Background/Purpose:

Previous studies have shown, that switching from oral to subcutaneous (SC) MTX can lead to improved efficacy and bioavailability (especially for doses ≥15mg/wk) as well as to a decreased frequency of adverse gastrointestinal effects in patients with RA. Furthermore, some reports consider that this switch may improve treatments adherence and persistence [1]. The purpose of the present study was to investigate the treatment adherence of RA patients switching from oral to injectable MTX or between two different MTX prefilled syringes.

Methods:

APRiM is a prospective, observational, multicenter study, which included adult patients with confirmed RA diagnosis (ACR/EULAR 2010 criteria) already treated by either oral MTX and requiring route modification (Gr1), or SC MTX in prefilled syringe (PFS) and eligible for a device switch (to an other PFS) (Gr2). The main objective of the study was to estimate at 6 months the proportion of patients with strong or improved to maximum treatment adherence evaluated by Morisky self-assessment (8: stong/maximum adherence, 6-7: medium adherence, <6: poor adherence) in both groups.

Results:

Between June 2016 and June 2017, 110 rheumatologists, at 90% with private practice, included 466 pts, 433 of which composed the analyzable baseline set. Pts baseline characteristics Gr1/Gr2 were [mean (SD)]: age: 59.2 (13.0) / 61.5 (12.2) yrs; RA duration: 6.5 (7.9) / 9.9 (10.5) yrs; MTX use duration: 3.6 (4.6) / 6.0 (5.1) yrs; DAS28: 3.9 (0.9) / 3.2 (1.2); Erosive RA: 37% / 53%. All pts were receiving MTX at a mean (SD) dose of 15.1 (4.0) / 15.6 (4.0) mg/wk. Mean (SD) Morisky’s scores were 6.5 (2.0) / 6.6 (1.8) for respectively Gr1 / Gr2 at baseline, they improved up to 6.9 (1.8) / 7.0 (1.5) at 6 months. Treatment adherence remained strong or improved to max for 48% of patients in both Gr1 and Gr2. Interestingly, when rheumatologists were asked to estimate their patients’ adherence, they reported respectively 77% and 84% [Gr1 / Gr2] of patients with “no missed injections”. No new safety signals were identified during this study.

Conclusion:

The results of the observational study APRiM revealed that less than 50% of patients are perfectly adherent to injectable MTX treatment, irrespectively of whether was their previous MTX way of administration. Though, this proportion seems to be highly overestimated by the rheumatologists. This underlies the importance of patient/physician effective communication.

[1] Bello et al., Open access Rheumatol. 2017

ACR Meeting Abstracts - https://acrabstracts.org/abstract/is-treatment-adherence-of-ra-patients-to-injectable-mtx-influenced-by-previous-mtx-route-of-administration/