Evaluating the risk of heart-related side effects in patients treated with immune checkpoint inhibitors

This study evaluated the risk of heart-related (HR) side effects in patients with melanoma treated with immune checkpoint inhibitors (ICI). Patients with melanoma were shown to have a higher risk of developing HR side effects when treated with ICIs.

ICIs are a type of cancer therapy used to treat a wide variety of cancers. Tumor cells try to avoid death by switching off our immune system. ICI work by blocking the off switch of the immune system. This allows the immune system to fight and kill tumor cells.

There are different types of ICIs. PD1 inhibitors (PD1i) such as pembrolizumab (Keytruda) and nivolumab (Opdivo) target the PD1 off switch. CTLA-4 inhibitors (CTLA4i) such as ipilimumab (Yervoy) block the CTLA-4 off switch.

ICIs have been shown to cause HR side effects in some patients. HR side effects include heart attack, irregular heartbeat, and infection of the lining around the heart. The risk of HR side effects in patients with melanoma is not currently known.

This study included data from different trials. 145 patients with melanoma were treated with PD1i and 212 were treated with CTLA4i. The average follow-up time for patients treated with PD1i was 326 days and for those treated with CTLAi was 315 days.

Patients treated with PD1i were 4.3 times more likely to have HR side effects compared to those without PD1i. Patients treated with CTLAi were 4.93 times more likely to have HR side effects compared to those without CTLAi. These risks were higher in the first 6 months after the first dose. The risk of HR side effects was 2.46 times higher after 6 or more months from the first PD1i dose and 3.48 times higher after 6 months from the first CTLA4i dose.

This study showed that patients with melanoma who were treated with ICIs had an increased risk of HR side effects. 

Because this study was based on previous data, the treatments were not randomized. The sample sizes were small. The follow up time was short which meant some outcomes could not be evaluated. There was no information on risk factors such as smoking or sun exposure which could have impacted HR side effects.

If you have concerns about HR side effects, please discuss this with your doctor.