Alex Trebek says he has restarted chemotherapy on his doctor’s orders.

Tuesday on “Good Morning America,” the “Jeopardy!” host said he “was doing so well” and his medical reports had approached normal levels after his first round of chemo for stage 4 pancreatic cancer. But he suddenly began losing weight.

“I lost about 12 pounds in a week,” Trebek said. “And my numbers went sky high, much higher than they were when I was first diagnosed. So, the doctors have decided that I have to undergo chemo again, and that’s what I’m doing.”

Trebek announced his diagnosis in March.

He told People magazine in May he was “near remission,” according to his doctors.

“It’s kind of mind-boggling,” Trebek said then. “The doctors said they hadn’t seen this kind of positive result in their memory … some of the tumors have already shrunk by more than 50 percent.”

Trebek recently returned to work and talked to “GMA” about the toll the disease, including pain, fatigue and depression.

“Early on, I was down on myself. I didn’t realize how fallible each of us is in his or her own way,” he said. “I talk to the audience sometimes and I get teary-eyed for no reason. I don’t even bother to explain it anymore. I just experience it. I know it’s a part of who I am and I just keep going.”

He said he is not afraid of death.

“The thought of passing on doesn’t frighten me,” he said. “Other things do. The effect it will have on my loved ones — yes, that bothers me. It makes me sad. But the thought of myself moving on? Hey, folks, it comes with the territory.”