Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of SPL84 in Patients with Cystic Fibrosis

A Phase 2a, Randomized, Placebo-Controlled, Double Blind Multiple Ascending Dose Study in Patients with Cystic Fibrosis Carrying the 3849 +10 Kb C->T Mutation to Evaluate the Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of SPL84

Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of SPL84 in Patients with Cystic Fibrosis (NCT06429176) is a Phase 2 interventional studying Cystic Fibrosis, sponsored by SpliSense Ltd.. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

The goal of this clinical trial is to learn if drug SPL84 is safe for adult patients with cystic fibrosis (CF). It will also learn if the drug works to treat works to treat CF with a specific mutation. The purpose of this research study is to: * test the safety and effectiveness of multiple doses of the study drug, SPL84 * test how multiple doses of the drug are processed by the body Researchers will compare drug SPL84 to a placebo (a look-alike substance that contains no drug) to see if drug SPL84 is safe and if it works to treat CF. Participants will: Take drug SPL84 or a placebo by inhalation every week for 9 weeks months Visit the clinic approximately 14 times over 17.5 weeks for checkups and tests

What Stage of Research Is This?

Phase 2 trials evaluate whether a treatment actually works against Cystic Fibrosis and continue monitoring side effects. Phase 2 enrolls larger groups (typically 100–300 patients) and produces the first real efficacy signal. A successful Phase 2 readout is what unlocks the much larger Phase 3 confirmatory trials needed for FDA approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

With a target enrollment of 24 participants, this is a small study — typical of early-phase research, rare-disease trials, or pilot studies designed to generate preliminary signal before a larger study is launched.

Who May Be Eligible (Plain English)

Who May Qualify: - Diagnosis of CF and two CF causing mutations; 3849+10 Kb C-\>T mutation on one allele in the CF transmembrane conductance regulator (CFTR) gene (homozygote or compound heterozygote). Source documentation from a certified genetic laboratory is required. - Body mass index (BMI) of ≥ 17 kg/m2. - FEV1 40-90% predicted at screening. - Non-smokers or vapers for at least 180 days (6 months) prior to screening, per participant report. Who Should NOT Join This Trial: - Use of Kalydeco, Orkambi, Symdeko/Symkevi or Trikafta/Kaftrio within 30 days of first dose with study intervention. - Use of any investigational drug (other than SPL84) or device within 30 days of first dose with study intervention. - Use of systemic steroids over 3 consecutive months in the last 6 months prior to screening, or use of systemic steroids in the last month prior to screening. Use of inhaled steroids above 1 mg. - Use of CF medications, e.g. inhaled antibiotics, dornase alfa (Pulmozyme), hypertonic saline and physiotherapy should be on stable regimen for the period 28 days prior to screening; those participants taking inhaled antibiotics for prophylaxis must be on a stable regimen of these drugs for at least 90 days prior to first dose with study intervention. - Any acute infection including acute upper respiratory or lower respiratory infections, pulmonary exacerbation, changes in therapy for pulmonary disease, or any non CF-related illness which results in the initiation of any new therapy within 14 days prior to first dose with study intervention. - Hemoptysis of greater than 30 mL within 90 days prior to Day 1, or hospitalization for hemoptysis within 6 months of first dose with study intervention. - Liver disease characterized by clinically significant cirrhosis and/or documented portal hypertension. - History of any organ transplantation. - Documented coronavirus disease (COVID-19) infection within 4 weeks prior to dosing. Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: * Diagnosis of CF and two CF causing mutations; 3849+10 Kb C-\>T mutation on one allele in the CF transmembrane conductance regulator (CFTR) gene (homozygote or compound heterozygote). Source documentation from a certified genetic laboratory is required. * Body mass index (BMI) of ≥ 17 kg/m2. * FEV1 40-90% predicted at screening. * Non-smokers or vapers for at least 180 days (6 months) prior to screening, per participant report. Exclusion Criteria: * Use of Kalydeco, Orkambi, Symdeko/Symkevi or Trikafta/Kaftrio within 30 days of first dose with study intervention. * Use of any investigational drug (other than SPL84) or device within 30 days of first dose with study intervention. * Use of systemic steroids over 3 consecutive months in the last 6 months prior to screening, or use of systemic steroids in the last month prior to screening. Use of inhaled steroids above 1 mg. * Use of CF medications, e.g. inhaled antibiotics, dornase alfa (Pulmozyme), hypertonic saline and physiotherapy should be on stable regimen for the period 28 days prior to screening; those participants taking inhaled antibiotics for prophylaxis must be on a stable regimen of these drugs for at least 90 days prior to first dose with study intervention. * Any acute infection including acute upper respiratory or lower respiratory infections, pulmonary exacerbation, changes in therapy for pulmonary disease, or any non CF-related illness which results in the initiation of any new therapy within 14 days prior to first dose with study intervention. * Hemoptysis of greater than 30 mL within 90 days prior to Day 1, or hospitalization for hemoptysis within 6 months of first dose with study intervention. * Liver disease characterized by clinically significant cirrhosis and/or documented portal hypertension. * History of any organ transplantation. * Documented coronavirus disease (COVID-19) infection within 4 weeks prior to dosing.

Treatments Being Tested

DRUG

SPL84

SPL84 solution for nebulization

OTHER

Placebo

Placebo solution for nebulization

Locations (2)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Boston Children'S Hospital

Boston, Massachusetts, United States

Nationwide Children'S Hospital

Columbus, Ohio, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT06429176), the sponsor (SpliSense Ltd.), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT06429176 clinical trial studying?

The goal of this clinical trial is to learn if drug SPL84 is safe for adult patients with cystic fibrosis (CF). It will also learn if the drug works to treat works to treat CF with a specific mutation. The purpose of this research study is to: * test the safety and effectiveness of multiple doses of the study drug, SPL84 * test how multiple doses of the drug are processed by the body Researchers will compare drug SPL84 to a placebo (a look-alike substance that contains no drug) to see if drug SPL84 is safe and if it works to treat CF. Participants will: Take drug SPL84 or a placebo by inh… The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT06429176?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT06429176?

Contact information for this trial may be available directly on the ClinicalTrials.gov record. Click "View on ClinicalTrials.gov" in the sidebar for the official source. Always discuss any potential trial with your doctor before contacting the study site.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT06429176. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT06429176. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.