Chemoradiotherapy produced superior survival outcomes compared with radiation and cetuximab in a cohort of patients with HPV-associated oropharyngeal cancer, according to randomized, phase 3 trial results presented at the American Society for Radiation Oncology Annual Meeting.
“We’ve now established that high-dose cisplatin chemotherapy — in combination with radiation — is the standard of care for HPV-related oral cancers,” Andy Trotti, MD, a radiation oncologist at Moffitt Cancer Center and co-lead investigator of the NRG Oncology/RTOG 1016 study, said in a press release. “Prior to this study, there were no definitive, state-of-the-art trials in this specific cancer population.”
Cetuximab (Erbitux, Eli Lilly), an EGFR inhibitor approved in the United States for treatment of head and neck cancer, plus radiotherapy has been proposed as a less-toxic alternative to cisplatin plus radiotherapy. The treatments also were evaluated in study results presented at European Society for Medical Oncology Congress.
Trotti and colleagues randomly assigned 805 patients (median age, 58 years; 90% men) with locoregionally advanced HPV-related oropharynx cancer to two cycles of cisplatin 100 mg/m2 every 3 weeks plus radiation, or weekly cetuximab and the same radiation regimen.
“We had hypothesized that survival with cetuximab might be very close, within 5%, to that of cisplatin,” Trotti said in a press release. “But that was not the case.”
The cisplatin regimen appeared associated with improved OS compared with cetuximab (HR = 1.45; 95% CI, 1.03-2.05), according to an interim data analysis. A similar outcome was reported for 5-year PFS, with an estimated 78.4% of patients in the cisplatin group reaching this endpoint, compared with 67.3% of those in the cetuximab group (HR = 1.72; 95% CI, 1.29-2.29).
The cisplatin group demonstrated lower estimated 5-year rates of local-regional failure (9.9% vs. 17.3%) and distant metastases (8.6% vs. 11.7%) and a substantially higher 5-year survival rate (84.6% vs. 77.9%) than the cetuximab group.
Rates of grade 3 to grade 5 adverse events were higher among the cisplatin group than the cetuximab group (82% vs. 77%). Researchers suggested that the novel T-score reporting system for adverse events may paint a clearer picture of the toxicity profile of the two regimens. Using this system, cisplatin demonstrated a 40% increase in incidence of high-grade events.
A variety of adverse events were associated with cisplatin, including anemia, hearing loss, nausea, vomiting, neutropenia and kidney injuries. Cetuximab yielded a higher rate of rash. Long-term dysphagia rates were 4% for cisplatin and 6% for cetuximab.
Trotti said cetuximab may still be considered a viable treatment option for patients who cannot tolerate cisplatin, including those with significant hearing loss or severe diabetes-related neuropathy. – by Rob Volansky
Trotti A, et al. Abstract LBA-4. Presented at: American Society for Radiation Oncology Annual Meeting; Oct. 21-24, 2018; San Antonio.
Disclosure: HemOnc Today could not confirm Trotti’s relevant financial disclosures at the time of reporting.