RSP-1502 Inhalation for Cystic Fibrosis

Recruiting at 25 trial locations

Overseen By Caralee Forseen, MD

Age: Any Age

Sex: Any

Trial Phase: Phase 1 & 2

Sponsor: Respirion Pharmaceuticals Pty Ltd

Must not be taking: Nephrotoxic, Neurotoxic, Ototoxic, others

Disqualifiers: HIV, Active Hepatitis B/C, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

Duration: 2 weeks

72 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new inhalation treatment, RSP-1502, for individuals with cystic fibrosis who have lung infections caused by Pseudomonas aeruginosa. The study aims to assess the safety and effectiveness of RSP-1502 compared to the existing treatment, Tobramycin inhalation solution. Suitable candidates include those with cystic fibrosis who have had frequent positive sputum tests for Pseudomonas aeruginosa in the past year. As a Phase 1, Phase 2 trial, this research seeks to understand how the treatment works in people and measure its effectiveness in an initial, smaller group, offering participants a chance to contribute to groundbreaking advancements in cystic fibrosis care.

Will I have to stop taking my current medications?

You may need to stop taking certain medications. Specifically, you must stop all inhaled tobramycin from 28 days before the study until 28 days into the study, and all other inhaled antibiotics from 14 days before the study until 28 days into the study. If you are taking medications with known nephrotoxic, neurotoxic, or ototoxic potential, you may need to stop those as well, unless you are on low dose azithromycin with inhaled tobramycin and have no evidence of ototoxicity.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that RSP-1502 is being tested for safety in people with cystic fibrosis. Early results suggest that this treatment, which combines tobramycin with CaEDTA, looks promising. Another study tested Tris-CaEDTA with inhaled tobramycin and found it well-tolerated, with no severe side effects reported.

The current trial is in its early stages, focusing on assessing safety and determining the best dose. Since tobramycin is already used for lung infections, its safety profile provides some confidence. However, the added ingredient, CaEDTA, is still under evaluation to ensure its safety when inhaled. While studies so far show encouraging results, more research is needed to fully confirm safety. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising for cystic fibrosis?

Researchers are excited about RSP-1502 for cystic fibrosis because it offers a novel approach by combining tobramycin with CaEDTA. This combination could potentially enhance the effectiveness of tobramycin by aiding in the breakdown of biofilms that protect harmful bacteria in the lungs. Unlike standard treatments that typically rely on tobramycin alone, this combination aims to improve drug penetration and effectiveness. Additionally, RSP-1502 is administered via inhalation, which targets the lungs directly, potentially leading to better outcomes for patients.

What evidence suggests that this trial's treatments could be effective for cystic fibrosis?

Research shows that RSP-1502, a combination of the antibiotic tobramycin and a helper ingredient called CaEDTA, is being tested in this trial for treating lung infections in people with cystic fibrosis. Participants may receive RSP-1502, which aims to enhance the effectiveness of inhaled tobramycin, a common treatment for these infections. Early results suggest that adding CaEDTA might help the antibiotic combat bacteria more effectively. Other participants will receive inhaled tobramycin alone, which studies have already shown to be effective for lung infections in cystic fibrosis patients. This trial will evaluate whether RSP-1502 can enhance these effects and provide improved results for patients. ^{1 2 3 5 6}

Are You a Good Fit for This Trial?

Adults over 18 with cystic fibrosis and chronic lung infection caused by P. aeruginosa, who haven't had significant respiratory symptoms or changes in their CF treatments for the past month. They must be able to avoid other inhaled antibiotics during the study and have a stable organ function as determined by tests. Women of childbearing age should use contraception, men should either be infertile or agree to use condoms.

Inclusion Criteria

I can stop using inhaled tobramycin from Day 28 to Day 28 of the study.

I am a male and will use condoms or am infertile.

Your blood, urine, and other test results must be normal and not interfere with the study assessments.

Exclusion Criteria

You have tested positive for COVID-19 using a rapid test at the screening or on the first day of the trial.

I am currently on medication that could harm my kidneys, nerves, or hearing.

I do not currently have a lung infection with rapidly worsening bacteria.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive aerosolized RSP-1502 or active control via inhalation for 14 days

2 weeks

Daily visits for dosing

Follow-up

Participants are monitored for safety and effectiveness after treatment

2 weeks

1-2 visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• RSP-1502
• Tobramycin inhalation solution

Trial Overview

The trial is testing RSP-1502, an aerosolized drug combined with different doses of CaEDTA compared to Tobramycin inhalation solution. Participants will inhale their assigned treatment twice daily for two weeks while being monitored for safety and effectiveness. The best dose will be chosen based on tolerance levels observed across groups.

How Is the Trial Designed?

Group I: RSP-1502 Experimental Treatment 1 Intervention

Cohorts 1-4 will receive RSP-1502 (300 mg tobramycin plus an ascending dose of CaEDTA). Cohort 5 will receive 300 mg tobramycin + CaEDTA at the MTD.

Group II: Active Control Active Control 1 Intervention

• Tobramycin Inhalation Solution 300 mg.

Who Is Running the Clinical Trial?

Respirion Pharmaceuticals Pty Ltd

Lead Sponsor

Trials

1

Recruited

70+

Published Research Related to This Trial

The TOBI Podhaler, a dry powder formulation of tobramycin, is effective for treating chronic Pseudomonas aeruginosa infections in cystic fibrosis patients aged 6 and older, showing a safety and efficacy profile similar to the traditional tobramycin inhaled solution.

The TOBI Podhaler offers a shorter administration time and more convenient usage, which may help reduce the treatment burden for patients compared to previous inhalation methods.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[TOBI Podhaler for treating chronic Pseudomonas aeruginosa infection in cystic fibrosis patients]. Pierart, F.[2020]

A retrospective cohort study using Cystic Fibrosis Foundation registry data found that patients with cystic fibrosis who used Tobramycin solution for inhalation (TSI) for 4 or more months had a crude risk of death 3.5 times greater than those who did not use TSI, highlighting the challenge of confounding by indication.

After adjusting for factors like age and lung function, the risk ratio decreased to 1.2, suggesting that TSI may actually have a protective effect against mortality, aligning with preliminary randomized trial findings that indicated lower mortality rates in TSI users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mortality of cystic fibrosis patients treated with tobramycin solution for inhalation. Rothman, KJ., Wentworth, CE.[2019]

In a clinical trial involving 41 adults with severe bronchiectasis, tobramycin solution for inhalation (TSI) significantly improved respiratory symptoms and quality of life, as shown by a reduction in symptom severity scores and St. George Respiratory Questionnaire scores.

While TSI was effective for many, some patients experienced adverse events, including cough and wheezing, leading to 10 withdrawals from the study, indicating the need for careful monitoring of patients during treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A pilot study of the safety and efficacy of tobramycin solution for inhalation in patients with severe bronchiectasis. Scheinberg, P., Shore, E.[2022]

A new dry powder inhaler (DPI) for tobramycin, designed to simplify administration, was developed and tested, showing a direct relationship between the amount of drug loaded and the emitted dose, which could enhance treatment for cystic fibrosis patients.

In an in vivo study, healthy volunteers were able to inhale 120 mg of the tobramycin powder in just 3-6 inhalation acts, suggesting that the new inhaler could improve patient adherence to antibiotic therapy by making it more convenient.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dose administration maneuvers and patient care in tobramycin dry powder inhalation therapy. Buttini, F., Balducci, AG., Colombo, G., et al.[2018]

In a study of 2,534 cystic fibrosis patients, initiating chronic tobramycin inhalation solution (TIS) therapy led to an improvement in forced expiratory volume in 1 second (FEV1) over two years, compared to a comparator group of 17,656 patients who used TIS less than 10% of the time.

While TIS therapy improved the FEV1 levels, it did not change the rate of decline in lung function, indicating that the benefits of TIS were sustained without altering the overall decline trend in lung function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Clinical use of tobramycin inhalation solution (TOBI®) shows sustained improvement in FEV1 in cystic fibrosis. Konstan, MW., Wagener, JS., Pasta, DJ., et al.[2021]

Both formulations of inhaled tobramycin (Tobi and Bramitob) significantly improve lung function and reduce Pseudomonas aeruginosa density in patients with cystic fibrosis, based on randomized controlled studies.

Inhaled tobramycin is well tolerated, with no evidence of serious side effects like renal or ototoxicity, and it may enhance patient compliance by reducing nebulisation time, which can improve overall quality of life and reduce healthcare costs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tobramycin for inhalation in cystic fibrosis: Beyond respiratory improvements. Chuchalin, A., Amelina, E., Bianco, F.[2013]

Tobramycin solution for inhalation (TSI) significantly improves lung function and reduces Pseudomonas aeruginosa density in cystic fibrosis patients, with a notable effect observed in adolescents, and is more effective than colistin.

TSI is well tolerated with minimal side effects, showing no renal toxicity or hearing loss, and provides a safer alternative to parenteral aminoglycosides while effectively targeting lung infections.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Inhaled tobramycin (TOBI): a review of its use in the management of Pseudomonas aeruginosa infections in patients with cystic fibrosis. Cheer, SM., Waugh, J., Noble, S.[2018]

High strength tobramycin solution (20% tobramycin sulfate) can be effectively nebulized using various nebulizer systems, with the NE-U22 Omron® and Aeroneb Go® showing the highest efficiency in delivering the medication.

Compared to the standard TOBI® solution, the high strength tobramycin solution resulted in over 73% more respirable inhaled dose, potentially improving treatment outcomes for cystic fibrosis patients with chronic Pseudomonas aeruginosa infections.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

In vitro aerodynamic characterization of the dose emitted during nebulization of tobramycin high strength solution by novel and jet nebulizer delivery systems. Mashat, M., Clark, BJ., Assi, KH., et al.[2018]

Citations

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clinicaltrials.gov

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Study Details | NCT06016088 | A Double-Blind, Active- ...

This dose escalation safety study will evaluate several doses of RSP-1502 or active control administered by inhalation for 14 days.

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thekids.org.au

thekids.org.au/news--events/news-and-events-nav/2025/october/promising-results-for-new-WA-pioneered-cystic-fibr/

Promising results for new Western Australian-pioneered ...

The Phase 1b study was conducted under US FDA oversight and tested ascending doses of the RSP-1502 combination in cystic fibrosis patients, with ...

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withpower.com

withpower.com/trial/phase-2-infections-9-2023-ef619

RSP-1502 Inhalation for Cystic Fibrosis

Trial Overview The trial is testing RSP-1502, an aerosolized drug combined with different doses of CaEDTA compared to Tobramycin inhalation solution.

4.

sciencedirect.com

sciencedirect.com/science/article/pii/S156919932030936X

Role of Tris-CaEDTA as an adjuvant with nebulised ...

The objectives of the study were to compare the safety and efficacy of Tris-CaEDTA in combination with inhaled tobramycin vs inhaled Tris-buffered tobramycin ...

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC4362982/

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A challenging double-blind placebo-controlled study of tobramycin inhalation powder in cystic fibrosis: results of the EDIT trial [abstract] J Cyst Fibros.

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pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12208834/

Pulmonary delivery of excipient-free tobramycin DPIs for ...

This study demonstrates that excipient-free tobramycin inhalable powder with good delivery and deposition performance can be successfully obtained using the ...