The first presentation of solid tumor results Sunday from Agios Pharmaceuticals' (AGIO) cancer metabolism drug AG-120 met expectations -- a lot of arrested tumor growth in patients with advanced cancers that are difficult to treat.
In 55 patients with a variety solid tumors no longer responsive to available therapies, there was a single partial response following treatment with Agios' AG-120. Another 29 patients reported tumors which didn't grow, representing a stable disease rate of 53%.
The signal of activity for AG-120 was durable beyond six months and out to a year in some patients. The drug was well tolerated with no serious adverse events reported.
AG-120 data were presented Sunday at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics.
Dr. Howard Burris III, chief medical officer at Nashville's Sarah Cannon Research Institute and the lead investigator of the Agios study, called the AG-120 solid tumor results "encouraging" and worthy of continued study.
AG-120 is a pill designed to block a mutated, metabolic enzyme known as IDH1. Normally, cells use the enzyme to help break down nutrients and generate energy. When mutated, the IDH enzyme alters the genetic programming of cells, preventing them from maturing and allowing them to grow uncontrollably.
Agios is furthest along developing AG-120 and a sister drug AG-221 (which blocks a related enzyme IDH2) in types of blood cancers. The response rates attributed to boths drugs in blood cancer studies to date have been impressive and registration studies are underway. Patients with acute myeloid leukemia, for instance, have bone marrow crowded with undifferentiated, rapidly dividing blast cells. In these patients, AG-120 blocks the mutated IDH1 enzyme and allows the leukemic cells in the bone marrow to mature into normal blood cells.