, the most frequent of which was colorectal (n = 19). RESULTS: In both schedules, the 37 mg/m(2) dose level was defined as the MTD. The main DLT was grade 4 neutropenia. Adverse events consisted of neutropenia, thrombocytopenia, asthenia, fatigue, nausea, vomiting, anorexia, and diarrhea. Administration of MSC1992371A prior to gemcitabine had no effect on the metabolism or elimination of gemcitabine. Time to reach maximum plasma concentration and area under the plasma concentration-time curve for MSC1992371A increased proportionally with dose. Exploration of drug-target-related and tumor biomarkers did not identify predictors of biologic activity or response. Two patients (1 with lung carcinoma and 1 with hepatocellular carcinoma) had durable partial responses in schedule 2, and 5 patients had stable disease (SD) lasting 6 - 14 months. CONCLUSION: Oral MSC1992371A can be administered at a MTD of 37 mg/m(2) in combination with the standard 1,000 mg/m(2) dose of gemcitabine, but hematologic toxicity requires careful monitoring. Preliminary signs of efficacy were indicated by durable responses and SD.

A phase l study of three different dosing schedules of the oral aurora kinase inhibitor MSC1992371A in patients with solid tumors.

Aurora kinase inhibitors (AKIs) are a class of antimitotic, small-molecule anticancer agents. MSC1992371A is an AKI being evaluated for the treatment of patients with solid tumors. This phase I, open-label, dose-escalation study determined the maximum tolerated dose (MTD) of MSC1992371A in different dosing schedules in patients with locally advanced or metastatic solid tumors. MSC1992371A was administered on days 1 and 8 (schedule 1) or on days 1, 2, and 3 (schedule 2) of a 21-day cycle. The study was expanded with a third schedule (study drug on days 1-3 and 8-10). Adverse events were monitored throughout the study. Antitumor efficacy, drug pharmacokinetics, and pharmacodynamics were evaluated. Ninety-two patients were enrolled. MSC1992371A was dosed over eight levels in schedules 1 and 2, and the MTD was determined as 74 mg/m(2) per cycle for both schedules and as 60 mg/m(2) in schedule 3, albeit only in three patients due to discontinuation of the study. Overall, the most common grade 3 or 4 treatment-emergent adverse events were neutropenia, febrile neutropenia, thrombocytopenia, anemia, and fatigue. The most frequent dose-limiting toxicity over all schedules was neutropenia. MSC1992371A plasma concentrations tended to increase with increasing dose levels. Although no complete or partial responses were seen, stable disease ≥3 months was observed in 11 patients. Analysis for markers of target modulation and pharmacodynamics effects was unsuccessful. MSC1992371A was generally well tolerated in patients, with mainly transient hematologic toxicities apparent at an MTD of 60-74 mg/m(2)/21-day cycle, independent of dosing frequency.