At the 2019 meeting of the American Cancer Society of Clinical Oncologists (ASCO), Emily Bergsland, MD, University of California, San Francisco, reported on the results of a phase II clinical trial of pazopanib (PZ). The study evaluated how well PZ treats patients with advancing gastrointestinal neuroendocrine tumor (NETs), which were in the gut rather than the pancreas.
PZ is a drug taken orally that may stop or slow tumor growth by blocking cell processes required for the growth and expansion of the tumor cells. This clinical trial tested the efficacy of treating 171 study participants with either PZ or a placebo (inactive agent). Neither the patient nor the physician knew which treatment they received (PZ vs. placebo).
Tumor image analyses determined whether cancers had continued to grow following the treatments. Results showed that patients taking PZ went an average of 11.6 months with no cancer progression, compared to 8.5 months for those taking the placebo. This promising difference in tumor progression-free survival with PZ is “statistically significant” and not the result of chance.
“This is the first randomized study suggesting the VEGF pathway is a valid target for therapy in carcinoid. Additional work is needed, and predictive biomarker analyses are already pending,” said Emily Bergsland, MD.
Study data undergoes secondary analysis
Importantly, understanding how PZ is having its positive effects on the tumors may lead to ways to further improve its efficacy and its therapeutic potential.
NETRF recently awarded a grant to Dr. Bergsland and colleagues to conduct detailed analyses of patient blood samples and CAT scans of tumor images collected throughout this trial of PZ to better understand the tumor responses to treatment. This very novel work could contribute to the identification of biomarkers that could help identify those most likely to benefit from PZ.
What this trial means
Larger clinical studies of PZ are still needed to further understand whether the PZ treatment is beneficial and safe. Clinical trials are designed to be performed in three phases spread out over many years to establish safe and optimal treatment regimens before a drug may be included in routine patient treatment. This study represents a successful second phase of work assessing the clinical effectiveness of PZ. Learn more about the phases of clinical trials.