Tremelimumab

Tremelimumab

Monoclonal antibody
Type	Whole antibody
Source	Template:Infobox drug/mab source
Target	CTLA-4
Identifiers
CAS Number	745013-59-6
ATC code	none
Chemical data
Formula	C65000H9974N1726O2026S52
Molar mass	146.4 kDa[[]]

Tremelimumab (formerly ticilimumab, CP-675,206) is a fully human IgG2 monoclonal antibody produced by Pfizer. It binds to the protein CTLA-4, which is expressed on the surface of activated T lymphocytes. Tremelimumab blocks the binding of the antigen-presenting cell ligands B7.1 and B7.2 to CTLA-4, resulting in inhibition of B7-CTLA-4-mediated downregulation of T-cell activation; subsequently, B7.1 or B7.2 may interact with another T-cell surface receptor protein, CD28, resulting in a B7-CD28-mediated T-cell activation unopposed by B7-CTLA-4-mediated inhibition.

Tremelimumab is thought to stimulate patients’ immune systems to attack their tumors. It has been shown to induce durable tumor responses in patients with metastatic melanoma in Phase 1 and Phase 2 clinical studies.

On April 2, 2008, Pfizer announced that it has discontinued a Phase III clinical trial for patients with advanced melanoma after the review of interim data showed that the trial would not demonstrate superiority to standard chemotherapy. Studies for other tumors are planned as of October 2009, namely for prostate cancer and bladder cancer.

Similar drugs

As of October 2009, there are two fully human anti CTLA-4 monoclonal antibodies in advanced clinical trials, tremelimumab and ipilimumab (from Medarex and Bristol-Myers Squibb).