PD-1/PD-L1 Inhibitor Plus Chemotherapy Versus PD-1/PD-L1 Inhibitor in Microsatellite Instability Gastrointestinal Cancers: A Multicenter Retrospective Study.

PURPOSE: To investigate the efficacy of PD-1/PD-L1 inhibitors plus chemotherapy versus anti-PD-1/PD-L1 monotherapy in advanced microsatellite instability (MSI)/mismatch repair-deficient (dMMR) gastrointestinal cancers. METHODS: We retrospectively recruited patients with MSI/dMMR gastrointestinal cancer who received anti-PD-1/PD-L1 with or without chemotherapy and compared objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) of PD-1/PD-L1 inhibitor plus chemotherapy (chemo-anti-PD-1/PD-L1 group) and PD-1/PD-L1 inhibitor alone (anti-PD-1/PD-L1 group). Propensity score-based overlap weighting analysis was conducted to adjust the baseline covariable imbalance. Sensitivity analysis was performed to confirm the stability of the results by propensity score matching and multivariable Cox and logistic regression models. RESULTS: A total of 256 patients were eligible, with 68 and 188 receiving chemo-anti-PD-1/PD-L1 and anti-PD-1/PD-L1, respectively. The chemo-anti-PD-1/PD-L1 group showed significant improvements versus the anti-PD-1/PD-L1 group in ORR (61.8% v 38.8%; P = .001), DCR (92.6% v 74.5%; P = .002), PFS (median PFS [mPFS], not reached [NR] v 27.9 months; P = .004), and OS (median OS [mOS], NR v NR; P = .014). After overlap weighting, the improvements tended to be more significant with chemo-anti-PD-1/PD-L1 versus anti-PD-1/PD-L1 in ORR (62.5% v. 38.3%; P < .001), DCR (93.8% v 74.2%; P < .001), PFS (mPFS, NR v 26.0 months; P = .004), and OS (mOS, NR v NR; P = .010). These results were solidified through sensitivity analysis. CONCLUSION: Chemo-anti-PD-1/PD-L1 is superior to anti-PD-1/PD-L1 in MSI/dMMR gastrointestinal cancers with improved efficacy.

Functions of WRKYs in plant growth and development.

As sessile organisms, plants must overcome various stresses. Accordingly, they have evolved several plant-specific growth and developmental processes. These plant processes may be related to the evolution of plant-specific protein families. The WRKY transcription factors originated in eukaryotes and expanded in plants, but are not present in animals. Over the past two decades, there have been many studies on WRKYs in plants, with much of the research concentrated on their roles in stress responses. Nevertheless, recent findings have revealed that WRKYs are also required for seed dormancy and germination, postembryonic morphogenesis, flowering, gametophyte development, and seed production. Thus, WRKYs may be important for plant adaptations to a sessile lifestyle because they simultaneously regulate stress resistance and plant-specific growth and development.

The Optimal Therapy after Progression on Immune Checkpoint Inhibitors in MSI Metastatic Gastrointestinal Cancer Patients: A Multicenter Retrospective Cohort Study.

BACKGROUND: In microsatellite instability (MSI)/mismatch repair-deficient (dMMR) gastrointestinal cancers, the optimum therapy after the progression of immune checkpoint inhibitors (ICIs) is yet unknown. Here, we compared the efficacy of programmed death 1 (PD1)/programmed death ligand-1 (PD-L1) inhibitors plus other therapy and chemotherapy with or without targeted therapy in MSI/dMMR gastrointestinal cancer patients after progression on anti-PD1/PD-L1 monotherapy. METHODS: We retrospectively recruited MSI/dMMR gastrointestinal cancer patients who had progressed on anti-PD1/PD-L1 monotherapy. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and PFS ratio (PFSr) were compared between patients who received anti-PD1/PD-L1 plus other therapy (ICI-plus group) and patients who received chemotherapy with or without targeted therapy (chemo-targeted group). RESULTS: In total, 26 and 25 patients were recruited in the ICI-plus group and chemo-targeted group, respectively. Significantly better DCR (80.8% vs. 44.0%, p = 0.007), PFS (median PFS 6.9 months vs. 3.0 months, p = 0.001), OS (median OS NR vs. 14.1 months, p = 0.043), and PFSr (2.4 vs. 0.9, p = 0.021), along with a numerically higher ORR (23.1% vs. 12.0%, p = 0.503) were observed in the ICI-plus group compared with the chemo-targeted group. Multivariate analyses identified the therapy regimen as an important prognostic factor in gastrointestinal cancers. CONCLUSIONS: Compared to conventional chemotherapy with or without targeted therapy, continuing anti-PD1/PD-L1 in combination with other treatments showed better clinical outcomes in MSI/dMMR gastrointestinal cancer patients who progressed on PD1/PD-L1 blockade, which should be validated prospectively in clinical trials.

Envafolimab - first PD-1/PD-L1 antibody to be administered by subcutaneous injection for microsatellite instability-high or deficient mismatch repair advanced solid tumors.

INTRODUCTION: Programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors mobilize and activate the anti-tumor activity of the immune system by blocking the inhibitory effects of the PD-1/PD-L1 signaling pathway in T cells. Several anti-PD-1 or -PD-L1 monoclonal antibodies have been approved for the treatment of advanced solid tumors. However, most of immune checkpoint inhibitors (ICIs) are administered via intravenous infusion, which is inconvenient and leads to unsatisfactory patient compliance in the treatment process. Therefore, subcutaneous envafolimab is a potential treatment modality for advanced solid tumors. AREA COVERED: A phase I clinical trial showed that the safety and pharmacokinetic profiles of envafolimab were similar to those of other traditional antibodies. Additionally, clinical findings from a phase II trial revealed that envafolimab monotherapy exhibited satisfactory clinical therapeutic effects and no significant adverse events in patients with microsatellite instability-high/deficient mismatch Repair (MSI-H/dMMR) solid tumors who failed at least one line of prior systemic therapy. EXPERT OPINION: Subcutaneous envafolimab may serve as a more convenient and acceptable treatment modality than those approved PD-1/PD-L1 inhibitors for patients with an advanced solid tumor, which may revolutionize the modes of immunotherapy in the future.

Combination of AKT1 and CDH1 mutations predicts primary resistance to immunotherapy in dMMR/MSI-H gastrointestinal cancer.

BACKGROUND: Gastrointestinal (GI) cancer is the second most common cancer type with mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) phenotype that is expected to respond to immune-checkpoint inhibitors (ICIs). However, approximately half of the patients with dMMR/MSI-H GI cancer derive no benefit from ICIs. We sought to identify the predictors of primary resistance to ICIs in dMMR/MSI-H GI cancer. METHODS: Three independent cohorts were included: (1) the discovery cohort (65 patients with dMMR/MSI-H GI cancer) with ICI efficacy data and pre-ICIs tissue samples for genomic profile and tumor immune infiltration; (2) the validation cohort (22 patients with dMMR/MSI-H GI cancer) with ICI efficacy data and pre-ICIs plasma samples for genomic profile; and (3) the TCGA (The Cancer Genome Atlas) cohort not receiving ICIs (152 patients with MSI-H GI cancer) with genomic profile and survival data. RESULTS: AKT1 and CDH1 mutations were identified as independent predictors of poor progression-free survival (PFS) and primary resistance to ICIs in dMMR/MSI-H GI cancer. We combined these two genes as an immuno-oncology therapy predictor (IOpred), which could recognize 52.4% (11/21) of dMMR/MSI-H patients with primary resistance to ICIs with a positive predictive value (PPV) of 91.7% (11/12). Receiver operating characteristic analysis demonstrated IOpred with a good performance in predicting primary resistance (area under the curve 0.751). Patients with IOpred-Mut (mutant AKT1 or CDH1) GI cancer had significantly shorter PFS (HR=8.36, p<0.001) and overall survival (OS, HR=5.17, p<0.001) than IOpred-WT (wild-type for both AKT1 and CDH1) cases upon ICI treatment. The validation cohort also confirmed the correlation between IOpred-mutation and poorer prognosis (PFS, HR=4.68, p=0.004; OS, HR=15.98, p<0.001) in dMMR/MSI-H patients after ICIs. The PPV of IOpred in identifying primary resistance to ICIs was 80% (4/5) in the validation cohort. Additionally, IOpred-WT patients could be further stratified by tumor mutational burden (TMB), wherein TMB-low patients (TMB ≤26.19 mutations per megabase (Mb)) had a significantly higher primary resistance rate to ICIs (34.8% vs 6.7%, p=0.014) and poorer PFS (HR=3.46, p=0.008) and OS (HR=4.42, p=0.047) than TMB-high patients (TMB >26.19 mutations/Mb). CONCLUSIONS: IOpred was identified as a powerful predictor of primary resistance to ICIs in dMMR/MSI-H GI cancer, which might serve as a promising biomarker to help guide immunotherapy decision-making.

Efficacy and Safety Comparison of Regorafenib and Fruquintinib in Metastatic Colorectal Cancer-An Observational Cohort Study in the Real World.

BACKGROUND: Regorafenib and fruquintinib are tyrosine kinase inhibitors that are recommended for refractory colorectal cancer (CRC) in China. However, to date, no head-to-head trials have been conducted to guide clinical practice. METHODS AND PATIENTS: An ambispective observational cohort study was conducted in Beijing Cancer Hospital. Patients with metastatic CRC who received regorafenib or fruquintinib were retrospectively collected between January 2018 and April 2020, and prospectively enrolled between May 2020 and February 2021. The primary outcome was time-to-treatment failure (TTF), and secondary outcomes were overall survival (OS) and adverse events. An additional goal of the study was to explore the appropriate sequence of regorafenib and fruquintinib treatment. RESULTS: A total of 366 patients with metastatic CRC were enrolled to receive regorafenib (n = 260) or fruquintinib (n = 106) between January 2018 and February 2021. No difference was observed for median TTF (regorafenib 2.7 months vs. fruquintinib 3.1 months, P = .200) or median OS (regorafenib 13.8 months vs. fruquintinib 11.3 months, P = .527). The propensity score analysis showed similar results for median TTF and median OS between the 2 groups, as did the results of subgroup analysis for prospective set (n = 146). For sequence analysis, patients with regorafenib followed by fruquintinib (n = 84) showed longer OS than that with the reverse (n = 29) (28.1 months vs. 18.4 months, P = .024). Most patients tolerated regorafenib at a reduced dose (93.1%), and most patients tolerated fruquintinib at a standard dose (68.9%). The incidences of most adverse events were similar between the two groups, while any grade of hand-foot skin reaction and hyperbilirubinemia were more frequently observed in the regorafenib group and ≥grade 3 hypertension was more common in the fruquintinib group. CONCLUSION: Regorafenib and fruquintinib had similar efficacy and toxicity profiles with various frequency. Regorafenib followed by fruquintinib showed longer OS than the reverse, but the sequence needs to be further confirmed.

The emerging role of jasmonate in the control of flowering time.

Plants dynamically synchronize their flowering time with changes in the internal and external environments through a variety of signaling pathways to maximize fitness. In the last two decades, the major pathways associated with flowering, including the photoperiod, vernalization, age, autonomous, gibberellin, and ambient temperature pathways, have been extensively analyzed. In recent years, an increasing number of signals, such as sugar, thermosensory, stress, and certain hormones, have been shown to be involved in fine-tuning flowering time. Among these signals, the jasmonate signaling pathway has a function in the determination of flowering time that has not been systematically summarized. In this review, we present an overview of current knowledge of jasmonate control of flowering and discuss jasmonate crosstalk with other signals (such as gibberellin, defense, and touch) during floral transition.