September 09, 2021
FDA gives thumbs down to Tenapanor for control of Phosphorus in kidney patients on dialysis
The US Food and Drug Administration (FDA) has asked for an additional clinical trial to demonstrate the benefits of Tenapanor before it can approve the drug. Tenapanor has shown good prospects in trials for the control of serum phosphorus in adults with chronic kidney disease (CKD) on dialysis. Tenapanor is an oral drug that inhibits the sodium-proton exchanger NHE3. The drug was submitted for approval to treat hyperphosphatemia in patients with CKD on dialysis. The data is supported by three phase-3 clinical trials involving more than 1000 patients.
The FDA stated that approval of the application would require the drug manufacturer to conduct an additional “adequate and well-controlled trial demonstrating a clinically relevant treatment effect on serum phosphorus or an effect on the clinical outcome thought to be caused by hyperphosphatemia in CKD patients on dialysis.”
Patients receiving dialysis for the management of CKD are highly likely to be hyperphosphatemic. Current Therapies for Hyperphosphatemia are only moderately effective and difficult to implement. Current strategies for the management of hyperphosphatemia include more frequent hemodialysis, dietary phosphate restriction, and phosphate binder therapy. Untreated, hyperphosphatemia can lead to dystrophic calcification, accelerated arteriosclerotic vascular disease, and fractures.
In a study, 236 patients who were on dialysis and had hyperphosphatemia despite treatment with phosphate binder therapy were given 4 weeks of treatment with either the twice-daily oral Tenapanor or placebo. The results showed that the Tenapanor treatment group had a significantly greater change in serum phosphorus concentration versus placebo.
Tenapanor has previously received FDA approval in 2019 for the treatment of irritable bowel syndrome (IBS) with constipation in adults.
Dr. Umair Haider