Program: Oral and Poster Abstracts
Session: 623. Mantle Cell, Follicular, and Other Indolent B-Cell Lymphoma—Clinical Studies: Therapeutic Approaches to Mantle Cell Lymphoma
Methods: Eligibility criteria were: patients with MCL, relapsing after or refractory to at least one rituximab-containing chemotherapy regimen, WHO PS 0-3, and measurable disease. The primary endpoint was maximal overall response rate (ORR) measured with CT and PET/CT. Minimal residual disease (MRD) monitoring by PCR was performed during follow-up, according to EuroMRD criteria. Ion Torrent sequencing was performed on frozen tumor cells from bone marrow at time of relapse, including the following genes: ATM, CCND1, TP53, KMT2D, NOTCH1, NOTCH2, WHSC1 and BIRC3.
Treatment schedule: Induction phase: Up to twelve 28-day cycles with: Lenalidomide 15 mg p o daily, days 1-21, Ibrutinib 560 mg p o days 1-28, Rituximab 375 mg/m2 i v day 1 in cycle 1, then 1400 mg s c (or 375 mg/m2i v) days 8, 15 and 22 in cycle 1, then day 1 in cycles 3, 5, 7, 9 and 11. Maintenance phase: For patients in CR, PR or SD, not in need of other treatment. Given until progression, cycle duration 56 days. Ibrutinib: 560 mg p o days 1-56, 2. Rituximab 1400 mg s c (or 375 mg/m2i v) day 1 of each cycle.
Results: Accrual of 50 pts was completed in 12 months, June 2016, at 10 centres in Sweden, Norway, Denmark and Finland. The median age was 69.5 years, with a median MIPI score of 6.2. Patients had received a median of two previous regimens, four had progressed after single agent ibrutinib, and three had received prior allo-SCT. In total, 17/50 pts have discontinued treatment (n=9 due to PD, n=4 due to AE, n=2 withdrew consent, n=1 proceeded to alloSCT and n=1 due to other cause). Treatment emergent-AEs of any grade in ≥20% of patients were rash (24%) and fatigue (20%). Five pts (10%) experienced rash grade 3, mainly during cycle 1. Hematological toxicity was generally of low grade, apart from grade 3-4 neutropenia in 5 patients. One patient died due to possible treatment-related toxicity (septic shock). One event of laboratory tumor lysis syndrome was reported, and two events of atrial fibrillation, without reduction or discontinuation of ibrutinib. With a median follow up time of 7 months, 29 patients were evaluable for efficacy as of July 14, 2016. The ORR to date is 83% with 12 patients achieving CR (41%) and 12 PR (41%). Median duration of response and PFS has not been reached. One of three evaluable patients with progression on single agent ibrutinib responded with a PR, with ongoing response at 9 months. Of the 13 patients evaluable for MRD at 6 months, 7/12 patients have achieved molecular remission in blood and 7/13 in bone marrow.
Conclusions: So far, the combination of ibrutinib, lenalidomide and rituximab has been shown to be an active and well tolerated regimen in patients with R/R MCL, associated with molecular remission. Cutaneous toxicity was manageable, in contrast to what has been reported with a similar combination in untreated patients with follicular lymphoma. Up-dated results will be presented at the annual meeting, including data on mutational profile as biomarker for efficacy. This trial was registered at http://clinicaltrials.gov as NCT02460276.
Disclosures: Jerkeman: Gilead: Research Funding; Mundipharma: Research Funding; Celgene: Research Funding; Amgen: Research Funding; Janssen: Research Funding. Niemann: Abbvie: Research Funding; Roche: Consultancy; Gilead: Consultancy; Abbvie: Consultancy; Janssen: Consultancy. Geisler: Roche: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Sanofi: Consultancy.
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