Immune-checkpoint inhibitors: long-term implications of toxicity

Immune-checkpoint inhibitors (ICIs) have dramatically improved the outcomes of patients with advanced-stage solid tumours, including the potential for long-term remission in a subset. However, long-term follow-up data reveal a risk of chronic toxicities from these agents, which can have important quality-of-life implications. In this Review, the authors describe the current level of evidence of chronic toxicities of ICIs and their implications for patients The development of immune-checkpoint inhibitors (ICIs) has heralded a new era in cancer treatment, enabling the possibility of long-term survival in patients with metastatic disease, and providing new therapeutic indications in earlier-stage settings. As such, characterizing the long-term implications of receiving ICIs has grown in importance. An abundance of evidence exists describing the acute clinical toxicities of these agents, although chronic effects have not been as well catalogued. Nonetheless, emerging evidence indicates that persistent toxicities might be more common than initially suggested. While generally low-grade, these chronic sequelae can affect the endocrine, rheumatological, pulmonary, neurological and other organ systems. Fatal toxicities also comprise a diverse set of clinical manifestations and can occur in 0.4-1.2% of patients. This risk is a particularly relevant consideration in light of the possibility of long-term survival. Finally, the effects of immune-checkpoint blockade on a diverse range of immune processes, including atherosclerosis, heart failure, neuroinflammation, obesity and hypertension, have not been characterized but remain an important area of research with potential relevance to cancer survivors. In this Review, we describe the current evidence for chronic immune toxicities and the long-term implications of these effects for patients receiving ICIs.

Automated summary

Immune-checkpoint inhibitors have improved outcomes for advanced-stage solid tumour patients, but they also carry the risk of chronic toxicities that can affect patients' quality of life. While evidence on chronic toxicities is limited, emerging evidence suggests that they may be more common than previously thought. These toxicities can affect various organ systems and may even lead to fatal outcomes. Research on the effects of immune-checkpoint blockade on other immune processes is also important for cancer survivors.