Promising Antitumor Activity Research Articles

Irinotecan hydrochloride liposome HR070803 in combination with 5-fluorouracil and leucovorin in locally advanced or metastatic pancreatic ductal adenocarcinoma following prior gemcitabine-based therapy (PAN-HEROIC-1): a phase 3 trial

Liposomal irinotecan has shown promising antitumor activity in patients with advanced or metastatic pancreatic ductal adenocarcinoma (PDAC) who have undergone prior gemcitabine-based therapies. This randomized, double-blind, parallel-controlled, multicenter phase 3 study (NCT05074589) assessed the efficacy and safety of liposomal irinotecan HR070803 combined with 5-fluorouracil (5-FU) and leucovorin (LV) in this patient population. Patients with unresectable, locally advanced, or metastatic PDAC who had previously received gemcitabine-based therapies were randomized 1:1 to receive either HR070803 (60 mg/m2 anhydrous irinotecan hydrochloride, equal to 56.5 mg/m2 free base) or placebo, both in combination with 5-FU (2000 mg/m2) and LV (200 mg/m2), all given intravenously every two weeks. The primary endpoint of the study was overall survival (OS). A total of 298 patients were enrolled and received HR070803 plus 5-FU/LV (HR070803 group, n = 149) or placebo plus 5-FU/LV (placebo group, n = 149). Median OS was significantly improved in the HR070803 group compared to the placebo group (7.4 months [95% CI 6.1–8.4] versus 5.0 months [95% CI 4.3–6.0]; HR 0.63 [95% CI 0.48–0.84]; two-sided p = 0.0019). The most common grade ≥ 3 adverse events in the HR070803 group were increased gamma-glutamyltransferase (19.0% versus 11.6% in placebo group) and decreased neutrophil count (12.9% versus 0 in placebo group). No treatment-related deaths occurred in the HR070803 group, while the placebo group reported one treatment-related death (abdominal infection). HR070803 in combination with 5-FU/LV has shown promising efficacy and manageable safety in advanced or metastatic PDAC in the second-line setting, representing a potential option in this patient population.

Design, Synthesis, Anti-Proliferative Effects, and Mechanistic Details of Fluorine-Containing Biguanide Derivatives with Various Carbon Rings

Introduction/Objective: Biguanide derivatives are small molecules with promising antitumor activity. However, the effect of different carbon rings at the end of one guanide group of these compounds on anti-proliferation activity is unknown. Therefore, we synthesized novel fluorine- containing biguanide compounds with various carbon rings, evaluated their anticancer activities, and explored their anti-proliferative mechanisms. Methods: Guanidine derivatives containing trifluoromethoxy or 3,4-difluorophenyl with nine different carbon rings were synthesized using established chemical methods. The phenyl side chain was fixed to trifluoromethoxy or 3,4-difluorophenyl with changes in the number of cyclic aminocyclic carbons. The effects of these derivatives were evaluated using MTT and clonogenic assays, while the underlying mechanisms were investigated by analyzing protein expression levels via western blotting. Results: This study analyzed the effects of new biguanide derivatives on cell growth in three different cell lines: HepG2, Ovcar3, and T24. The results showed that T24 cells were the most sensitive cell line to these biguanides. All biguanide derivatives significantly inhibited the growth of T24 cells, while compound 4b exhibited the strongest inhibition in all three cell lines by MTT assay. The inhibitory effects of 4b were further confirmed using colony formation experiments. Western blotting results indicated that the representative biguanide derivative, 4b, inhibited the EGFR signaling pathway, thereby inhibiting tumor growth. Conclusion: 1a-5a and 1b-4b, the cyclooctyl-containing 3,4-difluorophenyl biguanide analogs, have demonstrated significant potential in developing novel anticancer drugs. The 3,4- difluorophenyl biguanide containing cyclooctyl showed the best antitumor activity among the nine derivatives. This finding offers a novel perspective in developing anticancer drugs and a further improvement in biguanide activity in the future.

Discovery of Novel [1,2,4]Triazolo[1,5-a]pyrimidine Derivatives as Novel Potent S-Phase Kinase-Associated Protein 2 (SKP2) Inhibitors for the Treatment of Cancer.

Skp1-CUL1-ROC1-F-box E3 ubiquitin ligases' main component S-phase kinase-associated protein 2 (Skp2) is responsible for specifically recognizing ubiquitination-modified substrates to be degraded such as p27 and p21 in the case of binding with adaptor protein Cks1. Pharmacological inhibition of Skp2 has exhibited promising antitumor activity. Herein, we present the design and optimization of a series of [1,2,4]triazolo[1,5-a]pyrimidine-based small molecules targeting Skp2. Among them, E35 demonstrated excellent inhibitory activities against the binding of Skp2-Cks1. In addition, compound E35 significantly inhibited colony formation and migration, as well as arrested the cell cycle at the S-phase. Mechanistically, compound E35 markedly decreased the expression of Skp2, as well as increased the expression of its substrates p21 and p27. Furthermore, compound E35 showed an obvious inhibitory effect on MGC-803 xenograft mice without obvious toxicity. All of these results suggest that compound E35 might be a valuable lead compound for antitumor agents targeting Skp2.

Abstract C018: Targeting KRAS inhibitor resistance by ferroptosis induction in PDAC

Abstract KRAS inhibitors (KRASi) have shown promising antitumor activity in PDAC patients; however, intrinsic and acquired resistance will likely preclude durable monotherapy responses in the clinic. Genetic and pharmacologic targeting of the KRAS pathway is associated with transcriptional and metabolic adaptations, including epithelial-to-mesenchymal transition (EMT) and dysregulated iron homeostasis that contribute to resistance. Therapy resistant mesenchymal cancer cells have a high reliance on iron that increases their susceptibility to ferroptosis, an iron-dependent form of cell death characterized by generation of lipid reactive oxygen species (ROS). We hypothesize that KRASi resistance characterized by EMT can be overcome by ferroptosis induction in PDAC. Here, we use in vitro and ex vivo PDAC models and transcriptomic and proteomic profiling to define critical ferroptotic liabilities in KRASi-treated PDAC. First, we evaluated the effect of inhibiting different ferroptosis defense mechanisms (e.g. SLC7A11, GPX4, FSP1) using newly developed ferroptosis inducers (FINs) in a panel of epithelial and mesenchymal PDAC cells. Mesenchymal cells were more sensitive to ferroptosis induction compared to epithelial cells. Since ferroptotic death is regulated by multiple ferroptosis defense pathways, and in general PDAC are relatively resistant to ferroptosis induction, it is unlikely that a single ferroptosis inducer will be successful. Therefore, targeting multiple nodes with FINs in a combinatorial approach may lead to a more pronounced effect. Combination GPX4 and SLC7A11 inhibition and GPX4 and FSP1 inhibition were the most effective combinations compared to respective monotherapies. Next, we evaluated if combination of KRASi and ferroptosis induction is synergistic. Transcriptomic analysis of KRAS-mutant PDAC cell lines sensitive or with a priori resistance to KRASi revealed that EMT-related gene sets were upregulated in KRASi resistant cell lines. Quantitative proteomics revealed that PDAC cells treated long-term with KRASi undergo EMT and likewise long-term KRASi in in vivo PDAC models induces EMT. A KRASi-anchored CRISPR/Cas9 screen showed that sgRNAs targeting GPX4 dropped out in multiple cell lines indicating that ferroptosis induction may be synergistic upon KRAS inhibition. Remarkably, KRASi induced an increase of lipid peroxidation levels in PDAC cells which was rescued with antioxidant ferrostatin-1. We also observed that previously generated KRASi resistant cells were more sensitive to GPX4 inhibition. Combination of GPX4 inhibitor with KRASi led to a synergistic effect on cell viability and a significantly higher level of lipid peroxidation compared to monotherapy. These findings highlight the importance of investigating ferroptosis induction as a novel strategy to overcome therapeutic resistance in KRAS-mutant PDAC. We aim to further evaluate these combinations in vivo to determine the best combinatorial strategies in PDAC to prevent or circumvent KRASi resistance. Citation Format: Aparna Padhye, Qijia Yu, Nicole Sindoni, Huan Zhang, Julien Dilly, Hanrong Feng, Andrew Aguirre, Joseph Mancias. Targeting KRAS inhibitor resistance by ferroptosis induction in PDAC [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C018.

First-in-human study of DP303c, a HER2-targeted antibody-drug conjugate in patients with HER2 positive solid tumors

DP303c is a HER2-targeted ADC with a cleavable linker-MMAE payload. Previous in vitro studies demonstrated that DP303c showed similar or better antitumor activity than T-DM1 in xenograft models. This was a multicenter, dose escalation and dose expansion phase 1 study in China. Eligible patients were 18-75 years old with HER2-positive advanced solid tumors who were unable to benefit from standard therapy. DP303c was administered intravenously every 3 weeks, with accelerated titration at lower dose of 0.5 mg/kg and 3 + 3 design with dose levels of 1.0, 2.0, 3.0 or 4.0 mg/kg at dose escalation part, followed by the selected dose level at dose expansion part. The primary endpoints were safety and tolerability, as well as identification of recommended phase 2 dose. As of Feb 28, 2023, 94 patients were enrolled and received DP303c (dose escalation: n = 22; dose expansion: n = 72), of whom 68 patients had breast cancer. One dose limiting toxicity (Grade 3 eye pain) was observed at 4.0 mg/kg dose, and the maximum tolerated dose was not reached. The most common treatment-related adverse events at grade 3 or higher were blurred vison (16.0%), dry eye (6.4%), and peripheral neuropathy (5.3%). No treatment-related death occurred. Overall, among 91 efficacy evaluable patients, 39 patients (42.9%) achieved an objective response. Disease control was observed in 62 patients (68.1%). In 66 efficacy evaluable patients with breast cancer, 34 patients achieved an objective response (51.5%). Disease control was achieved in 51 patients (77.3%). Median PFS was 6.4 months. On a molar basis, DP303c Cmax at 3.0 mg/kg doses was 132-folder higher than that for free MMAE. DP303c demonstrated promising anti-tumor activity with acceptable safety in patients with pre-treated advanced HER2 positive solid tumors, especially in breast cancer. Based on safety and efficacy results, 3.0 mg/kg Q3W was determined as recommended phase 2 dose for DP303c. (Trial registration: ClinicalTrials.gov Identifier: NCT04146610).

The DEBBRAH trial: Trastuzumab deruxtecan in HER2-positive and HER2-low breast cancer patients with leptomeningeal carcinomatosis.

Leptomeningeal disease (LMD) is associated with poor survival and diminished quality of life. Trastuzumab deruxtecan (T-DXd) has shown remarkable intracranial and extracranial activity in human epidermal growth factor receptor 2 (HER2)-positive and HER2-low advanced breast cancer (ABC). The DEBBRAH trial was designed to evaluate its efficacy and safety in patients with HER2-positive and HER2-low ABC with a history of brain metastases (BMs) and/or LMD. Here, we report results from cohort 5, which specifically included patients with pathologically confirmed LMD. This single-arm, open-label, five-cohort, phase 2 trial enrolled seven patients in cohort 5 who received 5.4mg/kg T-DXd intravenously every 21days until disease progression or unacceptable toxicity. The primary endpoint was overall survival (OS). Key secondary endpoints included progression-free survival (PFS) and safety profile. At data cutoff (April 4, 2023), the median duration of follow-up was 12.0months (range, 2.5-18.6). The median OS was 13.3months (95% confidence interval [CI], 5.7-NA, p<0.001), meeting the primary endpoint. The median PFS was 8.9months (95% CI, 2.1-NA). Two (28.6%) of seven patients remained on treatment after 18.6 and 11.9months, respectively. Of the five patients who progressed and died, none had intracranial progression or clinical worsening of leptomeningeal symptoms. Notably, 71.4% (95% CI, 29.0-96.3) achieved prolonged stabilization (≥24weeks) by response evaluation criteria in solid tumors (RECIST) v.1.1. No unexpected safety signals and no treatment-related deaths were observed. T-DXd showed promising antitumor activity in patients with HER2-positive and HER2-low ABC with previously untreated, pathologically confirmed LMD. These encouraging data warrant further investigation to address the unmet need in this difficult-to-treat condition. This work was funded by Daiichi Sankyo/AstraZeneca. This trial is registered with ClinicalTrials.gov: NCT04420598.

Synthesis and Preliminary Anticancer Evaluation of 4-C Derivatives of Diphyllin.

The natural lignan diphyllin has shown promising antitumor activity, although its clinical advancement has been impeded by challenges such as low solubility, poor metabolic stability, and limited potency. In response, we developed and synthesized two sets of diphyllin 4-C derivatives, comprising six ester derivatives and eight 1, 2, 3-triazole derivatives. Notably, among these derivatives, 1, 2, 3-triazole derivatives 7c and 7e demonstrated the most potent cytotoxic effects, with IC50 values ranging from 0.003 to 0.01 μM. Treatment with 0.2 μM of 7c and 7e resulted in a reduction of V-ATPase activity in HGC-27 cells to 23% and 29%, respectively.

Melatonin increases Olaparib sensitivity and suppresses cancer-associated fibroblast infiltration via suppressing the LAMB3-CXCL2 axis in TNBC

Triple-negative breast cancer (TNBC) is the most malignant breast cancer subtype, characterized with high aggressiveness and a high recurrence rate. Olaparib is the first US Food and Drug Administration-approved poly(ADP ribose) polymerase (PARP) inhibitor (PARPi) to treat breast cancer patients with a germline BRCA1 or BRCA2 mutation. However, resistance to Olaparib treatment restricts the therapeutic effects, and thus novel therapeutics are urgently required. In the present study, we identified that the combination of melatonin and Olaparib synergistically enhanced the sensitivity of TNBC cells. Moreover, melatonin exerted promising antitumor activities in Olaparib-resistant cells, implying the potential for its clinical application. An RNA-sequencing analysis revealed that melatonin treatment downregulated laminin subunit beta 3 (LAMB3) expression. Genetic ablation of LAMB3 significantly increased Olaparib sensitivity, and subsequently suppressed proliferation, epithelial-to-mesenchymal transition (EMT)-related gene expressions, and aggressiveness of breast cancer cells. Accordingly, LAMB3 expression was positively correlated with C-X-C motif chemokine ligand 2 (CXCL2), and they collaboratively promoted cancer-associated fibroblast (CAF) infiltration. An in vivo study demonstrated that combined treatment with melatonin and Olaparib showed enhanced inhibitory efficacy against tumor growth, LAMB3 expression, CXCL2 levels, and CAF infiltration compared to single treatment groups, and combined treatment with melatonin and Olaparib significantly ameliorated the immunosuppressive tumor microenvironment. These findings illustrate a promising therapeutic strategy using melatonin to overcome Olaparib resistance and activate antitumor immunity via attenuating the LAMB3-CXCL2 axis in breast cancer patients.

Phase 1a study of ESG401, a Trop2 antibody-drug conjugate, in patients with locally advanced/metastatic solid tumors

This phase 1a study assesses ESG401 in patients with heavily pretreated locally advanced or metastatic solid tumors, focusing on metastatic breast cancer. Forty patients are enrolled: three experience dose-limiting toxicities, establishing the maximum tolerated dose at 16mg/kg on days 1, 8, and 15 of a 28-day cycle. The most common grade ≥3 treatment-related adverse events are neutropenia and leukopenia. Among 38 efficacy-evaluable patients, the objective response rate (ORR) is 34.2%, the disease control rate (DCR) is 65.8%, and the clinical benefit rate (CBR) is 50.0% (including stable disease for at least 6months). The median progression-free survival is 5.1months, and the median duration of response is 6.3months. In patients receiving therapeutically relevant doses, the ORR, DCR, and CBR are 40.6%, 75.0%, and 56.3%, respectively. ESG401 demonstrates a favorable safety profile and promising antitumor activity in this heavily treated population. The trial is registered at ClinicalTrials.gov (NCT04892342).

A phase II study of tepotinib in patients with advanced solid cancers harboring MET exon 14 skipping mutations or amplification (KCSG AL19-17)

We evaluated the efficacy and safety of tepotinib in patients with various solid cancers harboring MET exon 14 skipping mutation (METex14) or MET gene amplification. A phase II, multicenter study was conducted in patients with advanced or metastatic solid cancers who progressed after standard treatment, harboring either METex14 or MET amplification detected in tissue-based next-generation sequencing (NGS). The primary endpoint was objective response rate (ORR). For exploratory analyses, we analyzed the gene profiles using plasma NGS test. Thirty-five patients were enrolled. The ORR was 57.6% for all patients, 52.2% for those with METex14, and 70% for those with MET amplification. Median progression-free survival (PFS) was 8 months [95% confidence interval (CI) 4.5-11.5 months] and median overall survival (OS) was 14 months (95% CI 7.8-20.2 months) in all patients. For patients with non-small-cell lung cancer with METex14, the median PFS was 9 months (95% CI 4.7-13.4 months) and the median OS was 17 months [95% CI not applicable (NA)-NA]. For patients with MET amplification, the median PFS was 7 months (95% CI 1.5-12.5 months) and the median OS was 10 months (95% CI 5.8-14.2 months). The ORR of patients with MET dysregulation detected by plasma NGS was 72.2%, whereas the ORR was 30% in those without detection. The most common adverse events were peripheral edema, asthenia, transaminase elevation, and anorexia, mostly grade 1 or2. Tepotinib demonstrated consistent antitumor activity in patients with METex14, and promising antitumor activity in various cancers with MET amplification. Detection of MET dysregulation by plasma NGS may predict the response to tepotinib.

Lisavanbulin (BAL101553), a novel microtubule inhibitor, plus radiation in patients with newly diagnosed, MGMT promoter unmethylated glioblastoma.

Lisavanbulin (BAL101553) is a small, lipophilic, oral microtubule destabilizer with promising antitumoral activity observed in preclinical glioblastoma (GBM) models. This multicenter phase 1 study sought to determine the MTD of oral Lisavanbulin in combination with standard RT (60 Gy/30 fractions) but without temozolomide in patients with newly diagnosed MGMT promoter unmethylated GBM (uGBM). Dose escalation followed a modified 3 + 3 design. Secondary objectives included estimation of OS and PFS and pharmacokinetic analysis. Twenty-six patients with uGBM (median age, 63 years, 42.3% male, 61.5% with gross total resection, median Karnofsky performance status 80) were enrolled; 2 tumors had an IDH1 mutation. Predefined dose levels of Lisavanbulin, administered daily concomitantly with RT, were: 4mg (5 pts), 6mg (5 pts), 8mg (7 pts), 12mg (5 pts), and 15mg (4 pts). The initial starting dose was 8mg. Due to grade 4 aseptic meningoencephalitis in the first patient, the dose was decreased to 4mg. Dose escalation resumed and continued to 15mg with dose-limiting toxicities of grade 2 confusion and memory impairment observed at 12mg. Avanbulin exposures increased in a relatively dose-proportional manner with increasing oral dose of Lisavanbulin from 4 to 15mg. Lisavanbulin in combination with RT was considered safe up to the highest predefined oral dose level of 15mg daily.

Camrelizumab plus apatinib in patients with advanced or recurrent endometrial cancer after failure of at least one prior systemic therapy (CAP 04): a single-arm phase II trial

BackgroundThe combination of anti-programmed death 1 (PD-1) inhibitors and tyrosine kinase inhibitors is an effective treatment strategy in endometrial cancer. We aimed to explore the efficacy and safety of camrelizumab plus apatinib as an alternative therapeutic option in patients with previously treated endometrial cancer.MethodsThis single-arm Simon’s two-stage phase II trial was conducted at the Fudan University Shanghai Cancer Center. Patients with advanced or recurrent endometrial cancer who had failed at least one prior systemic therapy were screened for potential participation. Eligible patients were treated with intravenous camrelizumab (200 mg d1 q2w) and oral apatinib (250 mg qd) every 4 weeks. The primary end point was the objective response rate (ORR) per RECIST v1.1 in the intention-to-treat principle.ResultsBetween January 20, 2020, and October 14, 2022, 36 patients (29 with microsatellite stability/mismatch repair proficient [MSS/pMMR] tumors; two with microsatellite instability-high/mismatch repair deficient [MSI-H/dMMR] tumors) were enrolled and treated. The confirmed ORR was 44.4% (95% CI: 27.9, 61.9) and the disease control rate was 91.7% (95% CI: 77.5, 98.2). The median duration of response was 9.3 (95% CI: 4.3, not reached) months, the median progression-free survival was 6.2 (95% CI: 5.3, 11.1) months, and the median overall survival was 21.0 (95% CI: 13.4, not reached) months during a median follow-up of 14.2 (interquartile range: 10.3, 27.6) months. Treatment-related adverse events of grade 3 or 4 occurred in 20 (55.6%) patients, with the most common being increased γ-glutamyl transferase (27.8%), alanine aminotransferase (16.7%) and aspartate aminotransferase (13.9%), and hypertension (11.1%). No treatment-related death occurred.ConclusionsCamrelizumab plus apatinib showed promising antitumor activity with manageable toxicity in patients with advanced or recurrent endometrial cancer who had failed at least one prior systemic therapy. The findings of this study support further investigation of camrelizumab plus apatinib as an alternative therapeutic option, especially for patients with MSS/pMMR tumors.Trial registrationThis trial was retrospectively registered with ChiCTR.org.cn, number ChiCTR2000031932.

The KEYVIBE program: vibostolimab and pembrolizumab for the treatment of advanced malignancies.

Vibostolimab, a humanized IgG1 monoclonal antibody, blocks the interaction between TIGITand its ligands, preventing the immunosuppressive effects of TIGIT. The addition of vibostolimab to the PD-1 inhibitor pembrolizumab has shown promising antitumor activity, warranting further exploration of vibostolimab as a potential therapeutic option. The KEYVIBE program consists of nine trials that will evaluate the safety and efficacy of vibostolimab monotherapy and vibostolimab-based combination therapy in advanced solid tumors and hematological malignancies. These studies will also evaluate coformulated immunotherapy addressing issues that occur with the sequential administration of immunotherapy. The KEYVIBE program will provide further insight into the clinical utility of vibostolimab-based therapy across multiple indications and various stages of disease.

Transition-Metal-Free Radical Relay Cascade Annulation of Amides: Access to Antitumor Active Benzo[b]azepine and Oxindole Derivatives.

Efficient metal-free synthesis of benzo[b]azepines and oxindoles is achieved via a radical relay cascade strategy employing halogen atom transfer (XAT) for aryl radical generation followed by intramolecular hydrogen atom transfer (HAT). Optimization yielded moderate to substantial yields under visible light irradiation. Preliminary biological assessments revealed promising anti-tumor activity for select compounds. This study underscores the potential of XAT-mediated radical relay cascades in medicinal chemistry and anticancer drug discovery.

CAR-T Cells in the Treatment of Nervous System Tumors.

Chimeric antigen receptor T cells (CAR-Ts) have shown a remarkable efficacy in hematological malignancies but limited responses in solid tumors. Among solid tumors, CAR-T cell therapy has been particularly explored in brain tumors. CAR-T cells have shown a limited clinical efficacy in various types of brain tumors due to several factors that have hampered their activity, including tumor antigen heterogeneity, the limited access of CAR-T cells to brain tumor cells, limited CAR-T cell trafficking and in vivo persistence and the presence of a highly immunosuppressive tumor microenvironment. Despite these considerations, some recent studies have shown promising antitumor activity of GD2-CAR-T cells on diffuse midline gliomas and neuroblastomas and of CARv3-TEAM-E cells in glioblastomas. However, strategies are required to improve the effect of CAR-T cells in brain tumors, including advanced CAR-T cell design with multiple antigenic targeting and incorporation of combination therapies.

Gouregine, an α-Gem-Dimethyltetradehydrocularine Alkaloid, and Other Aporphinoid Alkaloids from the Bark of Guatteria olivacea (Annonaceae) and Their In Vitro Cytotoxic Activities.

Guatteria olivacea R.E. Fries is an Amazonian species known as 'envira-bobó' and 'envira-fofa' and is common in the states of Amazonas, Acre, and Pará. Recently, the essential oil from the leaves of this species has shown promising antitumor activity both in vitro and in vivo. The presence of isoquinoline-derived alkaloids, including aporphinoids and tetrahydroprotoberberine alkaloids, has also been previously reported. In our ongoing search for bioactive compounds from Annonaceae Amazonian plants, the bark of G. olivacea was investigated via classical chromatography techniques, which revealed nine compounds, eight isoquinoline-derived alkaloids, a rare alkaloid with a α-gem-dimethyltetradehydrocularine structure known as gouregine, seven known aporphinoid alkaloids: isopiline, O-methylisopiline, melosmine, 9-hydroxyiguattescine, dihydromelosmine, lysicamine, and guattouregidine, and one known pimaradiene diterpene: acanthoic acid. All the isolated compounds were described for the first time in the bark of G. olivacea, and their structures were elucidated by extensive analyses of their 1D and 2D NMR spectra in combination with MS data. The NMR data of the alkaloids isopiline, O-methylisopiline, melosmine, dihydromelosmine, and guattouregidine were revised due to incomplete data in the literature and some ambiguities. The in vitro cytotoxic activities of the isolated compounds were evaluated against human cancer (HepG2, KG-1a, and HCT116) and noncancerous (MRC-5) cell lines via the Alamar blue assay after 72 h of incubation. Among the compounds evaluated against human cancer cell lines, the most active was the oxoaporphine alkaloid lysicamine, which has strong activity against HCT116 cells, with an IC50 value of 6.64 µg/mL (22.79 µmol/L). Melosmine had a moderate effect on HCT116 cells, with an IC50 value of 16.77 µg/mL (49.70 µmol/L), whereas acanthoic acid had moderate effects on HepG2 and HCT116 cells, with IC50 values of 14.63 µg/mL (48.37 µmol/L) and 21.25 µg/mL (70.25 µmol/L), respectively.

Ciclopirox platinum(IV) conjugates suppress tumors by promoting mitophagy and provoking immune responses

Mitophagy is an important target for antitumor drugs development. A series of ciclopirox (CPX) platinum(IV) hybrids targeting PTEN induced putative kinase 1 (PINK1)/Parkin mediated mitophagy were designed and prepared as antitumor agents. The dual CPX platinum(IV) complex with cisplatin core was screened out as a candidate, which displayed promising antitumor activities both in vitro and in vivo. Mechanistically, it caused serious DNA damage in tumor cells. Then, remarkable mitochondrial damage was induced accompanied by the mitochondrial membrane depolarization and reactive oxygen species generation, which further promoted apoptosis through the Bcl-2/Bax/Caspase3 pathway. Furthermore, mitophagy was ignited via the PINK1/Parkin/P62/LC3 axis, and exhibited positive influence on promoting the apoptosis of tumor cells. The antitumor immunity was boosted by the block of immune check point programmed cell death ligand-1 (PD-L1), which further increased the density of T cells in tumors. Subsequently, the metastasis of tumor cells was inhibited by inhibiting angiogenesis in tumors.

Surufatinib plus toripalimab in advanced soft tissue sarcoma (STS): Results from a multicenter, single-arm, basket study.

42 Background: Soft tissue sarcomas (STS) are highly malignant despite their low incidence and prone to recurrence, with limited therapeutic options after failure of first-line treatment. Several antiangiogenic monotherapies have shown some efficacy but limited benefit. The open-label, multi-cohort, single-arm, basket study was performed to evaluate the efficacy and safety of the combination of surufatinib (a small-molecule inhibitor of VEGFR 1-3, FGFR1 and CSF-1R) with toripalimab (an anti-programmed death 1 [PD-1] antibody) for Chinese patients (pts) with advanced solid tumors. Here, we reported the results from the STS cohort. Methods: Pts with STS who had progressed on ≤ 2 lines of systemic chemotherapy, or were intolerant to standard treatment, or for whom there was currently no effective therapy were eligible. They received 21-day cycles of surufatinib 250 mg orally, once daily, plus toripalimab 240 mg intravenously, once every 3 weeks, until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) per RECIST 1.1. Results: As of data cutoff (Feb 28, 2023), a total of 20 pts (incl. 4 treatment-naïve pts) were enrolled and received the combination treatment (mean duration: 5.81 months [m]). Median (range) age was 50 (23-74) years, 10 pts were male, 17 pts were TNM stage IV. The pathological types include leiomyosarcoma (n=4, incl. 1 naïve patient), synovial sarcoma (n=4), alveolar soft part sarcoma (n=3, incl. 2 naïve pts), undifferentiated pleomorphic sarcoma (n=3), liposarcoma (n=2, incl. 1 naïve patient) and fibrosarcoma (n=1), malignant fibrous histiocytoma (n=1) and others (n=2). Seven (35%) pts had PD-L1 combined positive score of ≥1. The median follow-up duration was 27.14 m. Confirmed ORR and disease control rate (DCR) for 19 efficacy-evaluable pts was 10.5% and 68.4%, respectively; median duration of response was 7.05m. The median progression-free survival (mPFS) and median overall survival (mOS) was 2.69 m and 16.23 m for all dosed pts. For 16 previously treated pts, ORR and DCR was 6.3% and 62.5% respectively; median duration of response (DoR) was 7.13 m; mPFS was 2.65 m; mOS was 14.32 m. 18 (90%) pts experienced at least one treatment-related adverse event (TRAE), and 7 (35%) of them reported grade ≥3 TRAEs. The incidence of immune-related adverse events (irAEs) was 70%, only 2 pts had grade ≥3 irAEs, which were immune-related pancreatitis and immune-related diabetes. 2 pts were permanently discontinued due to TRAEs, which were grade 2 renal impairment and grade 3 hyperglycemia. No new safety signals were observed. Conclusions: Surufatinib plus toripalimab had a promising antitumor activity and a manageable safety profile in pts with advanced STS. Clinical trial information: NCT04169672 .

Enfortumab vedotin and pembrolizumab as first-line treatment in recurrent or metastatic head and neck squamous cell carcinoma: A cohort of the EV-202 trial.

TPS148 Background: Novel treatment strategies are needed to treat recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) given the poor durability of response and prognosis with standard therapy. In KEYNOTE-048, among patients with R/M HNSCC and PD-L1 combined positive score (CPS) ≥1, first-line (1L) treatment with pembrolizumab demonstrated a median overall survival (OS) of 12.3 months. Nectin-4 is widely expressed in a variety of solid tumors, including bladder cancers and HNSCC. Enfortumab vedotin (EV) is a Nectin-4–directed antibody–drug conjugate approved for use in previously treated (EV monotherapy) or 1L (EV + pembrolizumab) locally advanced or metastatic urothelial carcinoma (la/mUC). EV + pembrolizumab showed superior OS and progression-free survival (PFS) vs chemotherapy in 1L la/mUC. EV-202 is a multicenter, open-label, phase 2 study (NCT04225117) evaluating the efficacy and safety of EV in multiple tumor-specific cohorts. In the previously treated R/M head and neck cancer cohort, 11 of 46 patients (23.9%) had a confirmed objective response with EV monotherapy; median PFS was 3.9 months (Swiecicki P, et al. ASCO 2023. Poster #6017). We hypothesize that EV + pembrolizumab may demonstrate benefit as a 1L therapy in patients with R/M HNSCC and CPS ≥1. Methods: Patients in the R/M HNSCC cohort of EV-202 have histologically or cytologically confirmed HNSCC, an ECOG performance status 0 or 1, no prior systemic therapy administered in the R/M setting (with the exception of systemic therapy completed &gt;6 months prior if given as part of treatment for locally advanced disease), and CPS ≥1. A total of 40 patients are expected to be enrolled. An interim analysis will be conducted when 20 patients are evaluable for tumor response; 5 responders will be needed to proceed. Of 40 total patients, 14 must demonstrate response to claim promising antitumor activity. Patients will receive EV 1.25 mg/kg intravenously on days 1 and 8 and 200 mg of pembrolizumab intravenously on day 1 of each 21-day cycle until discontinuation, for reasons including disease progression or toxicity. Disease assessments will be performed 9 weeks from the first dose and every 6 weeks thereafter until disease progression, start of subsequent anticancer therapy, death, consent withdrawal, loss to follow-up, or study end, whichever occurs first. The primary endpoint is investigator-assessed, confirmed ORR per RECIST v1.1. Secondary endpoints include investigator-assessed duration of response, disease control rate, PFS, OS, and safety/tolerability. Analyses will also be evaluated per iRECIST. Exploratory analyses will include pharmacokinetics, immunogenicity, quality of life, and assessment of biomarkers that may correlate with treatment outcome, including Nectin-4 expression. Recruitment for this cohort began in November 2023 and is ongoing. Clinical trial information: NCT04225117 .

Updated efficacy of anti-TROP2 ADC ESG401 for first-line metastatic TNBC in phase 1b study.

2 Background: ESG401, a novel ADC comprising a humanized anti-TROP2 IgG1 monoclonal antibody conjugated to SN-38, with a Drug-Antibody Ratio of 8 and a stable cleavable linker, demonstrated preliminary efficacy and tolerability in the Phase Ia trial (Ma, ASCO 2023). This report presents updated results from the first-line mTNBC cohort of the Phase Ib trial and results from patients with brain metastases. Methods: Patients (pts) aged ≥18 years with confirmed local advanced/unresectable or metastatic TNBC, without prior metastatic treatment, received ESG401 (16 mg/kg IV on Day 1,8, and 15, with a 28-day cycle) until unacceptable toxicity, progressive disease, or consent withdrawal. Results: As of the cutoff date (Apr 7th, 2024), 24 pts in the cohort received ≥1 dose of ESG401. Median age was 53 years (range: 33-73), 33.3% were ECOG 0, 25.0% were de novo stage IV, 70.8% had visceral disease (8.3% brain, 33.3% liver, 50.0% lung). Updated efficacy results are shown in the Table. Thirteen pts (68.4% of 19 efficacy evaluable pts) remained on treatment, with the longest on-treatment duration being 10.3 mons. Median PFS has not been reached. Two pts in this cohort had brain metastases, with one achieving a complete intracranial response and an overall response of PR, and the other demonstrating overall PR with a -13.8% reduction in brain lesion size. Totally 16 pts with brain metastases were enrolled in the entire Phase Ia/1b trials, for these pts, the best overall intracranial response rate was 31%, with an intracranial disease control rate of 75%, while the corresponding overall response rate and disease control rate were 50% and 69%, respectively. The response of intracranial lesions to the treatment is consistent with that of extracranial lesions. The safety profile of ESG401 remained consistent with previous reports, showing no new or unexpected safety signals. Conclusions: ESG401 monotherapy demonstrates promising antitumor activity in 1L mTNBC pts, characterized by a high response rate and durable response. The ORR numerically exceeded that reported in the BEGONIA Study arm 7 in which pts with the same indication were treated with TROP-2 ADC and PD-L1 combination therapy. Additionally, ESG401 shows clear potential for treating HER2-negative breast cancer with brain metastases, including mTNBC and HR+/HER2- BC. These results support further clinical investigation of ESG401. Clinical trial information: NCT04892342 . [Table: see text]