Andrew McGarry, Michael McDermott, Karl Kieburtz, Elisabeth A. de Blieck, Flint Beal, Karen Marder, Christopher Ross, Ira Shoulson, Peter Gilbert, William M. Mallonee, Mark Guttman, Joanne Wojcieszek, Rajeev Kumar, Mark S. LeDoux, Mary Jenkins, H. Diana Rosas, Martha Nance, Kevin Biglan, Peter Como, Richard M. Dubinsky, Kathleen M. Shannon, Padraig O'Suilleabhain, Kelvin Chou, Francis Walker, Wayne Martin, Vicki L. Wheelock, Elizabeth McCusker, Joseph Jankovic, Carlos Singer, Juan Sanchez-Ramos, Burton Scott, Oksana Suchowersky, Stewart A. Factor, Donald S. Higgins, Eric Molho, Fredy Revilla, John N. Caviness, Joseph H. Friedman, Joel S. Perlmutter, Andrew Feigin, Karen Anderson, Ramon Rodriguez, Nikolaus R. McFarland, Russell L. Margolis, Eric S. Farbman, Lynn A. Raymond, Valerie Suski, Sandra Kostyk, Amy Colcher, Lauren Seeberger, Eric Epping, Sherali Esmail, Nancy Diaz, Wai Lun Alan Fung, Alan Diamond, Samuel Frank, Philip Hanna, Neal Hermanowicz, Leon S. Dure, Merit Cudkowicz, John Adams, Mandar Jog, Christopher Hyson, Sarah Furtado, Andrew Duker, Melissa Armstrong, Christian Lachner, Hubert Fernandez, Michael S Okun, David Shprecher, Michael Cartwright, Clement Loy, Joohi Jiminez-Shahed, Bradley Robottom, Gregory Suter, Theresa Moore, Jane Forsyth, Andrea Hurt, Joann Belden, Katie Price, Diane Erickson, Breanna Nickels, Misty M Thompson, Linda Cole, Julie Megens, Emilija Makaji, Sara-Lynn Masse, Keith Malarick, Louisa Mook, Susan Maya, Alex Bender, Jessica Meyer, Puja Turakhia, Katherine Harwood, Kathryn Duderstadt, Sarah Lenarz, Judy Hamerlinck, Patricia Edern, Charlyne Hickey, Ashley Owens, Clare Gibbons, Carolyn Gray, Jean A Jaglin, Kimberly Janko, Holly Lawrence, Barbara Estes, Brigid Hayward, Allison Johnson, Amit Gode, Giselle Huet, Beverly Romero-Kersh, Kristine Wernette, Elizabeth Sullivan, Jamie Guyot, Julie Konkle, Christine O'Neill, Pamela King, Amanda Martin, John Bautista, Nicole Mans, Jane Griffith, Erica Surles, Sharon Halton, Alicia Palao, Nathalie Padron, Kolleen Elliott, Lynn Oelke, London Butterfield, Peggy Perry-Trice, Sarah Wyne, Carol Pantella, Lorelei Tainsh, Elaine Sperin, Sharon Evans, Maureen Gartner, Amy Duffy, Pamela Kristof, Lisa Niles, Steven Rainone, Angie Wernle, Ronda Clouse, Michelle Cines, Kelly Dustin, Maura Deeley, Stacy Merritt, Heather Ferreri, Alison McMurray, Alanna Sheinberg, Marsha Hughes-Gay, Kori Ladonna, Erin Chung, Jennifer Lee, Rachel Goldstein, Lindsay Esposito, Nicholas Scoglio, Matthew Grana, Carol Zimmerman, Lucia M Blasucci, William Thayer, Jennifer Hawkins, Julia Koch, Victoria Hunt, Jessica Bargoil, Ingrid Scott, Terry Tempkin, Linda Stewart, Emily Hayes, Donna Galea, Beatriz Belmar, Kylie Richardson, Christine Hunter, Ernesto Jimenez, Monica Quesada, Wendy Levy, Anita Blenke, Lisa Gauger, Joanna Stoner, Mary Lou Klimek, Barbara Sommerfeld, Mary Eglow, Katy Regan, Erin Neefus, Marie Malikowski, Teri Radam, Marci Zomok, Margaret Lannon, Rhonda Agramonte, Johanna Hartlein, Constance Nickerson, Samantha Gibson, Erin Hastings Monari, Camille Swartz, Anne Smith-Bova, Randi Jones, Catherine Wielinski, Shanthi Graham, David Gunn, Jillian McMillan

To test the hypothesis that chronic treatment of early-stage Huntington disease (HD) with high-dose coenzyme Q10 (CoQ) will slow the progressive functional decline of HD. We performed a multicenter randomized, double-blind, placebo-controlled trial. Patients with early-stage HD (n = 609) were enrolled at 48 sites in the United States, Canada, and Australia from 2008 to 2012. Patients were randomized to receive either CoQ 2,400 mg/d or matching placebo, then followed for 60 months. The primary outcome variable was the change from baseline to month 60 in Total Functional Capacity score (for patients who survived) combined with time to death (for patients who died) analyzed using a joint-rank analysis approach. An interim analysis for futility revealed a conditional power of <5% for the primary analysis, prompting premature conclusion in July 2014. No statistically significant differences were seen between treatment groups for the primary or secondary outcome measures. CoQ was generally safe and well-tolerated throughout the study. These data do not justify use of CoQ as a treatment to slow functional decline in HD. NCT00608881. This article provides Class I evidence that CoQ does not slow the progressive functional decline of patients with HD.