Researchers have constructed baseline event-free survival outcomes as a comparison for future pediatric osteosarcoma trials, so that time to disease progression can be used as an end point, according to a paper recently published in the Journal of Clinical Oncology.1
Because of the calcified tumor matrix, radiographic response as the primary end point may limit optimal detection of treatment response. Researchers determined whether time to progression could be substituted for radiographic response in subsequent phase 2 trials.
Investigators retrospectively analyzed outcome data from patients with recurrent/refractory osteosarcoma enrolled in 1 of 7 phase 2 trials conducted by the Children’s Oncology Group, the Pediatric Oncology Group, or the Children’s Cancer Group. They also evaluated data from 42 patients enrolled in the phase 2 AOST0221 study to determine the historical disease control rate for patients with fully resected osteosarcoma.
In each of the 7 trials, the drugs tested were deemed inactive due to low radiographic response rates. Among the 96 patients with measurable disease, researchers found that event-free survival at 4 months was 12% (95% CI, 6-19), with no significant difference in event-free survival across trials.
For the 42 evaluable patients who received inhaled granulocyte-macrophage colony-stimulating factor with first pulmonary recurrence as part of the AOST0221 trial, the 12-month event-event survival was 20% (95% CI, 10-34).
1. Lagmay JP, Krailo MD, Dang H, et al. Outcome of patients with recurrent osteosarcoma enrolled in seven phase II trials through Children’s Cancer Group, Pediatric Oncology Group, and Children’s Oncology Group: Learning from the past to move forward. J Clin Oncol. 2016 Jul 11. doi: 10.1200/JCO.2015.65.5381 [Epub ahead of print]