Bay Area boy celebrates year in remission after rare blood cancer diagnosis

A Bay Area 3-year-old who was diagnosed with a rare blood cancer as an infant is now celebrating a year in remission after undergoing treatment through a clinical trial at UC San Francisco.

Lennox Pieraldi was just 8 months old when he was diagnosed.

"It just started with a little bump on his mouth, in his gums," his father, Matthew Pieraldi, told CBS News Bay Area.

Doctors eventually discovered three tumors in Lennox's head — one in his gums, one behind his eye and another near the base of his brain.

"That was scary for us," Matthew said.

Lennox was diagnosed with Langerhans cell histiocytosis, or LCH, a rare condition that affects certain immune cells and can cause tumors or lesions in different parts of the body.

His mother, Hanh Ly, said Lennox remained a source of hope for his family and the people around him throughout treatment.

"He has been such a ray of sunshine through this. He's given us hope. He's given the doctors and kids at the chemo ward hope," Ly said. "We had some tough times, and we stuck together."

Lennox underwent chemotherapy and steroid treatments for about a year, but the treatments eventually stopped working.

That's when his family turned to UCSF, where Lennox enrolled in a 12-month clinical trial. He took a medication called tovorafenib once a week.

"Almost every case of LCH is driven by one single mutation," Dr. Russell Valle, a UCSF assistant clinical professor and pediatric oncologist, told CBS News Bay Area. "And what these newer drugs and what this drug in this clinical trial is doing is targeting that very specific mutation to kill the LCH cells and just the LCH cells."

Valle said clinical trials like this are initially used for patients whose disease has returned or has not responded to previous treatment. Researchers are now gathering enough data to explore using these medications earlier in treatment to help prevent relapses.

"In the upcoming months, we've gotten enough data that we're going to start to use these drugs in the upfront setting before patients relapse to try to prevent relapse as much as possible," Valle said.

Lennox's nurse practitioner, Erica Southworth, said his story is inspiring.

"When we find these breakthroughs in helping these kids, our goal is to get families and kids through their treatments intact. Kids get to be kids. They still get to have fun," Southworth said.

She said treatments that reduce side effects and limit the number of clinic visits can give children more opportunities to enjoy everyday activities.

After completing treatment, Lennox has now been in remission for a year.

"We're excited to say Lennox just started preschool. He went on his first playdate," his father said.

The family was honored during Blood Cancer United's annual Light the Night event, and they hope to help raise awareness and support for people affected by blood cancers.

Matthew said supporting the organization's mission means helping families, funding patient support and advocating for health care policies.

Ly said Lennox's journey has shown their family the importance of facing challenges together.

"He makes us know that together we can get through anything, and together we're going to fight this and win," she said.