In a 12-month trial involving patients with “preclinical” rheumatoid arthritis, treatment with the immunomodulator abatacept (Orencia) kept the condition from becoming clinical, according to findings presented at the European Alliance of Associations for Rheumatology (EULAR) annual meeting.
Rheumatologists have long sought to nip rheumatoid arthritis (RA) in the bud, with many studies supporting early aggressive treatment on RA diagnosis. This has never been recommended for biologic therapies however.
Nevertheless, some patients show up at arthritis clinics with a few painful joints and other features such as RA-related serum biomarkers that suggest progression to full-blown RA is likely. Would aggressive treatment help slow their decline into RA?
In a phase IIb randomised trial involving patients in the UK and Netherlands who were at high risk for developing RA, only seven of the 110 assigned to abatacept had gone on to develop clinical arthritis after 1 year, compared with 30 of 103 in a placebo group.
The effect waned after abatacept was stopped at the one-year mark, and in the following year, 20 more patients in the abatacept group developed clinical arthritis, as did another eight in the placebo group.
Though the abatacept regimen held the edge for a full two years, projections showed that it was likely that the abatacept group would catch up with additional follow-up. At the same time, abatacept had no particular safety issues and thus could likely be continued.
A decade ago, Andrew Cope, MD, MBBS, of King’s College London colleagues thought about aggressive prevention, registering the current trial, Arthritis Prevention in the Pre-clinical Phase of RA with Abatacept (APIPPRA), in 2014. In a 2019 description of the protocol, they explained the selection of abatacept because “it targets immune reactions early in the chain of events leading to inflammation in RA. It functions by interrupting the interaction between T cells and antigen-presenting cells, attenuating the co-stimulatory signals required for T-cell activation, differentiation and effector responses,” thereby resulting “in downstream immunomodulatory effects on other inflammatory cells of the immune system.”
Participants had to show joint pain but no synovitis, plus either test positive for anti-citrullinated protein antigen (ACPA) antibodies and for rheumatoid factor (RF), or show high levels of ACPA antibodies without RF. The primary endpoint was development of clinically apparent arthritis in at least three joints or diagnosis of RA according to standard criteria.
While the preventive effect seen in the primary analysis did not hold up across the whole sample, Cope noted that it appeared more so in one very-high-risk subgroup: 49 patients who had some level of IgG ACPA antibodies and who were also positive for a series of other biomarkers, including RF, IgA ACPA antibodies, anti-carbamylated protein antibodies, and anti-acetylated peptide antibodies. For this subgroup, only about 10% of those who had taken abatacept progressed to clinical arthritis after two years, versus 50% of those assigned to placebo.
Source: MedPage Today
