On 24 July, 2015 the US Food and Drug Administration (FDA) approved sonidegib (Odomzo) to treat patients with locally advanced basal cell carcinoma that has recurred following surgery or radiation therapy, or who are not candidates for surgery or radiation therapy.
Skin cancer is the most common cancer and basal cell carcinoma accounts for approximately 80% of non-melanoma skin cancers. Basal cell carcinoma starts in epidermis and usually develops in areas that have been regularly exposed to the sun and other forms of ultraviolet radiation. According to the US National Cancer Institute, the number of new cases of non-melanoma skin cancer appears to be increasing every year.
Odomzo is a pill taken once a day. It works by inhibiting an Hedgehog signalling pathway, which is active in basal cell cancers. By suppressing this pathway, Odomzo may stop or reduce the growth of cancerous lesions.
In 2012, another Hedgehog pathway’s inhibitor, vismodegib (Erivedge) was the first drug approved to treat locally advanced and metastatic basal cell carcinoma.
Odomzo carries a Boxed Warning alerting healthcare professionals that Odomzo may cause death or severe birth defects in a developing foetus when administered to a pregnant woman. Pregnancy status should be verified prior to the start of Odomzo treatment, and both male and female patients should be warned about these risks and advised to use effective contraception.
The efficacy of Odomzo was established in a multi-center, double-blind clinical trial, in which 66 patients with locally advanced basal cell carcinoma were randomly assigned to receive Odomzo 200 mg daily and 128 patients were assigned to receive Odomzo 800 mg daily.
The study’s primary endpoint was objective response rate. Results showed that 58% of patients treated with Odomzo 200 mg had their tumours shrink or disappear. This effect lasted at least 1.9 to 18.6 months, and approximately half of the responding patients’ tumour shrinkage lasted six months or longer. Response rates were similar in patients who received Odomzo 800 mg daily, however side effects were more common at this dose.
At a dose of 200 mg daily, the most common side effects of Odomzo were muscle spasms, alopecia, dysgeusia, fatigue, nausea, musculoskeletal pain, diarrhoea, decreased weight, decreased appetite, myalgia, abdominal pain, headache, pain, vomiting and pruritus. Odomzo also has the potential to cause serious musculoskeletal-related side effects, including increased serum creatine kinase levels (with rare reports of rhabdomyolysis), muscle spasms, and myalgia.
Odomzo is marketed by East Hanover, New Jersey-based Novartis Pharmaceuticals Corporation. Erivedge is marketed by Genentech in San Francisco, California.