Phase 1 Study of SL-172154 (SIRPα-Fc-CD40L) in Subjects With Ovarian Cancer

Phase 1 Dose Escalation Study of the Agonist Redirected Checkpoint, SL-172154 (SIRPα-Fc-CD40L) Administered Intravenously in Subjects With Ovarian Cancer

This is a Phase 1 first in human, open label, multi-center, dose escalation study to evaluate the safety, tolerability, PK, anti-tumor activity and pharmacodynamic effects of SL-172154 in subjects with ovarian cancer.

Study Overview

• Status: Completed
• Conditions: Ovarian Cancer; Fallopian Tube Cancer; Primary Peritoneal Carcinoma
• Intervention / Treatment: Drug: SL-172154

Detailed Description

This Phase 1 trial will evaluate the safety, tolerability, pharmacokinetics, anti-tumor and pharmacodynamic effects of SL-172154 and identify the dose and schedule i.e., recommended Phase 2 dose for future development (RP2D). Subjects eligible for enrollment are required to have platinum-ineligible ovarian, fallopian tube, and primary peritoneal cancers. The study design consists of dose escalation cohorts, an optional pharmacodynamic cohort, and an optional dose expansion cohort. In the dose escalation phase of the study, subjects will be enrolled into sequential dose levels. The study may also enroll a pharmacodynamic cohort to obtain additional pharmacodynamic data at one or more dose levels that have completed evaluation for safety without exceeding the maximum tolerated dose (MTD). Subjects enrolled in the pharmacodynamic cohort will not inform dose escalation decisions. A dose expansion cohort may be opened to further characterize safety, tolerability, PK, anti-tumor activity, and pharmacodynamic data to inform the selection of a RP2D.

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • California
    • Duarte, California, United States, 91016
      • City of Hope
  • Michigan
    • Grand Rapids, Michigan, United States, 49546
      • START Midwest
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599
      • University of North Carolina at Chapel Hill
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73104
      • Stephenson Cancer Center at Oklahoma University
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Sarah Cannon Research Institute
  • Utah
    • West Valley City, Utah, United States, 84119
      • START Mountain Region

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Participants are eligible to be included in the study only if all the following criteria apply:

1. Subject has voluntarily agreed to participate by giving written informed consent in accordance with ICH/GCP guidelines and applicable local regulations.
2. Subject must have a histologically confirmed diagnosis of an unresectable, locally advanced or metastatic ovarian cancer, or primary peritoneal cancer or fallopian tube cancer.
3. Subjects must be refractory or intolerant to existing therapy(ies) known to provide clinical benefit for their condition. Subject must have received platinum-based therapies, and should not be eligible for further platinum therapy, or should be intolerant to such therapy. Subjects with HRD positive disease may participate if they have received prior polyadenosine diphosphate ribose polymerase (PARP) inhibitor therapy given alone or with bevacizumab.
4. Subjects should not be primary platinum refractory as defined by progressing during or within 1 month of upfront platinum therapy.
5. Has measurable disease by RECIST v1.1 using radiologic assessment.
6. Subject age is 18 years and older.
7. Has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
8. Has life expectancy of greater than 12 weeks.
9. Has adequate organ function.
10. Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy test within 72 hours of D1 of IP.
11. Recovery from prior anti-cancer treatments including surgery, radiotherapy, chemotherapy or any other anti-cancer therapy to baseline or ≤ Grade 1.
12. Willing to consent to mandatory pre-treatment and on-treatment tumor biopsy(ies), unless there is excessive risk as determined by the investigator.

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

1. Prior treatment with an anti-CD47 or anti-SIRPα targeting agent or a CD40 agonist.
2. Any anti-cancer therapy within the washout period prior to first dose (D1) of SL-172154.
3. Concurrent chemotherapy, immunotherapy, biologic or hormonal/hormonal suppression therapy for cancer treatment is prohibited. Concurrent use of hormones for non-cancer related conditions is acceptable.
4. Use of corticosteroids or other immunosuppressive medication, current or within 14 days of D1 of SL-172154 treatment.
5. Receipt of live attenuated vaccine within 28 days of D1 of IP.
6. Active or documented history of autoimmune disease. Exceptions include controlled Type I diabetes, vitiligo, alopecia areata or hypo/hyperthyroidism.
7. Hypersensitivity to the active drug substance or to any of the excipients for the agent to be administered or subjects with known hypersensitivity to Chinese hamster ovary cell products.
8. Active pneumonitis (i.e. drug-induced, idiopathic pulmonary fibrosis, radiation-induced, etc.).
9. Ongoing or active infection (e.g., no systemic antimicrobial therapy for treatment of infection within 5 days of D1 of IP).
10. Symptomatic peptic ulcer disease or gastritis, active diverticulitis, other serious gastrointestinal disease associated with diarrhea within 6 months of D1 of IP.
11. Clinically significant or uncontrolled cardiac/thromboembolic disease.
12. Untreated central nervous system or leptomeningeal metastases.
13. Women who are breast feeding.
14. Psychiatric illness/social circumstances that would limit compliance with study requirements and substantially increase the risk of AEs or compromised ability to provide written informed consent.
15. Another malignancy that requires active therapy and that in the opinion of the investigator and Sponsor would interfere with monitoring of radiologic assessments of response to IP.
16. Has undergone allogeneic stem cell transplantation or organ transplantation.
17. Known history or positive test for human immunodeficiency virus, or positive test for hepatitis B.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SL-172154; Intravenous administration	Drug: SL-172154; The investigational product (IP), SL-172154, is a novel fusion protein consisting of human SIRPα and CD40L (SIRPα -Fc-CD40L) linked via a human Fc.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety Profile of SL-172154	Number of participants with treatment emergent adverse events	From Day 1 to 90 days after Last Dose of SL-172154
Maximum Tolerated Dose (MTD) of SL-172154	Number of participants with dose limiting toxicities (DLTs)	From Day 1 to 90 days after Last Dose of SL-172154

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recommended Phase 2 Dose (RP2D) for SL-172154	Based on review of all data, including safety, tolerability, PK, antitumor activity, and PD effects	Approximately 24 months
Assess Preliminary Evidence of Anti-tumor Activity of SL-172154	Number of participants with an objective response per investigator assessment according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v 1.1). Objective response includes complete response (disappearance of all target lesions) and partial response (>/= 30% decrease in the sum of the longest diameter of target lesions).	Approximately 24 months
Immunogenicity to SL-172154	Number of participants with positive anti-drug antibody (ADA) titer, sustained ADA response (positive ADA in >/= 2 samples without reverting to negative ADA or positive ADA in the last sample), or persistent ADA response (positive ADA in >/= 2 samples where the first and last samples are >/= 16 weeks apart, or positive ADA in the last sample, or only one sample but < 16 weeks before a negative last sample).	Approximately 24 months
Maximum Serum Concentration (Cmax) of SL-172154	The Cmax is the maximum observed serum concentration of SL-172154 following single and multiple doses	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)
Minimum Serum Concentration (Cmin) of SL-172154	The Cmin is the minimum observed serum concentration of SL-172154 following at least one dose	Cycle 1 Day 15 and Cycle 2 Day 1 (each cycle = 28 days)
Time at Which Maximum Concentration of SL-172154 is Observed (Tmax)	The Tmax is the time at which the maximum concentration of SL-172154 is observed following single and multiple doses	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)
Area Under the Serum Concentration-time Curve (AUC)	The AUC is the area under the serum concentration time curve following single and multiple doses of SL-172154. AUC (0-last; from time 0 to the last quantifiable concentration) is reported for C1D1 and AUC (tau; over a dosing interval) is reported for C1D15 and C2D1.	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)
Terminal Elimination Half-life (t1/2)	Terminal elimination half-life (t1/2) of SL-172154	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)
Clearance (CL)	Clearance of SL-172154	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)
Volume of Distribution	Volume of distribution of SL-172154	Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1 (each cycle = 28 days)

Collaborators and Investigators

• Sponsor: Shattuck Labs, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): June 29, 2020
• Primary Completion (Actual): February 2, 2023
• Study Completion (Actual): February 2, 2023

Study Registration Dates

• First Submitted: May 19, 2020
• First Submitted That Met QC Criteria: May 22, 2020
• First Posted (Actual): May 28, 2020

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 3, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Endocrine System Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Neoplasms by Histologic Type; Genital Diseases, Female; Endocrine Gland Neoplasms; Neoplasms, Glandular and Epithelial; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Carcinoma; Fallopian Tube Diseases; Carcinoma, Ovarian Epithelial; Ovarian Neoplasms; Fallopian Tube Neoplasms
• Other Study ID Numbers: SL03-OHD-101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No