Melanoma research summary from ASCO
7 July 2016
The last 10 years has witnessed a surge in successful therapies for the treatment of advanced melanoma. Data recently presented at the 2016 ASCO Annual Meeting continued to showcase advances, in particular revealing some impressive long-term survival data from clinical trials.
A decade ago, only a quarter of advanced melanoma patients would survive to one year. Today, research is giving greater hope to patients, with one trial (Keynote-001) reporting that 4 out of 10 patients were still alive after three years with the immunotherapy drug pembrolizumab (Keytruda), and another trial (COMBI-d) reporting near identical results with the targeted drugs dabrafenib and trametinib (Tafinalar and Mekinist).
However, although patients are living longer on treatment, melanoma can become resistant to therapy. In patients who initially respond to pembrolizumab, tumours starts growing again in one-third of patients after 3 years treatment, a problem that happens with targeted therapy also. Much more work needs to be done to explore how and why this happens.
On the brighter side, for patients who have a complete response to therapy (where all the melanoma disappears on scans), who then stop pembrolizumab treatment, disease returned in only a small percentage (3%) after 10 months. These results suggest that patients who have the best response to treatment can consider having a break off therapy, with high likelihood that melanoma will remain in remission.
While most clinical trials have included patients with melanoma that began on the skin, several studies also investigated the use of anti-PD-1 therapies in patients with other types of melanoma, specifically from uveal (from the eye), acral (from the soles of the feet and palm of the hand) and mucosal (from inside the body e.g. sinuses, gut, vagina) sites. Results revealed that unfortunately, responses were low in patients with uveal melanoma, but some success was seen in acral and mucosal melanoma subtypes.
In summary, research that was presented at ASCO 2016 indicates that leveraging the immune system appears to be the way forward to treating advanced melanoma. However, there are still many challenges that we need to investigate, such as overcoming resistance, finding out which patients are likely to respond to which therapies and understanding which combinations and order of therapies works best.