Jeopardy! host Alex Trebek announced Tuesday that he is resuming chemotherapy roughly a week after he returned as the show’s host.

Trebek, 79, told ABC News his doctors suggested more chemotherapy after “his numbers went sky high” and he lost 12 pounds within a week.

“I was doing so well,” the beloved game show host told ABC News. “My numbers went down to the equivalent of a normal human being who does not have pancreatic cancer. So we were all very optimistic. And they said, ‘Good, we’re gonna stop chemo, we’ll start you on immunotherapy.'”

But Trebek’s doctors quickly decided that more chemotherapy was needed for his treatment, so he decided to follow their advice.

Trebek announced in March that he had been diagnosed with stage 4 pancreatic cancer, but vowed to fight it before returning to host the game show.

Trebek had a lot of support from some Jeopardy! contestants and fans since his diagnosis. One Jeopardy! contestant, James Holzhauer, donated some of his winnings to a local charity walk raising money to fight pancreatic cancer in Trebek’s honor.

“I’ve got a couple million people out there who have expressed their good thoughts, their positive energy directed toward me and their prayers,” Trebek shared. “I told the doctors, this has to be more than just the chemo, and they agreed it could very well be an important part of this.”

He returned to Jeopardy! on September 9 to host the show’s 36th season.