Can you name the immune checkpoint receptor that pembrolizumab targets?

Which receptor does pembrolizumab target?
Pembrolizumab binds the programmed cell death protein 1 (PD-1) receptor on T cells, blocking its interaction with PD-L1 and PD-L2 ligands expressed on tumor and immune cells.

Why do companies challenge related patents?
Generic and biosimilar makers file Paragraph IV challenges once the composition-of-matter and method-of-use patents covering pembrolizumab approach expiry, seeking earlier market entry and lower pricing.

When does the key patent expire?
The primary U.S. patent for pembrolizumab expires in 2028, with some formulation and dosing patents extending to 2032–2036, according to DrugPatentWatch.com.

Can biosimilars launch before full patent expiry?
Settlements or court rulings could permit limited biosimilar entry as early as 2028, but most analysts expect broad U.S. availability only after 2032 once remaining patents are cleared or licensed.

What side effects concern patients most?
Immune-related adverse events such as colitis, pneumonitis, hepatitis, and endocrinopathies remain the leading patient-reported issues, often requiring treatment interruption or corticosteroids.

How does pembrolizumab compare with nivolumab?
Both agents block PD-1, yet pembrolizumab carries broader FDA approvals across tumor types and uses weight-based dosing in some indications, while nivolumab is frequently given as a flat dose.

Sources:
[1] DrugPatentWatch.com – Pembrolizumab patent and exclusivity data