Phase I/II Study of ubamatamab plus drug combination in patients with ovarian cancer who have poor response to first‑line chemotherapy

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What is this study about?

The study focuses on ovarian cancer that has not responded well to the first round of chemotherapy and may have been only partially removed by surgery. Participants receive a combination of medicines given through a vein (intravenous administration): the experimental antibody Ubamatamab, the chemotherapy drugs carboplatin and paclitaxel, and the anti‑angiogenic agent bevacizumab, which helps stop new blood vessels from feeding the tumor. A supportive medicine, filgrastim, may also be given to help keep the white‑blood‑cell count normal.

The purpose of the trial is to evaluate the safety and effectiveness of this drug combination. The study begins with a short safety‑checking phase and, if tolerated, moves to a larger phase that looks at how well the treatment shrinks or controls the tumor. Participants receive the infusions every few weeks and undergo regular imaging scans to see changes in tumor size; the study continues until the disease progresses, the participant chooses to stop, or the study ends.

1 initial visit and baseline assessments

after joining the study, a baseline visit is scheduled.

during this visit, medical history, physical examination, blood tests, and imaging studies are performed to document the current condition of ovarian cancer.

2 start of treatment (safety run‑in phase i)

treatment begins with an intravenous infusion of ubamatamab, carboplatin, paclitaxel, and bevacizumab according to the study protocol.

the exact dose and infusion schedule are defined by the investigators and follow the protocol guidelines.

if needed, filgrastim may be given intravenously to support white‑blood‑cell counts.

3 treatment cycles and monitoring for dose‑limiting toxicity

the combination of drugs is administered in repeated cycles; each cycle is given as directed by the protocol, typically every three weeks.

during the first four weeks of treatment, known as the dose‑limiting toxicity (dlt) period, close monitoring for side effects is performed.

any serious adverse event that meets the dlt criteria may lead to dose adjustment or discontinuation.

4 transition to efficacy phase ii

if the safety run‑in phase is completed without unacceptable toxicity, treatment continues into the efficacy phase.

the same drug regimen is given for additional cycles as defined by the protocol.

5 response assessment after three cycles

after completing three treatment cycles, imaging studies are repeated to evaluate tumor response.

the result is classified as complete response, partial response, stable disease, or progressive disease based on standard criteria.

6 optional surgery after three cycles

patients whose disease is amenable to surgery may undergo late cytoreductive surgery after the three‑cycle assessment.

the goal of surgery is to remove any remaining visible tumor.

7 continued treatment until progression or unacceptable toxicity

treatment cycles continue until disease progression is documented, unacceptable side effects occur, or the predetermined number of cycles is completed.

regular clinical visits, blood tests, and imaging are performed to monitor disease status.

8 follow‑up for survival outcomes

after the last dose of study medication, follow‑up visits are scheduled to record overall survival and progression‑free survival.

survival data are collected until death or the end of the study period.

Who Can Join the Study?

You must have a confirmed diagnosis of a high‑grade epithelial ovarian, primary peritoneal, or fallopian‑tube cancer (the cancer type is verified by looking at the tumor cells under a microscope).
Your kidneys and liver must be working well enough, as shown by blood tests that are within the required limits (tests include AST and ALT for liver, bilirubin for liver, albumin for overall health, and creatinine clearance for kidney function).
Your heart must be able to pump blood normally, measured by an echocardiogram showing a left‑ventricular ejection fraction of at least 50%, and your troponin blood level must not be unusually high (troponin is a protein that rises when the heart is damaged).
You should have a life expectancy of at least three months.
You must sign a written informed consent form agreeing to take part in the study.
You need to be covered by a social insurance plan.
You must be willing and able to follow the study schedule, including taking the study medication and attending all required visits and tests.
You must be an adult (18 years of age or older).
Your cancer must be at an advanced stage (stage III or IV).
You must have already received three or four standard cycles of carboplatin‑paclitaxel chemotherapy before surgery, and you must have both of the following: (a) a low KELIM score (< 1.0), which means the tumor did not respond well to chemotherapy, and (b) disease that could not be completely removed by surgery (the surgeon could not achieve no visible tumor after the operation).
Your tumor must be measurable on imaging scans (CT, PET‑CT, or MRI) according to RECIST 1.1 criteria (RECIST is a set of rules for measuring tumor size on scans).
A sample of your tumor tissue must be available for research (either from a previous biopsy, surgery, or a new sample).
Your overall health performance must be rated as 0 or 1 on the ECOG scale (ECOG is a simple way doctors rate how well a patient can carry out daily activities).
Your BRCA and HRD genetic status must be known or be tested during the trial (these genes can affect how the cancer behaves and responds to treatment).
Your bone‑marrow function must be adequate, shown by blood counts of: hemoglobin at least 7 g/dL, white‑blood‑cell count (neutrophils) at least 1,500 cells per mm³, and platelets at least 100,000 per mm³ (these numbers indicate the marrow can make enough blood cells).
You must be a female participant.

Who Cannot Join the Study?

Having a tumor type that is low‑grade endometrioid, clear cell, mucinous, sarcoma, low‑grade serous, or a borderline ovarian tumor (these are specific tissue patterns of ovarian cancer).
Having ongoing severe side effects from previous cancer treatment that are grade 3 or higher on the CTCAE scale (a system that grades treatment toxicity).
Currently receiving another experimental (investigational) medication.
Having serious bowel problems that prevent taking pills, such as a blockage, inflammatory bowel disease, immune‑related colitis, or conditions that cause poor absorption of nutrients.
Having active, serious heart disease, including a recent heart attack (within 6 months), heart muscle inflammation, major irregular heartbeats, chest pain, heart failure, an abnormal heart‑rate test called a QTc interval longer than 470 ms, certain types of heart‑block, or high levels of heart‑damage proteins (troponin) in the blood.
Having an untreated blood clot in the lungs (pulmonary embolism) or deep veins of the legs (deep‑vein thrombosis).
Having a significant autoimmune disease that needed strong immune‑suppressing medication in the past 5 years (common mild conditions like vitiligo, resolved childhood asthma, hormone‑treated hypothyroidism, type 1 diabetes, or psoriasis that does not need systemic immunosuppression are not exclusions).
Having uncontrolled infections such as HIV, hepatitis B, hepatitis C, a weakened immune system, or known latent tuberculosis.
Having any other active infection that required a hospital stay or intravenous antibiotics within 2 weeks before starting the study.
Receiving a live vaccine (for example, certain flu, yellow fever, or measles vaccines) within 30 days before the planned first dose.
Being pregnant, breastfeeding, or planning to become pregnant during the time the study is conducted.
Having cancer that did not respond to platinum‑based chemotherapy and got worse during the initial (neo‑adjuvant) treatment.
Being a woman who could become pregnant and not willing to use a highly effective birth‑control method before, during, and for at least 6 months after the last study dose.
Having a known psychiatric disorder that would make it difficult to follow the study procedures.
Being incarcerated, under a legal guardian, or otherwise deprived of personal liberty.
Having a medical reason (contraindication) that prevents the use of the drugs carboplatin, paclitaxel, or bevacizumab (for example, a severe allergy).
Having already received bevacizumab as part of the initial standard chemotherapy regimen.
Having previously been treated with anti‑PD‑1 therapies, T‑cell therapies, or any other experimental systemic cancer treatment.
Having a second, separate primary cancer, unless it was a non‑melanoma skin cancer, an early‑stage cervical cancer treated curatively, or another solid tumor that has been cured with no evidence of disease for at least 2 years.
Having cancer that has spread to the brain, unless the brain lesions were treated, have been symptom‑free for at least 4 weeks, cause no current neurological problems, and the patient is not taking high‑dose steroids (more than 10 mg prednisone daily).
Having had encephalitis, meningitis, or uncontrolled seizures within the past year.
Receiving any systemic chemotherapy or radiation therapy (except for symptom‑relief purposes) within 3 weeks before the first dose of the study drug ubamatamab.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country	Status
Institut Gustave Roussy	Villejuif	France
Centr Georges Francois Leclerc	Dijon	France

Other Sites

Site Name	City	Country
Centre Hospitalier Lyon Sud	Pierre Benite	France
Centre Leon Berard	Lyon	France
Centre François Baclesse	Caen	France
Iwqfyirz Rumuiawy Da Cyockp Dz Mjcacqzylzq	Montpellier	France
Ibxkkgrl Pstfofwnidfqzys Czxiyy Cyapbu	Marseille	France
Hknsvbxw Uiukbszxpjwynh Slqrybnlxq &hrudbk Hhqdfxt di Hhxouwruipz	STRASBOURG, Alsace	France

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	01.04.2026

Trial locations

Investigated drugs:

Carboplatin is a chemotherapy drug given through a vein. It works by damaging the DNA of cancer cells, which helps stop them from growing and spreading. In this study, it is part of the standard treatment that all participants receive.

Bevacizumab is a targeted therapy that is also given by IV. It blocks a protein that tumors use to make new blood vessels, which can slow down tumor growth. It is used together with the chemotherapy drugs as part of the regular treatment plan.

Filgrastim is a medication that helps the body produce more white blood cells. It is given by IV to reduce the risk of infections that can happen after chemotherapy lowers the immune system.

Paclitaxel is another chemotherapy drug administered through a vein. It stops cancer cells from dividing by interfering with their internal structure, helping to shrink or control the tumor. It is included in the background treatment for all patients.

Ubamatamab is the experimental drug being tested in this trial. It is given as an IV solution and is designed to help the immune system recognize and attack ovarian cancer cells. The study is looking at how safe it is and whether it improves treatment outcomes when added to the standard chemotherapy and targeted therapy.

Investigated diseases:

Ovarian cancer

Ovarian cancer – Ovarian cancer begins in the cells of one or both ovaries and may grow locally within the pelvic region. Over time the tumor can spread to the lining of the abdomen, nearby organs, and lymph nodes. The disease often progresses silently, with the tumor increasing in size before it is noticed. As it advances, cancer cells can detach and implant on other surfaces inside the abdomen, leading to widespread involvement.

Trial ID:

2025-524232-20-00

Protocol code:

Gineco-ov133b

Trial Phase:

Phase I and Phase II (Integrated) – First administration to humans

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Phase I/II Study of ubamatamab plus drug combination in patients with ovarian cancer who have poor response to first‑line chemotherapy

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?