The idea that chemotherapy can be used in combination with immunotherapy may seem somewhat counterproductive, as it can theoretically eliminate the immune cells needed for antitumour immunity. However, much preclinical work has now demonstrated that in addition to direct cytotoxic effects on cancer cells, a proportion of DNA damaging agents may actually promote immunogenic cell death, alter the inflammatory milieu of the tumour microenvironment and/or stimulate neoantigen production, thereby activating an antitumour immune response. Some notable combinations have now moved forward into the clinic, showing promise in phase I–III trials, whereas others have proven toxic, and challenging to deliver. In this review, we discuss the emerging data of how DNA damaging agents can enhance the immunogenic properties of malignant cells, focussing especially on immunogenic cell death, and the expansion of neoantigen repertoires. We discuss how best to strategically combine DNA damaging therapeutics with immunotherapy, and the challenges of successfully delivering these combination regimens to patients. With an overwhelming number of chemotherapy/immunotherapy combination trials in process, clear hypothesis-driven trials are needed to refine the choice of combinations, and determine the timing and sequencing of agents in order to stimulate antitumour immunological memory and improve maintained durable response rates, with minimal toxicity.

Effective targeting of somatic cancer mutations to enhance the efficacy of cancer immunotherapy requires an individualized approach. Autogene cevumeran is a uridine messenger RNA lipoplex-based individualized neoantigen-specific immunotherapy designed from tumor-specific somatic mutation data obtained from tumor tissue of each individual patient to stimulate T cell responses against up to 20 neoantigens. This ongoing phase 1 study evaluated autogene cevumeran as monotherapy (n = 30) and in combination with atezolizumab (n = 183) in pretreated patients with advanced solid tumors. The primary objective was safety and tolerability; exploratory objectives included evaluation of pharmacokinetics, pharmacodynamics, preliminary antitumor activity and immunogenicity. Non-prespecified interim analysis showed that autogene cevumeran was well tolerated and elicited poly-epitopic neoantigen-specific responses, encompassing CD4⁺ and/or CD8⁺ T cells, in 71% of patients, most of them undetectable at baseline. Responses were detectable up to 23 months after treatment initiation. CD8⁺ T cells specific for several neoantigens constituted a median of 7.3% of circulating CD8⁺ T cells, reaching up to 23% in some patients. Autogene cevumeran-induced T cells were found within tumor lesions constituting up to 7.2% of tumor-infiltrating T cells. Clinical activity was observed, including one objective response in monotherapy dose escalation and in two patients with disease characteristics unfavorable for response to immunotherapy treated in combination with atezolizumab. These findings support the continued development of autogene cevumeran in earlier treatment lines. ClinicalTrials.gov registration: NCT03289962.

Maintenance of genomic stability is a critical determinant of cell survival and relies on the coordinated action of the DNA damage response (DDR), which orchestrates a network of cellular processes, including DNA replication, DNA repair and cell-cycle progression. In cancer, the critical balance between the loss of genomic stability in malignant cells and the DDR provides exciting therapeutic opportunities. Drugs targeting DDR pathways taking advantage of clinical synthetic lethality have already shown therapeutic benefit – for example, the PARP inhibitor olaparib has shown benefit in BRCA-mutant ovarian and breast cancer. Olaparib has also shown benefit in metastatic prostate cancer in DDR-defective patients, expanding the potential biomarker of response beyond BRCA. Other agents and combinations aiming to block the DDR while pushing damaged DNA through the cell cycle, including PARP, ATR, ATM, CHK and DNA-PK inhibitors, are in development. Emerging work is also uncovering how the DDR interacts intimately with the host immune response, including by activating the innate immune response, further suggesting that clinical applications together with immunotherapy may be beneficial. Here, we review recent considerations related to the DDR from a clinical standpoint, providing a framework to address future directions and clinical opportunities.

Dysregulation of cell division resulting in aberrant cell proliferation is a key hallmark of cancer, making it a rational and important target for innovative anticancer drug development. Three selective cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors are FDA and European Medicines Agency (EMA) approved for hormone receptor–positive/HER2-negative advanced breast cancer. A major emerging appreciation is that these inhibitors not only are cytostatic, but also play critical roles in the interaction between tumor cells and the host immune response. However, to trigger an effective immune response, lymphocytes must also proliferate. This review aims to assimilate our emerging understanding on the role of CDK4/6 inhibitors in cell-cycle control, as well as their biological effect on T cells and other key immune cells, and the confluence of preclinical evidence of augmentation of anticancer immunity by these drugs. We aim to provide a framework for understanding the role of the cell cycle in anticancer immunity, discussing ongoing clinical trials evaluating this concept and challenges for developing rational combinations with immunotherapy.