Toripalimab
Overview
Toripalimab is a humanized IgG4 monoclonal antibody that targets the programmed death-1 (PD-1) receptor, blocking its interaction with PD-L1 and PD-L2 to restore T-cell–mediated immune responses against cancer cells. It is used in the treatment of advanced or metastatic cancers, particularly nasopharyngeal carcinoma, melanoma, and non-small cell lung cancer in specific clinical contexts. Toripalimab works as an immune checkpoint inhibitor, enabling the immune system to recognize and attack tumor cells. It is administered via intravenous infusion under specialist supervision. The drug is part of a rapidly expanding class of immunotherapies that have transformed cancer treatment by offering durable responses in certain patients. Its safety profile is primarily characterized by immune-mediated adverse effects that require careful monitoring and prompt management.
Background and Date of Approval
Toripalimab was originally developed by Shanghai Junshi Biosciences. It received its first regulatory approval in China in 2018 for unresectable or metastatic melanoma. Subsequent approvals in China expanded its use to recurrent/metastatic nasopharyngeal carcinoma and other malignancies. In the United States, Toripalimab gained FDA approval in October 2023 for recurrent or metastatic nasopharyngeal carcinoma that has progressed after platinum-based chemotherapy, marking it as the first FDA-approved treatment for this indication. The European Medicines Agency (EMA) granted approval in 2023 for similar indications. Its development has been supported by multiple pivotal clinical trials showing improved survival outcomes in heavily pretreated patients.
Uses
Toripalimab is approved for the treatment of recurrent or metastatic nasopharyngeal carcinoma following disease progression on or after platinum-based chemotherapy. It has also demonstrated efficacy in unresectable or metastatic melanoma and certain forms of non-small cell lung cancer in other regulatory jurisdictions. Investigational studies are ongoing for gastric cancer, esophageal squamous cell carcinoma, and urothelial carcinoma. Toripalimab may be used as monotherapy or in combination with chemotherapy depending on the indication and clinical setting.
Administration
Toripalimab is administered by intravenous infusion. The recommended dose for adults with nasopharyngeal carcinoma is 240 mg every 3 weeks, continued until disease progression or unacceptable toxicity. Infusion times are typically around 60 minutes, with patients monitored during and after administration. Dose modifications or treatment delays may be required for immune-mediated toxicities. No routine premedication is generally required unless the patient has a history of infusion-related reactions.
Side Effects
The most common side effects of Toripalimab include fatigue, rash, pruritus, diarrhea, nausea, decreased appetite, cough, and pyrexia. Mild to moderate immune-related adverse effects such as thyroid dysfunction or hepatitis can occur and may require temporary treatment interruption.
Warnings
Serious immune-mediated reactions may include pneumonitis, hepatitis, colitis, endocrinopathies (including adrenal insufficiency and hypophysitis), nephritis, and severe dermatologic reactions. Infusion-related reactions can occur and require immediate medical management. Toripalimab carries warnings for use in patients with pre-existing autoimmune diseases or those receiving systemic immunosuppression.
Precautions
Patients should be assessed for baseline organ function before initiating Toripalimab. Caution is required in patients with active autoimmune disease, history of organ transplantation, or chronic infections. The use of systemic corticosteroids before starting treatment may reduce efficacy, though they can be required for managing immune-related adverse events. There are no significant pharmacokinetic drug-drug interactions, but immunosuppressants may counteract the therapeutic effect.
Expert Tips
Early recognition of immune-related adverse events is critical to prevent complications. Education of patients and caregivers about potential symptoms is recommended. Regular monitoring of liver enzymes, renal function, thyroid hormones, and adrenal function is necessary. Toripalimab should be stopped permanently if severe or life-threatening immune-mediated reactions occur. Multidisciplinary collaboration with oncologists, endocrinologists, and other specialists improves patient outcomes.