telaglenastat

Drug Overview

Telaglenastat represents an exciting frontier in modern cancer care. It is an advanced medication that changes the way we think about treating tumors. Unlike older chemotherapy drugs that act like a sledgehammer against all fast-growing cells, telaglenastat is a highly specialized tool designed to attack a specific weakness in cancer cells.

• Generic Name: telaglenastat (also referred to in medical research as telaglenastat hydrochloride or CB-839).
• US Brand Names: None yet. Because it is still being researched, it does not have a commercial brand name.
• Drug Class: Glutaminase Inhibitor / Metabolic Inhibitor.
• Route of Administration: Oral (taken by mouth as a pill or capsule).
• FDA Approval Status: Currently investigational. It is not yet approved by the US Food and Drug Administration (FDA) for standard public use. It is actively being studied in advanced clinical trials around the world.

What Is It and How Does It Work? (Mechanism of Action)

To understand how telaglenastat works, we first need to look at how cancer cells eat and grow. All cells in the human body need energy. Healthy cells typically use blood sugar (glucose) to get the energy they need. However, cancer cells are greedy and grow completely out of control. To keep up with this rapid growth, they need massive amounts of energy and raw building materials.

Many cancer cells develop an “addiction” to a specific nutrient called glutamine. Glutamine is a common amino acid (a building block of protein) found naturally in your blood. For these tumors, glutamine is the ultimate fuel.

This is where a specific enzyme called glutaminase comes into play. Inside the cancer cell’s power plants (called mitochondria), the glutaminase enzyme acts like a factory worker. It takes the glutamine from the blood and breaks it down into a new chemical called glutamate. The cancer cell then uses this glutamate to generate massive amounts of energy and to build the structural parts needed to divide and spread.

Telaglenastat is a “Smart Drug” and a highly focused Targeted Therapy. It is scientifically designed to find and lock onto the glutaminase enzyme, completely blocking it from doing its job. When the enzyme is blocked, the cancer cell can no longer turn glutamine into usable energy. Even though the cancer cell is surrounded by glutamine, it cannot use it. Without this vital fuel source, the cancer cell effectively starves, stops multiplying, and eventually dies. Because telaglenastat specifically targets this unique cancer weakness, it aims to spare the healthy cells in your body that do not rely on glutamine to survive.

FDA Approved Clinical Indications

Because telaglenastat is an investigational medication, it does not currently have official FDA-approved indications for routine, everyday clinical practice. However, it is being extensively tested in approved clinical trials for the following conditions:

• Oncological Uses (In Clinical Trials):
  • Renal Cell Carcinoma (RCC): A common type of kidney cancer that is known to rely heavily on glutamine for its energy.
  • Non-Small Cell Lung Cancer (NSCLC): Specifically being studied in lung tumors that have certain genetic mutations (such as KEAP1, NRF2, or STK11 mutations).
  • Melanoma: An aggressive and fast-growing form of skin cancer.
  • Multiple Myeloma: A cancer of the plasma cells located inside the bone marrow.
• Non-oncological Uses:
  • None currently. This drug is strictly being investigated for its cancer-fighting abilities.

Dosage and Administration Protocols

Because this medication is taken as an oral pill, it offers a more convenient option compared to traditional intravenous (IV) chemotherapy that requires long hospital visits. The following table outlines the standard administration based on current phase clinical trials:

Dose Adjustments

Because telaglenastat is an investigational drug, there are no standard, widespread rules for dose adjustments just yet. Adjustments for patients with mild kidney (renal) or liver (hepatic) insufficiency are handled very carefully on a case-by-case basis by the clinical trial doctor. If a patient experiences severe side effects, the doctor may temporarily pause the medication or reduce the dose to 600 mg twice daily.

Clinical Efficacy and Research Results

Researchers have been gathering important data from clinical trials between 2020 and 2025 to see how well telaglenastat works in real patients.

• Kidney Cancer (RCC) Outcomes: In a 2020 trial called the ENTRATA study, doctors tested heavily pre-treated kidney cancer patients. They found that combining telaglenastat with a drug called everolimus successfully improved the time patients lived without their cancer growing (progression-free survival) compared to those taking everolimus alone. However, a larger 2021 study called the CANTATA trial evaluated telaglenastat combined with cabozantinib. In this group of 444 patients, the combination resulted in a median progression-free survival of 9.2 months, which was very similar to the 9.3 months seen in patients taking cabozantinib alone. The overall response rate (the percentage of patients whose tumors shrank) was 31.2% with the combination, compared to 27.8% without it.
• Solid Tumors and Immune Combinations: A recent 2025 study explored combining telaglenastat with an immune-boosting drug called nivolumab. Across 107 patients with various advanced solid tumors, the overall response rate was 8.4%. The results were particularly encouraging for a specific group of kidney cancer patients who had never received immune treatments before, showing a much higher tumor response rate of 24%.

Safety Profile and Side Effects

Overall, telaglenastat is generally well-tolerated. Because it targets tumor metabolism rather than killing all fast-growing cells, it typically avoids the extreme hair loss and severe immune suppression caused by standard chemotherapy.

Black Box Warning: There is no FDA Black Box Warning for this investigational agent at this time.

Common Side Effects (>10%)

• Fatigue: Mild to moderate tiredness affects roughly 23% to 42% of patients.
• Nausea: An upset stomach is reported in about 19% to 39% of patients.
• Photophobia: A unique side effect where the eyes become overly sensitive to bright lights, seen in about 32% of users.
• Diarrhea: Loose or frequent bowel movements.
• Decreased Appetite: A general lack of desire to eat.

Serious Adverse Events

• Blood Cell Drops: In rare cases, especially when combined with other strong cancer drugs, patients may experience a drop in red blood cells (anemia) or blood-clotting cells (thrombocytopenia).
• Liver Stress: Some patients experience elevated liver enzymes (such as ALT or AST), which indicates that the liver is working too hard to process the medication.

Management Strategies

• If nausea occurs, doctors can prescribe safe anti-nausea medications (antiemetics) to take before swallowing the telaglenastat pills.
• For fatigue, patients are advised to get plenty of rest, stay well-hydrated, and engage in light daily walks to keep their energy levels steady.
• If routine blood tests show elevated liver enzymes, the clinical trial doctor will likely pause the telaglenastat treatment to let the liver rest, and then restart it safely at a lower dose.

Connection to Stem Cell and Regenerative Medicine

Telaglenastat has a brilliant connection to Immunotherapy, which is a type of regenerative biological treatment that uses the patient’s own immune system to fight disease. Because tumors consume massive amounts of glutamine, they actually steal this vital nutrient from the surrounding tissue. This completely starves the body’s natural cancer-fighting immune cells (known as T-cells). Starved T-cells become too weak and exhausted to attack the tumor.

When telaglenastat blocks the tumor from eating all the glutamine, the nutrient remains in the bloodstream. The body’s immune T-cells can then use this leftover glutamine to “wake up” and multiply. This metabolic shift makes treatments like Adoptive T-Cell Therapy (where immune cells are grown in a lab and given back to the patient) and standard immune checkpoint inhibitors significantly more powerful.

Patient Management and Practical Recommendations

To ensure safety and optimal outcomes, patients in telaglenastat trials must follow strict protocols.

Pre-treatment Tests
Genomic profiling (e.g., KEAP1/NRF2), baseline CT/MRI scans, and full blood panels to assess organ function.

During Treatment
Regular monitoring visits are required. Effective contraception is mandatory due to unknown fetal risks.

Do’s & Don’ts
Take doses on schedule, stay hydrated, and report severe symptoms immediately. Avoid double-dosing or starting new medications without oncologist approval.

Legal Disclaimer

The information provided in this guide is for educational and informational purposes only and does not constitute medical advice. Telaglenastat is an investigational diagnostic and therapeutic agent and is not currently approved by the US Food and Drug Administration (FDA) for general clinical use. It is available only through participation in approved clinical trials. Always consult with a qualified healthcare professional or your treating oncologist regarding diagnosis, treatment options, and your personal eligibility for clinical trials.