Question

Which one of the following drugs is NOT an immune checkpoint inhibitor?

• A. Ipilimumab
• B. Pembrolizumab
• C. Nivolumab
• D. Trastuzumab

Hint:

- Checkpoint inhibitors: block CTLA-4, PD-1, PD-L1.
- Trastuzumab: HER2-targeted therapy, not a checkpoint inhibitor.
- Common checkpoint inhibitors: Ipilimumab, Nivolumab, Pembrolizumab, Atezolizumab.

Answer 1

The Correct Option is D

Step 1: Immune checkpoint inhibitors are drugs that block inhibitory pathways (like CTLA-4, PD-1, or PD-L1) in T-cells to enhance immune system activity against tumors.
Step 2:
- Ipilimumab targets CTLA-4 (checkpoint inhibitor).
- Pembrolizumab targets PD-1 (checkpoint inhibitor).
- Nivolumab also targets PD-1 (checkpoint inhibitor).
Step 3: Trastuzumab, on the other hand, is a monoclonal antibody against HER2/neu receptor, used in breast cancer therapy. It is not an immune checkpoint inhibitor but rather a targeted therapy drug.
Final Answer: Trastuzumab is NOT an immune checkpoint inhibitor.
\[\boxed{\text{Correct Answer: (D)}}\]