Do immune related side effects from immunotherapy affect survival of patients with advanced melanoma?

This study was carried out to assess whether immune related side effects (IRSE) of anti-PD1 therapy affect the survival of patients with advanced melanoma. The authors of this study found that patients who had IRSE had better outcomes.

Advanced melanoma is a form of skin cancer that comes from a cell called a melanocyte (pigment producing skin cell). It commonly metastasizes (spreads) to other parts of the body. The standard treatment for advanced melanoma is a combination of immunotherapy, chemotherapy, surgical removal of tumors, and radiation therapy. 

Anti-PD1 therapy is a form of immunotherapy. It blocks the PD1 protein. This protein is found on the surface of some cancer cells and results in decreasing the activity of the immune system in finding and killing cancer cells. By blocking this protein, anti-PD1 therapy alows the immune system to recognize and kill cancer cells.

By turning the immune system on, anti-PD1 drugs such as pembrolizumab (Keytruda) and nivolumab (Opdivo) can cause IRSEs. Previous studies have shown that patients with melanoma who have IRSEs from immunotherapy respond better to treatments. However, whether IRSEs impact survival in these patients remains under investigation.

There were 186 patients with advanced melanoma in this study. Patientsd were treated with either pembrolizumab or nivolumab alone. The follow-up for this study was on average 24 months. IRSEs were registered and were compared with patients' outcomes.

Overall, IRSEs occurred in 47% of patients. The most common IRSEs were skin rash (16%) or a discoloring of the skin (9%). The majority of these IRSEs were experienced early during the treatment phase. The occurrence of IRSEs decreased with longer treatment duration. 

The average survival was  significantly longer in patients who experienced any IRSE (39 months) compared with those who did not have IRSE (23 months). Another factor associated with poorer survival in patients was an elevated blood level of lactate dehydrogenase (LDH). 

The authors concluded that IRSEs from anti-PD1 therapy was associated with improved survival in patients with advanced melanoma. 

This study was based on medical records. The IRSEs were reported by treating doctors. There may have been a lower number of IRSEs reported. This may have affected the results.