Horizon Pharma has agreed to pay $145m upfront to buy River Vision Development Corp, enabling GlaxoSmithKline and Lundbeck to exit.

Biopharmaceutical company Horizon Pharma agreed on Monday to acquire River Vision Development Corp, a US-based thyroid eye disease (TED) treatment developer backed by pharmaceutical firms GlaxoSmithKline and Lundbeck, for an initial $145m.

The $145m will be provided in cash up front, and the price could rise in future if River Vision meets certain regulatory and sales milestones.

River Vision is developing a monoclonal antibody called teprotumumab to treat TED, a rare autoimmune inflammatory disorder that inflames the eye muscles and…