Patients with cancer of the head and neck may benefit from treatment with a combination of chemotherapy and ONYX-015, a modified adenovirus, say researchers from the US.
ONYX-015 is a DNA virus that has been modified so that it selectively replicates in and lyses p53-deficient cancer cells, while sparing normal cells. When given with chemotherapy, ONYX-015 promotes tumour regression in patients with recurrent squamous cell cancer of the head and neck, say Dr Fadlo Khuri (division of cancer medicine, University of Texas) and colleagues.
In a phase II trial involving 30 patients, they combined injecting ONYX-015 directly into tumours with intravenous cisplatin and 5-fluorouracil and evaluated the response.
Tumours (some as large as 10cm in diameter) shrank in 25 out of 30 cases. There were eight complete and 11 partial responses. None of these tumours had progressed after a mean follow-up of five months, say the authors, and the median survival time for patients was 10.5 months.
Combination chemotherapy without ONYX-015 induces responses in up to 40 per cent of patients, with a median survival time of about six months, they say.
Severe adverse events were experienced by 46 per cent of patients and life-threatening adverse events by 14 per cent. Although 53 per cent of patients suffered injection site pain, only one discontinued treatment as a result, say Dr Khuri et al (Nature Medicine 2000;6:879).