Poor adherence and persistence to anticancer treatment are serious issues in the management of cancer patients since nonadherence has been shown to lead to higher treatment failure rates, worse outcome and higher total costs of care. The combination of the proteasome inhibitor carfilzomib (Kyprolis®) with lenalidomide (Revlimid®) and dexamethasone (CAR/LEN/DEX) or with dexamethasone alone (CAR/DEX) is approved for the treatment of patients with multiple myeloma who have received at least one prior therapy. According to the current approved schedule, carfilzomib has to be given twice weekly in both regimens. Real-world data on the implementation of this treatment recommendation are still limited.
The prospective, multicenter, non-interventional, observational CARO study was designed to collect data on 300 patients with multiple myeloma (CAR/LEN/DEX: 200, CAR/DEX: 100) from 90 sites across Germany. Primary objective is patients' adherence and persistence to carfilzomib therapy as prescribed by the treating physician according to current Summary of Product Characteristics (SmPC). Secondary objectives are patients' adherence and persistence to lenalidomide and dexamethasone as well as the real-world implementation of the recommended CAR/LEN/DEX or CAR/DEX dosing regimen in clinical routine (i.e., the comparison of actually administered medication versus recommended medication according to current SmPC). Exploratory objectives are effectiveness, safety and health-related quality of life. The first interim analysis of the CARO study was scheduled to assess the primary and secondary endpoints 12 months after the recruitment of the first patient.
Between October 2016 and October 2017, 102 patients had been enrolled, thereof 68 patients into the CAR/LEN/DEX cohort and 32 patients into the CAR/DEX cohort at the time of the pre-specified interim analysis (database cut: 25 October 2017).
Here, the focus is on the adherence of the twice weekly carfilzomib schedule in evaluable patients who received CAR/LEN/DEX (N=64) and on the implementation of the SmPC in terms of timing, dosing and frequency. Median age of patients was 72.3 years (range 43.4-84.3), 45.3% were female and 70.3% of the patients had a good performance status (PS) with a Karnofsky PS score of 80 to 100. The relative mean dose intensity of carfilzomib was 88.1%. 1368 of the scheduled 1591 carfilzomib administrations (86.0%) were given in time. 7.9% (n=125) of administrations were omitted, 5.0% (n=80) of administrations were delayed and 1.1% (n=18) of doses were administered earlier. Carfilzomib was omitted at least once in 43.8% of patients (n=28). 62.5% (n=40) and 18.8% (n=12) of patients, respectively, had a delayed or earlier carfilzomib administration documented at least once during their course of treatment. Reasons for deviations from the recommended carfilzomib dosing schedule concerning timing are depicted in Table 1. 1328 of 1466 carfilzomib administrations (90.6%) were given at the recommended dose. 6.2% (n=91) of doses were reduced. The main reason for dose reduction was the occurrence of adverse events (4.0%, n=58). Other reasons were: nonadherence (1.2%, n=18), organizational reasons (0.1%, n=2) and others (0.9%, n=13). 23.4% (n=15) of patients received at least one reduced carfilzomib dose during their course of treatment.
The mean adherence to the carfilzomib dosing regimen (i.e., the percentage of doses administered as scheduled by the treating physician and not modified for adherence reasons) was 94.8%.
According to our interim results, 86% of carfilzomib administrations were given in time and more than 90% of administrations were given at the recommended dose. Deviations from the recommended carfilzomib regimen were mainly due to safety issues or organizational reasons, but not due to nonadherence. Carfilzomib treatment adherence was almost 95%. Though, despite the required twice weekly dosing schedule, the carfilzomib regimen seems to be a convenient treatment option for multiple myeloma patients. Results have to be confirmed at final analysis.
Knauf:Celgene: Consultancy, Honoraria; Roche: Consultancy; Amgen: Consultancy, Honoraria; Mundipharma: Consultancy; Gilead Sciences: Consultancy; AbbVie: Consultancy; Janssen: Consultancy. Marschner:Amgen: Consultancy, Honoraria; IOMEDICO: Employment, Equity Ownership; Sandoz: Honoraria.
Asterisk with author names denotes non-ASH members.