Safety and Efficacy of STL303 In Patients With Primary Immunoglobulin A (IgA) Nephropathy

NCT07606352 | Not Yet Recruiting Phase 2

• 1 other identifier: STL303-201
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 3

Brief Summary

This is a multicenter, randomized, double-blind, placebo controlled Phase IIb study to explore the efficacy and safety of STL303 capsules in IgAN patients. About 15 patients dignosed with primary IgAN will be enrolled and randomized to three cohorts and take different dosage of STL303 or placebo capsules orally according to protocol.

Conditions

IgAN

Keywords

IgAN

Outcome Measures

Primary Outcomes (1)

• Treatment emergent adverse events (TEAEs), adverse events (AEs) and serious adverse events (SAEs)

  All participants will be observed for any AE during the clinical study, including abnormalities in clinical symptoms and vital signs, physical examination, laboratory tests, and 12-lead ECG. Incidence, severity, and relationship of TEAEs and serious adverse events (SAEs) to STL303. Possible adverse events include: palpitations, nausea, vomiting, dizziness, sore throat, upper respiratory infection, loss of appetite, high temperature, chest discomfort, weakness, rash, headache, lethargy (feeling tired and low on energy) and urinary tract infection.

  Adverse events will be closely monitored, and participants will report to the clinic on Days 7, 14, 30, 45, 60, 90, 135 and at end of treatment on Day 180. On Day 210 an End of study safety follow up will also be conducted.

Secondary Outcomes (14)

• Change from baseline urine protein-to-creatinine ratio (UPCR)

  24-hour urine collection pre-dose on Days 1 (baseline), 30, 60, 90 and 180

• Change in UPCR

  24-hour urine collection pre-dose on Days 1 (baseline), 30, 60 and 90

• Change in urine albumin-to-creatinine ratio (UACR)

  24-hour urine collection pre-dose on Days 1 (baseline), 30, 60, 90 and 180

• Change in blood creatinine level

  Blood sampling pre-dose on Days 1 (baseline), 14, 30, 45, 60, 90 and 180

• Change in eGFR slope

  Blood sampling pre-dose on Days 1 (baseline), 14, 30, 45, 60, 90 and 180

Study Arms (3)

STL303 dose level 1

EXPERIMENTAL

Participants will receive STL303 dose level 1

Drug: STL303

STL303 Dose Level 2

EXPERIMENTAL

Participants will receive STL303 dose level 2

Drug: STL303

Placebo

PLACEBO COMPARATOR

Participants will receive placebo

Drug: Placebo capsule

Interventions

STL303 DRUG

STL303 arm participants will receive a specific dose of STL303

STL303 dose level 1

Placebo capsule DRUG

Placebo arm participants will receive placebo capsules

Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male and female patients aged 18 years and older, with primary IgAN confirmed by renal biopsy:
• eGFR (Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula) greater than or equal to 30 mL/min/1.73 m2 at screening and after completion of run-in.
• UPCR greater than or equal to 0.75 g/g at screening and after completion of run-in.
• Vaccinated against Neisseria meningitidis and Streptococcus pneumoniae before the first dose.
• Have received stable treatment with RASis (ACEi or ARB) at the maximum recommended dose or MTD for at least 90 days prior to the first dose.
• If the patient has been treated with SGLT2i, diuretics, other antihypertensive treatments, ERA, and/or hydroxychloroquine for IgAN prior to the first dose, the drug should also be used stably for at least 90 days.

You may not qualify if:

• Rapidly progressive IgAN (eGFR decline greater than or equal to 50% in 3 months, or less than 50% but at high risk).
• Other systemic diseases causing proteinuria/CKD or severe urinary obstruction.
• Known or suspected immunodeficiency or hereditary complement deficiency.
• Any organ transplant recipients except corneal.
• Poorly controlled blood pressure (SBP greater than 150 or DBP great than 90).
• Use of immunosuppressive drugs within 90 days or 5 half-lives.
• Prior oral budesonide (Nefecon/Tarpeyo/Kinpeygo) within 6 months.
• Prior complement inhibitors within 30 days, 5 half-lives, or residual effect period.
• Major systemic diseases preventing participation (e.g., NYHA IV, severe pulmonary disease).
• Significantly abnormal liver function (greater than 3× ULN enzymes or greater than 2× ULN bilirubin).
• QTcF greater than 500 ms.
• History of malignancy within 5 years (exceptions apply).
• History of meningococcal, pneumococcal, or Hib infection.
• Chronic/recurrent infections in past year (e.g., liver abscess, pyelonephritis).
• Active systemic infections within 2 weeks or fever greater than 38°C within 7 days.

Sponsors & Collaborators

• Sitala Bio LTD: lead

Study Sites (3)

Research Site

Woolloongabba, Queensland, 4102, Australia

Location

Research Site

Clayton, Victoria, 3168, Australia

Location

Research Site

Saint Albans, Victoria, 3021, Australia

Location

Study Officials

• Eugenia Pedagogos

  Western Health (Sunshine Hospital)

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Clinical Operations Manager

CONTACT

+61 421 585707; studies@sitala.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: May 26, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): September 1, 2027
• Last Updated: May 28, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

AU (3)