The familial Mediterranean fever (FMF) 50 score: does it work in a controlled clinical trial? Re-analysis of the trial of rilonacept for patients with colchicine-resistant or intolerant FMF.

Abstract

BACKGROUND:

The familial Mediterranean fever 50 score (FMF50) score was recently devised to define response to treatment and as an outcome measure for clinical trials of FMF.

OBJECTIVES:

To examine the performance of the FMF50 score in a previously published trial of rilonacept for patients whose FMF was resistant or intolerant to colchicine.

METHODS:

We re-analyzed the data from our controlled trial of rilonacept vs. placebo in 14 patients with colchicine-resistant or intolerant FMF using the FMF50 score as the primary outcome. The FMF50 score required improvement by ≥ 50 in five of six criteria (attack frequency, attack duration, global patient assessment, global physician assessment, frequency of attacks with arthritis, and levels of acute-phase reactants) without worsening of the sixth criterion.

RESULTS:

In the original trial rilonacept was considered effective according to the primary outcome measure (differences in the attack frequency) with eight analyzable patients considered responders and four as non-responders. According to the FMF50 score, only two participants would have been considered respondersto rilonacept, and one to placebo. Only two participants had ≥ 50% differences between rilonacept and placebo in five criteria. The major explanation for non-response to treatment was that with rilonacept the duration of attack decreased by ≥ 50% in only 2 participants and 5 participants had no attacks of arthritis either during screening (before randomization) or during treatment with rilonacept.

CONCLUSIONS:

The proposed FMF50 score did not differentiate well between responders and non-responders compared to the a priori defined primary outcome measure in this successful controlled study.

• Authors: Philip J Hashkes, Bin Huang
• Journal: The Israel Medical Association journal : IMAJ (Isr Med Assoc J) Vol. 17 Issue 3 Pg. 137-40 (Mar 2015) ISSN: 1565-1088 [Print] Israel
• PMID: 25946762 (Publication Type: Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antirheumatic Agents
• Recombinant Fusion Proteins
• rilonacept
• Colchicine

Topics

• Adult
• Antirheumatic Agents (administration & dosage, adverse effects)
• Child, Preschool
• Colchicine (administration & dosage, adverse effects)
• Drug Resistance
• Drug Tolerance
• Familial Mediterranean Fever (diagnosis, drug therapy)
• Female
• Humans
• Male
• Outcome Assessment, Health Care (methods, standards)
• Recombinant Fusion Proteins (administration & dosage, adverse effects)
• Research Design
• Treatment Outcome