Ohio State Treasurer Josh Mandel, a Republican, announced Friday that he is withdrawing from his campaign for the U.S. Senate Friday due to a family medical issue.

Mandel, in his second Senate bid, was aiming to take on Sen. Sherrod Brown, D-Ohio, in November.

"We recently learned that my wife has a health issue that will require my time, attention and presence. In other words, I need to be there," Mandel said in a note to his supporters. "Understanding and dealing with this health issue is more important to me than any political campaign. For as long as that takes, whether it is months or years, it is important that I heed my dad’s advice and be there for my wife and our kids."

"After recent discussions with our family and healthcare professionals, it has become clear to us that it’s no longer possible for me to be away from home and on the campaign trail for the time needed to run a US Senate race," Mandel said.

"Therefore, I’m writing today to let you know that I am ending my campaign for US Senate in order to be there for my wife and our three children," he said. "This was a difficult decision for us, but it’s the right one."

Mandel, 40, was the front-runner for the GOP nomination to take on Brown. His absence leaves Republicans without a top-tier candidate in the state as they look to hold onto the Senate in in the fall. Brown is one of ten Democratic incumbents running for re-election in a state Donald Trump carried in 2016.