Significant Antitumor Activity Research Articles

5 A Phase 1b, Open-Label, Safety, Tolerability, and Efficacy Study of HC-7366 in Combination with Belzutifan (WELIREGTM) in Patients with Advanced or Metastatic Renal Cell Carcinoma, NCT06234605

Abstract Background HC-7366 is a novel, orally administered, highly selective and potent activator of general control nonderepressible 2 (GCN2) kinase, a core regulator of metabolic stress through activation of the integrated stress response (ISR). Activation of GCN2 promotes cell survival, whereas prolonged activation induces apoptosis. GCN2 activation also suppresses general protein synthesis and induces cell cycle arrest, thereby preventing cell growth during nutrient scarcity. Additionally, HC-7366 decreases HIF expression and inhibits glycolysis, oxidative phosphorylation, and TCA cycle function. HC-7366 also inhibits HIF expression in immunosuppressive myeloid cells, including macrophages. These effects of HC-7366 on metabolism, HIF signaling, and immune suppression suggest therapeutic benefit in ccRCC with clear rationale for combinations with HIF2a antagonists and immune checkpoint inhibitors. HC-7366 (0.5-1 mg/kg), combined with belzutifan (1 mg/kg), exhibited combination benefit in HIF-2 dependent A-498 and 786-O RCC xenografts, yielding 90% tumor growth inhibition and a three-fold increase in complete responses, respectively. Additionally, HC-7366 drives significant monotherapy antitumor activity in PDX models that demonstrated belzutifan resistance. Mechanism of action studies have identified several pathway engagement and potential efficacy biomarkers (Stokes, et al., 2024). Trial design/schema This multicenter, open-label phase 1b study will identify the Maximum Tolerated Dose (MTD) and/or the Recommended Phase 2 Dose (RP2D) of HC-7366 in combination with fixed-dose belzutifan, 120 mg po qd, in patients with advanced or metastatic RCC with renal cell histology irrespective of VHL gene mutation. Monotherapy HC-7366 will be evaluated in parallel. The monotherapy arm, HC-7366, 60 mg p.o. qd, includes patients who have relapsed after 1 to 4 prior lines of standard of care that may include belzutifan or another HIF-2α inhibitor. The combination arm includes patients who have received 1 to 3 prior lines of standard of care and are belzutifan or HIF-2α naïve. HC-7366 dose escalation arm evaluates combination fixed dose belzutifan, 120 mg po qd plus HC-7366 at 20, 40, or 60 mg po qd. Enrollment will start with the HC-7366 monotherapy arm. Subsequently, patients will begin to enroll in the combination therapy HC-7366 dose escalation arm, while the monotherapy arm will continue to enroll. Expansion will evaluate the combination of fixed dose belzutifan with two doses of HC-7366 selected from escalation. Assessments include safety, PK, and anti-tumor activity. The study will enroll up to 80 patients at US study sites. Significance and vision Combination HC-7366 plus belzutifan, supported by preclinical evidence, is being studied to assess antitumor activity in the RCC relapsed setting. Determining safety and evaluation of dose are foundational to this study. Reference Stokes M, Tameire F, Wojnarowicz P, et al. HC-7366, a potent GCN2 activator, complements belzutifan, a HIF-2⍺ antagonist, by providing combination benefit in belzutifan-sensitive models and monotherapy activity in belzutifan-resistant models. Meeting of the American Association for Cancer Research; 2024 Apr 5-10; San Diego (CA); AACR; 2024. Abstract 4615. This study is in collaboration with Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA

In vitro and In vivo anticancer activities of Bi(III) 2-thiazolecarboxaldehyde thiosemicarbazone complex

While the currently available platinum-based antitumor drugs have severe side effects, there is a need to develop highly efficient and low-toxicity metal agents. In this study, we synthesized four bismuth (Bi) complexes (C1–C4) derived from 2-thiazolecarboxaldehyde thiosemicarbazones. These Bi(III) complexes showed significant antitumor activity, with C4 exhibiting the highest efficacy in structure–activity relationship studies. Notably, C4 effectively inhibited tumor growth and produced fewer side effects in vivo. We further confirmed the antitumor mechanisms of the C4 complex, which include inducing apoptosis, arresting the cell cycle at the S phase, inducing mitochondrial and its DNA damage, and suppressing angiogenesis.

Combined inhibition of KRASG12C and mTORC1 kinase is synergistic in non-small cell lung cancer

Current KRASG12C (OFF) inhibitors that target inactive GDP-bound KRASG12C cause responses in less than half of patients and these responses are not durable. A class of RASG12C (ON) inhibitors that targets active GTP-bound KRASG12C blocks ERK signaling more potently than the inactive-state inhibitors. Sensitivity to either class of agents is strongly correlated with inhibition of mTORC1 activity. We have previously shown that PI3K/mTOR and ERK-signaling pathways converge on key cellular processes and that inhibition of both pathways is required for inhibition of these processes and for significant antitumor activity. We find here that the combination of a KRASG12C inhibitor with a selective mTORC1 kinase inhibitor causes synergistic inhibition of Cyclin D1 expression and cap-dependent translation. Moreover, BIM upregulation by KRASG12C inhibition and inhibition of MCL-1 expression by the mTORC1 inhibitor are both required to induce significant cell death. In vivo, this combination causes deep, durable tumor regressions and is well tolerated. This study suggests that the ERK and PI3K/mTOR pathways each mitigate the effects of inhibition of the other and that combinatorial inhibition is a potential strategy for treating KRASG12C-dependent lung cancer.

A Novel Tryptanthrin Derivative D6 Induces Apoptosis and DNA Damage in Non-small-cell Lung Cancer Cells Through Regulating the EGFR Pathway.

Non-small-cell lung cancer is a prevalent malignancy associated with significant morbidity and mortality rates. Tryptanthrin and its derivatives have exhibited potent antitumor activity. This study aims to investigate the inhibitory effect of a novel synthesized tryptanthrin derivative D6 on proliferation and the possible mechanism of human non-small cell lung cancer cell lines (A549) in vitro. In this study, MTT assay, cell migration, colony formation assay, cell cycle analysis, cell apoptosis, JC- 1 staining assay, reactive oxygen species analysis, proteomics, western blotting, high content screening and absorption titrations analysis were performed. We found that D6 inhibited both the proliferation and migration, induced cell cycle arrest in the G2/M phase, increased levels of ROS, decreased mitochondrial membrane potential, and promoted apoptosis in A549 cells. Further mechanistic studies found that D6 reduced EGFR expression in A549 cells and inhibited the EGFR pathway by decreasing phosphorylation levels of EGFR, Stat3, AKT and Erk1/2. Moreover, DNA damage induced by D6 involved an increase in p53/MDM2 ratio and concentration-dependent accumulation of micronuclei. D6 demonstrated significant antitumor activity against A549 cells by inhibiting the EGFR signaling pathway, inducing DNA damage, and subsequently leading to oxidative stress, apoptosis, and cell cycle arrest. Our findings suggest that D6 exhibits potential as an NSCLC drug, owing to its attributes such as antiproliferative activity and ability to induce apoptosis by attenuating the EGFR-mediated signaling pathway.

Total triterpenoids from apple peels exert pronounced anti-breast-cancer activity in vivo and in vitro.

Apples are among the most nutritionally valuable fruits and have a history of use in traditional Chinese medicine. Triterpenoids, the primary bioactive compounds found in apples, demonstrate significant antitumor activity. Following enrichment and optimization, the total content of major triterpenoids in total triterpenoids from apple peels (ATT) reached 5.76 g kg-1. The growth of MDA-MB-231 xenograft tumors was significantly inhibited after treatment with ATT. Network pharmacology analysis conclusively identified a close association between the antitumor effect of ATT and the phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway. Experimental validation using MDA-MB-231 cells and a xenograft nude mouse model confirmed that ATT suppressed tumor cell proliferation effectively by modulating the PI3K-Akt signaling pathway, which was consistent with the findings from network pharmacology. The total triterpenoids from apple peels also induced cell apoptosis by mediating the PI3K-Akt signaling pathway. The total triterpenoids from apple peels can inhibit tumor cell proliferation and induce cell apoptosis effectively through the PI3K-Akt signaling pathway, suggesting that ATT holds promise as a prospective therapeutic agent for breast cancer treatment. © 2024 Society of Chemical Industry.

Synthesis, enzyme inhibition assay, and molecular modeling study of novel pyrazolines linked to 4-methylsulfonylphenyl scaffold: antitumor activity and cell cycle analysis.

Antitumor activity using 59 cancer cell lines and enzyme inhibitory activity of a newly synthesized pyrazoline-linked 4-methylsulfonylphenyl scaffold (compounds 18a-q) were measured and compared with those of standard drugs. Pyrazolines 18b, 18c, 18f, 18g, 18h, and 18n possessed significant antitumor activity, with a positive cytotoxic effect (PCE) of 22/59, 21/59, 21/59, 48/59, 51/59, and 20/59, respectively. The cancer cell lines HL60, MCF-7, and MDA-MB-231 were used to measure the IC50 values of derivatives 18c, 18g, and 18hvia the MTT assay method, and the results were compared with those of reference drugs. Derivatives 18g and 18h showed potent and broad-spectrum antitumor activities against HL60 (IC50 of 10.43, 8.99 μM, respectively), MCF-7 (IC50 of 11.7 and 12.4 μM, respectively), and MDA-MB-231 (IC50 of 4.07 and 7.18 μM, respectively). Compound 18c exhibited strong antitumor activity against HL60 and MDA-MB-231 cell lines with IC50 values of 8.43 and 12.54 μM, respectively, and moderate antitumor activity against MCF-7 cell lines with an IC50 value of 16.20 μM. Compounds 18c, 18g, and 18h remarkably inhibited VEGFR2 kinase (IC50 = 0.218, 0.168, and 0.135 μM, respectively) compared with the reference drug sorafenib (IC50 = 0.041 μM). Compounds 18g and 18h effectively inhibited HER2 kinase (IC50 = 0.496 and 0.253 μM, respectively) compared with erlotinib (IC50 = 0.085 μM). Compound 18h inhibited EGFR kinase (IC50 = 0.574 μM) with a potency comparable with that of the reference drug erlotinib (IC50 = 0.105 μM). Pyrazolines 18c, 18f, and 18h arrested the S/G2 phase of the cell cycle in HL-60 cells. In addition, derivatives 18c, 18f, and 18h revealed lower Bcl-2 protein expression anti-apoptotic levels and higher Bax, caspase-3, and caspase-9 expression levels. Molecular docking studies of derivative 18h into the binding sites of EGFR, HER2, and VEGFR2 kinases explored the interaction mode of these pyrazoline derivatives and their structural requirements for antitumor activity.

First-in-human phase I clinical trial of RSO-021, a first-in class covalent inhibitor of mitochondrial peroxiredoxin 3 (PRX3), in patients with malignant pleural effusion due to mesothelioma and other advanced solid tumors (MITOPE).

3019 Background: Malignant cells rely on buffering oxidative stress through mitochondrial PRX3. Oxidative stress is selectively lethal to cancer cells and may be leveraged therapeutically. RSO-021 is a naturally-occurring, sulfur-rich, cyclic oligopeptide of the thiopeptide class, which covalently inactivates PRX3, leading to catastrophic oxidative stress and cell death. We conducted a phase 1 study to explore safety and identify the maximum tolerated dose (MTD) of intra-pleural RSO-021 in patients with mesothelioma, or other predominantly pleural cancer, with pleural effusion. Methods: MITOPE was a multicenter trial of weekly intrapleural RSO-021 (90, 120, and 180 mg) with a 3 + 3 dose-escalation design. The primary objective was to assess RSO-021 safety/tolerability. Secondary objectives included establishing local and systemic pharmacokinetic profiles and early anti-tumor activity. We defined dose-limiting toxicity (DLT) as grade (G) ≥3 non-hematological AEs with exceptions for some manageable G3 AEs that resolved within 72 h and complicated G4 hematological AEs or those lasting >7 days. We also studied inflammatory and pharmacodynamic markers in local/systemic samples. Efficacy was assessed using mRECIST 1.1 (mesothelioma) and RECIST 1.1 (other tumors). Results: Of 15 patients treated (90 mg/wk, n=7; 120 mg/wk, n=6; 180 mg/wk, n=2), 12 (80%) had ≥3 prior anti-cancer regimens; 12 (80%) had mesothelioma. See table for AE and efficacy data. The commonest all-grade treatment-related AEs (TRAE) were fatigue (33%), pyrexia (20%), and elevated creatinine (20%). Three patients (20%) had DLTs: G3 dyspnea and G3 acute inflammatory response at 120 mg/wk; G3 dyspnea at 180 mg/wk. MTD was 90 mg/wk. Pro-inflammatory cytokines in pleural fluid/serum correlated with AEs suggestive of local inflammation. Prophylaxis mitigated local inflammatory TRAEs. PRX3 target binding in cell pellets from pleural fluid confirmed on-target activity. Systemic exposure was minimal. Disease control was 70% in 10 evaluable patients. The partial response at 90 mg/wk was a 59% reduction in mesothelioma target lesions. Median PFS at MTD was 5.7 months (95% CI, 1.4-NR). Two patients had disease control (DC) >30 wks. Conclusions: Weekly intrapleural RSO-021 was safe with signs of anti-tumor activity in patients with pleural mesothelioma. Phase 2 exploration of this novel agent is ongoing at 2 doses, as a single agent and in combination. Clinical trial information: NCT05278975 . [Table: see text]

Phase I safety and preliminary efficacy of PM1009, a bispecific antibody targeting TIGIT and PVRIG, in patients with advanced solid tumors.

e14695 Background: PM1009 is an anti-TIGIT x PVRIG bispecific antibody containing a fully human anti-TIGIT IgG1 fused with a fully human anti-PVRIG scFv at the C terminus. PM1009 can potently block the TIGIT/CD155/CD112 and PVRIG/CD112 signaling pathways, and supports the depletion of TIGIT-positive Treg cells in the tumor microenvironment through FcγR engagement. This leads to the enhancement of T cell and NK cell activity towards the killing of tumor cells. PM1009 showed robust in vitro and in vivo efficacy with good safety in preclinical studies. Methods: This is the first-in-human study of PM1009, which includes a dose escalation stage (accelerated titration & 3+3 design) followed by dose expansion. In the dose escalation stage, PM1009 was administered as flat doses of 120, 300, 600 and 1200 mg for DLT evaluation after 3 weeks followed by administration Q2W. Primary endpoints were safety and tolerability, and the secondary endpoints were PK, ORR and DCR (per RECIST 1.1). Results: As of February 1, 2024, a total of 12 patients were enrolled for dose escalation and received at least one dose of PM1009, with 3 patients in each of the 120, 300, 600 and 1200 mg dose-levels. Median number of prior therapies was 5 lines (range 1- 9). No DLTs were observed up to 1200 mg. Any-grade TRAEs occurred in 11 patients (91.7%), and ≥ Grade 3 TRAEs occurred in 2 patients (16.7%). Any-Grade irAEs occurred in 7 patients (58.3%), and ≥ Grade 3 irAEs occurred in 1 patient (8.3%). Treatment interruption due to TRAE occurred in 2 patients (16.7%), with infusion related reaction (the main symptom was nausea, and the single infusion was eventually completed), and neutrophil count decrease respectively. Treatment discontinuation due to TRAE occurred in 2 patients (16.7%), with acute myocardial infarction, and neutrophil count decrease respectively. The most common TRAEs were ALP elevation (33.3%) and AST elevation (25.0%). 12 patients completed at least one tumor evaluation. The DCR per RECIST 1.1 by investigator was 33.3% (4/12; 95% CI: 9.92 - 65.11), best overall response was SD. Pharmacokinetics were dose-proportional with a terminal half-life of 5.2-7.4 days across the dose range of 120-1200 mg. Conclusions: PM1009 was well-tolerated up to 1200 mg with signs of anti-tumor activity. These findings support further clinical investigation of PM1009 especially for the combination with chemotherapy or PD-1/L1-based checkpoint inhibitors. Clinical trial information: NCT05607563 .

In silico discovery and anti-tumor bioactivities validation of an algal lectin from Kappaphycus alvarezii genome

Lectins are proteins that bind specifically and reversibly to carbohydrates, and some of them have significant anti-tumor activities. Compared to those of lectins from land plants, there are far fewer studies on algal lectins, despite of the high biodiversity of algae. However, canonical strategies based on chromatographic feature-oriented screening cannot satisfy the requirement for algal lectin discovery. In this study, prospecting for novel OAAH family lectins throughout 358 genomes of red algae and cyanobacteria was conducted. Then 35 candidate lectins and 1843 of their simulated mutated forms were virtually screened based on predicted binding specificities to characteristic carbohydrates on cancer cells inferred by a deep learning model. A new lectin, named Siye, was discovered in Kappaphycus alvarezii genome and further verified on different cancer cells. Without causing agglutination of erythrocytes, Siye showed significant cytotoxicity to four human cancer cell lines (IC50 values ranging from 0.11 to 3.95 μg/ml), including breast adenocarcinoma HCC1937, lung carcinoma A549, liver cancer HepG2 and romyelocytic leukemia HL60. And the cytotoxicity was induced through promoting apoptosis by regulating the caspase and the p53 pathway within 24 h. This study testifies the feasibility and efficiency of the genome mining guided by evolutionary theory and artificial intelligence in the discovery of algal lectins.

Evaluating antitumor activity and response determinants to trastuzumab deruxtecan in pediatric solid tumors.

10049 Background: Trastuzumab deruxtecan (T-DXd) is an anti-HER2 antibody-drug conjugate (ADC) linked to a topoisomerase inhibitor FDA-approved for several indications, including the treatment of HER2+ breast and gastric cancer. Although HER2 amplification is uncommon in pediatric cancers, recent demonstration of T-DXd efficacy in HER2-low breast cancer patients prompted us to examine the potential clinical relevance of T-DXd in pediatrics by evaluating HER2 expression and activity of T-DXd in preclinical pediatric solid tumor models. Methods: Cell viability was assessed in a panel of histologically diverse pediatric solid tumor cell lines and 2 HER2-amplified adult cancer cell lines treated with T-DXd, payload (DXd), and a control IgG-ADC. HER2 protein expression in patient-derived xenograft (PDX) tumors was evaluated by immunohistochemistry (IHC) using 5 clinically validated anti-HER2 antibodies. RNAseq was performed on clinical (n=290) and PDX (n=184) tumors to determine relative expression of ERBB2. In vivo activity of T-DXd was evaluated in osteosarcoma (OS, n=10), Wilms tumor (WT, n=1) and malignant rhabdoid tumor (MRT, n=1) PDX models and a desmoplastic small round cell tumor (DSRCT) cell line xenograft model. Differences in tumor volume and time to disease progression was assessed and compared across treatments and models. Responses were correlated with HER2 expression by IHC. Results: In vitro, HER2-amplified control cell lines demonstrated a >30-fold reduction of IC50 when comparing T-DXd to ADC control. In contrast, the ADC control IC50 was nearly identical to T-DXd across all pediatric cancer cell lines, consistent with the absence of HER2 amplification in these models. We observed focal and membranous staining of HER2 by IHC in PDXs but was quite variable across antibodies tested: WT 0-17% HER2+ cases (n=6), MRT 0-40% (n=5), DSRCT 0-33% (n=24), OS 0-7% (n=30). ERBB2 gene expression was highest in DSRCT followed by WT, OS and MRT. In vivo efficacy studies demonstrated complete and partial responses in OS, WT, and DSRCT and improved disease control rates (OS: 67%, p=0.006, Mann-Whitney; WT: 100%; DSRCT: 100%). However, T-DXd and ADC control demonstrated similar activity in all tumor types with no consistent correlation between in vivo response and HER2 expression. Consistent with these preclinical studies, 4 patients with progressive DSRCT were treated with T-DXd via compassionate/off-label access with signs of clinical and radiographic responses. Conclusions: T-DXd shows significant preclinical antitumor activity across multiple pediatric solid tumors but little correlation with HER2 expression suggesting a mechanism of action similar to the clinical activity observed in HER2-low breast cancer. Xenograft efficacy studies and preliminary clinical experience with T-DXd in DSRCT patients warrant formal clinical trial investigation in this largely incurable disease.

Allogeneic chimeric antigen receptor T cells for children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia.

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a breakthrough cancer therapy over the past decade. Remarkable outcomes in B-cell lymphoproliferative disorders and multiple myeloma have been reported in both pivotal trials and real-word studies. Traditionally, the use of a patient's own (autologous) T cells to manufacture CAR products has been the standard practice. Nevertheless, this approach has some drawbacks, including manufacturing delays, dependence on the functional fitness of the patient's T cells, which can be compromised by both the disease and prior therapies, and contamination of the product with blasts. A promising alternative is offered by the development of allogeneic CAR-cell products. This approach has the potential to yield more efficient drug products and enables the use of effector cells with negligible alloreactive potential and a significant CAR-independent antitumor activity through their innate receptors (i.e., natural killer cells, γδ T cells and cytokine induced killer cells). In addition, recent advances in genome editing tools offer the potential to overcome the primary challenges associated with allogeneic CAR T-cell products, namely graft-versus-host disease and host allo-rejection, generating universal, off-the-shelf products. In this review, we summarize the current pre-clinical and clinical approaches based on allogeneic CAR T cells, as well as on alternative effector cells, which represent exciting opportunities for multivalent approaches and optimized antitumor activity.

A first-in-human trial of selective CDK7 inhibitor Q901, in patients with advanced solid tumors: Interim results of a phase I study (QRNT-009).

3078 Background: Q901 is a potent, covalently binding CDK7 inhibitor with excellent specificity for CDK7 against other protein kinases. Transcriptional regulation by CDK7 inhibition in cancer cells leads to DNA damage repair response inhibition and increased genomic instability. Q901 also regulates cell cycle checkpoints by inhibiting T-loop phosphorylation and transcriptionally downregulating CDK1, 2 and 4. In preclinical in vivo models, intravenous (iv) administration of Q901 once a week and once every three-week dosing regimen was well tolerated and showed significant antitumor activity. The safety profile, pharmacokinetics (PK), pharmacodynamics (PD) and efficacy data for 18, 36 and 60 mg/m2 are presented. Methods: QRNT-009 (NCT05394103) is an ongoing Phase 1/2 multicenter, open-label, dose escalation and expansion study. Q901 is administered iv once weekly for four weeks, then once every two weeks thereafter in patients with advanced or metastatic ovarian cancer, castration-resistant prostate cancer (CRPC), breast cancer, endometrial cancer, colorectal cancer, small cell lung cancer (SCLC), or pancreatic cancers. Results: As of data cutoff (12Jan2024), 17 patients received Q901 across 3 dose levels: 5 patients at 18 mg/m2, 4 patients at 36 mg/m2, and 8 patients at 60 mg/m2. The median prior lines of systemic therapy were 4 (range 2 - 17). Of 17 patients who received Q901 across all doses, there were no treatment related SAEs, treatment discontinuations, or dose reductions. Most common TRAEs ≥ 15% were nausea (29.4%), anemia (23.6%) and fatigue (23.5%). As of data cutoff, no DLTs were observed. All plasma PK analyses across dose levels showed dose dependent increase of AUC0-last and Cmax. No major metabolite was observed. POLR2A, which is a CDK7 target engagement marker showed biologically effective change starting from 18 mg/m2. 1 patient with pancreatic cancer who received 18 mg/m2 had a partial response with CA19-9 reduction from 4,632 to 219. 2 patients at 18 mg/m2 and 2 patients at 36 mg/m2 had stable disease. Additional safety and efficacy data will be presented. Conclusions: Preliminary data from QRNT-009 study showed that selective CDK7 inhibitor Q901 is well tolerated. Preliminary antitumor activity and pharmacodynamic observations are encouraging. Dose escalation is ongoing to identify MTD or recommended dose for further studies. Clinical trial information: NCT05394103 .

Efficacy and safety of disitamab vedotin (RC48) combined with camrelizumab and S-1 for neoadjuvant therapy of locally advanced gastric cancer with HER2 overexpression: Preliminary results of a prospective, single-arm, phase II study.

e16100 Background: A combination of HER2-targeted therapy, immunotherapy and chemotherapy is being explored in the perioperative treatment of gastric/gastric junction (GC/GEJ) adenocarcinoma.Disitamab vedotin (RC48), a HER2-directed antibody-drug conjugate (ADC), demonstrated significant anti-tumor activity. Moreover, data suggest that the combination of RC48 with immunotherapy exhibits a synergistic effect. Therefore, we conducted the study to investigate the effects of combining RC48 with camrelizumab and S-1 in the neoadjuvant setting for locally advanced, resectable GC/GEJC with HER2 overexpression. Methods: In this prospective, phase II, single-arm study, we included patients with histologically confirmed, resectable gastric/gastric junction adenocarcinoma (GC/GEJ) staged as cT3-4aN1-3M0 according to the TNM 8th edition, and demonstrating HER2 overexpression (IHC 3+ or IHC 2+). Participants received three cycles of treatment on a three-weekly basis (Q3W). Surgical resection was scheduled to occur 3-4 weeks following the completion of neoadjuvant therapy. The primary endpoint was the pathological complete response (pCR) rate; the secondary endpoints included the major pathological response (MPR) rate, clinical downgrading rate, disease-free survival (DFS), overall survival (OS), and safety. Results: Between Sep 18, 2022 and Feb 2, 2024, a total of 23 patients were enrolled. Seven patients had not completed neoadjuvant treatment.Two patients refused surgery due to organ preservation. Two patients refused study therapy after 2 cycles of neoadjuvant treatment. 12 patients who experienced D2 resection, 6 (50%) achieved MPR, including 4 (33.3%) with pCR (ypT0N0M0).The R0 resection rate was 100%. Median DFS and OS have not been reached. The most common reported AEs (grade≥3) were decreased neutrophil count (10%), bowel obstruction (5%), ALT increased (5%) and AST increased (5%). There have been no treatment-related mortalities documented. Conclusions: The preliminary findings suggest that the neoadjuvant combination of RC48, camrelizumab and S-1 presents a promising and safe treatment option for locally advanced resectable GC/GEJ adenocarcinoma with HER2 overexpression. Clinical trial information: ChiCTR2300075446.

Combining the potency of a neoantigen-expressing DNA vector, an anti-CTLA-4 antibody, and an attenuated poxvirus in a personalized immunization platform: Preclinical studies of ODI-2001.

e14674 Background: Immune checkpoint inhibitors (ICI) have transformed cancer treatment. Their impressive effectiveness is crucially dependent on pre-existing neoepitope-specific immune responses. ODI-2001 aims at increasing the immune response against tumors by combining a DNA expressing multiple neoepitopes of the tumor, a MVA vaccinia virus as physiologic adjuvant and DNA carrier, and an anti-CTLA4 antibody as amplifier of the immune response. Methods: ODI-2001 was administered by repeated subcutaneous injections after tumor cells implantation in mice melanoma model B16F10 and colorectal cancer model CT26, and both before and after implantation in breast cancer model 4T1. In B16F10 model combination of ODI-2001 with anti-PD1 was assessed also. Neoepitopes were chosen from literature in B16F10 and CT26 models. In 4T1 model they were predicted using a dedicated neoepitope prediction algorithm (ImmunoEngine, myNEO, Gent, Belgium). Tumor volume and mice survival were assessed over time. Tumors were also analysed by immunofluorescence for immune cell infiltration. Each experiment received approval from the ethics committee for animals. Results: A significant improvement in survival was observed in mice treated with ODI-2001 in B16F10, and CT26 syngeneic mice models. In B16F10 the combination of ODI-2001 with anti-PD1 antibody demonstrated synergistic activity and a significant improvement in survival, while anti-PD1 alone or combined with anti-CTLA-4 failed to show any therapeutic effect (ODI-2001 + anti-PD1 vs. anti-CTLA-4 + anti-PD1 p<0.01). ODI-2001 treatment was associated with tumor rejections in the three animal models. In 4T1 model the ImmunoEngine epitope prediction algorithm demonstrated an improved efficacy as compared to a set of neoepitopes chosen from the literature. In B16F10, following immunization with ODI-2001, an increased CD8 immune cell infiltration of the tumor was documented. ODI-2001 was well tolerated by the treated animals. Conclusions: These data demonstrate a significant antitumoral activity of ODI-2001 as a neoantigen immunization platform across different preclinical cancer models, both in monotherapy and combined with anti-PD1. ODI-2001 represents a promising option to induce de novo cancer-specific immune responses, potentially increasing the proportion of patients responding to immunotherapy treatments. Based on this preclinical program a phase I with ODI-2001 in patients with advanced colorectal carcinoma is currently under preparation.

A phase 2 clinical trial of regorafenib in patients with advanced pretreated melanoma (RegoMel).

9518 Background: A majority of advanced melanoma patients (pts) will eventually progress despite treatment with PD-(L)1/CTLA-4/LAG-3 immune checkpoint- and BRAF-/MEK-inhibitors (BRAF-/MEKi; restricted to BRAFV600-mutant pts). Retrospective case observations indicate activity of regorafenib (REGO) in this setting (1). Methods: This single center, prospective, two-stage, phase 2 clinical trial, investigates REGO 80 mg QD (continuous dosing) in pts with advanced melanoma refractory to standard of care treatment. Objective response rate (ORR, by RECIST v1.1) served as the primary endpoint. The sample size (n=16) was determined according to a Simon’s two-stage minimax statistical design; the trial is considered positive if 3 or more responses are observed. Response assessments are performed every 6 weeks (q6w) during the first 24w, and q12w thereafter. Secondary endpoints are safety, progression free survival (PFS) and overall survival (OS). REGO treatment beyond first progression was permitted if considered to be of potential clinical benefit. Database lock was on Jan 9th, 2024. Results: From Oct 2022 to Sep 2023, 16 pts were enrolled (9 male, med age 61y; AJCC stage IIIC: 1; IV-M1a: 1; -M1c: 12, -M1d: 2, ECOG PS 0-1: 100%). Oncogenic driver mutations were identified in BRAFV600: 7-, KIT: 3-, NF1: 3-, NRASQ61K: 2-, RAF fusion: 1 pt. The ORR was 31% (: 5 partial responses (PR) - 4 confirmed in 3 KIT-,and 1 BRAFV600 -mut pt; and 1 unconfirmed in a BRAFV600-mut pt). One KIT-mut pt had previously progressed on imatinib. The median duration of response (DoR) was 29.7w (range 12-44). The disease control rate (DCR) was 56%. The median time on REGO monotherapy was 12.3w [95% CI 2.3-22.3], treatment is ongoing in 3 pts. At first progression, 6 BRAFV600-mut pts continued REGO in association with BRAF-/MEKi, in 5 response evaluable pts there is an ORR of 40% (2 PR with DoR of 24w and 30w) and DCR of 80%. At database lock, 11 pts were alive with a median follow up of 48.4w (range 24-63), 13 pts have progressed on REGO monotherapy (median PFS 11.9w [95% CI 3.5-20.3]; median OS was not reached). There were no grade ≥ 4 treatment related adverse events (TRAE); 56% of pts had at least one grade 3 TRAE, including hypertension (n=3) and maculo-papular rash (n=2). There was one toxicity-related REGO discontinuation. Conclusions: This phase 2 clinical trial on REGO monotherapy in advanced pretreated melanoma patients met its primary endpoint and demonstrated significant anti-tumor activity in KIT-mutant melanoma patients. In BRAFV600-mutant melanoma, continuation of REGO in combination with BRAF-/MEK-inhibitors demonstrated promising activity in patients who previously progressed on BRAF-/MEK-inhibitors for which further prospective investigation is ongoing. 1. Dirven I. et al. ESMO Meeting 2023. Clinical trial information: NCT05370807 .

Efficacy and safety of disitamab vedotin (RC48) combined with camrelizumab and S-1 for neoadjuvant therapy of locally advanced gastric cancer with HER2 overexpression: Preliminary results of a prospective, single-arm, phase II study.

e16100 Background: A combination of HER2-targeted therapy, immunotherapy and chemotherapy is being explored in the perioperative treatment of gastric/gastric junction (GC/GEJ) adenocarcinoma.Disitamab vedotin (RC48), a HER2-directed antibody-drug conjugate (ADC), demonstrated significant anti-tumor activity. Moreover, data suggest that the combination of RC48 with immunotherapy exhibits a synergistic effect. Therefore, we conducted the study to investigate the effects of combining RC48 with camrelizumab and S-1 in the neoadjuvant setting for locally advanced, resectable GC/GEJC with HER2 overexpression. Methods: In this prospective, phase II, single-arm study, we included patients with histologically confirmed, resectable gastric/gastric junction adenocarcinoma (GC/GEJ) staged as cT3-4aN1-3M0 according to the TNM 8th edition, and demonstrating HER2 overexpression (IHC 3+ or IHC 2+). Participants received three cycles of treatment on a three-weekly basis (Q3W). Surgical resection was scheduled to occur 3-4 weeks following the completion of neoadjuvant therapy. The primary endpoint was the pathological complete response (pCR) rate; the secondary endpoints included the major pathological response (MPR) rate, clinical downgrading rate, disease-free survival (DFS), overall survival (OS), and safety. Results: Between Sep 18, 2022 and Feb 2, 2024, a total of 23 patients were enrolled. Seven patients had not completed neoadjuvant treatment.Two patients refused surgery due to organ preservation. Two patients refused study therapy after 2 cycles of neoadjuvant treatment. 12 patients who experienced D2 resection, 6 (50%) achieved MPR, including 4 (33.3%) with pCR (ypT0N0M0).The R0 resection rate was 100%. Median DFS and OS have not been reached. The most common reported AEs (grade≥3) were decreased neutrophil count (10%), bowel obstruction (5%), ALT increased (5%) and AST increased (5%). There have been no treatment-related mortalities documented. Conclusions: The preliminary findings suggest that the neoadjuvant combination of RC48, camrelizumab and S-1 presents a promising and safe treatment option for locally advanced resectable GC/GEJ adenocarcinoma with HER2 overexpression. Clinical trial information: ChiCTR2300075446.

A phase I clinical trial investigating the safety, tolerability, and pharmacokinetics of HX301 (narazaciclib), a novel multi-kinase inhibitor targeting CSF1R, CDK 4/6, and ARK5, in patients with advanced solid tumors.

e15106 Background: HX301 (narazaciclib) is a promising novel multi-kinase inhibitor with potent activity against Colony Stimulating Factor 1 Receptor (CSF1R), Cyclin-Dependent Kinase 4/6 (CDK4/6), and Aurora Kinase 5 (ARK5), with a half-maximal inhibitory concentration (IC50) values in 0.29-4.95 nM range. It is an oral bioavailable agent and has the ability to cross blood-brain barrier. Preclinical data have showed significant antitumor activities, warranting further clinical trials to evaluate the safety, and potential efficacy in human subjects. Methods: Utilizing the standard 3+3 design, the study aimed to evaluate the safety, tolerability and pharmacokinetics of ascending doses of HX301. Patients with heavily pretreated advanced solid tumors received HX301single agent via oral administration, with doses ranging from 40mg to 200mg once daily for the first 21 days of each 28-day cycle. Results: As of December 27, 2023, a total of 20 patients (5 males, 15 females) were enrolled in the study, with varying doses of HX301 administered: 40 mg (n=3), 80 mg (n=3), 120 mg (n=4), 160 mg (n=3), and 200 mg (n=7). The median age of the patients was 55 years, ranging from 30 to 71. Notably, 15 patients (75%) had metastatic breast cancers. Dose-limiting toxicities (DLTs) were observed in 2 patients in the 200 mg group. These included a Grade 4 increase in alanine aminotransferase (ALT) and a Grade 3 decrease in platelet counts with associated epistaxis, both of which resolved after discontinuation of treatment. The most common treatment-related adverse events (AEs) observed were elevated aspartate aminotransferase (AST) (65.0%), decreased white blood cell count (50%), decreased neutrophil count (50%), elevated ALT (45%), elevated creatine kinase (45%), and elevated creatinine (35%). Additionally, 4 patients experienced Grade 3 or higher treatment-related AEs, including 1 patient in the 160 mg group with Grade 3 elevated γ-glutamyl transferase and alkaline phosphatase, and 3 patients in the 200 mg group with Grade 4 elevated ALT and Grade 3 elevated AST and Dyspepsia, Grade 3 decreased neutrophil and platelet counts, and Grade 3 hyperglycemia. Notably, no AEs led to death. Among the 20 patients evaluable for tumor assessment using RECIST 1.1 by Investigators, 4 obtained stable disease, including 2 patients in the 200 mg group, 1 in the 120 mg group, and 1 in the 80 mg group. Furthermore, 1 patient with HR+ breast cancer in the 200 mg group received study drug for over a year and achieved prolonged stable disease for more than 12 months, highlighting a notable clinical outcome. Conclusions: HX301 at dose levels ranging from 40mg to 160mg was tolerable with a manageable toxicity profile. Further clinical studies are needed to explore the drug's anti-tumor activity, particularly in combination settings. Clinical trial information: NCT05731934 .

VISTA‐targeted antibody‐drug conjugates exhibit potent antitumor effects on malignant pleural mesothelioma

AbstractMalignant pleural mesothelioma (MPM) is a malignant tumor of the pulmonary pleural tissue for which there is a lack of effective targeted therapy. In this study, moderate to high V‐domain immunoglobulin T‐cell activation suppressor (VISTA) expression levels were observed in most MPM clinical tumor samples. We prepared two high‐affinity anti‐VISTA monoclonal antibodies (mAbs) and generated two novel VISTA‐targeted antibody‐drug conjugates (ADCs) by conjugating anti‐VISTA mAbs with the potent cytotoxic drug monomethyl auristatin E (MMAE). αV1‐MMAE and αV2‐MMAE showed potent killing effects to VISTA‐positive cell lines in vitro, with half‐maximal inhibitory concentration (IC50) of nanomolar levels. αV1‐MMAE and αV2‐MMAE were also able to significantly induce apoptosis and cause G2/M phase arrest in VISTA‐positive cells. In the VISTA‐positive human MPM xenograft model, both αV1‐MMAE and αV2‐MMAE showed significant antitumor activity, led to a significant survival advantage compared to mice in the control group, and effectively induced apoptosis in the tumor tissues of mice. In conclusion, we demonstrated that the novel VISTA‐targeted ADCs (αV1‐MMAE and αV2‐MMAE), especially αV1‐MMAE, had potent killing effects against VISTA‐positive MPM cells both in vitro and in vivo. Therefore, through further development, they may have the potential to become new drugs for the treatment of MPM.

Advances in CAR-NK cell therapy for lung cancer: is it a better choice in the future?

Lung cancer remains one of the leading causes of cancer-related mortality worldwide necessitating the development of innovative therapeutic strategies. Chimeric antigen receptor (CAR) natural killer (NK) cell therapy represents a promising advancement in the field of oncology offering a novel approach to target and eliminate tumor cells with high specificity and reduced risk of immune-related adverse effects. This paper reviews the mechanism, potential targets, and recent advances in CAR-NK cell therapy for lung cancer, including the design and engineering of CAR-NK cells, preclinical studies, and the outcomes of early-phase clinical trials. We highlight the unique advantages of using NK cells, such as their innate ability to recognize and kill cancer cells and their reduced potential for inducing graft-versus-host disease (GvHD) and cytokine release syndrome (CRS) compared to CAR T-cell therapies. Results from recent studies demonstrate significant antitumor activity in lung cancer models with improved targeting and persistence of CAR-NK cells observed in vitro and in vivo. Finally, we discuss the challenges in optimizing CAR-NK cell therapies, including the potential resistance mechanisms. The paper concludes with an outlook on the future directions of CAR-NK cell research and its implications for lung cancer treatment emphasizing the importance of continued innovation and collaboration in the field.

Synthesis, structure and in vitro anticancer activity of copper(II) and platinum(II) complexes with pyrrol-appended dipicolylamine ligand

Copper complexes exhibit important potential applications as non-platinum based metallodrugs particularly in the field of anticancer research. In this paper, mononuclear copper(II) and platinum(II) complexes containing pyrrole-linked dipicolylamine, namely PPMdpa-Cu and PPMdpa-Pt, were synthesized and characterized. Among these complexes, PPMdpa-Cu exhibited a stronger ability to bind to CT-DNA (calf-thymus DNA) compared to PPMdpa-Pt. In addition, an MTT assay performed throughout our studies demonstrated that PPMdpa-Cu featured significant antitumor activity against the three cancer cell lines U87, AsPC-1 and HepG2, superior to that of PPMdpa-Pt as well as the ligand, PPMdpa. Particularly, the IC50 of PPMdpa-Cu against HepG2 was found to be as low as 27.3 μM. Finally, anticancer mechanism studies showed that PPMdpa-Cu could induce apoptosis in HepG2 cells associated with mitochondrial damage and oxidative stress caused by the generation of reactive oxygen species (ROS).