Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer
Posted: Monday, August 5, 2019
A study conducted by Thomas J. George, MD, FACP, of the University of Florida Health Cancer Center, Gainesville, and colleagues suggests that using veliparib as part of total neoadjuvant therapy for locally advanced rectal cancer appears to be safe and associated with high rates of chemotherapy completion. However, the results of this experimental arm of the phase II NRG-GI002 trial revealed that the addition of the PARP inhibitor did not demonstrate a significant improvement in the mean neoadjuvant rectal cancer score, a short-term clinical trial surrogate endpoint. The findings were presented at the 2019 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 3505).
The multiarm, randomized trial enrolled 178 patients with stage II or III locally advanced rectal cancer. After treatment with the combination chemotherapy regimen of neoadjuvant FOLFOX (leucovorin, fluorouracil, oxaliplatin; x 4 months), patients in the experimental arm (n = 90) received veliparib and capecitabine plus radiotherapy followed by surgery. Patients in the control arm (n = 88) received the same therapy with the omission of veliparib.
Of the 140 evaluable patients, the mean neoadjuvant rectal cancer score in the experimental and control arms were 13.7 and 12.6, respectively, with a lower number reflective of more downstaging (P = .69). More patients achieved a pathologic complete response with veliparib (21.6% vs. 33.8%), although the rate was not statistically significant (P = .14). As for safety, the most common grade 3 and 4 adverse events were diarrhea and cytopenias.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.