Theratope vaccine (STn-KLH)

Area of Science:

• Oncology
• Immunology
• Carbohydrate Chemistry

Background:

• Active specific immunotherapy (ASI) shows promise for cancer treatment by stimulating immune responses against tumor-associated antigens.
• Sialyl-Tn (STn), a carbohydrate antigen linked to MUC1 mucin, is associated with aggressive human cancers, making it a target for ASI.
• The Theratope vaccine incorporates a synthetic STn antigen to elicit an immune response against cancer cells.

Purpose of the Study:

• To outline the clinical trials conducted with the Theratope vaccine.
• To evaluate the safety and efficacy of the Theratope vaccine in patients with metastatic breast cancer.

Main Methods:

• Clinical trials were conducted using the Theratope vaccine, which contains a synthetic STn antigen.
• Patients received the vaccine in various settings, including non-transplant and high-dose autologous transplant settings.
• A definitive Phase III trial compared Theratope vaccine with non-specific immune stimulants (Keyhole Limpet Hemocyanin and Detox-B) in metastatic breast cancer patients.

Main Results:

• Theratope vaccine was generally well-tolerated with minimal toxicity, primarily injection site reactions (duration and erythema).
• A trend was observed indicating that Theratope vaccine decreased the risk of relapse and prolonged time to relapse in both non-transplant and transplant settings.
• The Phase III trial enrolled over 1000 women with distant metastatic breast cancer.

Conclusions:

• Theratope vaccine demonstrates a favorable safety profile with minimal toxicity.
• The Theratope vaccine shows a potential to impact overall survival by reducing relapse risk and prolonging time to relapse in metastatic breast cancer.
• Further evaluation in Phase III trials is crucial for confirming the therapeutic benefits of STn-based ASI in cancer treatment.