Re-Employment of MTX in RA: Effectiveness after Failure of a Previous Course

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Re-Employment of Methotrexate in Rheumatoid Arthritis (RA).

Effectiveness after Failure of a Previous Course

Category: 15 RA—clinical aspects

Theresa Kapral, Aletaha, Tanja A. Stamm, Klaus P. Machold, f

S. Smolen. University of Vienna, Vienna, Austria

Presentation Number: 1444

Poster Board Number: 266

Objective. Effectiveness of therapy with individual disease modifying

antirheumatic drugs (DMARDs) in RA is limited, and also the number of

available DMARDs is finite. Therefore, at some stage in the long course

of RA traditional DMARDs that had already been applied might be

considered for renewed institution.. Here we investigated the

effectiveness of reemployment of the most frequently used DMARD,

Methotrexate (r-MTX), in patients with a history of prior MTX failure

(original course, o-MTX).

Methods. 1490 RA patients (80% female, 59% RF positive) were followed

from their first presentation throughout all their outpatient visits

(total: 6470 years of observed DMARD therapy). We searched for all

patients, in whom MTX was reemployed after at least one intermittent

course of DMARDs between o-MTX and r-MTX Reasons of treatment

discontinuation, changes in disease activity over time, using CRP and

ESR as surrogates, and drug survival were analyzed for o-MTX and r-MTX.

Results: 96 paired courses of MTX were eligible for analysis. In 26%

o-MTX courses were discontinued for toxicity (n=25). Of their associated

r-MTX courses, 8 (32%) were also limited by toxicity. If o-MTX had been

ineffective (n= 51, 53% of all pairs), 21 of the respective r-MTX

courses were also limited by inefficacy (41%). CRP was somewhat lower at

the time of MTX reemployment (CRP: 30.6 vs. 20.7mg/L for o- and r-MTX,

respectively, p=n.s.), but relative CRP and ESR improvement were similar

between the two groups at 3, 6, 9, and 12 months after start.

The overall drug retention was longer for r-MTX compared to o-MTX,

(median: 28 months vs. 12 months). We identified the higher dose of

r-MTX as the major determinant of this finding (median doses: o-MTX:

10mg/week, r-MTX: 17.5mg/week). There was a significant difference in

drug survivals if doses of r-MTX exceeded 12.5mg/week (median survival:

o-MTX: 12 mo; r-MTX: 29 mo, p<0,01, n=65).

Conclusion: Reemployment of MTX despite prior inefficacy may be a viable

therapeutic option especially in patients in whom original MTX dose did

not exceed 12.5mg/week.

Commercial Relationship: T. Kapral, None; D. Aletaha, None; T.A. Stamm,

None; K.P. Machold, None; J.S. Smolen, None.