Prognostic impact of cytogenetic abnormalities by FISH in AL amyloidosis with daratumumab-based frontline therapy

• +1q is associated with worse hematologic response rate and event-free survival with daratumumab-based frontline therapy in AL amyloidosis

• t(11;14) is no longer an adverse prognostic factor in AL amyloidosis in the daratumumab era

We performed an international retrospective cohort study to investigate the prognostic impact of cytogenetic abnormalities by FISH in 283 patients with AL amyloidosis treated with frontline daratumumab-bortezomib-cyclophosphamide-dexamethasone (Dara-VCD) or Dara-VD. The cytogenetic subgroups of interest were t(11;14), gain/amp(1q) [hereafter, +1q], hyperdiploidy, deletion(13q), del(17p), and myeloma high-risk (HR) translocations (t[4;14], t[14;16], or t[14;20]). The endpoints of interest were rate of hematologic complete response (heme CR), very good partial response or better (≥VGPR), and hematologic event-free survival (Heme EFS). The incidence of abnormalities was following: t(11;14)-53.4%; deletion (13q)-28.9%; +1q-22.3%; hyperdiploidy-19.4%; HR translocations-6.6%; and deletion(17p)-4.5%. The heme-CR rate by cytogenetic subgroups were: t(11;14) vs no t(11;14)-45.2% vs 41.8% (p=0.597); del(13q) vs no del(13q)-46.8% vs 42.8% (p=0.594); +1q vs no +1q-30.2% vs 47.9% (p=0.022); hyperdiploidy vs no hyperdiploidy-39.5% vs 44.9% (p=0.541); HR translocations vs none: 45.5% vs 43.1% (p=0.877); and del(17p) vs no del(17p)-50.0% vs 42.9% respectively (p=0.658). Similarly, +1q was the only subgroup with a significantly lower ≥VGPR rate (64.2% vs 79.0%; p=0.033). At a median follow-up of 19.8 months, the median heme-EFS was 49.6 months (95% CI, 24.7-not reached [NR]), and the 2-year OS was 80.98% (95% CI, 75.6-85.4). The presence of+1q was significantly associated with worse heme-EFS on multivariate analysis (HR 2.06, 95% CI, 1.14-3.71; p=0.017). Notably, there was no adverse prognostic impact of t(11;14) on heme EFS or OS. In conclusion, +1q is associated with worse outcome in the daratumumab-era. Clinical trials testing novel immunotherapies frontline should be enriched in +1q to further improve outcomes in this subgroup.