Advances in Improving Therapeutic Outcomes
At Cambridge Healthtech Institute’s recently held Peptalk Conference (January 13-17, Palm Springs, CA), several exciting tracks provided in-depth coverage of different aspects of biopharmaceutical development. One particularly interesting session focused on novel approaches for patient selection that will help physicians pre-qualify patients based on expression of the intended molecular target for antibody therapeutics. Often this diagnosis is performed on cancer patients using immunohistochemistry on biopsies to obtain a yes/no answer on the presence or absence of the molecular target. Dr. Anna M. Wu, Professor, Department of Molecular and Medical Pharmacology at the David Geffen School of Medicine at UCLA, presented her cutting-edge alternative approach, which is based on developing in vivo molecular diagnostic tools that will provide not only the yes/no answer but also the spatial distribution, level of target throughout the body, and continued presence of the target over time. This type of approach has been attempted in the past using whole antibodies, but this method requires a lag of 5-7 days between injection and result due to the long half-life of the antibodies. To combat this problem and obtain meaningful data quickly, Dr. Wu and her colleagues have developed engineered antibody-based binding domains with shorter half-lives than whole antibodies, but with the same exquisite specificity and affinity for the target. By developing such binding domains as a cysteine-linked diabody or a minibody (two scFv fragments connected by a partial Fc region) and coupling these to PET imaging agents with appropriate half-lives, Dr. Wu can obtain same-day or next-day in vivo images of the tumor load and location in patients waiting for treatment options. The speed at which this critical information can be obtained plus the advance knowledge of the location and presence of the target will facilitate treatment of patients worldwide and, I believe, will improve therapeutic outcomes through careful adjustment and monitoring of treatment results.
Blog article by: Susan Dana Jones, Ph.D.