Ask to take part

Contact the study team using the details below to take part. If there are no contact details below please ask your doctor in the first instance.

Contact Information:

George Naumov, PhD
(617) 835-5633

Study Location:

Skip to Main Content

Keep up to date

Sign up for news and information about taking part and shaping research.

Study of RSO-021 in Patients With Malignant Pleural Effusion Due to Advanced/Metastatic Solid Tumors Including Mesothelioma


Open to: All Genders

Age: 18 Years - N/A

Medical Conditions

Malignant Pleural Effusion
Malignant Pleural Mesothelioma
Solid Tumor

This information is provided directly by researchers and we recognise that it isn't always easy to understand. We are working with researchers to improve the accessibility of this information.

This is an open-label, non-randomized, multicenter, translational Phase 1/2 dose-escalation and expansion study designed to determine the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of RSO-021 after intrapleural (IP) administration in patients with malignant pleural effusion (MPE) (non-mesothelioma) and MPE from mesothelioma.

Start dates may differ between countries and research sites. The research team are responsible for keeping the information up-to-date.  

The recruitment start and end dates are as follows:

Mar 2022

Apr 2025


Intervention Type : Drug
Intervention Description : A naturally-occurring, sulfur-rich, cyclic oligopeptide antibiotic of the thiopeptide class.

Intervention Arm Group : Phase 1 - Dose Escalation;Phase 2 - Dose Expansion - MPE from mesothelioma;Phase 2 - Dose Expansion - MPE from non-mesothelioma solid tumors

You can take part if:

Inclusion Criteria: 1. Male or female ≥ 18 years old. 2. ECOG performance status 0-1. 3. Dose escalation: histological diagnosis of MPE from any solid tumor, including mesothelioma. Dose expansions: histological diagnosis of MPE caused by non-mesothelioma solid tumor or mesothelioma. 4. For patients with MPE from any other solid tumors, the MPE must be considered the priority for symptom control as potentially life limiting (or quality of life limiting). 5. MPE other solid tumors: patients must have received at least 1 prior standard of care treatment regimen for advanced, unresectable malignancy, with documented progression per RECIST 1.1. MPE mesothelioma: patients must have received at least 1 prior standard of care treatment regimen for advanced, unresectable malignancy, with documented progression (revised mRECIST 1.1 for mesothelioma) and there is no approved life extending alternative available. 6. Resolution of all acute reversible toxic effects of prior therapy or surgical procedure to Grade ≤1 (except alopecia). 7. For dose escalation cohorts: tumor tissue (a minimum of 10 and up to 15 unstained slides), or paraffin block, ideally from the patient's most recent biopsy, should be provided prior to the first dose of study therapy if sufficient tissue is available. For dose expansion: fresh tumor biopsy will be obtained. 1. Patients enrolled in the mesothelioma expansion stage will be requested to undergo a tumor biopsy during the screening period and after the third dose. 2. Patients enrolled in the non-mesothelioma expansion stage will be requested to undergo a tumor biopsy during the screening period and after the third dose only if medically feasible. 8. Patients must have adequate organ function. 9. If not postmenopausal or surgically sterile, patients must be willing to practice at least one of the following highly effective methods of birth control (defined as having a low failure rate, i.e., less than 1% per year) for at least a (partner's) menstrual cycle before and for 4 months after last study drug administration: 1. True abstinence, when this is in line with the preferred and usual lifestyle of the patient, from sexual intercourse with a member of the opposite sex; 2. Sexual intercourse with vasectomized male/sterilized female partner; 3. Hormonal female contraceptive (oral, parenteral, intravaginal, implantable or transdermal) for at least 3 consecutive months prior to investigational product administration (when not clinically contraindicated as in breast, ovarian and endometrial cancers); 4. Use of an intrauterine contraceptive device. 10. Willingness and ability to comply with scheduled visits, treatment plan, laboratory tests, and other trial procedures. Exclusion Criteria: 1. Last dose of prior anti-cancer therapies: 1. Systemic anti-cancer therapy within 3 weeks or 5 half-lives prior to study entry, whichever is shorter. 2. Thoracic radiation therapy or significant surgery within 3 weeks prior to study entry. Localized palliative radiotherapy for pain control in non-target lesions is allowed during the screening period. 3. Received an investigational product or been treated with an investigational device within 30 days prior to first drug administration or plans to participate in any other clinical trial while on this study. 2. Previous or concurrent malignancy that would prevent evaluation of the primary endpoint (e.g. R/R hematological malignancy). 3. Patients whose extent of tumor or loculations would render intrapleural administration incomplete and/or ineffective. 4. Known hypersensitivity to the active ingredient or any excipient contained in the drug formulation. 5. History or clinical evidence of any surgical or medical condition which the investigator and/or medical monitor judges as likely to interfere with the results of the study or pose an additional risk in participating, e.g., rapidly progressive or uncontrolled disease involving a major organ system-vascular, cardiac, pulmonary, gastrointestinal, gynecologic, hematologic, neurologic, neoplastic, renal, endocrine, or an immunodeficiency, or clinically significant active psychiatric or abuse disorders. 6. Active infection with human immunodeficiency virus (HIV) and CD4+ T-cell count < 350/μL. Patients not on established anti-retroviral therapy for at least four weeks prior to first dose of study drug and having a detectable HIV viral load. Testing is not required for eligibility. 7. Active infection with hepatitis B (surface antigen); or infection with hepatitis C in absence of sustained virologic response. Testing is not required for eligibility. 8. Pregnant or breast-feeding patients. 9. Patients with symptomatic or unstable CNS primary tumor or metastases and/or carcinomatous meningitis. Patients with documented treated CNS metastases stable off steroids may be enrolled at the discretion of the investigator. 10. Therapeutic oral anticoagulation for a thromboembolic event (prophylactic anticoagulation is allowed as long as patient can undergo catheter placement and biopsy). LMWH is allowed on condition that it is medically acceptable to interrupt LMWH therapy for all study procedures. 11. Use of systemic corticosteroids to treat inflammatory or autoimmune symptoms within 15 days or other immunosuppressive drugs within 3 weeks prior to start of the study. Inhaled and topical corticosteroids are permitted. Up to 10 mg/day prednisone or equivalent is permitted.

You may not be able to take part if:

This is in the inclusion criteria above

Below are the locations for where you can take part in the trial. Please note that not all sites may be open.

  • The Royal Marsden
    SW3 6JJ
  • Facility: HOPE Clinical Trials Facility, Leicester Royal Infirmary
    LE1 5WW
  • Barts Health NHS Cancer Institute
  • Guys and St Thomas NHS Foundation Trust
  • The Christie NHS
  • Newcastle University
    Newcastle Upon Tyne
  • Oxford University Hospitals NHS Foundation

The study is sponsored by RS Oncology LLC

We'd like your feedback

Your feedback is important to us. It will help us improve the quality of the study information on this site. Please answer both questions.

Is this study information helpful?

What will you do next?

Read full details

for Trial ID: NCT05278975

Last updated

This page is to help you find out about a research study and if you may be able to take part

You can print or share the study information with your GP/healthcare provider or contact the research team directly.