RESUMO
BACKGROUND: Nivolumab, an immune checkpoint inhibitor used to treat several malignancies, is associated with immune-related adverse events (IrAEs). Original dosing for melanoma was 3 mg/kg (maximum 240 mg) every 2 weeks (Q2W). Based on simulation studies depicting similar efficacy and toxicity to original dosing, extended interval dosing of 6 mg/kg (maximum 480 mg) every 4 weeks (Q4W) was introduced. OBJECTIVE: This study will compare safety between Q2W and Q4W dosing at BC Cancer in melanoma patients. METHODS: Retrospective chart review for reported incidence, onset, and severity of IrAEs in melanoma patients treated with nivolumab Q2W and Q4W dosing was completed. Fisher's test was conducted for first incidence IrAEs using Microsoft Excel. RESULTS: Seventy-one patients were identified (Q2W n = 35, Q4W n = 36). Baseline characteristics were similar in both groups. No statistically significant difference was found in incidence of IrAEs between Q2W and Q4W dosing (Q2W 40% vs Q4W 50%, p = 0.477). Rash was most common (Q2W 79% vs Q4W 50%) followed by hypothyroidism (Q2W 33% vs Q4W 20%). Median onset of IrAEs seemed later with Q4W dosing (Q2W cycle 1 vs Q4W cycle 4). Regardless of dosing, most IrAEs were grade 1-2 in severity (Q2W 100% vs Q4W 89%). CONCLUSION: Q4W dosing is associated with comparable incidence and potentially later onset of IrAEs compared to Q2W dosing. Most IrAEs in both dosing groups were similar and mild. Therefore, Q4W dosing offers a safe alternative to Q2W dosing while providing benefits including decreased workload for staff, decreased clinic visits, and viral exposure by patients.
RESUMO
BACKGROUND: Despite a better understanding of the increasing incidence of young-onset colorectal cancer (yCRC; age at diagnosis <50 years), little is known about its economic burden. Therefore, we estimated direct medical spending on yCRC before and after diagnosis. METHODS: We used linked administrative health databases in British Columbia, Canada, to create a study population of yCRC and average-age onset colorectal cancer (aCRC; age at diagnosis ≥50 years) cases, along with cancer-free controls. Over the 1-year period preceding a colorectal cancer diagnosis, we estimated direct medical spending on hospital visits, healthcare practitioners, and prescription medications. After diagnosis, we calculated cost attributable to yCRC and aCRC, which additionally included the cost of cancer treatments (e.g., chemotherapy and radiotherapy) across phases of care. RESULTS: We included 1,058 yCRC (45.4% females; age at diagnosis 42.4 ± 6.2 years) and 12,619 aCRC (44.8% females; age at diagnosis of 68.1 ± 9.2 years) cases. Direct medical spending on the average yCRC and aCRC case during the year before diagnosis was $6,711 and $8,056, respectively. After diagnosis, the overall average annualized cost attributable to yCRC significantly differed in comparison with aCRC for the initial ($50,216 vs. $37,842; P < 0.001), continuing ($8,361 vs. $5,014; P < 0.001), and end-of-life cancer phase ($86,125 vs. $61,512; P < 0.001) but not end-of-life non-cancer phase ($77,273 vs. $23,316; P = 0.372). CONCLUSIONS: Reported cost estimates may be used as inputs for future economic evaluations pertaining to yCRC. IMPACT: We provided comprehensive cost estimates for healthcare spending on young-onset colorectal cancer.