72% complete response in Ph II leukemia study of Amgen's blinatumomab

USA-based Amgen (Nasdaq: AMGN), the world's largest independent biotech firm, has announced updated results from a Phase II study that showed treatment with blinatumomab (AMG 103) helped achieve a high-rate of complete response (CR) in 72% of adult patients with relapsed or refractory B-precursor acute lymphoblastic leukemia (ALL) treated in the study.

Blinatumomab is the first of a new class of agents called bi-specific T cell engagers (BiTE) antibodies, designed to harness the body's cell-destroying T cells to kill cancer cells. It is the lead compound of Micromet (Nasdaq: MITI), which entered a collaboration with Amgen last year worth a potential $990 million to Micromet for BiTE antibodies against three undisclosed solid tumor targets (The Pharma Letter July 12, 2011). However, Amgen decided to acquire Micromet, a $1.16 billion transaction (TPL January 27) which completed in March.

Blinatumomab targets cells expressing CD19, a protein found on the surface of B-cell derived leukemias and lymphomas, such as ALL. Full results of the study will be presented during an oral abstract session at the 48th Annual Meeting of the American Society of Clinical Oncology (ASCO) on June 4.