How much decrease in eGFR do you tolerate before discontinuing finerenone started in patients with diabetic kidney disease?

I use the same approach investigators did in the Fidelio DKD study: patient on max dose of ACEi/ARB. Add finerenone--> check GFR in 4 weeks. If more than 30% drop hold any NS-MRA up titration and recheck GFR in 1 week. If stable, continue same drug regimen, if GFR further decreases, hold finerenone, and assess patient clinically (volume status, BP, etc.)

Bakris et al., PMID 33264825

I usually tolerate quite a bit of a decline in eGFR after starting ACE/ARB, SGLT-2, finerenone and diuretics. This is especially true if the blood pressure is better controlled and the degree of albuminuria is lower. Each patient is different. If the eGFR is very low and one can buy dialysis free time without using it then I would be more likely to stop it. Frequent repeat of the renal function to make sure there is not ongoing decline in eGFR is also useful.