O'Malley told Geier, who has only a bachelor's degree, that he does not qualify under Maryland law to serve as a "diagnostician," the title he held on the advisory commission. The governor also cited charges brought against him this week by the Maryland Board of Physicians.
"I regret that you were not willing to withdraw from the Commission and that this action is therefore necessary," the governor said.
The Maryland Board of Physicians charged Geier this week with practicing medicine without a license while working with his father, Dr. Mark Geier. The men operate a network of clinics, two of them in Maryland, where they treat children for autism using controversial Lupron therapy.
David Geier, through his attorneys, has said he works only in an "administrative" capacity in the clinics.
Attorney J. Steven Wise, said Friday he was unaware of the governor's action until contacted by a reporter. "David Geier denies the charges of the Board of Physicians, and we look forward to a full hearing on those charges," he said.
The board set a July 6 hearing date in the case.
Lupron is a testosterone suppressor. It is approved for treating prostate cancer and ovarian fibroids, and for chemically castrating sex offenders.
The Geiers believe testosterone is elevated in autism patients and worsens the vaccine-related mercury toxicity they blame for the disorder. And they have gained a following, including parents of five children who have filed affidavits expressing support for Mark Geier and Lupron therapy.
Mainstream autism experts, however, say Lupron's "off-label" use in treating autism is based on junk science and puts children at risk.
The board suspended Mark Geier's medical license this month. The doctor has appealed the decision.
O'Malley appointed David Geier to the 26-member Commission on Autism when it was formed in 2009. Geier was one of 19 gubernatorial appointees selected from 61 applicants.
David Paulson, a spokesman for the state Department of Health and Mental Hygiene, has said the state was aware of Geier's controversial therapies at the time but recommended him to the governor in an effort to assemble a "diverse" panel.
The department asked David Geier to step down from the panel in April, after his father's medical license was suspended. He refused.
On Friday, Paulson said the governor's letter "speaks for itself. … Serving on a commission like this is a privilege and, given the recent actions of the Board of Physicians, we remain firm in our belief that David Geier should not serve on this commission."
The search for a replacement "will begin immediately," Paulson said. "Given the magnitude of this issue alone, we don't expect to have any trouble finding a qualified individual for this position."
The commission's next meeting is scheduled for July 17. They are working on an interim report to the governor and legislature that will outline the state's resources and what needs to be done to improve services.