Xemilofiban/orbofiban: insight into drug development.

Area of Science:

• Cardiology
• Pharmacology
• Thrombosis

Background:

• Intravenous glycoprotein IIb/IIIa receptor antagonists show success in acute settings like unstable angina and percutaneous interventions.
• The potential for chronic platelet aggregation inhibition led to the development of oral agents for longer-term use.

Purpose of the Study:

• To review and evaluate the development programs of oral glycoprotein IIb/IIIa receptor antagonists, specifically xemilofiban and orbofiban.
• To understand the selection process for therapeutic targets based on pharmacokinetic and pharmacodynamic profiles.
• To analyze pivotal Phase III trial results and identify reasons for the lack of demonstrated benefit.

Main Methods:

• Review of development programs for xemilofiban and orbofiban.
• Analysis of pharmacokinetic and pharmacodynamic data.
• Evaluation of pivotal Phase III clinical trial outcomes.

Main Results:

• The development of oral glycoprotein IIb/IIIa antagonists was explored for chronic administration in cardiovascular conditions.
• Pivotal Phase III trials for xemilofiban and orbofiban were conducted to assess efficacy and safety.
• These agents did not show significant clinical benefit in the trials reviewed.

Conclusions:

• Despite a strong theoretical basis and promising initial research, oral glycoprotein IIb/IIIa receptor antagonists did not translate into significant clinical benefits in Phase III trials.
• Further investigation into the complex pharmacokinetic and pharmacodynamic responses was insufficient to overcome the lack of efficacy.
• The development of these specific agents for chronic use in unstable angina was ultimately unsuccessful.