The management of light chain (
AL) amyloidosis has improved in recent years thanks to accurate
biomarker-based staging systems and response criteria and availability of novel effective
therapies. However, previous studies have focused on newly diagnosed patients, and little is known on relapsed patients, despite the fact that trials of new agents are often performed in this setting. In the present study, we report the outcome of 259 patients who responded to up-front
therapy. Ninety-two patients (35%) needed second-line
therapy after a median of 49 months. Cardiac and renal progression were observed in 22% and 12% of patients who received second-line
therapy, respectively. Complete response after up-front treatment and frontline
therapy with combined
bortezomib,
melphalan, and
dexamethasone independently prolonged time to second-line
therapy. Median survival of relapsing patients was 59 months. Patients who had a "high-risk dFLC progression," which we defined as a difference between involved and uninvolved free light chains (dFLC) of >20 mg/L, a level >20% of baseline value, and a >50% increase from the value reached at best response, had a shorter survival after initiation of second-line
therapy on univariate, but not on multivariate, analysis, where cardiac progression was the only independent predictor of survival after starting rescue treatment. Patients with
AL amyloidosis who need second-line
therapy after response to up-front treatment generally have a good outcome. A "high-risk dFLC progression" should trigger rescue treatment, and cardiac progression should not be awaited.