Abatacept
Abatacept was the predecessor of belatacept; in the latter two amino
acid substitutions provided a more potent binding of its ligands CD80
and CD86. This led to the approval of belatacept for use in kidney
transplantation while abatacept is used in rheumatoid arthritis. While
belatacept is available for intravenous use only, abatacept can also be
given by subcutaneous injections. This led a French group to test the
replacement of belatacept by abatacept sc in stable transplant
recipients, as a feasible alternative to belatacept to reduce their need
to visit the hospital during the initial stay-at-home order in France
under the COVID-19 pandemic. Data on the use of abatacept in kidney
transplantation are scarce, patients in the study were switched from
abatacept after three months. In this perspective the treatment was
successful with only two rejection episodes (n=176) while 19 patients
(11%) had abatacept discontinued for various reasons. In this study the
abatacept dosage was 125mg sc every week for all patients [32].
This study raises questions whether abatacept sc could be an alternative
to belatacept in stable kidney transplant recipients long term. Another
alternative, if feasible, would be to have a formulation of belatacept
for sc administration. If these options should be further explored, it
could also provide an opportunity to investigate the potential for a
more individualized dosing. So far this has not been advocated for
abatacept on any of its indications [33].