The experimental drug PV-10, which is injected directly into melanoma tumors, may work partly by boosting the immune system. To find out, researchers are launching a clinical trial to see if patients treated with PV-10 have immune biomarkers in their tumors and blood. The study will enroll up to 15 patients.
A British Medical Journal report questions an invasive, expensive standard practice for melanoma patients in the U.S. Called sentinel node biopsy, the approach involves testing lymph nodes near tumors for cancer cells and removing nodes that test positive. The report cites a 2006 study showing that sentinel node biopsy did not increase 5-year survival rates and calls for further analysis of the practice’s effectiveness. Sentinel node biopsies are not standard in the UK.
Based on current data, researchers have developed a new treatment guide for melanomas with the most common mutations (BRAF V600). While these melanomas can be targeted with vemurafenib and dabrafenib, challenges remain. Not all tumors respond, some become resistant, and side effects can include another type of skin cancer called squamous cell carcinoma. Other treatment options include trametinib, which targets a protein called MEK, as well as immunotherapies such as high-dose interleukin 2 and ipilimumab, both of which can control tumors completely.
A JAMA Surgery study clarified when melanoma is likely to return in people determined to be cancer-free by sentinel lymph node biopsy. The researchers found that melanoma recurred in 16% of 515 such patients and that 4% of them had tumors in the lymph nodes that had been tested. Recurrence was more likely when the initial tumors were on the head or neck and were deeper (2.7 vs. 1.8 mm). Recurrence was less likely in women and in people who were younger when first diagnosed.
A JAMA Dermatology study shows the dangers of using smartphone apps to self-diagnose melanomas. The researchers compared diagnoses of 60 melanomas and 128 benign lesions by a board-certified dermatopathologist to those of four apps. Three of the apps incorrectly said that 30% or more of the melanomas were harmless. The fourth app, which sent images to board-certified dermatologists, was better, but still misdiagnosed one of the melanomas as benign. These apps are not subject to regulatory oversight.
Biotech company Genentech has added a MEK inhibitor to a phase III trial of vemurafenib, an FDA-approved BRAF inhibitor. MEK inhibitors have been shown to counteract resistance to BRAF inhibitors. The experimental MEK inhibitor is called GDC-0973, and is also known as XL-518 or RG7421. Vemurafenib (Zelboraf®) targets melanomas with BRAF V600 mutations, which are found in about half of these aggressive skin cancers. Genentech is part of the Roche Group; the two companies are conducting this combination treatment trial jointly.
New research in Nature shows that the immune system can control tumors permanently without destroying cells. The researchers treated cancers with two proteins that activate the immune system (interferon-g and tumor necrosis factor) and found that the combination kept tumors from growing by making the cells dormant. This work could ultimately lead to cancer treatments that are both effective and free of side effects, suggesting that we shift from the “war on cancer” strategy of killing tumor cells to focus instead on restoring the body’s innate ability to arrest tumor development.
Treatment with vemurafenib, a drug in the BRAF inhibitor family, results in rapid tumor shrinkage in metastatic melanoma patients with the V600E BRAF mutation. The response lasts for months, but unfortunately, tumors ultimately become resistant to the treatment. Currently, vemurafenib is given as an oral dose on a daily basis. But a new study published in Nature (doi:10.1038/nature11814) suggests that a 4-weeks-on, 2-weeks-off dosing schedule may help to stave off resistance. Continue reading…