A Possible Treatment for NDI Is Moving Closer to Reality

For most NDI families, the question has always been the same: is anyone actually working on a real treatment?

The answer, finally, is yes. And as of this spring 2026, that work has taken a significant step forward.

The NDI treatment drug: NDI-5001

A pharmaceutical company called NephroDI Therapeutics, in partnership with Otsuka Pharmaceutical, has been developing a drug specifically designed for X-linked congenital NDI. Their therapy, NDI-5001, works by activating a pathway in the kidney called AMPK — essentially helping kidney cells do what they can't do on their own in NDI: hold onto water.

Rather than just managing symptoms with high fluid intake and low-sodium diets, NDI-5001 aims to address the underlying problem directly.

"X-linked NDI pediatric patients and their caregivers currently navigate a lifetime of intense symptom management. There are minimally effective treatments currently available for NDI that do little to significantly improve the quality of life for patients and their families." — Rachael Hagan, CEO, NephroDI Therapeutics

The milestone: a human trial is now registered

In mid-2023, NephroDI and Otsuka announced their partnership to develop NDI-5001. In June 2024, additional investment funding confirmed the therapy was advancing. In April 2026, the first human trial of NDI-5001 was officially registered with the U.S. government.

The trial (NCT07525960) is a Phase 1b study. The primary goal is to confirm the drug is safe and well-tolerated in humans with NDI, and to begin measuring whether it actually reduces urine volume and improves urine concentration. Participants will take NDI-5001 as a daily oral capsule for 9 consecutive days while researchers track how the drug behaves in the body and whether urine output begins to decrease.

Who this trial is for

This first phase has specific eligibility requirements. To be considered, participants must:

• Be adult males, ages 18 to 55

• Have a confirmed AVPR2 gene mutation (X-linked NDI) with no AQP2 mutation

• Have a first-morning urine osmolality of 200 mOsm/kg or less, confirming active, significant NDI

• Be willing to follow a low-sodium diet during the in-clinic portion

The trial is enrolling 24 participants and is sponsored by Otsuka.

"All parties share in the common goal of advancing therapeutic options for patients suffering with NDI." — Jeff Sands, MD, CMO, NephroDI Therapeutics

What this means for families

This first trial is limited to adult males. Children and other NDI types are not yet included, but this Phase 1b is the essential safety step that makes future broader trials possible.

If you or someone in your family may meet the criteria, or if you want to be notified as trials expand to include children and other populations, the most important thing you can do right now is stay connected.

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