Combination therapy with biologic agents in rheumatoid arthritis: perils and promise

Summarizing current refractory disease definitions in rheumatoid arthritis and polyarticular juvenile idiopathic arthritis: systematic review

OBJECTIVES

To identify how refractory disease (or relevant terminology variations) in RA and polyarticular JIA (polyJIA) is defined and establish the key components of such definitions.

METHODS

Searches were undertaken of English-language articles within six medical databases, including manual searching, from January 1998 to March 2020 (PROSPERO: CRD42019127142). Articles were included if they incorporated a definition of refractory disease, or non-response, in RA/polyJIA, with clear components to the description. Qualitative content analysis was undertaken to describe refractory disease in RA/polyJIA and classify each component within each definition.

RESULTS

Of 6251 studies screened, 646 met the inclusion criteria; 581 of these applied non-response criteria while 65 provided refractory disease definitions/descriptions. From the non-response studies, 39 different components included various disease activity measures, emphasizing persistent disease activity and symptoms, despite treatment with one or more biologic DMARD (bDMARD). From papers with clear definitions for refractory disease, 41 components were identified and categorized into three key themes: resistance to multiple drugs with different mechanisms of action, typically two or more bDMARDs; persistence of symptoms and disease activity; and other contributing factors. The most common term used was 'refractory' (80%), while only 16.9% reported explicitly how their definition was generated (e.g. clinical experience or statistical methods).

CONCLUSION

Refractory disease is defined as resistance to multiple drugs with different mechanisms of action by persistence of physical symptoms and high disease activity, including contributing factors. A clear unifying definition needs implementing, as the plethora of different definitions makes study comparisons and appropriate identification of patients difficult.

Meta-Regression of a Dose-Response Relationship of Methotrexate in Mono- and Combination Therapy in Disease-Modifying Antirheumatic Drug-Naive Early Rheumatoid Arthritis Patients

OBJECTIVE

To investigate a possible short-term dose-response relationship of initial treatment with methotrexate (MTX) in monotherapy and combination therapy in recent-onset rheumatoid arthritis (RA) patients.

METHODS

A systematic literature search was performed on trials and cohorts, including early, disease-modifying antirheumatic drug (DMARD)-naive RA patients treated with MTX, with data on clinical results within 6 months from treatment start. Cohen's effect sizes were calculated for the Health Assessment Questionnaire (HAQ), erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) level, and/or Disease Activity Score (DAS)/in 28 joints (DAS28) in 4 treatment groups: MTX monotherapy, or MTX in combination with synthetic (cs) DMARDs, biologic (b) DMARDs, or glucocorticoids. Random-effects meta-regression analyses were performed for each outcome, with treatment group as the predictor corrected for baseline HAQ or disease activity and assessment point.

RESULTS

Thirty-one studies including 5,589 patients were included. The meta-regression did not support higher effectiveness of increasing MTX dose in monotherapy. The number of treatment groups using combination therapy with csDMARDs was too small to perform meta-regression analyses. In combination therapy with glucocorticoids, a higher MTX dose was associated with higher (worse) outcome HAQ, but not with DAS/DAS28 or ESR/CRP level. In combination therapy with bDMARDs, a higher MTX dose was associated with higher outcome HAQ and DAS/DAS28, but not with ESR/CRP level. All effect sizes were small.

CONCLUSION

In DMARD-naive, early RA patients who start MTX, either as monotherapy or in combination with bDMARDs or glucocorticoids, a higher initial dose of MTX was not associated with better clinical outcomes. This finding suggests that there is little short-term gain from starting with high compared to low MTX doses.

Maintenance of infliximab treatment in ankylosing spondylitis: results of a one-year randomized controlled trial comparing systematic versus on-demand treatment

OBJECTIVE

Continuous treatment with the anti-tumor necrosis factor alpha (anti-TNFalpha) antibody infliximab is efficacious in ankylosing spondylitis (AS), whereas treatment discontinuation results in disease relapse, with variable delay. This study was undertaken to compare the efficacy of continuous treatment with infliximab with that of a treatment regimen adapted to symptom recurrence. Methotrexate (MTX) in combination with infliximab was also tested.

METHODS

Patients with active AS were randomly assigned at week 0 to receive infliximab every 6 weeks (continuous treatment) or upon symptom recurrence (on-demand treatment), following infusions at weeks 4, 6, and 10. Patients in the on-demand group were randomly assigned to receive either MTX in combination with infliximab or infliximab alone. Patients were monitored for 1 year. The primary end point was the proportion of patients who met the ASsessment in AS International Working Group criteria for 20% improvement (ASAS20) at week 58.

RESULTS

Of 247 patients, 124 were assigned to receive infliximab every 6 weeks and 123 to receive on-demand treatment. Among the latter, 62 received MTX, and 61 received infliximab alone. A greater proportion of patients receiving infliximab every 6 weeks fulfilled ASAS20 response criteria at week 58 than did patients receiving on-demand treatment (75% versus 46%; P<0.0001). Patients in the continuous treatment group received more infliximab infusions after week 10 than did those in the on-demand group (mean+/-SD 5.8+/-2.2 versus 3.5+/-2; P<0.0001). Addition of MTX did not significantly affect the proportion of patients with an ASAS20 response at week 58, nor the number of infliximab infusions administered.

CONCLUSION

These findings indicate that continuous treatment of AS with infliximab is more efficacious than on-demand treatment, and that the addition of MTX to infliximab provides no significant benefit.

Infliximab and leflunomide combination therapy in rheumatoid arthritis: an open-label study

OBJECTIVE

To study the safety and efficacy of infliximab plus leflunomide combination therapy in adult rheumatoid arthritis (RA).

METHODS

Twenty patients with active RA received leflunomide 100 mg for 3 days followed by 20 mg daily for 32 weeks. At week 2 all patients started infliximab 3 mg/kg, and received a further four infusions at weeks 4, 8, 16 and 24.

RESULTS

Adverse events led to 11 patients being withdrawn before the end of the study. The commonest adverse event was pruritus associated with an eczematous rash. Other serious reactions included infliximab infusion reactions in four patients and Stevens-Johnson syndrome in one. There was no relationship between the serum concentration of A77 1726, the active metabolite of leflunomide, and adverse events. The mean Disease Activity Score (DAS28) fell from 7.18 at week 0 to 5.18 (P<0.0001, paired t-test) at week 4 and remained between 3.85 and 4.85 up to week 32. In those patients remaining on treatment, more than 80% achieved an ACR20 response from week 8 to week 28, and up to 46% achieved an ACR70 response.

CONCLUSION

Infliximab plus leflunomide combination therapy appears to be highly efficacious in the treatment of adult RA. However, widespread use may be limited by adverse events, which were common and in some cases severe.

Combinations of conventional disease-modifying antirheumatic drugs

During the last decade, numerous new treatments and treatment approaches have literally transformed current thinking about rheumatoid arthritis (RA) and, more importantly, about the way patients are treated. The nearly universal acceptance of the use of combinations of disease-modifying antirheumatic drugs (DMARDs) to more effectively treat a growing percentage of patients with RA has been a central theme. Importantly, controlled studies have now shown many combinations to be well tolerated and significantly more effective than mono-DMARD therapy.

Combination therapy with multiple disease-modifying antirheumatic drugs in rheumatoid arthritis: a preventive strategy

The traditional "pyramid" or sequential approach to treatment of patients with rheumatoid arthritis involved use of a nonsteroidal anti-inflammatory drug for months to years while seeking to avoid use of second-line antirheumatic drugs until evidence of joint damage was seen. This approach led to short-term reduction of inflammation and a few remissions. However, long-term remissions were rare, and most patients experienced poor long-term outcomes, including joint destruction, severe functional declines, considerable economic losses, work disability, and premature mortality. At this time, a "preventive" strategy is evolving in which early aggressive treatment with disease-modifying antirheumatic drugs is used, seeking to minimize long-term joint damage. When residual inflammation remains after maximum doses of single agents, as is usually the case, combinations of disease-modifying antirheumatic drugs appear to be a reasonable consideration for many patients. Methotrexate is the most commonly used "anchor drug" in combination therapy. Evidence from randomized, controlled clinical trials and observational studies have indicated increased efficacy and acceptable (and often lower) toxicity for combinations of methotrexate plus cyclosporine, hydroxychloroquine, sulfasalazine, leflunomide, etanercept, and infliximab. Further studies lasting 5 years or more are needed to determine the long-term effectiveness, toxicities, and optimal clinical use of disease-modifying antirheumatic drug combinations. At this time, such combinations are taken by at least some patients under care of almost all rheumatologists, and it appears likely that they will be used increasingly in the coming decades.