P22: A NON-INTERVENTIONAL, PROSPECTIVE, OBSERVATIONAL STUDY OF RELAPSED/REFRACTORY MULTIPLE MYELOMA PATIENTS TREATED WITH IXAZOMIB IN REAL-WORLD SETTINGS IN GREECE; INTERIM RESULTS OF THE ‘OL-ORAL’ STUDY
Authors: E Katodritou, MC Kyrtsonis, S Delimpasi, E Spanoudakis, G Vassilopoulos, P Zikos, N Viniou, G Kaiafa, M Papathanasiou, V Pappa, E Michalis, I Adamopoulos, K Kokoviadou, G Tsirakis, C Poziopoulos, E Terpos
Journal: HemaSphere (2022)

Background: Ixazomib (IXA) combined with lenalidomide (LEN) and dexamethasone (DEX) (IRd) is approved for adults with multiple myeloma (MM) after ≥1 prior therapy. Real world data on IRD use in Greece are limited. Aims: The objective of this study is to generate data on progression-free (PFS) and overall survival (OS) rates, as well as on medication adherence in IRd-treated MM patients. Methods: Relapsed/refractory MM patients prescribed IRd for the first time, after 1-3 prior therapies, per the approved label, were eligible to consent and consecutively enrolled. Patients refractory to bortezomib (BOR), pre-treated with IXA, and having received >1 IRd cycles, are excluded. Data were collected by routine assessments, patient self-report, and medical chart review. We present the interim analysis results with cut-off at 24 months after first patient’s enrollment. Results: Forty eligible patients [57.5% (23/40) males; median (interquartile range, IQR) age: 71.7 (64.8-77.3) years] were enrolled from Sep-2018 to Sep-2020 by 14 hospitals. Prior to IRd, 80.0% (32/40) of patients had received proteasome inhibitors [77.5% BOR; 7.5% carfilzomib], 65.0% (26/40) immunomodulatory drugs (57.5% LEN; 10.0% thalidomide; 2.5% pomalidomide), and 30.0% (12/40) autologous stem cell transplantation. At IRd initiation, the median (IQR) time since MM diagnosis was 3.5 (1.7-5.5) years. Of the patients, 85.0% (34/40) had ECOG PS 0-1, while 55.0% (22/40) had relapsed, 37.5% (15/40) relapsed and refractory, and 7.5% (3/40) refractory MM; 42.5% (17/40) were refractory to LEN. IRd was initiated as 2nd, 3rd and 4th line in 67.5% (27/40), 22.5% (9/40) and 10.0% (4/40) of patients, respectively, at the recommended dose in 40.0% (16/40); IXA, LEN and DEX were started at a lower dose in 12.5%, 42.5%, and 50% of patients, respectively. Patient characteristics are shown in Table 1. Over a median (IQR) observation period of 6.9 (4.4-15.5) months, a median (IQR) of 7.5 (4.5-12.5) IRd cycles were received. Overall confirmed response rate [≥ partial response (PR)] in the response-evaluable patients was 56.7% (17/30) [61.1% in 2nd and 50% in ≥3rd line]. Mean (SD) time to first documented response ≥ PR was 58.1 (27.0) days. Kaplan-Meier estimated 12-month PFS and OS rates were 58.0% (95% CI: 37.8-73.7) and 82.9% (95% CI: 65.6-92.0) (Figure 1). Adherence to IXA was high (median ratio of capsules taken/prescribed: 1). IRd discontinuation rate was 59.0% (23/39), due to disease progression (12/23), adverse event (AE) (8/23), death (2/23; unrelated to IXA in both cases), and lack of efficacy (1/23). IXA-related AE rate was 42.5% (17/40) [serious AE rate: 17.5% (7/40)]. Conclusions: These results provide preliminary insight on patient and disease characteristics and clinical outcomes in MM patients treated with IRd in 2nd to 4th line in Greek routine settings. The final results are awaited to complement these findings in a larger patient cohort