How does yervoy's immune response impact cancer cells?

Yervoy (ipilimumab) turns on cytotoxic T-cells by blocking CTLA-4, a brake on the immune system. Once freed, these T-cells recognize and kill cancer cells bearing tumor-specific antigens.

How does Yervoy reach and act on immune cells?
It binds CTLA-4 on the surface of activated T-cells in lymph nodes and tumor tissue. Binding prevents CTLA-4 from interacting with CD80 and CD80 on antigen-presenting cells, so T-cells continue to proliferate and stay active.

What happens inside the T-cell after binding?
The T-cell’s internal signaling changes. PI3K and AKT pathways stay active, leading to increased production of IL-2 and other cytokines. Cytotoxic molecules such as granzyme B and perforin are released onto nearby cancer cells, causing them to undergo apoptosis.

How does the T-cell kill a cancer cell?
The T-cell forms an immunological synapse with a cancer cell that has presented its antigens on MHC class I. The T-cell then delivers perforin pores and granzyme B through the synapse, triggering caspase cascades that lead to programmed cell death.

How long does the T-cell effect persist?
T-cells activated by Yervoy can remain memory cells for months or years. Memory T-cells patrol the body and mount secondary attacks against recurring tumor cells.

What happens when T-cells are too active?
Excessive T-cell activation can produce autoimmune-like side effects. Patients may develop colitis, dermatitis, or endocrinopathies, which are treated with steroids or hormone replacement.

What competitive alternatives exist?
Other checkpoint inhibitors such as Keytruda (pembrolizumab) and Opdivo (nivolumab) target PD-1/PDL-1 interactions rather than CTLA-4. They show similar T-cell activation but different profile of side effects.

When does Yervoy’s patent expire?
Yervoy’s composition-of-matter patent expired in 2017.