Panitumumab in Recurrent or Metastatic p16 HPV-Negative Head and Neck Cancer

The Lancet Oncology findings in metastatic head and neck cancer suggest panitumumab (Vectibix) offers a promising new option.

These cancers form in or around the mouth, nose and throat. Smoking, alcohol and high-risk HPV infection are key risks. Symptoms include neck swelling, voice changes, lip growths, blood in saliva or sputum lasting several days, swallowing problems, nonhealing lip, face or ear sores and persistent ear pain.

Head and neck cancer is one of the cancers that can be cured when diagnosed early. The appearance of early symptoms allows early diagnosis and the delivery of effective treatment.

However, treatment options are limited for patients with head and neck cancer that has spread to other parts of the body or recurred after initial treatment. Researchers continue studying new and more effective methods to expand these limited treatment options.

Panitumumab (Vectibix®) prevents cancer cells from surviving and growing by targeting a protein on their surface known as the epidermal growth factor receptor (EGFR). Previous preliminary research findings have suggested that panitumumab may provide benefits in the treatment of recurrent metastatic head and neck cancer.

Researchers planned a study to evaluate the effectiveness and safety of adding panitumumab to the cisplatin/fluorouracil (5-FU) combination used to treat patients with metastatic or recurrent head and neck cancer.

Across 26 countries and 126 sites, 657 metastatic or locally recurrent patients unsuitable for surgery or radiation participated. Some received cisplatin/5-FU plus panitumumab, while others received cisplatin/5-FU alone. Special diagnostic methods also examined HPV's laryngeal-cancer-associated p16 component. Primary endpoint was survival.

In conclusion, adding panitumumab (Vectibix®) to the cisplatin/5-FU combination in patients with metastatic or recurrent head and neck cancer extended average overall survival to 11.1 months, compared with 9 months in the control group. This difference was not found to be significant. The duration of disease control with treatment was extended to 5.8 months in patients receiving panitumumab and was determined to be 4.6 months in the control group. Tumor blocks from %67 of patients (443 patients) were suitable for further testing and were tested for p16 HPV. Of these patients, %22 were p16 HPV-positive. In addition, among p16 HPV-negative patients with metastatic or recurrent head and neck cancer given panitumumab, average overall survival increased substantially to 11.7 months, compared with 8.6 months in the control group. In P16 HPV-negative patients, panitumumab significantly prolonged survival. Among P16 HPV-positive patients with metastatic or recurrent head and neck cancer, no notable difference in average overall survival was found between those given panitumumab and the control group.

The most common side effects in patients with recurrent or metastatic head and neck cancer given panitumumab were skin or eye toxicity (reactions related to drug use), low blood potassium and magnesium levels, diarrhea, and dehydration. The risk of treatment-related death was %4 in patients using panitumumab and %2 in the control group.

Among patients with HPV p16-negative recurrent or metastatic head and neck cancer, adding panitumumab to cisplatin/5-FU treatment was found to prolong survival with an acceptable level of toxicity.

Researchers believe that p16 human papillomavirus (HPV) may be a marker that predicts the course of the disease in these patients.

Head and neck cancers are among the cancers that have been neglected for years in terms of treatment options. Discovering drugs that offer benefits in this field and seeing benefits in clinical studies makes us extremely happy. Moreover, the benefit of panitumumab, a drug similar to cetuximab among targeted drugs acting through a comparable mechanism, is extremely important even if it applies only to a particular patient group.

More studies are needed; findings are insufficient to change routine practice yet, but promising.

Dear readers, remember that successful treatment of head and neck cancer depends on early diagnosis. Knowing and recognizing certain warning signs can save lives in head and neck cancer. If you think you have possible symptoms, you should inform your doctor as soon as possible. Preventing delays between the appearance of symptoms, diagnosis, and subsequent initiation of treatment allows early diagnosis and effective treatment to increase the chance of complete recovery. In addition, avoiding all harmful habits that increase cancer risk, especially smoking and alcohol, is the right choice for a healthy life.