Cost-effectiveness of immune checkpoint inhibitors for microsatellite instability-high/mismatch repair-deficient metastatic colorectal cancer.

BACKGROUND: Patients with microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) metastatic colorectal cancer (mCRC) show a significant response to checkpoint inhibitor therapies, but the economic impact of these therapies is unknown. A decision analytic model was used to explore the effectiveness and cost burden of MSI-H/dMMR mCRC treatment. METHODS: The treatment of hypothetical patients with MSI-H/dMMR mCRC was simulated in 2 treatment scenarios: a third-line treatment and an exploratory first-line treatment. The treatments compared were nivolumab, ipilimumab and nivolumab, trifluridine and tipiracil (third-line treatment), and mFOLFOX6 and cetuximab (first-line treatment). Disease progression, drug toxicity, and survival rates were based on the CheckMate 142, study of TAS-102 in patients with metastatic colorectal cancer refractory to standard chemotherapies (RECOURSE), and Cancer and Leukemia Group B/Southwest Oncology Group 80405 trials. The analyzed outcomes included survival (life-years), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). RESULTS: Ipilimumab with nivolumab was the most effective strategy (10.69 life-years and 9.25 QALYs for the third line; 10.69 life-years and 9.44 QALYs for the first line) in comparison with nivolumab (8.21 life-years and 6.76 QALYs for the third line; 8.21 life-years and 7.00 QALYs for the first line), trifluridine and tipiracil (0.74 life-years and 0.07 QALYs), and mFOLFOX6 and cetuximab (2.72 life-years and 1.63 QALYs). However, neither checkpoint inhibitor therapy was cost-effective in comparison with trifluridine and tipiracil (nivolumab ICER, $153,000; ipilimumab and nivolumab ICER, $162,700) or mFOLFOX6 and cetuximab (nivolumab ICER, $150,700; ipilimumab and nivolumab ICER, $158,700). CONCLUSIONS: This modeling analysis found that both single and dual checkpoint blockade could be significantly more effective for MSI-H/dMMR mCRC than chemotherapy, but they were not cost-effective, largely because of drug costs. Decreases in drug pricing and/or the duration of maintenance nivolumab could make ipilimumab and nivolumab cost-effective. Prospective clinical trials should be performed to explore the optimal duration of maintenance nivolumab.

A phase I open-label dose-escalation study of the anti-HER3 monoclonal antibody LJM716 in patients with advanced squamous cell carcinoma of the esophagus or head and neck and HER2-overexpressing breast or gastric cancer.

BACKGROUND: Human epidermal growth factor receptor 3 (HER3) is important in maintaining epidermal growth factor receptor-driven cancers and mediating resistance to targeted therapy. A phase I study of anti-HER3 monoclonal antibody LJM716 was conducted with the primary objective to identify the maximum tolerated dose (MTD) and/or recommended dose for expansion (RDE), and dosing schedule. Secondary objectives were to characterize safety/tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity. METHODS: This open-label, dose-finding study comprised dose escalation, followed by expansion in patients with squamous cell carcinoma of the head and neck or esophagus, and HER2-overexpressing metastatic breast cancer or gastric cancer. During dose escalation, patients received LJM716 intravenous once weekly (QW) or every two weeks (Q2W), in 28-day cycles. An adaptive Bayesian logistic regression model was used to guide dose escalation and establish the RDE. Exploratory pharmacodynamic tumor studies evaluated modulation of HER3 signaling. RESULTS: Patients received LJM716 3-40 mg/kg QW and 20 mg/kg Q2W (54 patients; 36 patients at 40 mg/kg QW). No dose-limiting toxicities (DLTs) were reported during dose-escalation. One patient experienced two DLTs (diarrhea, hypokalemia [both grade 3]) in the expansion phase. The RDE was 40 mg/kg QW, providing drug levels above the preclinical minimum effective concentration. One patient with gastric cancer had an unconfirmed partial response; 17/54 patients had stable disease, two lasting >30 weeks. Down-modulation of phospho-HER3 was observed in paired tumor samples. CONCLUSIONS: LJM716 was well tolerated; the MTD was not reached, and the RDE was 40 mg/kg QW. Further development of LJM716 is ongoing. TRIAL REGISTRATION: Clinicaltrials.gov registry number NCT01598077 (registered on 4 May, 2012).