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Study of OSE2101 vaccine alone or with pembrolizumab as maintenance therapy for patients with platinum-sensitive recurrent ovarian cancer after chemotherapy

Verified siteRegistered drugNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This study focuses on patients with platinum-sensitive recurrent ovarian cancer. The research evaluates two treatment approaches as maintenance therapy after chemotherapy. The first treatment uses a cancer vaccine called TEDOPI (also known as OSE2101) alone, while the second approach combines TEDOPI with pembrolizumab (also known as KEYTRUDA). These treatments will be compared to standard supportive care.

The main purpose is to determine how effective these maintenance treatments are in preventing cancer progression in patients who have responded to platinum-based chemotherapy. The study will last up to 24 months, during which patients may receive either TEDOPI as an injection under the skin, pembrolizumab as an infusion into a vein, a combination of both treatments, or supportive care.

TEDOPI is a type of treatment called a cancer vaccine that helps the body's immune system fight cancer cells. Pembrolizumab is a medication that works by helping the immune system detect and attack cancer cells. Both treatments are designed to strengthen the body's natural defenses against cancer.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial treatment preparation

    Your eligibility for the trial has been confirmed through genetic testing for HLA-A2 phenotype

    The treatment must begin within 8 weeks after your last chemotherapy dose

    Initial health assessments include blood tests to verify adequate organ function

  2. Step 2

    Treatment assignment

    You will be randomly assigned to one of three treatment groups:

    Group 1: TEDOPI vaccine alone, given by subcutaneous injection

    Group 2: TEDOPI vaccine plus KEYTRUDA (pembrolizumab) given by intravenous infusion

    Group 3: Best supportive care (standard medical care without the study medications)

  3. Step 3

    Treatment period

    Regular medical assessments will monitor your health status

    Imaging scans will be performed to evaluate your response to treatment

    Blood tests will be conducted to monitor organ function

    Side effects will be tracked using a standardized rating system

  4. Step 4

    Follow-up period

    Your health status will continue to be monitored after treatment completion

    Regular imaging scans will check for signs of disease progression

    The study will track how long it takes before any additional cancer treatments are needed

    Long-term survival monitoring will continue until the study ends in December 2025

  5. Step 5

    Study completion

    Your participation ends if the disease progresses

    You may need to provide tumor tissue samples for biomarker testing

    The study team will document your overall health status and survival information

Who can join the trial?

17 criteria

  • Must be 18 years or older
  • Must be diagnosed with non-mucinous epithelial ovarian cancer confirmed by tissue examination
  • Must have HLA-A2 positive genetic marker (determined by a blood test)
  • Must have good physical performance (able to carry out light daily activities)
  • Must be within 8 weeks from last chemotherapy treatment
  • Must have adequate organ function including:
    • White blood cells ≥3000/mm3
    • Neutrophils ≥1500/mm3
    • Platelets ≥100,000/mm3
    • Hemoglobin ≥9 g/dL
    • Liver and kidney function within acceptable ranges
    • Must have tumor tissue available for testing
    • For women who can become pregnant:
      • Must have a negative pregnancy test within 72 hours before starting treatment
      • Must use effective birth control during treatment and for 180 days after the last dose
      • Must be willing and able to follow all study procedures
      • Must have previously received platinum-based chemotherapy with a positive response
      • Must have either previously received PARP inhibitor treatment or be ineligible for it
      • Must have either previously received bevacizumab treatment or have a medical reason preventing its use

Who cannot join the trial?

15 criteria

  • Previous allergic reactions to any cancer treatments or medications
  • Active autoimmune diseases (conditions where the body's immune system attacks its own tissues) requiring systemic treatment
  • Participation in another clinical trial within the last 30 days
  • Male patients (study is designed for female participants only)
  • Patients under 18 years of age
  • Presence of active infections requiring treatment
  • Significant heart problems or uncontrolled high blood pressure
  • History of other cancers within the past 5 years (except successfully treated non-melanoma skin cancer)
  • Serious medical conditions that could interfere with study participation
  • Pregnancy or breastfeeding
  • Unable to understand or sign informed consent
  • Known brain metastases (cancer spread to the brain)
  • Active hepatitis B or C infection
  • Current treatment with other experimental drugs
  • History of organ transplantation
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Investigated drugs

OSE2101 (TEDOPI) is a neo-epitope based vaccine designed to stimulate the immune system to fight against ovarian cancer cells. It works by teaching the body's immune system to recognize and attack specific markers found on cancer cells. Pembrolizumab is an immunotherapy medication that belongs to a group called PD-1 inhibitors. It works by helping the immune system fight cancer cells. This medication blocks certain proteins that can prevent the immune system from attacking cancer cells effectively. Best supportive care is not a medication but rather a combination of treatments and care measures aimed at improving the quality of life of cancer patients. It includes managing symptoms, providing pain relief, and addressing other health concerns that may arise during cancer treatment.

What is already known about the treatment

  • OSE2101 (TEDOPI)

    A therapeutic cancer vaccine administered through injection, designed for maintenance treatment in platinum-sensitive recurrent ovarian cancer. This investigational medication works by targeting specific neo-epitopes to stimulate the patient's immune system to recognize and fight cancer cells. The vaccine is currently being studied in clinical trials as a potential maintenance therapy for patients who have responded to platinum-based chemotherapy.

  • Pembrolizumab

    An immunotherapy medication administered through intravenous infusion that belongs to the class of PD-1 inhibitors. This established cancer treatment works by blocking the PD-1 pathway, helping the immune system recognize and attack cancer cells more effectively. It is being studied in combination with OSE2101 for maintenance treatment in ovarian cancer patients who have responded to platinum-based chemotherapy, with the goal of preventing or delaying cancer recurrence.

Investigated diseases

Platinum-sensitive recurrent ovarian cancer - A form of ovarian cancer that returns after a period of remission following initial platinum-based chemotherapy treatment. The cancer is considered platinum-sensitive when it recurs more than six months after completing the initial platinum-based therapy. This condition develops when cancer cells begin to grow again in or around the ovaries, fallopian tubes, or nearby areas in the abdomen. The disease typically follows a pattern of remission and recurrence, where periods of cancer growth alternate with periods of response to treatment. It affects the female reproductive system and can spread to other parts of the body over time.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-516096-32-00Protocol codeGINECO-OV244bEstimated enrolment180 patientsSponsorArcagy Gineco

sourced from the EU Clinical Trials Register and site verification

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