The Food and Drug Administration (FDA) recently issued a Complete Response Letter (CRL) to Ardelyx concerning tenapanor’s New Drug Application (NDA) for chronic kidney disease (CKD)–hyperphosphatemia (HP). If eventually approved, tenapanor has the potential to capture a slice of the HP market by targeting dialysis-dependent patients who are not able to maintain recommended phosphate levels, despite treatment and adhering to restricting dietary phosphate intake, according to GlobalData, a leading data and analytics company.

Kajal Jaddoo, Pharma Analyst at GlobalData, comments: “Key opinion leaders interviewed by GlobalData emphasized that when it comes to CKD-HP, nephrologists want patients to reach a target serum phosphorous level of 2.5–4.5mg/dL. Analyses of the Phase III PHREEDOM study showed that tenapanor treatment resulted in sustained reductions in serum phosphorus concentrations and a decrease in mean serum phosphorus from 7.7mg/dL to 5.1mg/dL. Additionally, patients on tenapanor had a smaller percentage of deaths and hospitalizations compared to patients on the phosphate binder sevelamer.”

Ardelyx is expected to request a Type A meeting soon to discuss the FDA response letter and put together a plan for the approval of tenapanor for the control of serum phosphorus in adult patients with CKD on dialysis.

Jaddoo continues: “As a result of the FDA’s CRL, Ardelyx entered into a sales agreement on August 13, 2021 to offer and sell shares of its common stock in a public offering. Ardelyx is looking to use the net earnings from the $150m deal to develop and potentially commercialize tenapanor.

“Despite the FDA’s unexpected CRL, there were no concerns raised with regards to tenapanor’s overall safety.”