Combination treatment of STRO-002 and Bevacizumab for advanced ovarian cancer

A Phase 1 Open-Label, Safety, Pharmacokinetic and Preliminary Efficacy Study of STRO-002, an Anti-Folate Receptor Alpha Antibody Drug Conjugate, in Combination With Bevacizumab in Patients With Advanced Epithelial Ovarian Cancer (Including Fallopian Tube or Primary Peritoneal Cancers)

This study is testing a new combination of two treatments, STRO-002 and Bevacizumab, to see if they can help people with advanced ovarian cancer that hasn't responded to other therapies.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 58 (estimated)
• Ages: 18 Years and up
• Sex: Female
• Sponsor: Sutro Biopharma, Inc. (Industry-sponsored)
• Drugs / interventions: bevacizumab, chemotherapy
• Locations: 6 sites (Tampa, Florida and 5 other locations)
• Trial ID: NCT05200364 on ClinicalTrials.gov

What this trial studies

This Phase 1, open-label, multicenter trial evaluates the safety and preliminary efficacy of STRO-002, an anti-folate receptor alpha antibody drug conjugate, in combination with Bevacizumab for patients with advanced ovarian cancer that has relapsed or is refractory to standard therapies. The study involves a dose escalation phase to determine the recommended phase 2 dose (RP2D) of STRO-002, followed by a dose expansion phase enrolling approximately 40 subjects. Participants will undergo tumor tissue analysis for FOLRα expression prior to enrollment to assess eligibility.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with high-grade serous epithelial ovarian cancer, fallopian tube, or primary peritoneal cancer that has relapsed after standard therapy.

Not a fit: Patients with low-grade tumors or those who have not previously received standard therapies may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with advanced ovarian cancer who have limited treatment choices.

How similar studies have performed: While this approach is novel in combining STRO-002 with Bevacizumab, similar studies targeting folate receptor alpha have shown promise in other cancer types.

Eligibility criteria

Inclusion Criteria:

1. Age ≥ 18 years.
2. ECOG 0-1
3. Life expectancy \> 3 months
4. High Grade serous epithelial ovarian cancer (EOC), fallopian tube or primary peritoneal cancer with pathology report documentation of tumor type.
5. At least one measurable target lesion per RECIST v1.1.
6. Tumor tissue for FolRα expression testing prior to enrollment.

   1. For dose escalation: tissue may be from either archival tumor tissue or from a biopsy performed during screening.
   2. For dose expansion part of the study, tissue from both archival tumor tissue and a biopsy performed during screening is required.
7. Adequate bone marrow function defined as:

   1. Absolute neutrophil count (ANC) ≥1500/μL
   2. Hemoglobin ≥ 9g/dL
   3. Platelet count ≥ 100 x 10\^3/μL
8. Adequate liver function defined as:

   1. ALT and AST \< 2.5 x ULN
   2. ALP \< 2.5 x ULN
   3. Bilirubin \< 1.5 x ULN
9. Adequate renal function defined as serum creatinine ≤ 1.5 x ULN or creatinine clearance (CrCl) \> 40 mL/min.

   Subjects enrolling into Dose Escalation must also meet the following inclusion criteria:
10. Relapsed and/or PD on last treatment regimen and one of the following:

    1. Primary Platinum refractory and received no more than 1 prior regimen
    2. Primary platinum resistant and received no more than 4 prior regimens
    3. Platinum sensitive and all of the following:

       * received at least 2 platinum-based therapies or received 1 platinum and 1 non-platinum based therapy (if unable to receive a second platinum regimen due to toxicity) or received at least 1 platinum-based therapy (if the regimen contained a PARP inhibitor given as maintenance treatment)
       * received no more than 1 additional regimen after becoming platinum resistant
       * received no more than 4 prior regimens

    Subjects enrolling into Part 2, Dose Expansion must also meet the following inclusion criteria:
11. Relapsed and/or PD on last treatment regimen and one of the following:

    1. Platinum resistant and received no more than 4 prior regimens
    2. Platinum sensitive and

       * received at least 2 platinum-based therapies or received 1 platinum and 1 non-platinum based therapy (if unable to receive a second platinum regimen due to toxicity) or received at least 1 platinum-based therapy (if the regimen contained a PARP inhibitor given as maintenance treatment)
       * received no more than 1 additional regimen after becoming platinum resistant
       * received no more than 4 prior regimens

Exclusion Criteria:

1. Low grade ovarian carcinoma (Grade 1).
2. Clear cell, mucinous, endometrioid, sarcomatous, and mixed histology ovarian carcinomas, endometrial leiomyosarcoma, and endometrial stromal sarcomas.
3. Prior treatment with an ADC with a tubulin inhibitor warhead.
4. Prior treatment with other FolRα targeting agents unless approved by a Sutro medical monitor or designee.
5. Subjects who are primary platinum-refractory during frontline treatment are excluded from the Expansion Cohort (Allowed in Dose Escalation if no more than 1 prior regimen).
6. Greater than 4 prior lines of treatment (\> 1 prior if primary platinum refractory).
7. Any prior toxicity that required permanent discontinuation of bevacizumab or other contraindication to receive bevacizumab per institutional guidelines.
8. Previous solid organ transplantation.
9. Current signs/symptoms of bowel obstruction and/or signs/symptoms of or bowel obstruction within 3 months of initiation of study treatment.
10. Grade ≥2 toxicity from prior anticancer therapy with the exception of Grade 2 alopecia or Grade 2 neuropathy.
11. Uncontrolled hypertension
12. Sensory or motor neuropathy Grade \> 1 at screening prior to initiation of study treatment.
13. Potentially fatal concurrent or recent malignancy. Subjects with past or current malignancy need to be discussed with the sponsor to determine eligibility.
14. Chronic or ongoing active infection requiring systemic treatment.
15. Ongoing immunosuppressive therapy, including systemic corticosteroids. Note: Physiologic replacement and use of topical or inhaled corticosteroids are allowed. Dexamethasone may be used to treat chemotherapy induced nausea per institutional guidelines.
16. Clinically significant cardiac disease.
17. History or clinical signs of meningeal or active central nervous system involvement.
18. Known severe COPD or asthma
19. Active pneumonitis within 6 months of initiating study treatment.
20. History of stroke or history of significant cerebrovascular disease (i.e., transient ischemic attack) within 6 months of initiation of study treatment.
21. History of pulmonary embolism or any Grade 3 thromboembolic event within 6 months of initiation of study treatment.
22. Known human immunodeficiency virus seropositivity.
23. Active hepatitis B or hepatitis C and positive serology (unless due to vaccination or passive immunization due to immunoglobulin therapy) with the following exceptions:

    1. Subject has had HCV but received antiviral treatment and shows no detectible HCV viral DNA for 6 months prior to screening
    2. Subject has had HBV but is HBV surface antigen (HBsAg) and viral DNA negative at screening
    3. Subject has had HBV but received antiviral treatment and have undetectable viral DNA for 6 months prior to screening
24. Concurrent participation in another therapeutic treatment trial
25. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, hematological, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease
26. Females who are pregnant or breastfeeding, and all women of childbearing potential unwilling to use adequate barrier contraception while on treatment and for 16 weeks after last dose of STRO-002/bevacizumab and 6 months after the last dose of bevacizumab.

Where this trial is running

Tampa, Florida and 5 other locations

• University of South Florida, — Tampa, Florida, United States (Recruiting)
• Thomas Jefferson University — Philadelphia, Pennsylvania, United States (Recruiting)
• University of Pennsylvania — Philadelphia, Pennsylvania, United States (Recruiting)
• Tennessee Oncology — Nashville, Tennessee, United States (Recruiting)
• Virginia Cancer Specialists — Fairfax, Virginia, United States (Recruiting)
• Medical College of Wisconsin — Milwaukee, Wisconsin, United States (Recruiting)

Study contacts

• Study coordinator: Craig Berman, MD

Conditions Ovarian Cancer; Ovarian Carcinoma; Ovary Cancer; Fallopian Tube Cancer; Primary Peritoneal Carcinoma