Impact of ipilimumab on metastatic melanoma: Evaluation using patient registry in Canada

Abstract

Background: The evaluation of new treatments on patients outside of clinical trials is crucial. The Canadian Melanoma Research Network (CMRN), is a multi-center pan-Canadian registry of melanoma patients. We utilize the CMRN to determine the clinical impact of Ipilimumab (Ipi) as 1st and 2d line therapy. Methods: 584 eligible patients, 353 males:231 females (mean age: 52 yrs), who treated for metastatic disease from 2000 to 2015 were included with their respective follow-up to Dec 2015. Patients in each year were selected based on the start date of their first metastatic treatment. The incorporation of Ipi into clinical practice was evaluated by the year of introduction. Patients may overlap in years if a patient received 2 regimens in 2 separate years, then this patient would exist in both categories. Results: We divided oor cohort into 2 groups, 388 patients who received Ipi and 196 who did not. Baseline characteristics, such as age, gender, performance status, presence of brain metastases for each cohort were similar. From 2011 to 2015, the percentage of patients who received Ipi increased from 68% to 81%. In patients who received Ipi, Cox exhibits a survival rate significantly better (p-value = 0.0010) than patients that were not treated with Ipi. The 3-year survival rate for Ipi treated patients was 32% compared to non-Ipi patients 25%. The survival over time data is available for Ipi patients: 1, 2 and 3 year survival 2011 (52%, 35%, 33%), 2012 (61%, 50%, 49%), 2013 (69, 62%), 2014 (75%), illustrating improved survival rates over time. Patients receiving Ipi 1st line had a 1-year survival rate of 43%, 2-year of 32% and 3 year of 23%. For Ipi given as 2nd line treatment, 1-year survival rate was 72%, 2-year of 47% and 3-year of 33%. For patients who received Ipi as 3d or more, 1-year survival rate was 70%, 2-year of 49%, and 3-year of 35%. Because Ipi 1st line was introduced after 2ndline, mean follow-up is necessarily shorter. Conclusions: This observational study illustrates the positive impact that Ipi has had on survival rates. Although the follow-up is still limited, the benefit seems to be incremental as higher proportion of patients received Ipi over time. The efficacy appears to be independent of whether it is given as 1st, 2nd or 3d+ line.