Phase 1 Study Evaluating Safety and Tolerability of SL-T10, GX-I7, and Pembrolizumab Triple Combination in mCRPC.

Phase 1

Recruiting

• Conditions: Metastatic Castration-resistant Prostate Cancer (mCRPC)
• Interventions: Biological: SL-T10; Biological: GX-I7; Biological: Pembrolizumab

• Registration Number: NCT06344715
• Lead Sponsor: SL VAXiGEN

Brief Summary

The purpose of this study is to evaluate the efficacy and safety of SL-T10 and GX-I7 or SL-T10, GX-I7 and pembrolizumab in patients with metastatic castration-resistant prostate cancer (mCRPC).

Detailed Description

The purpose of this study is to evaluate the safety, tolerability, and preliminary efficacy of SL-T10, GX-I7, and pembrolizumab in combination in patients with metastatic castration-resistant prostate cancer (mCRPC).

Study Timeline

• Study Start: 2022-10-17
• Status Verified: 2024-03
• Study First Submitted: 2024-03-19
• Study First Submitted QC: 2024-03-27
• Last Update Submitted: 2024-03-27
• Study First Posted: 2024-04-03
• Last Update Posted: 2024-04-03
• Primary Completion: 2024-10-31
• Study Completion: 2024-10-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Male
• Target Recruitment: 78

Inclusion Criteria

1. Male patients 19 years of age or older at the date of written informed consent.
2. Patients with histopathologically or cytologically confirmed adenocarcinoma of the prostate, documented by bone or soft tissue lesions.
3. Patients with castration-resistant prostate cancer with a blood testosterone level of less than 50 ng/dL at the screening visit.
4. patients with metastatic castration-resistant prostate cancer (mCRPC) who meet the following criteria (based on PCWG3.0 modified RECIST 1.1)

1. Prior taxane therapy for metastatic prostate cancer or confirmed refusal or inadequacy of such therapy 2) Patients who have received prior docetaxel and at least one of the following agents: abiraterone acetate or enzalutamide before or after docetaxel treatment 3) Patients with progression of prostate cancer during/after prior therapy, in the investigator's judgment, with either of the following, in the internal or external castration state

1. PSA progression defined as at least 2 PSA level increases (≥1 week interval between each test) and a PSA level of ≥2 ng/mL at Screening

2. Advanced soft tissue disease as defined by RECIST 1.1

3. Progressive bone disease defined as ≥2 new lesions on bone scan (per PCWG3)

4. Patients who are on androgen deprivation therapy (ADT) of any kind (patients who have not undergone bilateral orchiectomy must begin internal castration therapy, such as luteinizing hormone-releasing hormone (LHRH) agonists, LHRH antagonists, or anti-androgenic agents, at least 4 weeks prior to Baseline and must continue for the entire duration of the study)

Exclusion Criteria

1. patient has an active autoimmune disease or is receiving systemic steroid therapy or in immunosuppressive status.
2. Patient has history of chemotherapy, radiation chemotherapy, biological therapy, immunotherapy, or radiation therapy within 4 weeks prior to the screening visit (In case of nitrosoureas or mitomycin, 6 weeks prior to the screening visit)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Cohort a'	GX-I7	SL-T10 (3mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab
Cohort S2	GX-I7	SL-T10 (6mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM)
Cohort C	GX-I7	SL-T10 (6mg, multiple injections, IM), GX-I7 (960 ug 2 injections, IM), Pembrolizumab
Cohort a'	Pembrolizumab	SL-T10 (3mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab
Cohort S1	GX-I7	SL-T10 (3mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM)
Cohort S2	SL-T10	SL-T10 (6mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM)
Cohort A	Pembrolizumab	SL-T10 (6mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab
Cohort B	GX-I7	SL-T10 (6mg, multiple injections, IM) GX-I7 (720 ug 2 injections, IM) Pembrolizumab
Cohort B	Pembrolizumab	SL-T10 (6mg, multiple injections, IM) GX-I7 (720 ug 2 injections, IM) Pembrolizumab
Cohort C	SL-T10	SL-T10 (6mg, multiple injections, IM), GX-I7 (960 ug 2 injections, IM), Pembrolizumab
Cohort S1	SL-T10	SL-T10 (3mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM)
Cohort a'	SL-T10	SL-T10 (3mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab
Cohort B	SL-T10	SL-T10 (6mg, multiple injections, IM) GX-I7 (720 ug 2 injections, IM) Pembrolizumab
Cohort C	Pembrolizumab	SL-T10 (6mg, multiple injections, IM), GX-I7 (960 ug 2 injections, IM), Pembrolizumab
Cohort A	SL-T10	SL-T10 (6mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab
Cohort A	GX-I7	SL-T10 (6mg, multiple injections, IM), GX-I7 (320 ug 2 injections, IM), Pembrolizumab

Primary Outcome Measures

Name	Time	Method
Number of participants with Serious adverse events (SAEs) as assessed by CTCAE v5.0	Baseline to 48 weeks	Number of participants with Serious adverse events (SAEs) as assessed by CTCAE v5.0
Number of participants with treatment-emergent adverse events (TEAEs)	Baseline to 23 weeks	Number of participants with treatment-emergent adverse events (TEAEs)

Secondary Outcome Measures

Name	Time	Method
PSA response rate	Baseline to 48 weeks	% patients with a reduction in PSA level from baseline by 50% or greater
Radiographic progression free survival	Baseline to 48 weeks	The interval from the date of disease progression on CT and/or Tc bone scan or death from any cause, whichever occurred first.
PSA progression free survival	Baseline to 48 weeks	The interval from the date of randomisation to the date of first evidence of PSA progression or death from any cause, whichever occurred first.
Change of induced T-cell responses for SL-T10 vaccine	Baseline to 48 weeks	Vaccine-induced T-cell responses assessed by immunoassays in peripheral blood

Trial Locations

Locations (1)

Seoul National University Hospital; 🇰🇷 Seoul, Korea, Republic of