P0001
EFFECTS OF VEVERIMER ON SERUM BICARBONATE AND PHYSICAL FUNCTION IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND METABOLIC ACIDOSIS ARE INDEPENDENT OF ALBUMINURIA: SUBGROUP ANALYSES FROM A RANDOMIZED TRIAL Free

Veverimer, an investigational, novel, orally-administered, non-absorbed polymer that binds gastrointestinal hydrochloric acid and results in an increase in serum bicarbonate, is being developed as a treatment for metabolic acidosis in patients with chronic kidney disease (CKD). Metabolic acidosis is a complication of CKD that has deleterious effects on kidney function, bone (demineralization), and muscle (protein catabolism).¹ Albuminuria and metabolic acidosis are independently associated with CKD progression and treatment of each may reduce the risk of kidney failure.^2,3 We sought to assess (post-hoc) if albuminuria impacts the ability of veverimer to increase serum bicarbonate level and improve physical functioning.

TRCA-301E is a multicenter, Phase 3, randomized, blinded, placebo-controlled trial in 196 patients with CKD (eGFR 20 - 40 ml/min/1.73 m²) and metabolic acidosis (serum bicarbonate 12 - 20 mEq/L) who were treated for up to 1 year with veverimer (previously TRC101) or placebo, with dose titration targeted to achieve a normal serum bicarbonate. ⁴ The randomization was performed in a ratio of 4:3 (veverimer:placebo).

We previously reported⁴ that, compared with placebo, veverimer significantly increased serum bicarbonate and significantly improved physical function as reported on the Kidney Disease and Quality of Life-Physical Function Domain (KDQOL-PFD) (e.g., walking several blocks, climbing stairs) and as measured objectively using the 5-times repeated chair stand test with a safety profile that was similar to placebo. Baseline characteristics of the subgroups of patients by baseline urine albumin to creatinine ratio (UACR) ≤ 300 vs. >300 mg/g are shown in the Table.

Neither albuminuria (log UACR) as a continuous covariate nor the presence of UACR > 300 mg/g had an effect on the efficacy of veverimer treatment in correction of acidosis or improvement of physical function (interaction p-values >0.4).

In patients with UACR > 300 mg/g, at Week 52, serum bicarbonate increased by 4.1 (0.5) mEq/L on veverimer (p = 0.047 vs. placebo) and a significantly higher percentage (vs. placebo) had a ≥ 4 mEq/L increase or normalization of serum bicarbonate (59% vs. 30%, p = 0.014). Patient-reported limitations of physical function (KDQOL-PFD) improved in the veverimer vs. placebo group (+10.4 vs. +1.2 seconds, respectively, p = 0.034). Objective physical performance on the chair stand test at Week 52 also improved in the veverimer group vs. placebo (p < 0.001).

In patients with UACR ≤ 300 mg/g, at Week 52, serum bicarbonate increased by 5.2 (0.5) mEq/L on veverimer (p = 0.003 vs. placebo) and a numerically higher percentage (vs. placebo) had a ≥ 4 mEq/L increase or normalization of serum bicarbonate (65% vs. 45%, p = 0.063). KDQOL-PFD improved in the veverimer vs. placebo group (+12.5 vs. -2.8 seconds, respectively, p = 0.001). The chair stand test at Week 52 also improved in the veverimer group vs. placebo (p = 0.002).

The drug candidate veverimer effectively treated metabolic acidosis and improved the ability to repeatedly stand from a seated position and physical function related to daily activities independent of albuminuria, and therefore independent of the kidney injury reflected by albuminuria.