28.6.2. Consensus guidelines for the conduct and reporting of clinical trials in systemic light-chain amyloidosis (2012)

Chapter 28

In 2012, Comenzo et al. [23] published consensus guidelines for the definition of organ involvement and response to treatment in AL amyloidosis. The guidelines are based on data from an international cohort of 816 patients from seven referral centres, for which haematological responses were assessed 3 and/or 6 months after initiation of first-line therapy. Haematological response categories were defined, as detailed in Table 28.2. There was a strong correlation between the haematological response category at 3 or 6 months and overall survival (Section 28.7). The haematological response criteria were subsequently validated in a prospective study of 374 patients [117], and have now been widely adopted and incorporated into national guidelines [24][25].

Haematologic response category Definition
Complete response Normalisation of sFLC levels and ratio,
negative serum and urine immunofixation
Very good partial response A reduction in the dFLC to <40 mg/L
Partial response A >50% reduction in the dFLC
No response Less than a PR
Progression From CR:
any detectable monoclonal protein or abnormal FLC ratio
(light chain must double)
From PR:
50% increase in serum monoclonal protein to >5 g/L,
or 50% increase in urine monoclonal protein to >200 mg/day
(a visible peak must be present) or FLC increase of 50% to >100 mg/L

Table 28.2. Haematologic response and progression criteria [23].

The definition of measurable disease by sFLC analysis was defined as a dFLC of >50 mg/L, and covers approximately 85% of newly diagnosed patients (Section 28.4). For the 15% of patients with unmeasurable sFLCs at baseline, standard criteria for response in MM are available (a monoclonal intact immunoglobulin concentration of >5 g/L is considered assessable for response, Chapter 25).