ETON ET-600 (Desmopressin Oral Solution) FDA Approval

ETON ET-600 Desmopressin FDA Approval: What Happened

On February 25, 2026, the FDA approved ETON Pharmaceuticals' ET-600 (Desmopressin Oral Solution) for the treatment of Arginine Vasopressin Deficiency, formerly known as Central Diabetes Insipidus. The PDUFA target action date was February 25, 2026, and the approval came on schedule.

ETON Pharmaceuticals stock experienced a +14.7% runup from T-25 (25 trading days before PDUFA) through T-0 (PDUFA day). As a micro-cap company with approximately $180M market capitalization, ETON showed larger price movement than typical large-cap PDUFA plays.

PDUFA.BIO's ODIN AI system assigned ETON a TIER_2 rating with 85.5% approval probability. TIER_2 means approval was predicted, but the score fell just below the 85.8% threshold for TIER_1 (high confidence) — placing it in the "approval likely but not a recommended position" category.

What Is ETON ET-600 (Desmopressin Oral Solution)?

ET-600 is an oral solution formulation of desmopressin, a synthetic analog of the naturally occurring hormone arginine vasopressin (antidiuretic hormone). Desmopressin has been FDA-approved for decades in other formulations (tablets, nasal spray, injection), but ET-600 provides a novel oral solution delivery.

Key Drug Details:

• Active Ingredient: Desmopressin acetate
• Formulation: Oral solution
• Indication: Arginine Vasopressin Deficiency (Central Diabetes Insipidus)
• Route: Oral administration
• PDUFA Date: February 25, 2026
• FDA Approval: February 25, 2026
• Application Type: 505(b)(2) NDA
• Designations: Orphan Drug

Arginine Vasopressin Deficiency (formerly Central Diabetes Insipidus) is a rare condition where the body cannot produce enough antidiuretic hormone, leading to excessive urination and extreme thirst. The oral solution formulation may offer dosing flexibility advantages over existing tablet and nasal formulations.

ODIN's TIER_2 Prediction for ETON PDUFA

ODIN assigned ETON ET-600 a TIER_2 rating with 85.5% approval probability. This fell just below the TIER_1 threshold of 85.8%, placing ETON in the "approval predicted but no recommended position" category.

Why ODIN Predicted Approval:

• 505(b)(2) Pathway: ETON utilized the 505(b)(2) regulatory pathway, which relies on FDA's previous findings of safety and efficacy for desmopressin. This pathway has historically higher approval rates than standard NDAs.
• Established Safety Profile: Desmopressin has been FDA-approved for decades in multiple formulations. The oral solution uses a well-characterized active ingredient.
• Orphan Drug Designation: FDA granted Orphan Drug designation, reflecting the rare disease indication and regulatory support for development.
• No Prior CRL: ETON had no Complete Response Letter (CRL) history for this application, a positive signal in ODIN's model.

Why TIER_2 (Not TIER_1):

Despite strong approval signals, ODIN scored ETON at 85.5% — just 0.3 percentage points below the TIER_1 cutoff of 85.8%. The TIER_2 classification meant ODIN predicted approval but did not recommend a trading position. The prediction was verified correct when FDA approved on February 25.

ETON Stock Runup: +14.7% Pre-PDUFA

ETON Pharmaceuticals stock exhibited a +14.7% runup from T-25 (25 trading days before PDUFA) through T-0 (PDUFA day, February 25, 2026). Unlike larger-cap PDUFA plays where the runup strategy exits at T-7, ETON's micro-cap status ($180M market cap) meant the price appreciation continued through the event.

PDUFA Runup Performance:

• Measurement Window: T-25 to T-0
• Runup Return: +14.7%
• PDUFA Date: February 25, 2026
• Outcome: FDA Approved
• Market Cap: ~$180M (micro-cap)

Learn more about the PDUFA runup trading strategy.

ODIN February 2026 Prediction Performance

ETON was one of several February 2026 PDUFA decisions correctly predicted by ODIN. Here is the complete February 2026 scorecard:

February 2026: 7/7 correct PDUFA binary predictions. All approvals called correctly, all CRLs avoided. View the full ODIN track record.

ODIN Track Record: 96.2% Overall Accuracy

ETON ET-600 is one of ODIN's 52 verified outcomes since August 2025, with 50 correct predictions (96.2% accuracy). In 2026, ODIN has maintained a 15/15 perfect record on PDUFA binary predictions.

ODIN tier accuracy breakdown:

• TIER_1 (High Confidence): 96.3% accuracy (26/27)
• TIER_2: 90.0% accuracy (9/10) — includes ETON
• TIER_4 CRL Detection: 100% accuracy (10/10)
• 2026 PDUFA Predictions: 15/15 perfect

Every prediction is cryptographically verified via SHA-256 hash before the FDA announcement. View the full ODIN track record and hash ledger.

ETON ET-600 PDUFA FAQs