In RCC tumors, activated mTOR further exacerbates accumulation of HIF-1a by increasing synthesis of this transcription factor and its angiogenic target gene products.

[11] In an international three-arm phase III study with 626 previously untreated, poor-prognosis patients, temsirolimus, interferon-α and the combination of both agents was compared.

Further studies are needed to determine the role of temsirolimus in the first-line treatment of patients with a more favorable prognosis, how it can be combined with other targeted agents and as sequential therapy with sunitinib or sorafenib.

In patients with RCC, the adverse effect profile of temsirolimus is primarily metabolic in nature, with minimal impact on QoL compared with the commonly seen side-effects with oral multikinase inhibitors.

[15] The risk of interstitial lung disease is increased with temsirolimus doses greater than 25 mg, symptoms of which may include dry cough, fever, eosinophilia, chest pain, and dyspnea on exertion.