Posts

marro replaced with aute lymphoblastic lukemia

New approach to maintenance chemotherapy may improve children’s quality of life

marro replaced with aute lymphoblastic lukemia

Marrow replaced with acute lymphoblastic leukemia.

According to a study that accrued over 9,000 patients, a new approach to maintenance therapy lessens the burden of treatment and potential toxicity in children experiencing the most common cancer — B-acute lymphoblastic leukemia (B-ALL). The average-risk (AR) B-ALL subset of patients demonstrated an overall five-year survival rate of 98% despite less frequent chemotherapy pulses. Researchers from Children’s National Hospital led the 10-year study published on Jan. 7, 2021, in the Journal of Clinical Oncology.

This phase III clinical trial, which opened at over 200 centers, helped inform an alternative maintenance therapy with less frequent administration of vincristine and dexamethasone. These standard drugs are part of a multiagent treatment approach used to treat acute lymphoblastic leukemia (ALL).

“For decades, the common maintenance therapy approach [within the Children’s Oncology Group] was administering vincristine or steroid pulses every four weeks. The steroids can trigger disruptive behaviors like moodiness, sleep disturbance, food cravings, poor school attendance or physical aggression and vincristine can cause declines in fine motor and sensory-perceptual performance,” said Anne Angiolillo, M.D., lead author of the study and director of the Leukemia and Lymphoma Program at Children’s National. “We can now lessen the burden of this therapy while still maintaining excellent outcomes, which is a huge benefit to our patients and their families.”

The findings suggest that the decreased frequency of both vincristine and dexamethasone pulses every four weeks to every 12 weeks alleviates the therapy burden and reduces toxicity, potentially improving children’s quality of life.

Simultaneously, the researchers tried increasing the starting dose of oral methotrexate, a standard chemotherapy drug, given once weekly in the maintenance phase to see if it would improve the five-year disease-free survival rate, but, according to the data, it did not improve outcomes.

The world’s largest organization devoted exclusively to pediatric cancer research, the Children’s Oncology Group (COG), adopted the approach of less frequent pulses into the frontlines of their new B-ALL trials, given the study’s findings, to help decrease the therapy burden for patients and their families.

“I am very excited that the results of AALL0932 [the clinical trial] will have a major effect on the schedule of maintenance therapy for children with standard and high-risk B acute lymphoblastic leukemia in all future COG therapeutic trials,” said Dr. Angiolillo.

Dr. Angiolillo, and co-author Reuven Schore, M.D., pediatric oncologist at Children’s National were the chair and vice-chair of the clinical trial, respectively. Dr. Schore is also a member of the Leukemia and Lymphoma Program at Children’s National.

ALL can progress quickly, affect the bone marrow and the blood, including B cells and T cells. Among the children with ALL, approximately 55% comprise of the newly diagnosed National Cancer Institute (NCI) standard-risk (SR) B-ALL.

The study enrolled 9,229 patients with B-ALL between August 2010 and March 2018. Only 2,364 patients classified as average-risk received a random assignment to one of the four maintenance arms at the start of maintenance therapy. The researchers administered either vincristine/dexamethasone pulses every 12 weeks or every four weeks and a starting dose of once-weekly oral methotrexate of 20 mg/m2 or 40 mg/m2 during the maintenance phase.

“This trial establishes that with improved risk stratification utilizing blast cytogenetics and rate of response, a relatively low-intensity premaintenance backbone with a three-drug induction, and lower exposure to chemotherapy in maintenance, results in outstanding outcomes,” said Angiolillo et al.

Jeffrey Dome

Treating Wilms Tumor with vincristine and irinotecan

Jeffrey Dome

“The study was impactful because it established the activity of vincristine/irinotecan against Wilms tumor. Based on these findings, this chemotherapy combination will be applied more broadly in the treatment of Wilms tumor,” says study leader Jeffrey S. Dome, M.D, Ph.D.

Wilms tumor, the most common kidney cancer of childhood, may be classified into different subtypes based on its appearance under the microscope. The “favorable histology” subtype is associated with an excellent survival rate of approximately 90%, whereas the “diffuse anaplastic” subtype is associated with survival rates of only 55% for patients with stage II-IV disease.

The Children’s Oncology Group AREN0321 study, led by Jeffrey S. Dome, M.D, Ph.D., vice president of the Center for Cancer and Blood Disorders at Children’s National Hospital, tested the anti-tumor activity of the chemotherapy combination vincristine and irinotecan in patients with metastatic diffuse anaplastic Wilms tumor.

The study also evaluated whether a new treatment regimen containing carboplatin in addition to the currently used agents (vincristine, doxorubicin, cyclophosphamide and etoposide) would improve patient outcomes. The results, published in the March 5th issue of the Journal of Clinical Oncology, showed that the vincristine/irinotecan combination is highly active. Out of the group, 78% of patients who received this combination had an objective tumor response.

The study also demonstrated that additional chemotherapy drugs can reduce the rate of relapse, but it is likely that we have reached the limit of what children can tolerate. “Future gains will likely be made by using agents with novel mechanisms of action, such as immunotherapy and new drugs that target the molecular abnormalities of Wilms tumor cells,” says Dr. Dome.

Moreover, the additional chemotherapy agents improved cancer-free survival rates to levels unprecedented for diffuse anaplastic Wilms tumor. However, the decrease in relapse rate came at the cost of increased toxicity.

“The study was impactful because it established the activity of vincristine/irinotecan against Wilms tumor. Based on these findings, this chemotherapy combination will be applied more broadly in the treatment of Wilms tumor,” Dr. Dome added.

Chromosomes

Precision medicine for Wilms tumor patients

Chromosomes

Previously, researchers discovered that loss of heterozygosity (LOH) on chromosomes 1 and 16 is associated with a significantly increased risk of relapse of Wilms tumor.

About 650 children are diagnosed each year in the U.S. with Wilms tumor, the most common pediatric kidney cancer. The vast majority of patients respond well to the current standard of care involving a combination of surgery, chemotherapy and radiation. However, approximately 20% of patients with “favorable histology” Wilms tumor experience recurrence.

Previously, researchers discovered that loss of heterozygosity (LOH) on chromosomes 1 and 16 is associated with a significantly increased risk of relapse. A research team in the Children’s Oncology Group (COG), led by Jeffrey Dome, M.D., Ph.D., vice president of the Center for Cancer and Blood Disorders at Children’s National Hospital, sought to determine whether an augmented chemotherapy regimen can overcome the negative effect of LOH.

More than 2,500 patients with Wilms tumor were enrolled in the biology and classification study over a 7–year period. Tumor tissue was tested for LOH and patients with LOH at both chromosomes 1 and 16 received more intensive chemotherapy regimens compared to the standard approach. The results showed that the increased treatment provided a statistically significant benefit in the 4-year event-free survival, with trends toward improved overall survival. For low-stage disease (stage I-II), the four-year event-free survival was 87.3%, compared to a historical rate of 68.8%. Similarly, for advanced stage disease (stage III/IV) four-year event-free survival was 90.2%, compared with 61.3% historically.

Although the new regimens involved additional chemotherapy agents compared to the standard regimens, the short-term toxicities were expected and manageable. There is an increased risk of long-term toxicity including infertility and second malignancies, which requires careful discussion with families. Future studies will seek to mitigate these risks with newer chemotherapy agents.

By better understanding which patients might benefit from more intensive treatment regimens through precision medicine, doctors can tailor therapy according to the risk of relapse, Dr. Dome says.

“This study represents a significant milestone in the treatment of Wilms tumor because it is the first to demonstrate that patient outcome can be improved using a molecular biomarker to guide treatment,” he explains. “We have entered the age of precision medicine for Wilms tumor.”