Immune checkpoint blockade (ICB) has heralded a new era in cancer therapy. Research into the mechanisms underlying response to ICB has predominantly focused on T cells; however, effective immune... Show moreImmune checkpoint blockade (ICB) has heralded a new era in cancer therapy. Research into the mechanisms underlying response to ICB has predominantly focused on T cells; however, effective immune responses require tightly regulated crosstalk between innate and adaptive immune cells. Here, we combine unbiased analysis of blood and tumors from metastatic breast cancer patients treated with ICB with mechanistic studies in mouse models of breast cancer. We observe an increase in systemic and intratumoral eosinophils in patients and mice responding to ICB treatment. Mechanistically, ICB increased IL-5 production by CD4(+) T cells, stimulating elevated eosinophil production from the bone marrow, leading to systemic eosinophil expansion. Additional induction of IL-33 by ICB-cisplatin combination or recombinant IL-33 promotes intratumoral eosinophil infiltration and eosinophil-dependent CD8(+) T cell activation to enhance ICB response. This work demonstrates the critical role of eosinophils in ICB response and provides proof-of-principle for eosinophil engagement to enhance ICB efficacy. Show less
Hummelink, K.; Noort, V. van der; Muller, M.; Schouten, R.D.; Lalezari, F.; Peters, D.; ... ; Thommen, D.S. 2022
Purpose: Durable clinical benefit to PD-1 blockade in non- small cell lung cancer (NSCLC) is currently limited to a small fraction of patients, underlining the need for predictive biomar-kers. We... Show morePurpose: Durable clinical benefit to PD-1 blockade in non- small cell lung cancer (NSCLC) is currently limited to a small fraction of patients, underlining the need for predictive biomar-kers. We recently identified a tumor-reactive tumor-infiltrating T lymphocyte (TIL) pool, termed PD-1T TILs, with predictive potential in NSCLC. Here, we examined PD-1T TILs as biomarker in NSCLC. Experimental Design: PD-1T TILs were digitally quantified in 120 baseline samples from advanced NSCLC patients treated with PD-1 blockade. Primary outcome was disease control (DC) at 6 months. Secondary outcomes were DC at 12 months and survival. Exploratory analyses addressed the impact of lesion-specific responses, tissue sample properties, and combination with other biomarkers on the predictive value of PD-1T TILs. Results: PD-1T TILs as a biomarker reached 77% sensitivity and 67% specificity at 6 months, and 93% and 65% at 12 months,respectively. Particularly, a patient group without clinical benefit was reliably identified, indicated by a high negative predictive value (NPV) (88% at 6 months, 98% at 12 months). High PD-1T TILs related to significantly longer progression-free (HR 0.39, 95% CI, 0.24-0.63, P < 0.0001) and overall survival (HR 0.46, 95% CI, 0.28-0.76, P < 0.01). Predictive performance was increased when lesion-specific responses and samples obtained immediately before treatment were assessed. Notably, the pre-dictive performance of PD-1T TILs was superior to PD-L1 and tertiary lymphoid structures in the same cohort. Conclusions: This study established PD-1T TILs as predictive biomarker for clinical benefit to PD-1 blockade in patients with advanced NSCLC. Most importantly, the high NPV demon-strates an accurate identification of a patient group without benefit. Show less
This thesis sought to obtain a better understanding of the composition of the immune microenvironment in NSCLC and how to modulate this tumor immune microenvironment by RT to induce amplified... Show moreThis thesis sought to obtain a better understanding of the composition of the immune microenvironment in NSCLC and how to modulate this tumor immune microenvironment by RT to induce amplified antitumor immune responses to ICIs in advanced NSCLC patients. In the first part of this thesis, a multiangular approach of a combination of protein and mRNA expression with clinicopathological characteristics in a large cohort of early stage, resected NSCLC samples will be discussed. The second part focusses on the immune modulating effects of RT, in particular when combined with immunotherapy treatment in metastatic NSCLC. Show less
Findings Overall, 148 patients were included in the pooled analysis, 76 of whom had been assigned pembrolizumab and 72 who had been assigned pembrolizumab plus radiotherapy. Median follow-up for... Show moreFindings Overall, 148 patients were included in the pooled analysis, 76 of whom had been assigned pembrolizumab and 72 who had been assigned pembrolizumab plus radiotherapy. Median follow-up for all patients was 33 months (IQR 32?4?33?6). 124 (84%) of 148 patients had non-squamous histological features and 111 (75%) had previously received chemotherapy. Baseline variables did not differ between treatment groups, including PD-L1 status and metastatic disease volume. The most frequently irradiated sites were lung metastases (28 of 72 [39%]), intrathoracic lymph nodes (15 of 72 [21%]), and lung primary disease (12 of 72 [17%]). Best ARR was 19?7% (15 of 76) with pembrolizumab versus 41?7% (30 of 72) with pembrolizumab plus radiotherapy (odds ratio [OR] 2?96, 95% CI 1?42?6?20; p=0?0039), and best ACR was 43?4% (33 of 76) with pembrolizumab versus 65?3% (47 of 72) with pembrolizumab plus radiotherapy (2?51, 1?28?4?91; p=0?0071). Median progression-free survival was 4?4 months (IQR 2?9?5?9) with pembrolizumab alone versus 9?0 months (6?8?11?2) with pembrolizumab plus radiotherapy (hazard ratio [HR] 0?67, 95% CI 0?45?0?99; p=0?045), and median overall survival was 8?7 months (6?4?11?0) with pembrolizumab versus 19?2 months (14?6?23?8) with pembrolizumab plus radiotherapy (0?67, 0?54?0?84; p=0?0004).Methods Inclusion criteria for the PEMBRO-RT and MDACC trials were patients (aged ?18 years) with metastatic nonsmall-cell lung cancer and at least one unirradiated lesion to monitor for out-of-field response. In the PEMBRO-RT trial, patients had previously received chemotherapy, whereas in the MDACC trial, patients could be either previously treated or newly diagnosed. Patients in both trials were immunotherapy-naive. In the PEMBRO-RT trial, patients were randomly assigned (1:1) and stratified by smoking status (<10 vs ?10 pack-years). In the MDACC trial, patients were entered into one of two cohorts based on radiotherapy schedule feasibility and randomly assigned (1:1). Because of the nature of the intervention in the combination treatment arm, blinding to radiotherapy was not feasible in either trial. Pembrolizumab was administered intravenously (200 mg every 3 weeks) with or without radiotherapy in both trials. In the PEMBRO-RT trial, the first dose of pembrolizumab was given sequentially less than 1 week after the last dose of radiotherapy (24 Gy in three fractions), whereas in the MDACC trial, pembrolizumab was given concurrently with the first dose of radiotherapy (50 Gy in four fractions or 45 Gy in 15 fractions). Only unirradiated lesions were measured for response. The endpoints for this pooled analysis were best out-of-field (abscopal) response rate (ARR), best abscopal disease control rate (ACR), ARR at 12 weeks, ACR at 12 weeks, progression-free survival, and overall survival. The intention-to-treat populations from both trials were included in analyses. The PEMBRO-RT trial (NCT02492568) and the MDACC trial (NCT02444741) are registered with ClinicalTrials.gov.Summary Background Radiotherapy might augment systemic antitumoral responses to immunotherapy. In the PEMBRO-RT (phase 2) and MDACC (phase 1/2 ) trials, patients with metastatic non-small-cell lung cancer were randomly allocated immunotherapy (pembrolizumab) with or without radiotherapy. When the trials were analysed individually, a potential benefit was noted in the combination treatment arm. However, owing to the small sample size of each trial, differences in response rates and outcomes were not statistically significant but remained clinically notable. We therefore did a pooled analysis to infer whether radiotherapy improves responses to immunotherapy in patients with metastatic non-small-cell lung cancer. Methods Inclusion criteria for the PEMBRO-RT and MDACC trials were patients (aged ?18 years) with metastatic non small-cell lung cancer and at least one unirradiated lesion to monitor for out-of-field response. In the PEMBRO-RT trial, patients had previously received chemotherapy, whereas in the MDACC trial, patients could be either previously treated or newly diagnosed. Patients in both trials were immunotherapy-naive. In the PEMBRO-RT trial, patients were randomly assigned (1:1) and stratified by smoking status (<10 vs ?10 pack-years). In the MDACC trial, patients were entered into one of two cohorts based on radiotherapy schedule feasibility and randomly assigned (1:1). Because of the nature of the intervention in the combination treatment arm, blinding to radiotherapy was not feasible in either trial. Pembrolizumab was administered intravenously (200 mg every 3 weeks) with or without radiotherapy in both trials. In the PEMBRO-RT trial, the first dose of pembrolizumab was given sequentially less than 1 week after the last dose of radiotherapy (24 Gy in three fractions), whereas in the MDACC trial, pembrolizumab was given concurrently with the first dose of radiotherapy (50 Gy in four fractions or 45 Gy in 15 fractions). Only unirradiated lesions were measured for response. The endpoints for this pooled analysis were best out-of-field (abscopal) response rate (ARR), best abscopal disease control rate (ACR), ARR at 12 weeks, ACR at 12 weeks, progression-free survival, and overall survival. The intention-to-treat populations from both trials were included in analyses. The PEMBRO-RT trial (NCT02492568) and the MDACC trial (NCT02444741) are registered with ClinicalTrials.gov. Findings Overall, 148 patients were included in the pooled analysis, 76 of whom had been assigned pembrolizumab and 72 who had been assigned pembrolizumab plus radiotherapy. Median follow-up for all patients was 33 months (IQR 32?4?33?6). 124 (84%) of 148 patients had non-squamous histological features and 111 (75%) had previously received chemotherapy. Baseline variables did not differ between treatment groups, including PD-L1 status and metastatic disease volume. The most frequently irradiated sites were lung metastases (28 of 72 [39%]), intrathoracic lymph nodes (15 of 72 [21%]), and lung primary disease (12 of 72 [17%]). Best ARR was 19?7% (15 of 76) with pembrolizumab versus 41?7% (30 of 72) with pembrolizumab plus radiotherapy (odds ratio [OR] 2?96, 95% CI 1?42?6?20; p=0?0039), and best ACR was 43?4% (33 of 76) with pembrolizumab versus 65?3% (47 of 72) with pembrolizumab plus radiotherapy (2?51, 1?28?4?91; p=0?0071).Median progression-free survival was 4?4 months (IQR 2?9?5?9) with pembrolizumab alone versus 9?0 months (6?8?11?2) with pembrolizumab plus radiotherapy (hazard ratio [HR] 0?67, 95% CI 0?45?0?99; p=0?045), and median overall survival was 8?7 months (6?4?11?0) with pembrolizumab versus 19?2 months (14?6?23?8) with pembrolizumab plus radiotherapy (0?67, 0?54?0?84; p=0?0004). No new safety concerns were noted in the pooled analysis. Interpretation Adding radiotherapy to pembrolizumab immunotherapy significantly increased responses and outcomes in patients with metastatic non-small-cell lung cancer. These results warrant validation in a randomised phase 3 trial. Show less
Immunotherapy has obtained a secure place in the treatment of metastatic non-small cell lung cancer (NSCLC) and has made a great impact on prognosis of responders. Unfortunately, not all NSCLC... Show moreImmunotherapy has obtained a secure place in the treatment of metastatic non-small cell lung cancer (NSCLC) and has made a great impact on prognosis of responders. Unfortunately, not all NSCLC patients derive benefit from this treatment. Several immune escape mechanisms have been postulated, explaining failure of tumor immune attack. A better understanding of these mechanisms helps us to seek treatment strategies to overcome resistance to immunotherapy. Radiotherapy has immunomodulatory qualities capable of enhancing the anticancer immune response by tackling a number of these tumor escape mechanisms. In this review, we focus on mechanisms of off-target effects of radiotherapy, the so-called abscopal effect, by describing the current role of immune checkpoint inhibitors (ICIs) in NSCLC, the possible reasons for its failures and evidence on how radiotherapy may be able to counteract these mechanisms. An oversight of pre-clinical and clinical data supporting augmentation of abscopal events by radiotherapy when combined with ICIs is presented. As much remains unclear regarding optimal dose, fractionation, target volume or timing of radiation therapy, future research will need to focus on implementing data from pre-clinical and translational findings in the development of new clinical trials in order to help optimizing the potential of the combination of immunotherapy with radiotherapy. Show less
