Bevacizumab shows early promise for nasopharyngeal cancer
MedWire News: Bevacizumab is a promising add-on therapy in patients with locoregionally advanced nasopharyngeal carcinoma, phase II study findings indicate.
Based on the data, the Radiation Therapy Oncology Group (RTOG)-0615 trial investigators say that bevacizumab could even delay the progression of subclinical distant disease.
The RTOG-0615 trial was funded by the US National Cancer Institute and included 44 patients with stage IIB-IVB nasopharyngeal carcinoma from centers throughout the USA and Hong Kong.
The treatment regimen comprised three cycles of bevacizumab (15 mg/kg) and cisplatin (100 mg/m2), both given on days 1, 22, and 43 of radiation, with intensity-modulated radiation therapy at 70 Gy delivered on 33 consecutive weekdays.
Patients then received three cycles of bevacizumab (15 mg/kg) and cisplatin (80 mg/m2), both given on days 64, 85, and 106 after radiation, and three cycles of fluorouracil (1000 mg/m2 per day), given on days 64-67, 85-88, and 106-109 after radiation.
The primary endpoint was a composite of any treatment-related grade 4 hemorrhage or any grade 5 adverse event in the first year. Neither of these outcomes occurred during the trial.
With regard to other safety outcomes, nine patients had a treatment-related grade 1-2 hemorrhage, nine patients had one or more grade 4 blood or bone-marrow-related complication, one patient had two grade 4 infections with grade 3-4 neutrophils, one patient reported grade 4 tinnitus, one patient reported grade 4 thrombosis, one reported grade 4 radiation mucositis, and two reported grade 4 pharyngolaryngeal pain.
The median duration of follow-up was 2.5 years. At 2 years, 83.7% of patients had no locoregional progression, 90.8% had no distant metastases, 74.7% had no disease progression, and 90.9% were alive.
Writing in The Lancet Oncology, Nancy Lee (Memorial Sloan-Kettering Cancer Center, New York, USA) and fellow investigators say that the addition of bevacizumab to chemoradiation for nasopharyngeal carcinoma is "feasible" and "causes no major compromise in the delivery of standard chemoradiation therapy."
Nevertheless, questions remain about who should receive bevacizumab, they say, and viral biomarkers may prove useful in directing therapy. "The next RTOG trial for nasopharyngeal carcinoma could incorporate circulating Epstein-Barr virus DNA titers as an integral biomarker to inform the intensity of treatment," they suggest.
In an accompanying commentary, Joseph Wee (National Cancer Center, Singapore) agrees that the results of the trial are "promising" and "give new hope to patients with nasopharyngeal cancer." He also writes that the use of biomarkers has "given new possibilities to tailor treatment to patients most likely to benefit" and notes that the use of EBV DNA titers in this setting is currently being evaluated by the Hong Kong Nasopharyngeal Cancer Study Group (NCT00370890).
By Joanna Lyford