Kidney Week

Abstract: SA-PO173

A Dose Escalation Study to Evaluate the Tolerability, Safety, and Efficacy of VS-505 in Hemodialysis Patients With Hyperphosphatemia

Session Information

• Vascular Calcification, Nephrolithiasis, Bone
  November 05, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
  Abstract Time: 10:00 AM - 12:00 PM

Category: Bone and Mineral Metabolism

• 402 Bone and Mineral Metabolism: Clinical

Authors

• Gan, Liangying, Peking University People's Hospital, Beijing, China

Liangying Gan,

• Zhuang, Bing, Nanjing Medical University, Nanjing, Jiangsu, China

Bing Zhuang,

• Yang, Junwei, Nanjing Medical University, Nanjing, Jiangsu, China

Junwei Yang,

• Wang, Song, Peking University Third Hospital, Beijing, China

Song Wang,

• Luo, Yuan, Nanjing Medical University, Nanjing, Jiangsu, China

Yuan Luo,

• Ye, Hong, Nanjing Medical University, Nanjing, Jiangsu, China

Hong Ye,

• Zhang, Zhizheng, Alebund Biotech Inc., Shanghai, China

Zhizheng Zhang,

• Hong, Jiajun, Alebund Biotech Inc., Shanghai, China

Jiajun Hong,

• Zhang, Weifeng, Alebund Biotech Inc., Shanghai, China

Weifeng Zhang,

• Li, Xiaoling, Alebund Biotech Inc., Shanghai, China

Xiaoling Li,

• Tian, Jin, Alebund Biotech Inc., Shanghai, China

Jin Tian,

• Zuo, Li, Peking University People's Hospital, Beijing, China

Li Zuo,

Background

VS-505 is a novel non-absorbed phosphate binder with the component of iron and gum Arabic. This was a dose escalation study to evaluate the safety and efficacy of VS-505 in hemodialysis (HD) patients with hyperphosphatemia.

Methods

Adult HD patients with serum phosphorus (P) level between 6 - 10 mg/dL were enrolled. Treatment with VS-505 was 6 weeks with dose escalation every 2 weeks from 2.25 g/d, 4.5 g/d to 9.0 g/d, guided by serum P levels. The dose was divided into 3 times administered orally with meals. Primary efficacy endpoint was the change from baseline to end of treatment in serum P. Secondary efficacy endpoints were time course of serum P, the change from baseline to end of treatment in serum calcium (Ca), Ca×P product and iPTH. Safety endpoints include adverse events, etc. Analyses were based on intent to treat set.

Results

24 out of 25 patients completed 6-week treatment and 15 out of 25 patients received full dose escalation to 9.0 g/d. The average dose intensity was 4.34 g/d and the average exposure was 40.8 days. At the end of treatment, serum phosphorus level decreased by 2.01 ± 1.55 mg/dL (95% CI -2.65 to -1.37) from baseline (7.73±1.12mg/dL), which was clinically and statistically significant. Serum P was back to baseline in 2 weeks after study drug discontinuation. The time course of serum P is showed in Figure 1.
Serum Ca×P product decreased by 18.07 mg²/dL² (95% CI -23.89 to -12.25) from baseline (69.25± 11.91 mg²/dL²). No significant change of Ca and iPTH were observed during the treatment. The most frequently reported AEs were gastrointestinal reactions, mainly fecal discoloration (76%) and diarrhea (28%) in mild severity. No increase in the frequency of AEs was recorded with dose escalation. No SAE was related to VS-505 as assessed by the investigator.

Conclusion

VS-505, a novel non-absorbed phosphate binder, was safe and well tolerated and showed great effect on lowering serum phosphorus in HD patients with hyperphosphatemia.