Which factors could predict immunotherapy outcomes in patients with advanced melanoma?

This study evaluated if there were any clinical indicators to identify which patients with advanced melanoma would benefit from immune checkpoint blocker (ICB) therapy. The data showed that blood LDH levels, the extent of disease, number of white blood cells, and immune-related side effects were all associated with better treatment outcomes in these patients.

Melanoma is an aggressive type of skin cancer. It has a high tendency to spread to other parts of the body (metastasis). The standard treatment for advanced melanoma is a combination of immunotherapy, chemotherapy, surgical removal of tumors, and radiation therapy.

Immunotherapy uses the body’s own immune system to fight cancer. Immune checkpoint blockers (ICBs) are a type of immunotherapy used to treat a wide variety of cancers. ICBs work by blocking the off switch of the immune system. Pembrolizumab (Keytruda) and nivolumab (Opdivo) are examples of ICBs that work by inhibiting (blocking) PD-1, an important protein in the immune system. This inhibition triggers the immune system to attack tumor cells and kill them.

However, there are no clinically approved biomarkers to help select patients for immunotherapy in melanoma. There are no studies investigating which patients would benefit from ICB therapy by studying easily accessible clinical indicators.

This study involved 134 patients with advanced melanoma. All patients were treated with ICB therapy alone. The average follow-up time was 13.7 months.

The average overall survival (OS) was 18.4 months and the average survival without cancer worsening was 3.4 months.

Metastases to the bone and other organs, high lactate dehydrogenase (LDH) levels before treatment, low number of white blood cells (WBCs) within 3 months were all significantly associated with poorer survival. Low thyroid function and vitiligo (loss of pigment from skin cells) as side effects within 6 months were associated with a 65% higher chance of survival.

Patients with normal LDH levels and no metastases to the bone and other organs had a longer OS (40.4 months) than those who had high baseline LDH levels and metastases to the bone and other organs (13.6 months).

Patients who developed immune side effects within 6 months had a longer OS (43.6 months) than those who did not (13.1 months).

This study concluded that LDH level, metastases to the bone and other organs, number of white blood cells, and immune side effects could predict treatment outcomes in patients with advanced melanoma who received ICB therapy.

The sample size was very small. This study looked back in time at medical records. Future studies with larger sample sizes are necessary to validate the conclusions.