In short
Oberotatug ravtansine (also known as OBT076) is an investigational antibody-drug conjugate being studied in a Phase 1/1b clinical trial for adults with recurrent or metastatic solid tumors that express the CD205 marker. The trial, listed as NCT04064359, plans to enroll 240 participants and is currently authorised to proceed. It evaluates the safety and tolerability of the drug both alone and in combination with another immunotherapy called balstilimab.
Key points
- Oberotatug ravtansine targets CD205-positive solid tumors, including gastric, lung, endometrial, and ovarian cancers.
- The trial is in Phase 1/1b, the earliest stage of testing in humans.
- 240 participants are planned for enrollment.
- The study tests the drug alone and in combination with balstilimab, an immunotherapy.
- The main goal is to assess safety and tolerability, including dose-limiting toxicities and the maximum tolerated dose.
- The trial is currently authorised, meaning it is approved to begin or continue.
What is oberotatug ravtansine?
Oberotatug ravtansine, also known by its development code OBT076, is an investigational substance being studied for the treatment of certain solid tumors. It is an antibody-drug conjugate, a type of medicine that combines an antibody with a cancer-killing drug. The substance has not received marketing authorisation and is still in clinical development. In the trial record, it is given by intravenous use at a dose of 3 mg per kilogram of body weight.
How does oberotatug ravtansine work?
Oberotatug ravtansine is designed to target cells that carry a protein called CD205 on their surface. CD205 is found on certain tumor cells, including those from gastric cancer, non-small cell lung cancer (NSCLC), endometrial cancer, and ovarian cancer. The antibody part of the drug attaches to CD205, allowing the attached cancer-killing agent to be delivered directly to the tumor cells. This targeted approach aims to reduce damage to healthy cells compared to traditional chemotherapy.
Which conditions is it studied for?
The clinical trial for oberotatug ravtansine includes patients with CD205-positive recurrent and/or metastatic solid tumors. Specific tumor types mentioned in the trial record include:
- Gastric cancer — cancer of the stomach that has returned or spread.
- Non-small cell lung cancer (NSCLC) — the most common type of lung cancer.
- Endometrial cancer — cancer of the lining of the uterus.
- Ovarian cancer — cancer of the ovaries.
The trial notes that other tumor types may be added as more data become available.
How is oberotatug ravtansine given?
Oberotatug ravtansine is given by intravenous use, meaning it is administered directly into a vein. In the trial, the dose is 3 mg per kilogram of body weight. The trial also includes a comparison drug called Ribozar (600 mg per square meter by IV infusion) and the immunotherapy balstilimab (3 mg per kilogram intravenously), which is being tested in combination with oberotatug ravtansine.
What do the clinical trials show?
One clinical trial is registered for oberotatug ravtansine. It is a Phase 1/1b study, which is the earliest stage of testing in humans, focusing primarily on safety rather than effectiveness. The trial plans to enroll 240 participants and is currently authorised.
The primary goal of the trial is to assess safety and tolerability. Specifically, researchers are measuring dose-limiting toxicities (DLTs) — side effects severe enough to prevent increasing the dose — and the maximum tolerated dose (MTD), the highest dose that can be given without unacceptable side effects. These are evaluated using the NCI CTCAE criteria, a standard system for grading side effect severity.
The study tests oberotatug ravtansine in two ways: as a monotherapy (given alone) and in combination with balstilimab, an immunotherapy that helps the immune system fight cancer. The trial also aims to define the recommended Phase 2 dose (RP2D), which would be used in future larger studies if the drug is found to be safe enough.