Study finds that DFMO increases survival for children with high risk neuroblastoma

No one wants to deliver the news to parents that their four-year-old has neuroblastoma, a type of cancer. Yet that tends to be the most common age of diagnosis, said Jacqueline Kraveka, D.O., a pediatric hematologist-oncologist at the Children’s Hospital at the Medical University of South Carolina (MUSC).

It’s one reason Kraveka, who also is an MUSC Hollings Cancer Center researcher, was thrilled by a paper published September 27 in Scientific Reports that shows the positive results of a phase II clinical trial using the oral medication DFMO (eflornithine) to prevent relapse in children with High Risk Neuroblastoma (HRNB).

Neuroblastoma is a form of cancer that develops from immature nerve cells found in several areas of the body. It occurs most often in infants and young children, usually under the age of five. The disease remains a challenge in pediatric oncology and current treatments include therapies that have significant long-term side effects for patients.

HRNB accounts for 15 percent of all childhood cancer deaths, in part, because nearly half of all patients who reach remission will relapse.

Giselle Sholler, M.D., director of pediatric oncology research at Spectrum Health Helen DeVos Children’s Hospital and principal investigator of the study, said the results are promising and have changed the outlook for our patients with high risk neuroblastoma.

“By using DFMO for two years after finishing conventional therapy, we’ve seen an overall two-year survival rate for these children of 97 percent. This is a large increase in survival,” Sholler added. “Previously it was believed that children with refractory and relapsed neuroblastoma were considered incurable. This study shows more than 50 percent of patients remaining in remission up to four years.”

Kraveka, a principal investigator at MUSC, said survival for children with high risk neuroblastoma remains a challenge. “These results are groundbreaking and very exciting for oncologists and their patient families. I am thrilled to have our confirmatory study open at so many sites across the U.S. and Canada, enabling children to receive this treatment close to home,” she said.

There is an average of 6-10 children with high risk neuroblastoma diagnosed every year in South Carolina. “It is great to offer these innovative therapies for the children of South Carolina. Many of these children would be unable to travel out of state for this treatment.”

The Beat Childhood Cancer Research Consortium’s trial studied the use of difluoromethylornithine (DFMO) as a single agent for enrolled patients at 22 children’s hospitals from June 2012 to February 2016. The children received two years of oral DFMO twice daily and were evaluated for outcomes of event free survival (EFS*) and overall survival (OS). The study used targeted oral therapy of an ODC inhibitor (DFMO), as a maintenance therapy to prevent relapse in HRNB patients after standard therapy. DFMO works by targeting specific cancer stem cell pathways and “turning off” the cells, thereby preventing the cancer from growing back.

There were two arms in this study, the first designed for patients who had completed standard therapy, and the second for children who were able to achieve remission after having previously relapsed. Both of these patient populations are at very high risk of relapsing after completing treatment and therefore can be very good candidates for using a maintenance therapy with the goal of preventing relapse.

With a median follow up of 3.5 years, the first arm of the study had 100 eligible patients. The results show that two-year EFS was 84 percent and two-year OS was 97 percent.

With a median follow up of 3.7 years, the study enrolled 39 previously relapsed patients and the results reported in the journal showed that two-year EFS was 54 percent and two-year OS was 84 percent for these children who had previously relapsed.

“While these EFS and OS figures at two years are remarkable, the really exciting part of these results is that EFS and OS are stable out to four years,” said Patrick Lacey of Beat NB Cancer Foundation, one of the childhood cancer parent-led foundations that funded this clinical trial. “Not only did this oral drug lead to a prolonged and stable remission for the children in this study, but the drug was extremely safe and well tolerated in this patient population.”

Sholler added, “While many children have been able to attain remission with the current, albeit harsh, upfront therapies, these remissions are not historically durable. The current five-year survival curves have not changed significantly in the past two decades despite recent increases in two-year survival as a result of intensified therapies and new multimodal therapies.”

Hospitals other than MUSC and Spectrum Health Helen DeVos Children's Hospital participating in this study included, Cardinal Glennon Children’s Medical Center, Arkansas Children’s Hospital, Arnold Palmer Hospital for Children, Penn State Milton S. Hershey Medical Center and Children’s Hospital, Rady Children’s Hospital San Diego, Kapiolani Medical Center for Women and Children, Levine Children’s Hospital, Connecticut Children’s Medical Center, Phoenix Children’s Hospital and Children’s Hospitals and Clinics of Minnesota.

Beat Childhood Cancer’s DFMO trials are currently open at 40 hospitals in the U.S. and three hospitals in Canada.

(*Event-free survival (EFS): No progression of illness or other complications)