Early deep response boosts survival in AL amyloidosis

In patients with systemic amyloid light-chain (AL) amyloidosis, earlier deep haematologic response correlates with better survival, regardless of cardiac involvement, a recent study has found.

Researchers enrolled 1,194 AL amyloidosis patients (median age 66 years, 59.7 percent men) who had been treated with upfront bortezomib and were eligible for the intention-to-treat analysis. Response was assessed at months 1 and 3 using serum markers, and at 6 months using validated criteria, including urine markers.

Complete response (CR) was documented in 137 patients (11.5 percent) at 1 month. Very-good (VGPR) and partial (PR) response occurred in 270 (22.6 percent) and 252 (21.1 percent) patients respectively. In contrast, 413 (34.6 percent) had no response (NR) at this time point.

The median overall survival (OS) in the whole sample was 56 months. At 1 month, survival estimates were significantly better for patients with CR or VGPR than those who achieved only PR or NR (p<0.005). Similar findings were reported at the 3- and 6-month follow-ups.

Moreover, the timing of deep response, defined as having at least VGPR, likewise had a significant impact on survival. This analysis included 915 patients with available response data. More than half of this subgroup (54.75 percent; n=501) did not achieve deep response 1 month, of whom 44.71 percent (n=224 of 501) improved to CR or VGPR by month 6.

Median OS was 74 months in the late responders but was not reached in the early responders (p=0.027). Cox proportional hazards analysis confirmed that earlier CR or VGPR significantly correlated with better OS (hazard ratio, 1.454, 95 percent confidence interval, 1.039–2.033; p=0.029).