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PurposeKEYNOTE-158 (ClinicalTrials.gov identifier: NCT02628067) investigated the efficacy and safety of pembrolizumab across multiple cancers. We present results from patients with previously treated advanced well-differentiated neuroendocrine tumors (NET).Patients and methodsPembrolizumab 200 mg was administered every 3 weeks for 2 years or until progression, intolerable toxicity, or physician/patient decision. Tumor imaging was performed every 9 weeks for the first year and then every 12 weeks. Endpoints included objective response rate (ORR) per RECIST v1.1 by independent central radiologic review (primary) and duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety (secondary).ResultsA total of 107 patients with NETs of the lung, appendix, small intestine, colon, rectum, or pancreas were treated. Median age was 59.0 years (range, 29-80), 44.9% had ECOG performance status 1, 40.2% had received ≥3 prior therapies for advanced disease, and 15.9% had PD-L1-positive tumors (combined positive score ≥1). Median follow-up was 24.2 months (range, 0.6-33.4). ORR was 3.7% (95% CI, 1.0-9.3), with zero complete responses and four partial responses (three pancreatic and one rectal) all in patients with PD-L1-negative tumors. Median DOR was not reached, with one of four responses ongoing after ≥21 months follow-up. Median PFS was 4.1 months (95% CI, 3.5-5.4); the 6-month PFS rate was 39.3%. Median OS was 24.2 months (95% CI, 15.8-32.5). Treatment-related adverse events (AE) occurred in 75.7% of patients, 21.5% of whom had grade 3-5 AEs.ConclusionsPembrolizumab monotherapy showed limited antitumor activity and manageable safety in patients with previously treated advanced well-differentiated NETs.

The presence of Fusobacterium nucleatum is associated with an immunosuppressive tumor immune microenvironment (TIM) in primary colorectal cancer (CRC), contributing to tumor progression. Its persistence in CRC liver metastasis tissues raises questions about its role in modulating local and systemic immune responses and influencing recurrence patterns. This retrospective cohort study of 218 patients with CRC liver metastasis investigated the association of F. nucleatum in CRC liver metastasis tissues with systemic inflammation, TIM alterations, and the number of metastatic organs involved in recurrence. Two‐step polymerase chain reaction (PCR), including digital PCR, detected F. nucleatum in 42% (92/218) of fresh‐frozen specimens of CRC liver metastases. Compared with the F. nucleatum‐none group, the F. nucleatum‐high group showed higher C‐reactive protein levels (0.82 vs. 0.22 mg/dL; Ptrend = 0.02), lower numbers of CD8+ cells (33.2 vs. 65.3 cells/mm2; Ptrend = 0.04) and FOXP3+ cells (11.3 vs. 21.7 cells/mm2; Ptrend = 0.01) in the TIM, and a greater number of metastatic organs involved in recurrence (1.6 vs. 1.1; p < 0.001). The presence of F. nucleatum in CRC liver metastasis tissues was associated with increased systemic inflammation, TIM alterations, and a greater number of metastatic organs involved in recurrence. These findings suggest a potential contribution of F. nucleatum to the metastatic propensity of CRC cells and could inform future research to enhance understanding of the interaction between tumor, host, and microbes in the metastatic process. [ABSTRACT FROM AUTHOR]

Background: In the phase 3 EMPOWER‐Cervical 1/GOG‐3016/ENGOT‐cx9 study, cemiplimab significantly improved overall survival (OS) versus chemotherapy for patients with recurrent or metastatic cervical cancer who progressed after first‐line platinum‐based chemotherapy. We present a post hoc subgroup analysis of patients enrolled in Japan. Methods: Patients were enrolled regardless of programmed cell death‐ligand 1 status and randomized 1:1 to cemiplimab 350 mg intravenously every 3 weeks or investigator's choice single‐agent chemotherapy for up to 96 weeks. Primary endpoint was OS. Key secondary endpoints were progression‐free survival (PFS) and objective response rate (ORR). Results: Overall, 608 patients were randomized, of whom 56 (9.2%) were in Japan (cemiplimab, n = 29; chemotherapy, n = 27). The median (range) duration of follow‐up was 13.6 (6.0–25.3) versus 18.2 (6.0–38.2) months for patients in Japan and for the overall population, respectively. Median OS (95% confidence interval [CI]) was 8.4 (7.0‐not evaluable) and 9.4 (5.4–14.9) months for cemiplimab versus chemotherapy (hazard ratio [HR]: 0.86; 95% CI: 0.43–1.68). Median PFS (95% CI) was 4.0 (1.4–8.2) versus 3.7 (1.8–4.2) months with cemiplimab and chemotherapy (HR: 0.90; 95% CI: 0.50–1.61), respectively. ORR was 17.2% for cemiplimab and 7.4% for chemotherapy (odds ratio, 2.47; 95% CI, 0.44–13.99). Incidence of treatment‐emergent adverse events at any grade was 79.3% for cemiplimab and 100% for chemotherapy. Grade ≥3 adverse events were 37.9% versus 66.7% with cemiplimab and chemotherapy, respectively. Discussion: While acknowledging limitations inherent to a small subgroup analysis, the HR of 0.86 observed in Japanese patients suggests an emerging survival benefit despite a 4.6‐month shorter median duration of follow‐up versus the overall study population. [ABSTRACT FROM AUTHOR]

Simple Summary: This study explores whether Escherichia coli carrying the polyketide synthetase (pks) gene cluster in colorectal cancer (CRC) liver metastasis tissues influence immune responses and cancer recurrence patterns. Analyzing tissues from 239 patients, we found that pks+ E. coli was present in 66.7% of liver metastasis cases. Higher levels of pks+ E. coli were associated with lower levels of the serum C-reactive protein, fewer densities of CD4+ cells and CD163+ cells in the tumor microenvironment, and a reduction in the number of organs affected by recurrent metastasis. These findings suggest that pks+ E. coli may influence both systemic and local immune responses, potentially reducing the diversity of affected metastatic organs. Colibactin, a genotoxin produced by Escherichia coli strains harboring the polyketide synthetase (pks) gene cluster, causes DNA damage and somatic mutations. pks+ E. coli is enriched in primary colorectal cancer (CRC) and is associated with clonal driver mutations, but its role in CRC liver metastasis is unclear. We assessed the association of pks+ E. coli in CRC liver metastasis tissues with systemic and local immune responses and the number of organs involved in recurrence using specimens and clinicopathological data from 239 patients with CRC liver metastasis who underwent metastasectomy. The levels of pks+ E. coli in fresh-frozen specimens were quantified as "very low" (<50th percentile), "low" (50th to 75th percentiles), and "high" (>75th percentile) using a digital PCR. Immunohistochemical analysis of tumor-infiltrating immune cells was performed using tissue microarrays. Systemic inflammation was evaluated using serum C-reactive protein (CRP) levels. pks+ E. coli was detected in 66.7% (157 of 239) liver metastasis tissues. Higher levels of pks+E. coli were associated with decreased serum CRP levels and reduced densities of CD4+ cells and CD163+ cells in the tumor-immune microenvironment. The "high" pks+ E. coli group had fewer metastatic organs involved than the "very low" pks+ E. coli group (mean number of organs: 1.00 vs. 1.23). These findings suggest that pks+ E. coli play a modulating role in CRC metastasis. [ABSTRACT FROM AUTHOR]

Type I modular polyketide synthases assemble diverse bioactive natural products. Such multienzymes typically use malonyl and methylmalonyl-CoA building blocks for polyketide chain assembly. However, in several cases more exotic alkylmalonyl-CoA extender units are also known to be incorporated. In all examples studied to date, such unusual extender units are biosynthesized via reductive carboxylation of α, β-unsaturated thioesters catalysed by crotonyl-CoA reductase/carboxylase (CCRC) homologues. Here we show using a chemically-synthesized deuterium-labelled mechanistic probe, and heterologous gene expression experiments that the unusual alkylmalonyl-CoA extender units incorporated into the stambomycin family of polyketide antibiotics are assembled by direct carboxylation of medium chain acyl-CoA thioesters. X-ray crystal structures of the unusual β-subunit of the acyl-CoA carboxylase (YCC) responsible for this reaction, alone and in complex with hexanoyl-CoA, reveal the molecular basis for substrate recognition, inspiring the development of methodology for polyketide bio-orthogonal tagging via incorporation of 6-azidohexanoic acid and 8-nonynoic acid into novel stambomycin analogues.

Cancer genomic profile (CGP) testing, which is covered by the national health insurance system in Japan, has been introduced as a routine clinical practice. However, the effects of CGP testing on prognoses remain unclear. Drug accessibility rates and prognoses after CGP testing were retrospectively investigated in 713 patients who underwent CGP testing examined by our molecular tumor board between November 2019 and October 2022,. Overall survival (OS) was examined using the log‐rank test and the Kaplan–Meier method. The median age of patients (326 males and 387 females) was 58 years (12–85 years). CGP testing revealed one or more gene mutations in 681 cases (95.5%), among which actionable gene mutations were detected in 439 (61.6%). Although treatment options were recommended for 285 cases (40.0%) by the molecular tumor board, only 45 received treatment based on their gene mutations. During the median observation period of 8.6 months, 351 (49.2%) patients died of the exacerbation of existing diseases. No significant differences were observed in OS between patients treated with and without genomically matched therapy (p = 0.285). According to clinical responses to treatment based on gene mutations, median OS was significantly longer in patients who achieved partial response and stable disease (26.5 months; 95% CI 14.4–38.6) than in those with progressive disease and not evaluated (9.8 months; 95% CI 5.8–13.8, p = 0.013). Responses to treatment based on gene mutations may improve prognoses, and it is important to increase the drug accessibility rate after CGP testing. [ABSTRACT FROM AUTHOR]