Background: Immune checkpoint inhibitors (ICIs) have become standard-of-care at different stage disease in nonsmall cell lung cancer (NSCLC). Based on the increasing characterization of molecular aberrations and oncogenic drivers in NSCLC, it is expected that more and more patients will benefit from orally small targeted therapies in NSCLC. However, their concomitant or sequential use is associated with an increased risk of a various toxicity pattern. Methods: Relevant publications were included if they reported data on the question of toxicities associated with sequential or combined use of ICIs and small targeted therapies used in NSCLC treatment. MEDLINE, Google Scholar, and the Cochrane Library were searched for the following request, from database inception until June 2023.

Results: This review highlighted a various pattern of toxicities (i.e., interstitial lung disease, hepatitis, dermatoses) in the context of both sequential and concomitant administration of ICIs and small targeted therapies. Such toxicities seem rather a "drug-effect" than a "class-effect" and some of these toxicities are more specific of a small targeted therapy. This review highlights on the impact of treatment sequence administration and emphasis for physicians to be particularly careful whether small targeted therapy is administered within one to three months after last ICIs injection. Conclusion: Physicians have to be aware of severe toxicities in case of both concomitant or sequential ICIs/small targeted therapies administration in NSCLC. Further studies are needed to better understand the mechanisms underlying these toxicities in order to prevent them and to refine ICIs and small targeted therapy sequencing strategy.