Phase 1b Study of SL-172154 Administered With Combination Agent(s) in Subjects With Ovarian Cancers

An Open-Label, Phase 1b Study of SL-172154 (SIRPα-Fc-CD40L) Administered With Either Pegylated Liposomal Doxorubicin or Mirvetuximab Soravtansine in Subjects With Platinum-Resistant Ovarian Cancers

SL03-OHD-105 is an open-label, multicenter, phase 1b trial designed to evaluate SL-172154 administered in combination with pegylated liposomal doxorubicin (PLD) or mirvetuximab soravtansine (MIRV) in patients with platinum resistant ovarian cancer. Approximately 102 patients will be enrolled in this study.

Study Overview

• Status: Completed
• Conditions: Ovarian Cancer; Fallopian Tube Cancer; Epithelial Ovarian Cancer; Platinum-resistant Ovarian Cancer; Primary Peritoneal Carcinoma; Platinum-Resistant Fallopian Tube Carcinoma; Platinum-Resistant Primary Peritoneal Carcinoma
• Intervention / Treatment: Drug: Pegylated Liposomal Doxorubicin + SL-172154; Drug: Mirvetuximab + SL-172154

Detailed Description

Study SL03-OHD-105 is an open-label, multicenter, phase 1b trial designed to evaluate the safety, pharmacokinetics, pharmacodynamic effects, and preliminary anti-tumor activity of SL-172154 administered in combination with either PLD or MIRV in subjects with platinum-resistant ovarian, primary peritoneal, or fallopian tube cancers. Patients will be appropriate for combination therapy for their next line of therapy. For the SL-172154 + MIRV cohort, patients' tumors must be positive (defined as PS2+ ≥ 25%) for folate receptor alpha (FRα) as defined by the Ventana FOLR1 (Folate Receptor 1/Folate Receptor Alpha) Assay.

The first portion of the study will evaluate the safety of increasing dose levels of SL-172154 in combination with either PLD or MIRV and establish a combination dose for both regimens to be further evaluated in two dose expansion cohorts.

• Study Type: Interventional
• Enrollment (Actual): 86
• Phase: Phase 1

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, BC V5Z 4E6
      • BC Cancer Center
  • Ontario
    • Toronto, Ontario, Canada, M5G 2M9
      • University health Network (UHN)-University of Toronto
  • Quebec
    • Montreal, Quebec, Canada, H4A 3J1
      • McGill University Health Care
• Spain
  • Barcelona, Spain, 08028
    • Hospital Universitario Quirón-Dexeus Servicio de Oncologia Médica
  • Girona, Spain, 17007
    • Hospital Universitario Dr. Josep Trueta - ICO de Girona, Servicio de Oncología Av. Francia s/n
  • Madrid, Spain, 28013
    • Hospital Universitari Vall D Hebron
  • Madrid, Spain, 28040
    • Hospital Universitario Fundacion Jimenez Diaz START Madrid-FJD- Unidad de Ensayos Fase I
  • Murcia, Spain, 30120
    • Hospital Universitario Virgen de la Arrixaca. Servicio de Oncología Ctra. Madrid-Cartagena, s/n
  • Barcelona
    • Badalona, Barcelona, Spain, 08916
      • Hospital Universitari Germans Trias i Pujol
  • Catalonia
    • Barcelona, Catalonia, Spain, 08036
      • Hospital Clinic de Barcelona Servicio de Oncología, Esc. 2, Planta 5 dcha
• United Kingdom
  • London, United Kingdom, SW3 6JJ
    • The Royal Marsden NHS Foundation Trust
  • London, United Kingdom, SE1 7EH
    • Guy's & St Thomas' NHS Foundation Trust
  • London, United Kingdom, W1T 7HA
    • University College London Hospitals Nhs Foundation Trust
  • Manchester, United Kingdom, M20 4BX
    • The Christie NHS Foundation Trust
  • Sutton, United Kingdom, SM2 5PT
    • The Royal Marsden NHS Foundation Trust
  • Lancashire
    • Preston, Lancashire, United Kingdom, PR2 9HT
      • Lancashire Teaching Hospitals NHS Foundation Trust
• United States
  • Arkansas
    • Little Rock, Arkansas, United States, 72205
      • University of Arkansas for Medical Sciences
  • California
    • Duarte, California, United States, 91010
      • City of Hope
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Robert H.Lurie ComprehensiveCancer Center, Northwestern University
  • Michigan
    • Grand Rapids, Michigan, United States, 49546
      • START Midwest
  • Oklahoma
    • Oklahoma City, Oklahoma, United States, 73104
      • Stephenson Cancer Center, OU Health/ Sarah Cannon Research Institute

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Subject has voluntarily agreed to participate by giving written informed consent in accordance with ICH/GCP guidelines and applicable local regulations.
2. Age ≥18 years
3. [PLD Cohort] Subject has a histologically confirmed diagnosis of high grade epithelial ovarian cancer, including primary peritoneal cancer or fallopian tube cancer. Non-epithelial tumors and ovarian tumors with low malignant potential are excluded.
4. [PLD Cohort] Subject must have platinum-resistant disease, defined as radiologic disease progression within 180 days (6 months) following the last administered dose of platinum therapy. Subjects who are primary platinum-refractory, defined by progressing during or within 1 month of upfront platinum therapy, are excluded.
5. [PLD Cohort] Subjects may have received any number of prior lines of therapy for epithelial ovarian cancer; however, they may not have received more than 1 prior line of systemic anticancer therapy for platinum-resistant disease.
6. [MIRV Cohort] Subject has a histologically confirmed diagnosis of high grade serous epithelial ovarian cancer, including primary peritoneal cancer or fallopian tube cancer. Non-epithelial tumors and ovarian tumors with low malignant potential are excluded.

7. [MIRV Cohort] Subject must have platinum-resistant disease as defined by:

   • Subjects who have only had 1 line of platinum-based therapy must have received at least 4 cycles of platinum, must have had a response (complete response/remission [CR] or partial response/remission [PR]) and then progressed between >3 months and ≤6 months after the date of the last dose of platinum.
   • Subjects who have received 2 or 3 lines of platinum therapy must have progressed on or within 6 months after the date of the last dose of platinum.
   • Subjects who are platinum refractory during front-line treatment are excluded [primary platinum-refractory disease, defined as disease that did not respond to (CR or PR) or has progressed within 3 months of the last dose of first-line platinum-containing chemotherapy]
8. [MIRV Cohort] Subjects must have received at least 1 but no more than 3 prior systemic lines of anticancer therapy.
9. [MIRV Cohort] Willing to provide an archival tumor tissue block or slides or undergo procedure to obtain new biopsy using a low-risk, medically routine procedure for IHC confirmation of FRα positivity.
10. [MIRV Cohort] Subject's tumor must be positive for FRα expression (defined as PS2+ ≥ 25% by the Ventana FOLR1 Assay).
11. Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0 or 1.
12. Measurable disease by RECIST v1.1 using radiologic assessment.
13. Adequate organ and hematologic function
14. Subjects must have stabilized or recovered (Grade 1 or baseline) from all prior anti-cancer therapy-related toxicities.
15. [MIRV Cohort, Dose Expansion only] Willing to consent to 1 mandatory pre-treatment and 1 on-treatment tumor biopsy, unless there is excessive risk from the procedure as determined by the investigator

Exclusion Criteria:

1. Prior treatment with a signal-regulatory protein alpha (SIRPα) targeting agent, anti-CD47 agent or CD40 agonist.
2. [PLD Cohort] Prior treatment with doxorubicin or PLD
3. [MIRV Cohort] Prior treatment with MIRV or another FRα-targeting agent
4. Any anti-cancer therapy within the time intervals specified per protocol.
5. Concurrent chemotherapy, immunotherapy, biologic or hormonal therapy for cancer treatment is prohibited.
6. Receipt of live attenuated vaccine (including live attenuated vaccines for COVID-19) within 28 days of the first dose of study treatment.
7. Current or prior use of systemic immunosuppressive medication within 7 days prior to first dose of study treatment.
8. [MIRV Cohort] Requires use of folate-containing supplements (e.g., folate deficiency)
9. Active or documented history of autoimmune disease that has required treatment with a disease modifying agent or immunosuppressive therapy in the past two years, history of multiple sclerosis (MS) or other demyelinating disease and/or Lambert-Eaton syndrome (paraneoplastic syndrome). Exceptions include controlled Type I diabetes, vitiligo, alopecia areata or hypo/hyperthyroidism.
10. Ongoing or active infection (e.g., no systemic antimicrobial therapy for treatment of infection within 5 days of D1 of study treatment).
11. Known severe hypersensitivity to the active drug substance or to any of the excipients for the agents to be administered or known hypersensitivity to Chinese hamster ovary cell products.
12. Severe gastrointestinal conditions.
13. Clinically significant or uncontrolled cardiovascular disease
14. [MIRV Cohort] History of cirrhotic liver disease (Child-Pugh Class B or C)
15. [MIRV Cohort] Active or chronic corneal disorders, history of corneal transplantation, or active ocular conditions requiring ongoing treatment/monitoring, such as uncontrolled glaucoma, wet age-related macular degeneration requiring intravitreal injections, active diabetic retinopathy with macular edema, macular degeneration, presence of papilledema, and/or monocular vision.
16. Previous clinical diagnosis of noninfectious interstitial lung disease (ILD), including noninfectious pneumonia.
17. Untreated central nervous system or leptomeningeal metastases.
18. 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 the study treatment.
19. Has undergone allogeneic stem cell transplantation or organ transplantation.
20. Known history or positive test for human immunodeficiency virus (HIV), or positive test for hepatitis B (positive for hepatitis B surface antigen [HBsAg]) or hepatitis C virus ([HCV]

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Pegylated Liposomal Doxorubicin + SL-172154 (SIRPα-Fc-CD40L); Pegylated Liposomal Doxorubicin (PLD) will be administered via intravenous administration + SL-172154 (SIRPα-Fc-CD40L) will be administered via intravenous administration.	Drug: Pegylated Liposomal Doxorubicin + SL-172154; The investigational product, SL-172154, is a novel fusion protein consisting of human SIRPα and CD40L (SIRPα -Fc-CD40L) linked via a human Fc.; Other Names: Caelyx; Doxil; PLD
Experimental: Mirvetuximab + SL-172154 (SIRPα-Fc-CD40L); Mirvetuximab (MIRV) will be administered via intravenous administration + SL-172154 (SIRPα-Fc-CD40L) will be administered via intravenous administration	Drug: Mirvetuximab + SL-172154; The investigational product, SL-172154, is a novel fusion protein consisting of human SIRPα and CD40L (SIRPα -Fc-CD40L) linked via a human Fc.; Other Names: IMGN853; MIRV

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Evaluate Safety and Tolerability of SL-172154 When Administered With PLD or Mirvetixumab	Number of participants with treatment emergent adverse events from dose escalation and expansion cohorts	From Day 1 to 30 days after last dose of SL-172154, PLD or Mirvetixumab, an average of approximately 6 months
Establish the Recommended Phase 2 Dose (RP2D) for SL-172154 When Administered With PLD or Mirvetixumab	Based on review of all data, including safety, tolerability, PK, antitumor activity, and PD effects"	From Day 1 to 30 days after last dose of SL-172154, PLD or Mirvetixumab, an average of approximately 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To Assess Preliminary Evidence of Anti-tumor Activity of SL-172154 When Administered With PLD or Mirvetixumab	Overall response rate per investigator assessment according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v 1.1)	approximately 24 months
Immunogenicity to SL-172154	Number and proportion of participants with positive anti-drug antibody titer of those who were ADA negative at baseline	approximately 24 months
Immunogenicity to MIRV	Number and proportion of participants with positive anti-drug antibody titer of those who were ADA negative at baseline	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	C1D8, C1D15, C2D8
Area Under the Serum Concentration-time Curve (AUC) of SL-172154	The AUC is the area under the serum concentration time curve of SL-172154 following single and multiple doses	C1D8, C1D15 and C2D8
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	C1D8, C1D15 and C2D8
Maximum Serum Concentration (Cmax) of MIRV	The Cmax is the maximum observed serum concentration of MIRV following single and multiple doses	Day 1 of each cycle, pre-dose and end of infusion (EOI)
Maximum Serum Concentration (Cmax) of Total Antibody (MIRV)	The Cmax is the maximum observed serum concentration of Total Antibody (MIRV) following single and multiple doses	Day 1 of each cycle, pre-dose and end of infusion (EOI)
Maximum Serum Concentration (Cmax) of DM4 Payload and S-Methyl DM4 Payload (MIRV)	The Cmax is the maximum observed serum concentration of DM4 Payload and S-Methyl DM4 payload following single and multiple doses	Day 1 of each cycle, pre-dose and end of infusion (EOI)

Collaborators and Investigators

• Sponsor: Shattuck Labs, Inc.
• Investigators: Study Director: Shattuck Labs, Shattuck Labs

Study record dates

Study Major Dates

• Study Start (Actual): August 18, 2022
• Primary Completion (Actual): February 7, 2025
• Study Completion (Actual): February 7, 2025

Study Registration Dates

• First Submitted: July 26, 2022
• First Submitted That Met QC Criteria: July 29, 2022
• First Posted (Actual): August 2, 2022

Study Record Updates

• Last Update Posted (Estimated): December 23, 2025
• Last Update Submitted That Met QC Criteria: December 18, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: primary peritoneal cancer; Platinum-resistant; Combination; Pegylated Liposomal Doxorubicin; Ovarian; Peritoneal; High grade serous EOC; Fallopian; Mirvetuximab Soravtansine; SL-172154; SIRPα-Fc-CD40L
• 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; Antibiotics, Antineoplastic; Antineoplastic Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Topoisomerase Inhibitors; Topoisomerase II Inhibitors; mirvetuximab soravtansine; liposomal doxorubicin; 1-dodecylpyridoxal
• Other Study ID Numbers: SL03-OHD-105

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No