A Fulton County judge on Wednesday cleared the way for Georgia to execute an inmate using a new three-drug combination, rejecting the condemned man’s claims that the chemical the state plans to use is untested and unsafe.

Superior Court Judge Wendy Shoob denied the challenge brought by Roy Willard Blankenship, who is set to be put to death by injection Thursday for the 1978 murder of an elderly Savannah woman. She said Blankenship cannot prove that using the drug violates the Constitution’s ban on cruel and unusual punishment.