MIRV in Combination With Suvemcitug for Partially Platinum-Sensitive Ovarian Cancer (MISO)

A Phase 2 Study of Mirvetuximab Soravtansine (MIRV) in Combination With Suvemcitug for the Treatment of Folate Receptor Alpha (FRα)-Expressing Partially Platinum-Sensitive Ovarian Cancer (MISO)

This is a prospective, single-arm, phase II study designed to evaluate the efficacy and safety of mirvetuximab soravtansine combined with suvemcitug in patients with FRα-positive partially platinum-sensitive recurrent ovarian cancer.

Approximately 80 patients will be enrolled. Eligible patients must have recurrent high-grade serous ovarian cancer, fallopian tube cancer, or primary peritoneal cancer with FRα expression and disease recurrence occurring 6 to 12 months after completion of platinum-based chemotherapy.

Participants will receive mirvetuximab soravtansine and suvemcitug every 2 weeks until disease progression, unacceptable toxicity, withdrawal of consent, or study termination. Tumor response will be assessed according to RECIST version 1.1.

The primary objective is to evaluate the objective response rate (ORR). Secondary objectives include duration of response (DOR), progression-free survival (PFS), overall survival (OS), CA125 response, and safety outcomes. Exploratory analyses will assess the relationship between FRα expression, other biomarkers, and clinical outcomes.

Study Overview

• Status: Not yet recruiting
• Conditions: Platinum-Sensitive Recurrent Ovarian Cancer
• Intervention / Treatment: Drug: Mirvetuximab Soravtansine; Drug: Suvemcitug

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Hubei
    • Wuhan, Hubei, China, 430030
      • Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Signed written informed consent and able to comply with the protocol-specified visits and related procedures.

2. Female patients aged ≥18 years.

3. Patients with histologically or cytologically confirmed high-grade serous or endometrioid ovarian cancer, primary peritoneal cancer, or fallopian tube cancer.

4. Recurrence after prior standard platinum-based chemotherapy with or without bevacizumab ± PARP inhibitor, with the date of diagnosis of recurrence being 6-12 months from the last platinum-based chemotherapy.

5. Patients with a BRCA mutation must have received PARP inhibitor therapy.

6. Patients must have experienced disease progression during or after the most recent anticancer therapy received.

7. Tumor FRα expression has been determined by the VENTANA FOLR1 assay to be ≥25% (requiring ≥25% of tumor cells with staining intensity ≥2+ after FRα staining).

8. Patients must provide archived tumor tissue block or sections for central laboratory FRα testing and exploratory biomarker analysis. Tissue wax blocks are preferred; if wax blocks cannot be provided, no fewer than 10 unstained sections should be provided.

9. Patients must have at least one evaluable lesion per RECIST v1.1 (determined by the investigator via imaging).

10. Eastern Cooperative Oncology Group performance status (ECOG PS) must be 0-2.

11. Patients must have received at least 1 but no more than 2 lines of prior systemic anticancer chemotherapy:

    1. Neoadjuvant therapy ± adjuvant therapy is considered as 1 line of therapy;
    2. A change in treatment due to toxicity in the absence of disease progression is considered part of the same line of therapy (i.e., not counted separately).

12. Adequate major organ function, and the patient is considered by the investigator to be suitable for treatment with mirvetuximab soravtansine combined with suvemcitug, defined as:

    1. Absolute neutrophil count (ANC) ≥1.5 × 10^9/L (1,500/μL), and no use of G-CSF within the prior 10 days, or no use of long-acting WBC growth factors within the prior 20 days;
    2. Platelet count ≥100 × 10^9/L (100,000/μL) with no platelet transfusion within the prior 10 days;
    3. Hemoglobin ≥9.0 g/dL with no packed red blood cell (PRBC) transfusion within the prior 21 days;
    4. Serum creatinine ≤1.5 × upper limit of normal (ULN);
    5. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3.0 × ULN;
    6. Serum bilirubin ≤1.5 × ULN (patients with Gilbert's syndrome may be enrolled if total bilirubin <3.0 × ULN);
    7. Serum albumin ≥2 g/dL.

13. All toxicities related to prior treatment (except alopecia) must have recovered to ≤ Grade 1 per CTCAE v5.0.

14. Any major surgery the patient has undergone must have been completed at least 4 weeks prior to the first dose of mirvetuximab soravtansine and suvemcitug, and postoperative complications from prior surgical treatment must have resolved or be stable.

15. The subject's life expectancy is assessed by the investigator to be at least 12 weeks.

Exclusion Criteria:

1. Concurrent participation in another clinical study.
2. Patients with endometrioid, clear cell, mucinous, or sarcoma histology, mixed tumors containing any of these histologies, or low-grade/borderline ovarian tumors.
3. Patients whom the investigator considers to have other serious systemic diseases (including active infection, non-infectious interstitial lung disease, clinically significant cardiovascular or cerebrovascular disease within 6 months prior to the first dose, etc.) or other reasons that make them unsuitable for participation in this clinical study.
4. Known prior hypersensitivity to monoclonal antibody therapy or maytansinoids, or to the study drug and/or any of its excipients.
5. Patients with active or chronic corneal disease, history of corneal transplant, or active eye disease requiring continuous treatment/monitoring, for example: uncontrolled glaucoma, wet age-related macular degeneration requiring intravitreal injection therapy, active diabetic retinopathy with macular edema, macular degeneration, presence of papilledema, and/or monocular vision.
6. Patients with pleural effusion, pericardial effusion, or ascites that cannot be controlled by drainage or other methods should be excluded, except for small amounts of fluid that are asymptomatic or do not require clinical intervention.
7. Patients who have previously received mirvetuximab soravtansine or other FRα-targeted therapies.
8. Known active central nervous system (CNS) metastases and/or leptomeningeal disease. Subjects with untreated but asymptomatic brain metastases, or those with imaging evidence of sustained progression-free status for at least 4 weeks after treatment and no need for hormones or anti-epileptic therapy for at least 2 weeks, may be considered for enrollment.
9. Pregnant or breastfeeding women. Women of childbearing potential must agree to take highly effective contraceptive measures during the study drug period and for at least 7 months after the last dose of study drug. Women of childbearing potential are defined as fertile women from menarche until menopause, unless permanently sterile. Permanent sterilization methods include hysterectomy, bilateral salpingectomy, and bilateral oophorectomy.
10. Patients who have received anti-tumor therapy or participated in a clinical study and received an investigational drug within 2 weeks prior to the first dose of this study.
11. Patients with hypertension that cannot be reduced to the normal range with antihypertensive medication (systolic blood pressure > 150 mmHg, diastolic blood pressure > 90 mmHg).
12. Patients with NYHA Class III-IV cardiac insufficiency, or left ventricular ejection fraction (LVEF) < 50% as indicated by echocardiography
13. Patients with proteinuria (urine protein > 1+ found during screening; or urine protein 1+ that does not return to normal upon repeat testing within 24 hours);
14. Patients with a clear tendency for gastrointestinal bleeding, including the following conditions: presence of a local active ulcer lesion with fecal occult blood (++) making them ineligible for enrollment; history of melena or hematemesis within 2 months; presence of high bleeding risk: Grade ≥ 3 bleeding events within the past 6 months, hemoptysis ≥ 2.5 mL per episode; imaging suggesting tumor erosion into major blood vessels; or investigator judgment that the bleeding risk is unacceptable;
15. Presence of high risk of gastrointestinal perforation/fistula: gastrointestinal perforation or active peptic ulcer within the past 6 months; or pelvic tumor significantly invading the bladder/rectum with potential risk of fistula (investigator judgment);
16. Coagulation abnormalities (INR > 1.5, APTT > 1.5 × ULN) with a bleeding tendency;
17. Long-term unhealed wounds or fractures; major surgery or severe traumatic injury, fracture, or ulcer within 4 weeks.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Mirvetuximab Soravtansine + Suvemcitug; Patients with FRα-expressing partially platinum-sensitive recurrent ovarian cancer will receive mirvetuximab soravtansine combined with suvemcitug. Treatment will continue until disease progression, unacceptable toxicity, withdrawal of consent, death, or other protocol-specified discontinuation criteria.

Drug: Mirvetuximab Soravtansine; Mirvetuximab soravtansine is a folate receptor alpha (FRα)-targeting antibody-drug conjugate (ADC) consisting of a humanized monoclonal antibody linked to the maytansinoid DM4. It is administered intravenously in combination with suvemcitug for the treatment of patients with FRα-expressing partially platinum-sensitive recurrent ovarian cancer.; Drug: Suvemcitug; Suvemcitug is a recombinant humanized monoclonal antibody targeting vascular endothelial growth factor (VEGF). In this study, suvemcitug is administered intravenously in combination with mirvetuximab soravtansine to evaluate the efficacy and safety in patients with FRα-expressing partially platinum-sensitive recurrent ovarian cancer.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Response Rate（ORR）	Investigator-assessed ORR, including confirmed best overall response of CR or PR per RECIST v1.1.	up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-Free Survival（PFS）	Investigator-assessed PFS: Defined as the time from first dose to the first documented PD per tumor assessment follow-up or death from any cause (whichever occurs first).	up to 24 months
During of response*（DoR）	Investigator-assessed DOR: For patients who achieve an objective response, DOR is defined as the time from first meeting CR/PR criteria (whichever occurs first) to the date of PD or death from any cause (whichever occurs first).	up to 24 months
Overall Survival (OS)	OS: Defined as the time from first dose to death from any cause (for patients lost to follow-up prior to death, the last follow-up date is typically used as the date of death).	up to 24 months
CA125 response	CA125 response: Assessed according to GCIG (Gynecologic Cancer InterGroup) criteria. In the GCIG CA125 criteria, CA125 response is defined as a reduction in CA125 level of at least 50% after treatment, maintained for at least 28 days. CA125 assessment can only be performed if the patient's CA125 level is greater than twice the upper limit of normal within the 2 weeks before the start of treatment.	up to 24 months
Incidence, severity, and duration of treatment-emergent adverse events (TEAEs) and treatment-related adverse events (TRAEs). (Assessed by the investigator per CTCAE criteria.)		up to 24 months
Incidence of Grade ≥3 treatment-related adverse events (TRAEs) assessed by the investigator. (Assessed by the investigator per CTCAE criteria.)		up to 24 months

Other Outcome Measures

Outcome Measure	Time Frame
Correlation between baseline tumor tissue FRα expression levels and other exploratory biomarker characteristics with ORR, PFS, DOR, and treatment-related adverse events.	up to 24 months

Collaborators and Investigators

• Sponsor: Tongji Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): November 10, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): June 30, 2028

Study Registration Dates

• First Submitted: November 6, 2026
• First Submitted That Met QC Criteria: November 6, 2026
• First Posted (Actual): November 12, 2026

Study Record Updates

• Last Update Posted (Actual): November 12, 2026
• Last Update Submitted That Met QC Criteria: November 6, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: VEGF; Ovarian Cancer; ADC; Mirvetuximab Soravtansine; FRα; Suvemcitug
• 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; Genital Diseases, Female; Endocrine Gland Neoplasms; Ovarian Diseases; Adnexal Diseases; Genital Neoplasms, Female; Gonadal Disorders; Ovarian Neoplasms; mirvetuximab soravtansine
• Other Study ID Numbers: SMA-PSOC-001

Drug and device information, study documents

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