Impact of p16 Status on Cetuximab + Radiotherapy in Locally Advanced SCCHN
This was a retrospective analysis of the phase 3 IMCL-9815 trial assessing the role of HPV-p16 status in patients with locally advanced SCCHN receiving radiation therapy (RT) plus cetuximab (cetux) or RT alone (Rosenthal DI, et al. ASCO 2014. Abstract 6001). The 424 patients in this study had been randomized to receive RT + cetux or RT alone, and in this analysis of the data, HPV-p16INK4A status was determined in 312 of the patients. In both p16-positive and p16-negative patients, the addition of cetux to RT improved locoregional control (LRC), overall survival (OS), and progression-free survival, although the only statistically significant difference in the intent-to-treat population was in LRC among p16-positive patients favoring RT + cetux (P = .023). In the oropharyngeal subpopulation, adding cetux to RT significantly improved LRC and OS in the p16-positive patients (P = .20 and P = .030, respectively). However, interaction tests for LRC, OS, and disease-free survival did not demonstrate a significant interaction between p16 status and treatment effect. This analysis showed that patients with locally advanced SCCHN benefit more from treatment with cetux + RT than RT alone regardless of HPV-p16 status.