A Study of Subcutaneous FL115 Monotherapy in Participants With Advanced Solid Tumors

NCT07785193 | Not Yet Recruiting Phase 1

• 1 other identifier: FL115-105
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

This is an open-label, multicenter, dose-escalation Phase Ib clinical study to evaluate the safety, tolerability, efficacy, PK, and PD of FL115 injection administered subcutaneously as monotherapy in participants with advanced solid tumours. All enrolled participants will receive FL115 by subcutaneous injection. Each treatment cycle comprises 21 days, with administration once every 3 weeks (Q3W). Treatment will continue until initiation of new anti-tumour therapy, progressive disease (PD), unacceptable toxicity, death, withdrawal of informed consent, loss to follow-up, or study termination by the Sponsor, whichever occurs first.

Conditions

Advanced Solid Tumours

Outcome Measures

Primary Outcomes (2)

• Incidence of TEAEs and SAEs

  All treatment-emergent adverse events and serious adverse events are recorded and graded using the NCI Common Terminology Criteria for Adverse Events version 5.0.

  TEAEs: From first dose to 30 days after the last dose or initiation of new anti-tumour therapy, whichever occurs first. SAEs: From PICF signing through the TEAE collection period; thereafter, only treatment- or study-related SAEs will be collected.

• MTD and RP2D

  Maximum tolerated dose, Recommended Phase 2 dose

  through study completion, an average of 15 months

Study Arms (1)

A Single Arm

EXPERIMENTAL

Drug: FL115

Interventions

FL115 DRUG

FL115 is a novel long-acting IL-15 agonist designed as a fusion protein with a mutated IL-15 structure (IL-15\[N72D\]/IL-15Rα-sFc).

A Single Arm

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female participants aged ≥18 and ≤80 years.
• Able to understand and willing to sign the Participant Information and Consent Form (PICF).
• Participants with histologically or cytologically confirmed locally advanced unresectable and/or metastatic solid tumours who have disease progression after standard therapy, are intolerant to standard therapy, or for whom no standard therapy is available.
• The participant must have received and progressed on checkpoint inhibitors (CPIs).
• At least 4 weeks since prior major surgery and recovered from its effects (per investigator judgment).
• With at least one measurable lesion (according to RECIST v1.1).
• ECOG score: 0 - 1.
• Life expectancy ≥12 weeks (as judged by the investigator).
• Adequate organ function.
• Fertile subjects (male and female) and their partners agree to use acceptable, investigator-approved contraception during the study-required period.

You may not qualify if:

• Prior Anti-tumour Therapy:
• Prior treatment with IL-2/IL-15 agonists;
• Prior anti-tumour therapy without completion of the required washout period before first dose;
• Participants who have previously received extensive radiotherapy;
• Prior treatment with 3 or more lines of checkpoint inhibitors (CPIs).
• Other Prior Therapies and Recovery from Toxicities:
• Known or suspected allergy to FL115 or its excipients;
• Systemic immunomodulatory therapy within 4 weeks before first dose, except: hormone doses of ≤10 mg/day prednisone equivalent; topical, inhaled, or intranasal corticosteroids; prophylactic single use of corticosteroids before contrast-enhanced imaging for participants with contrast media allergy;
• History of allogeneic organ transplant or allogeneic peripheral blood stem cell (PBSC)/bone marrow transplant;
• Receipt of a live virus vaccine within 4 weeks prior to the first dose of the investigational product;
• Prior Grade ≥3 irAEs or irAEs leading to discontinuation of immunotherapy;
• Prior Medical and Surgical History:
• Participants with metastases to meninges, or symptomatic brain metastasis, or brain metastasis that has been stable for less than 4 weeks after treatment prior to the first dose , or with spinal cord compression or carcinomatous meningitis;
• Participants with other malignant diseases within 2 years prior to screening tests, other than the disease under study. Participants with curable local tumours (e.g., basal or squamous cell skin cancer, cervical or breast cancer in situ) may be enrolled after definitive cure;
• Active autoimmune disease or a known history of autoimmune disease requiring systemic hormones or immunosuppressants;

Sponsors & Collaborators

• Novotech (Australia) Pty Limited: collaborator
• Suzhou Forlong Biotechnology Co., Ltd: lead

Study Sites (1)

Integrated Clinical Oncology Network Pty Ltd

South Brisbane, Queensland, 4101, Australia

Location

Central Study Contacts

Xiajun Xu

CONTACT

+86-18101882657; xiajunxu@forlongbiotech.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 20, 2026
• First Posted: August 25, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2029
• Last Updated: August 26, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

AU (1)