Targeted failure of the week. Post No 28. Ridaforolimus

From here.

Merck & Co. has withdrawn its marketing authorization application with the European Medicines Agency for its treatment for patients with metastatic soft tissue, or bone sarcoma, citing insufficient data.

The pharmaceutical giant said the withdrawal of the ridaforolimus application was based on the provisional view of the agency's Committee for Medicinal Products for Human Use that the data available so far and provided in the application weren't sufficient to permit licensure of ridaforolimus in the European Union for the maintenance treatment of patients with soft tissue sarcoma or primary malignant bone tumor.

And do you know what? Ridaforolimus is very-very targeted drug! Ridaforolimus (also known as AP23573 and MK-8669; formerly known as Deforolimus is an investigational targeted and small-molecule inhibitor of the protein mTOR, a protein that acts as a central regulator of protein synthesis, cell proliferation, cell cycle progression and cell survival, integrating signals from proteins, such as PI3K, AKT and PTEN known to be important to malignancy. Blocking mTOR creates a starvation-like effect in cancer cells by interfering with cell growth, division, metabolism, and angiogenesis.

The question: what targeted drug will fail next?