Preliminary Antitumor Activity Research Articles

An open-label, multicenter phase 1 study to characterize safety, tolerability, preliminary antitumor activity, pharmacokinetics, and pharmacodynamics of VIP943 monotherapy in patients with advanced CD123+ hematologic malignancies.

TPS3167 Background: VIP943 is an anti-CD123 antibody-drug conjugate (ADC) with a unique linker cleaved only by legumain and a novel kinesin spindle protein inhibitor payload. The linker-payload was engineered to increase the therapeutic index thereby improving efficacy and reducing severe toxicities compared with current ADCs. In an in vivo MOLM-13 model, VIP943 had statistically significant (p <0.001) improvement in tumor growth inhibition compared with the only ADC approved for the treatment of acute myeloid leukemia (AML), gemtuzumab ozogamicin (GO). In a nonhuman primate (NHP) single dose toxicology study, VIP943 (20 mg/kg) showed no signs of toxicity as measured by hematology, serum chemistry and survival. In contrast, NHP treated with a single dose of GO (3 mg/kg) had significant toxicity including death and mandatory euthanasia. The single-dose toxicity of GO was ameliorated by substituting the VIP943 proprietary linker and payload on an anti-CD33 antibody (3 mg/kg) as measured by hematology, serum chemistry and survival. (1,2). Methods: This trial in progress (NCT06034275) is an open-label, multicenter, Phase 1, first-in-human (FIH), dose-escalation and dose-optimization study of VIP943 in subjects with relapsed or refractory CD123+ hematologic malignancies including AML, myelodysplastic syndrome, and B-cell acute lymphoblastic leukemia. A cycle of VIP943 treatment is 28 days of once weekly intravenous infusions with no pause between cycles. The dose-escalation portion of this study follows a standard 3+3 design. Dose escalation decisions will be made by the safety review committee, and decisions will be based on the incidence of dose-limiting toxicities (DLTs). Based on FDA guidance, a dose-optimization portion of this study will randomize subjects into ≥2 dose cohorts to derive a recommended dose range for Phase 2. The study will also characterize the pharmacokinetics of VIP943 and its components and explore potential biologic activity by assessing pharmacodynamic/exploratory biomarkers, and antitumor activity using standard response criteria. As this is a FIH study, only subjects with CD123+ hematologic malignancies who have exhausted all available therapies or are not fit for standard of care can be enrolled. The results from this study will form the basis for decisions for future studies. Enrollment for cohorts 1 (no DLTs) and 2 (safety review ongoing) has completed. 1. Stelte-Ludwig et al ASH 2022. 2. Stelte-Ludwig et al ASH 2023. Clinical trial information: NCT06034275 .

H3B-6545 + palbociclib in patients (pts) with locally advanced/metastatic estrogen receptor-positive (ER+), HER2 negative (–) breast cancer (BC).

1051 Background: H3B-6545 — a novel selective ER covalent antagonist (SERCA) that potently inactivates wild-type and mutant ERα — has shown preliminary antitumor activity and tolerable safety in pts with advanced/metastatic, ER+, HER2– BC. Palbociclib (palbo), an oral CDK4/6 inhibitor, has shown activity in metastatic disease when combined with endocrine therapy. The dose escalation part of this open-label, multicenter, phase 1b study of H3B-6545 + palbo in pts with ER+, HER2– BC aimed to identify the recommended phase 2 dose (RP2D) of H3B-6545 + palbo and characterize safety and efficacy. Methods: Females aged ≥18 years with ER+, HER2–, locally advanced/recurrent/metastatic BC, ECOG PS 0–1, and progression on/after standard therapy were eligible. In the dose escalation phase, pts had to have received ≥2 prior hormonal therapies. Palbo was to be escalated no higher than 125 mg orally QD (days 1–21) and H3B-6545 no higher than 450 mg orally QD (days 1–28). The MTD was the highest dose at which ≤1 of 6 pts had a dose-limiting toxicity (DLT). The primary endpoint was determination of the MTD and/or RP2D. Secondary endpoints included safety and efficacy (by investigator per RECIST v1.1). Results: At data cutoff (16 Sept 22), 31 pts were treated: Cohort (C) 1: H3B-6545 300 mg + palbo 100 mg (n=7); C2: H3B-6545 300 mg + palbo 125 mg (n=8); C3: H3B-6545 450 mg + palbo 125 mg (n=8); C3b: H3B-6545 450 mg + palbo 100 mg (n=8). 3 DLTs (grade 3/4 neutrophil count decreased [n=2] and grade (G) 3 QTcF prolongation [n=1]) were observed in C3 (5 DLTs were observed at C3b); C2 dose was deemed the MTD. Of all pts, 90.3% had G ≥3 TEAEs, 32.3% had serious TEAEs, and 6.5% had TEAEs leading to drug withdrawal. Sinus bradycardia (67.7% [G ≥3, 0%]) and anemia (54.8% [G ≥3, 19.4%]) were the most frequent TEAEs. QT prolongation and rash occurred in 19.4% [G ≥3, 12.9%] and 16.1% [G ≥3, 9.7%] of pts, respectively. ORR in response evaluable pts was 23.1% (95% CI 9.0–43.6). The Table shows additional results. Conclusions: H3B-6545 300 mg + palbo (100/125 mg) had manageable safety and encouraging preliminary antitumor activity. Further studies are warranted to identify the RP2D. Clinical trial information: NCT04288089 . [Table: see text]

The FIPO23 trial: First-in-human phase I/II study of XON7 in advanced solids tumors.

TPS2673 Background: XON7 is a first-in-class glyco-humanized polyclonal antibody (GH-pAb) targeting selectively multiple tumor-associated antigens. XON7 induces tumor cell apoptosis and promotes the elimination of tumor cells by immune effector cells through CDC (Complement Dependent Cytotoxicity) and ADCP (Antibody-Dependent Cell Phagocytosis). XON7 demonstrated anti-tumor efficacy in mice xenograft models with human solid tumors such as colon, prostate, lung and triple negative breast cancers. Safety pharmacology and toxicology studies in non-human primates demonstrated an acceptable safety profile for XON7. Taken together, these preclinical data support the initiation of human trials in patients with advanced solid tumors. Methods: First-in-patient, multicenter, open-label, two phases (dose-escalation (ESC) followed by dose expansion (EXP)) study of XON7 single agent, in patients with relapsed refractory, locally advanced or metastatic solid tumors without standard available treatments ( NCT06154291). Key eligibility criteria include disease progression after ≤ 4 lines of therapy; age > 18 years; ECOG performance status ≤2; adequate organ functions; no known CNS involvement. All advanced or metastatic tumor types except glioblastoma, can be included during ESC. Primary endpoints: safety, tolerability and determination of MTD/RP2D. Secondary endpoints: pharmacokinetics (PK), pharmacodynamics, immunogenicity and preliminary anti-tumor activity (RECIST 1.1). AEs graded according to CTCAE 5.0. In the ESC part, XON7 is administered as 60-min intravenous infusion every 2 weeks according to an escalating schedule of doses from 1.5 to 20 mg/kg for up to 12, 28-day cycles. Dose escalation/de-escalation is based on the Bayesian Optimal Interval (BOIN) design, up to 45 pts are planned. At the recommended dose, up to 7 EXP cohorts (30 pts each) defined according to the primary tumor site are planned. Bayesian sequential monitoring will be used. Patient recruitment is planned or ongoing at 25 sites worldwide. Results: As of Feb 3rd, 2024, 3 pts are enrolled in the first dose cohort and have received XON7 at dose 1,5 mg/kg Q2W for the first 28-days cycle. Conclusions Accrual is ongoing in this first-in-human trial of XON7. Clinical trial information: NCT06154291 .

HB-200 arenavirus-based immunotherapy plus pembrolizumab as first-line treatment of patients with recurrent/metastatic HPV16-positive head and neck cancer: Updated results.

6005 Background: Treatment options are limited for patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) with no approved treatment specifically targeting human papillomavirus (HPV) 16-positive tumors. In the first-line (1L) R/M setting, only a minority of patients (~20%) respond to pembrolizumab monotherapy, including those with high programmed death ligand 1 (PD-L1) expression in the tumor. HB-200 comprises an alternating sequence of two replicating attenuated arenavirus vectors derived from LCMV (HB-201) and Pichinde virus (HB-202), respectively. HB-200 vectors express a non-oncogenic HPV16 E7E6 fusion protein and induce E6 and E7-specific CD8 T-cell responses. Previously, we reported promising preliminary clinical activity of HB-200 in combination with pembrolizumab as 1L treatment for patients with HPV16+ PD-L1+ R/M HNSCC. Here, we report updated results with a focus on PD-L1 status. Methods: In this non-randomized Phase 2 part of the study, participants with HPV16+ PD-L1 combined positive score (CPS) ≥1 R/M HNSCC were treated with HB-200 intravenously (every 3 weeks [Q3W] then Q6W) in combination with pembrolizumab (200 mg Q3W or 400 mg Q6W). Safety, T cell response, and preliminary antitumor activity were assessed. Results: As of 12 January 2024, 42 patients with HPV16+ PD-L1+ R/M HNSCC (41 of oropharynx as primary cancer site) were treated with HB-200 plus pembrolizumab in the 1L setting. Median follow-up time was 5.6 months. Characteristics of this cohort included: median age 66 years (range 50-77), 41 (98%) male, 37 (88%) White, 14 (33%) with ≥ 10 pack/year smoking history, 40 (95%) check point inhibitor (CPI) naïve (2 received CPI in the adjuvant setting), and 21 (50%) with PD-L1 CPS ≥ 20. HB-200 + pembrolizumab were generally well tolerated. Grade ≥3 treatment-related adverse events (TRAEs) were reported in 6 (14%) patients, serious TRAEs in 3 (7%) patients, and TRAEs leading to treatment discontinuation in 2 (5%) patients. No treatment-related death were reported. Among 35 evaluable patients (those with ≥ 1 tumor response assessments), the overall response rate (ORR) was 43% (3 complete response [CR], 9 partial response [PR], 3 unconfirmed PR) and the disease control rate (DCR) was 71%. Notably, among patients with PD-L1 CPS ≥20 (N = 17), ORR was 59% (3 CR, 6 PR, 1 unconfirmed PR) and DCR was 88%. Conclusions: Updated data of HB-200 arenavirus-based immunotherapy plus pembrolizumab continued to demonstrate a favorable safety profile and promising clinical activity as 1L treatment in patients with HPV16+ PD-L1+ R/M HNSCC and confirms previously reported data. The results suggest that the subgroup of patients with PD-L1 CPS ≥20 may benefit more from this treatment, which warrants further development in a randomized pivotal study. Clinical trial# NCT04180215. Clinical trial information: NCT04180215 .

A phase 1 trial evaluating the safety, tolerability, PK, and preliminary efficacy of QTX3034, an oral G12D-preferring multi-KRAS inhibitor, in patients with solid tumors with KRASG12D mutation.

TPS3172 Background: KRAS is one of the most mutated driver oncogenes across solid tumors, and KRAS G12D missense mutations have high prevalence in pancreatic, colorectal (CRC), and endometrial cancers. QTX3034 is a highly-selective, non-covalent, orally bioavailable, multi-KRAS inhibitor with potent activity across several KRAS variants, particularly G12D. QTX3034 binds to GDP-bound forms of mutant and wild-type KRAS with (sub)nanomolar affinities, allosterically inhibiting its conversion to the active state. QTX3034 inhibits KRAS signaling in in vitro studies and displays synergy with EGFR inhibitors. In vivo evaluation of QTX3034 resulted in significant tumor growth inhibition across various tumor models, with tumor regressions observed in 100% of animals in both HPAC pancreatic and GP2D colorectal KRAS G12D xenograft models. QTX3034 exhibits brain penetration in preclinical studies, including an orthotopic model of intracranial efficacy. This clinical trial is now enrolling patients with advanced solid tumors harboring a KRASG12D mutation. Methods: This is a first-in-human, multicenter, open-label phase 1 study in adult patients with advanced solid tumors with KRASG12D mutations, without prior direct KRAS inhibitor treatment (NCT06227377). The primary objectives are to evaluate the safety and tolerability and to determine maximum tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) of QTX3034 alone, and in combination with cetuximab. Secondary objectives are characterization of the PK profile and preliminary antitumor activity. Part 1 consists of two dose-escalation arms: QTX3034 monotherapy (advanced solid tumors) and QTX3034 plus cetuximab (CRC) and will enroll 3-4 subjects per cohort in a Bayesian Logistic Regression Model (BLRM) design. QTX3034 will be administered orally in 21-day cycles until disease progression, intolerable toxicity, or withdrawal from treatment. Exploratory paired biopsies will be collected in Cycle 2 in a group of patients in the dose-escalation phase. Serial ctDNA will be collected in all patients. Following identification of a RP2D, QTX3034 will be evaluated in dose-expansion cohorts of up to 30 patients with various KRASG12D mutated tumor types to determine preliminary activity: pancreatic cancer, CRC, non-small cell lung cancer and endometrial cancer. To further optimize the recommended dose, patients will be randomized between two dose levels in the pancreatic cancer cohort. QTX3034 plus cetuximab will be explored following identification of a recommended combination dose in patients with CRC. Clinical trial information: NCT06227377 .

Evaluation of the safety, pharmacokinetics, and efficacy of JSKN003 in patients with advanced solid tumors: A phase I/II clinical study.

3031 Background: JSKN003 is a bispecific HER2-directed antibody-drug conjugate (ADC) conjugated to a topoisomerase I inhibitor via a dibenzocyclooctyne tetrapeptide linker on the glycan of a humanized bispecific antibody. Pre-clinical studies showed that JSKN003 had a good serum stability, that may lead to a broader therapeutic window. Methods: JSKN003-102 (NCT05744427) is a phase I (dose escalation and dose expansion) and phase II (cohort expansion) study in Chinese patients (pts) with advanced solid tumors. Pts (ECOG PS 0-1) with HER2-expressing (IHC ≥ 1+) or HER2-mutant cancers who failed prior systemic therapies were recruited and received JSKN003 monotherapy intravenously Q3W. The objectives were safety, MTD or RP2D, pharmacokinetics, and preliminary antitumor activity. Here the results from phase I were reported. Results: As of 5th Jan 2024, 46 pts (25 breast cancers, 11 gastric cancers, 8 colorectal cancers, 1 lung cancer, and 1 ovarian cancer) were enrolled and received JSKN003 across 6 dose levels, including 2.1 (n=1), 4.2 (n=10), 5.2 (n=14), 6.3 (n=15), 7.3 (n=3), and 8.4 mg/kg (n=3), Q3W, in phase I period. Among the 46 pts, 18 were IHC 3+, 21 were IHC 2+, and 7 were IHC 1+. Most pts (73.9%) received ≥ 3 prior lines of therapy, including 60.9% and 45.6% of pts received prior anti-HER2 and anti-HER2 ADC therapy, respectively. The median duration of treatment was 13.1 (range, 2.1 - 42.4) weeks, and 37 pts (80.4%) remained on treatment. Treatment-related adverse events (TRAEs) occurred in 44 pts (95.7%), and the common, mostly grade 1 and 2, were diarrhea (37.0%) and nausea (32.6%). Only 6 pts (13.0%) experienced grade ≥3 TRAEs, and the common were lymphopenia (4.3%) and neutropenia(4.3%). 1 pt (2.2%) had treatment related SAE (nausea, grade 3). No pts experienced DLT or interstitial lung disease, and no TRAE led to death or discontinuation. Following a single dose, exposures (Cmax and AUC) of JSKN003 increased proportionally over a dose range of 4.2 mg/kg to 6.3mg/kg. T1/2 of JSKN003 is approximately 3-5 days. No significant accumulation was observed after 4 cycles treatment. The exposure of released payload was very low, demonstrating the stability of the JSKN003 in circulation. 37 pts had at least one post-baseline tumor assessment. The ORR and DCR was 51.4% (95%CI: 34.4, 68.1) and 91.9% (95%CI: 78.1, 98.3), respectively. The ORR in pts with HER2 IHC 1+, 2+ and 3+ was 20.0% (95% CI: 0.5, 71.6), 33.3% (95% CI: 11.8, 61.6), and 76.5% (95% CI: 50.1, 93.2), respectively. For pts who received prior anti-HER2 ADC, the ORR was 57.9% (95% CI: 33.5, 79.7). For HER2 positive breast cancer and gastric cancer, the ORR was 66.7% (95% CI: 38.4, 88.2) in 15 pts and 100% (95% CI: 39.8, 100) in 4 pts, respectively. Conclusions: MTD of JSKN003 was not reached yet. And safety of JSKN003 was extremely excellent with encouraging preliminary antitumor activity in heavily pretreated pts with advanced solid tumors. Clinical trial information: NCT05744427 .

A phase I dose escalation trial of BCD-145 in patients with unresectable or metastatic melanoma.

9526 Background: BCD-145 (nurulimab) is a fully human IgG1 mAb with modified Fc-fragment (the 1st Gln is replaced by Glu in the heavy chain sequence, and there is no terminal dipeptide composed by Gly and Lys residues) that binds to cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and blocks the interaction between CTLA-4 and its ligands. This allows to stimulate T-cell proliferation, cytokine production and induces antitumor immune response. Here we present the results of multicenter open-label single-arm multi-cohort phase I trial of pharmacokinetics (PK), pharmacodynamics (PD), safety, and immunogenicity of BCD-145 in pts with unresectable/metastatic melanoma (unr/mM). Methods: BCD-145 monotherapy in 3+3 dose escalation [0.1, 0.3, 1, 3, 10 mg/kg intravenously Q3W] was given to 15 pts with unr/mM with measurable disease, who had failed prior therapy, ECOG 0-2. Pts with brain mts, previous therapy with aCTLA-4 and/or aPD-1/PD-L1 drugs were not allowed. The main objective of the study was to evaluate PK, PD, tolerability, immunogenicity, safety, dose-limiting toxicity (DLT), maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) identification. Secondary objectives included tumor response rate (irRECIST). Results: BCD-145 proved safety and overall was well tolerated. DLT and MTD were not reached. Any grade (Gr) adverse events (AEs) occurred in 100% (15/15) of pts. 33.3% (5/15) of pts had AE/SAE of Gr 3-4, including hypertension Gr 3 (1 at 1 mg/kg), hypercalcemia Gr 4 (2 at 1 mg/kg), hypokalemia Gr 3 (2 at 1 mg/kg), neutropenia Gr 3 (1 at 0.3 mg/kg), anemia Gr 3 (1 at 1 mg/kg), lung infection Gr 3 with hospitalization (1 at 1 mg/kg). Only 2 pts had a treatment-related AE Gr 3-4. Immuno-related AE were identified in 46.7% (7/15), manifested by symptoms of thyroiditis (mainly Gr 1) and diarrhea Gr 2 (1 at 10 mg/kg). There was 1 death (at 1 mg/kg) due to progression. There is dose-dependent peak study drug serum concentrations and systemic exposure. Two dosage regimens (1 mg/kg, 3 mg/kg Q3W) allowed to achieve the optimal concentration. BCD-145 increased subpopulations of activated HLA-DR+ CD4+ and CD8+ T lymphocytes, CD4+ICOS+ T-lymphocytes, absolute lymphocyte counts in all cohorts without significant differences. Binding and neutralizing Abs against BCD-145 were detected in 2 pts from different dose cohorts (0.3 mg/kg, 1 mg/kg). PR and SD were registered in 2 pts of each response group. 30.8% of pts achieved disease control, which is consistent with published data on other CTLA-4 inhibitors. A dose of 1 mg/kg is determined as recommended phase 2 dose (RP2D). Conclusions: BCD-145 demonstrated a tolerable safety profile and preliminary anti-tumor activity in pts with unr/mM. Anti-tumor effects of BCD-145 were observed in pts who had progressed on prior treatment. Further co-targeting PD-1 and CTLA-4 simultaneously will achieve a better anti-tumor activity due to cooperative binding to exhausted T-cell subsets. Clinical trial information: NCT03472027 .

Evorpacept plus enfortumab vedotin in patients (Pts) with locally advanced or metastatic urothelial carcinoma (la/mUC): Phase 1a dose escalation results.

4575 Background: Maximizing antibody dependent cellular phagocytosis (ADCP) in the tumor microenvironment requires both the inhibition of the myeloid CD47/SIRPα checkpoint and activation of the macrophage’s FcyR by an anti-cancer specific antibody (Lakhani et al. Lancet Oncol 2021). Evorpacept (EVO) is a CD47 inhibitor with an inactivated Fc effector domain that blocks the CD47-SIRPα interaction. Enfortumab vedotin (EV) is a nectin-4-directed antibody drug conjugate (ADC) which engages the FcyR on the macrophage. We evaluated whether EVO plus EV would be safe, tolerable and active in pts with la/mUC. Methods: 20 pts with la/mUC who had received prior platinum-based chemotherapy and progressed during or after treatment with a PD-1/L1 inhibitor were administered study drug in this phase 1 study (NCT05524545). Dose escalation (DE) cohorts were administered intravenous (IV) EVO 20 mg/kg or 30 mg/kg Q2W plus standard EV 1.25 mg/kg IV on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was first cycle dose limiting toxicity (DLT) using a Bayesian Optimal Interval design. Additional pts were enrolled in both dose levels as backfill cohorts to further characterize safety, PK, PD, and preliminary antitumor activity. Investigator response was based on RECIST v1.1, and data cut off was 18Jan(safety)/24Jan(efficacy) 2024. Results: Fourteen pts were administered EVO 20 mg/kg Q2W (DE n= 3; backfill n=11) and 6 pts EVO 30 mg/kg Q2W (DE n=6) plus standard EV. No DLTs were observed, and the maximum tolerated dose (MTD) of the combination was not reached. The maximum administered dose (MAD) of EVO was 30 mg/kg Q2W combined with EV. There were no treatment-related deaths on study. Treatment emergent adverse events (TEAEs) occurring in > 25% of subjects included fatigue, diarrhea, abnormal loss of weight, dysgeusia, decrease appetite, hyperglycemia, constipation, hypomagnesemia, lacrimation increased, nausea, peripheral sensory neuropathy, rash maculo-papular and urinary tract infection (UTI). There were 3 serious adverse events that were related to EVO plus EV (G3 UTI [1 pt]; G4 neutrophil count decreased and G3 UTI [1 pt]). Sixteen patients were response evaluable. The overall response rate (ORR) was 63% (1CR, 9PR). Accrual is ongoing and updated data will be provided at the time of presentation. Conclusions: This is the first study, to our knowledge, reporting data on the combination of a CD47 blocking agent in combination with an ADC in la/mUC. EVO plus EV is well tolerated at doses evaluated with no MTD reached and a MAD of 30 mg/kg Q2W. The combination shows early promising clinical activity compared to an ORR of 41% with EV alone in pts with la/mUC who had previously received platinum-based chemotherapy and a PD-1/L1 inhibitor (Powles et al. N Engl J Med 2021). Further investigation in this refractory population, including patients with prior EV exposure, is warranted. Clinical trial information: NCT05524545 .

A phase I/II study of C019199 in combination with sintilimab in advanced malignancy.

e15110 Background: C019199 is an oral CSF-1R/DDRs/VEGFR2 multiple kinase inhibitor and modulates the immune micro-environment of tumor cells. Previous phase I study of C019199 as a mono-therapy for advanced solid tumors has shown promising safety and anti-tumor activity. This phase I/II study is to evaluate the safety and efficacy of the combination of C019199 and Sintilimab in solid tumors. Methods: An open label, multicenter phase I/II study of C019199 combined with Sintilimab is currently enrolling (NCT06220318). Eligible subjects (age of ≥18 years and <76 years) with histologically or cytologically confirmed relapsed, refractory, or progressive metastatic solid tumors will be enrolled in. This trial consists of 2 parts: a phase I dose escalation study using a standard 3+3 design with 3 doses of C019199 (100 mg/qd, 200 mg/qd, 300 mg/qd) combined with a fixed dose of Sintilimab (200 mg, iv, q3w) to determine the maximum tolerated dose (MTD) and recommended phase Ⅱ dose (PR2D); A phase II study is planned to enroll about 20 patients in each tumor type, including but not limited to the following: colorectal cancer, gastric cancer, esophageal squamous cell carcinoma, pancreatic cancer, triple negative breast cancer, head and neck squamous cell carcinoma. Results: A total of 10 patients with advanced solid tumors were enrolled in the phase I study from Jul 20, 2023 to Nov 14, 2023. Median age was 54 (range, 37-71), with 6 males and 4 females. Tumor types were colorectal cancer (7 pts), non-small cell lung cancer (2 pts) and cervical cancer (1 pts), with a median 3 prior systemic therapies (range, 1-7). As of Jan 15, 2024, we have assessed safety in all pts and efficacy in pts with at least one tumor assessment result. No dose-limiting toxicities (DLT) observed in the dose range of 100 mg/qd~300 mg/qd and the MTD has not been reached. The most frequently reported TRAEs were aspartate aminotransferase increased (80%), γ-glutamyltransferase increased (70%), proteinuria (70%), creatine kinase-MB increased (70%), alkaline phosphatase increased (60%). Grade ≥3 TRAEs were hypertension (30%), proteinuria (10%), immune hepatitis (10%), diarrhea (10%). Among 7 colorectal cancer patients, 1 subject had partial responds (PR) and 6 had stable disease (SD) as the best responds with ORR of 14.3%, DCR of 100%. Four subjects were still on treatment. Median PFS was not reached (>3month). Two patients with non-small cell lung cancer and 1 patient with cervical cancer achieved the best response of SD, with a DCR of 100%. Phase II study is ongoing. Recommended dose is 200 mg/qd as the RP2D in selected solid tumors. Conclusions: The combination of C019199 and Sintilimab has shown good overall safety and tolerability. No DLT was observed in the dose range of 100 mg/qd ~ 300 mg/qd. Preliminary anti-tumor activity was observed in patients with advanced solid tumors. Phase II study is ongoing to accumulate more clinical data. Clinical trial information: NCT06220318 .

Preliminary safety, antitumor activity, and pharmacodynamics of intratumoral ABO2011 (IL-12 mRNA) in patients with advanced solid tumors.

e14583 Background: Interleukin (IL)-12 is a potent immunomodulatory cytokine demonstrating robust antitumor activity in multiple preclinical studies and potent immune-stimulating potential in humans. However, systemic delivery of IL-12 can result in life-threatening toxicity and therefore has shown limited efficacy at doses that can be safely administered. ABO2011 is a human IL-12 mRNA encapsulated in lipid nanoparticle and has been developed to be more effective and less toxic through the use of novel delivery technology and intratumoral injection. Methods: This phase I trial enrolled adults with advanced solid tumors who failed available standard treatments (NCT05392699). The trial was designed to primarily evaluate the safety of ABO2011 in single-dose cohorts and multiple-dose cohorts using “3+3” dose escalation approach. Patients (pts) would receive intratumoral ABO2011 at either a single dose, QW with 3 doses overall, every 3 weeks (Q3W) or QW followed by Q3W. Results: As of 09 December 2023, a total of 20 pts were enrolled and received at least one dose of ABO2011 at 4 μg single dose, 4 μg QW for 3 times, 12 μg single dose, 12 μg QW for 3 times followed by Q3W, 24 μg Q3W and 48 μg Q3W. Seventeen (85%) pts experienced treatment-related adverse events (TRAEs), and all were grade 1 or 2, including pyrexia (35%), pain (25%), and gamma-glutamyl transferase increased (25%). There were no dose-limiting toxicities or treatment-related SAEs reported and no TRAEs leading to treatment discontinuation. Of the 17 evaluable pts per RECISIT v1.1, 5 maintained stable disease, and the progression free survivals achieved 6.0 months, 5.6 months and 4.1 months for pts with colorectal cancer (6th line), non-small cell lung cancer (5th line) and pancreatic cancer (4th line), respectively. Peripheral blood IL-12 and IFN-γ levels increased and peaked at 24 hours and 48 hours after dosing, respectively, indicating expression of IL-12 and subsequent induction of IFN-γ after ABO2011 administration. Dose-dependent elevation of CXCL9, CXCL10, CXCL11 in peripheral blood was observed, consistent with the activation of downstream pathway of IFN-γ. CD8 T cells infiltration and PD-L1 expression were increased in tumor microenvironment (TME) at day 7, and further RNA sequencing analysis revealed increase of activated CD8 T cell and antigen processing and presentation after study treatment, suggesting the regulation of TME by ABO2011 and supporting the combination with PD-1(L1) inhibitor. Conclusions: Intratumoral ABO2011 was safe and well-tolerated in pts with advanced solid tumors. The pharmacodynamic changes were as expected. Promising preliminary antitumor activities of the single agent and the pharmacodynamic profiles support further investigation of ABO2011 in combination with immune checkpoint inhibitor. Clinical trial information: NCT05392699 .

Phase I study of MCLA-145, a bispecific antibody targeting CD137 and PD-L1, in solid tumors, as monotherapy or in combination with pembrolizumab.

2520 Background: MCLA-145, a human common light chain bispecific antibody targeting CD137 and the PD-1/PD-L1 axis, is designed to enhance both antigen-mediated T cell activation via CD137 costimulation, and blockade of inhibitory PD-L1. Interim data from the ongoing phase 1 study (NCT03922204) are presented. Methods: Patients (pts) with PD-L1 ≥1% advanced/metastatic solid tumors received MCLA-145 IV as monotherapy Q2W/Q3W in 21/28-d cycles respectively, or in combination with pembrolizumab 200 mg Q3W in 21-d cycles. Pts enrolled in combination had cancers that either relapsed after PD-(L)1 therapies or were immunotherapy naïve. Primary objectives are safety, tolerability and dose-limiting toxicity (DLT) of MCLA-145 alone or combined with pembrolizumab, and determination of the recommended dose for expansion (RDE). Secondary endpoints include efficacy, pharmacokinetics, pharmacodynamics (PD) and immunogenicity. Results: As of a December 4, 2023 data cutoff, 72 pts with 26 cancer types were treated; 25% of pts had non-small cell lung cancer (NSCLC). 3 pts were continuing combination therapy. Monotherapy: 53 pts (median age 60 y, 49% male) were treated across 8 dose levels (47 pts 0.4-75 mg Q2W, 6 pts 40 mg Q3W). Median number of cycles was 2 (range 1-39). 6 pts had DLTs in the 25-75 mg dose range (febrile neutropenia [2 pts], hemolytic anemia, myositis, ALT/AST increase, neutrophil/platelet decrease [1 pt each]). Most common adverse events (AEs; all grades/G3-4) were fatigue (51%/4%), decreased appetite (34%/2%), dyspnea (32%/0%), anemia (30%/9%), ALT/AST increase (25%/11%), and pyrexia (25%/0%). The incidence of any G3-4 AE was lower with 40 mg Q3W than across all Q2W dose levels (33% vs 66%). Combination: 19 pts (median age 61 y, 47% male) were treated with MCLA-145 10, 25 or 40 mg plus Q3W. Median number of cycles was 5 (range 1-16). No DLTs occurred. Most common AEs (all grades/G3-4) were fatigue (58%/11%), cough (42%/0%), constipation (32%/0%) and ALT/AST increase (21%/11%). The RDE was established at 40 mg Q3W for both monotherapy and combination. Preliminary antitumor activity was observed with monotherapy (52 evaluable pts): 5 partial responses (PRs) in glioblastoma (lasting >3 y), sarcoma, cervical, anal, and gastric cancer (treated for 2-11 mo); and combination (19 evaluable pts): 1 PR in Merkel cell carcinoma (treated 12+ mo), 1 complete response in PD-L1+ NSCLC (treated 6+ mo), both after prior immunotherapy. Disease control rate was 37% with monotherapy and 68% with combination. Exposure was dose-dependent with a terminal half-life of 69 h at 75 mg. Measure of peripheral blood Ki67+ CD8 T cells supports maximal PD activity at 40 mg. Conclusions: MCLA-145 given alone or in combination with pembrolizumab had a well-tolerated and manageable safety profile with encouraging clinical activity, including in pts who relapsed after PD-(L)1 therapies. Clinical trial information: NCT03922204 .

A phase I/II, first-in-human study of VLS-1488, an oral KIF18A inhibitor, in patients with advanced cancer.

TPS3181 Background: Chromosomal instability (CIN) is a hallmark of cancer characterized by high rates of chromosomal segregation errors during mitosis. This creates structural and numerical changes to chromosomes, driving genetic heterogeneity and cancer evolution. KIF18A is a mitotic kinesin protein shown to be important for successful division of cancer cells with CIN but not required for mitosis in normal diploid cells. Pre-clinical studies demonstrated that treatment of chromosomally unstable cancer cells in vitro and in xenograft models (HCC15 and OVCAR-3) with a KIF18A inhibitor resulted in failure of chromosomal congression, mitotic arrest, cell death and dose-dependent inhibition of tumor growth. VLS-1488 is an oral small molecule inhibitor of KIF18A that is being examined in an open-label, phase I/II, first-in-human study evaluating the safety, tolerability, pharmacokinetics (PK) and preliminary anti-tumor activity in advanced solid tumors with high prevalence of CIN. Methods: Key eligibility criteria include specific histologically confirmed metastatic or advanced tumor types with at least one site of measurable disease per RECIST 1.1, adequate organ function, and mismatch repair proficient/microsatellite stable.Eligible tumor types include high grade serous ovarian/fallopian tube/primary peritoneal cancer, squamous non-small cell lung cancer, triple negative breast cancer, gastric adenocarcinoma, gastroesophageal cancer, esophageal cancer, colorectal adenocarcinoma, transitional cell carcinoma of bladder, head and neck squamous cell carcinoma, ovarian or uterine carcinosarcoma, and uterine serous carcinoma. Subjects will receive VLS-1488 monotherapy continuously for 28-day cycles once daily. The study consists of two parts, Dose Escalation and Dose Expansion. Utilizing a Bayesian Optimal Interval (BOIN) design, Dose Escalation will examine the safety and tolerability of VLS-1488 at various dose levels (DLs) to identify the Maximum Tolerated Dose (MTD) and to select DLs for Dose Expansion. Dose Expansion may commence after the MTD or DLs of interest are identified. Dose Expansion will examine the safety, tolerability, preliminary efficacy and preliminary drug-drug interaction (DDI) and food effect risk of VLS-1488 in selected tumor types. Subjects enrolled to specific tumor type cohorts may be randomized to DLs of interest. Enrollment to Dose Escalation began in September 2023 and is ongoing. Clinical trial information: NCT05902988 .

An open-label, multicenter phase 1 study to characterize safety, tolerability, preliminary antitumor activity, and pharmacokinetics of VIP236 monotherapy in patients with advanced cancer.

An open-label, multicenter phase 1 study to characterize safety, tolerability, preliminary antitumor activity, and pharmacokinetics of VIP236 monotherapy in patients with advanced cancer.

A phase 2/3 study of Bicycle toxin conjugate BT8009 targeting nectin-4 in patients with locally advanced or metastatic urothelial cancer (la/mUC): Duravelo-2.

TPS4619 Background: BT8009 is a Bicycle toxin conjugate (BTC), comprising a highly selective bicyclic peptide targeting nectin-4 linked to the cytotoxin monomethyl auristatin E (MMAE) via a cleavable linker. Nectin-4 is an adhesion molecule commonly expressed in many tumor types, including urothelial cancer (UC), and is a validated therapeutic target (Hoffman-Censits 2021). BT8009 has a low molecular weight and short plasma half-life, with potential to rapidly penetrate solid tumors and reduce toxicity by minimizing exposure to normal tissue (Rigby 2022). Results from the ongoing phase 1/2 clinical trial of BT8009 (NCT04561362) indicate preliminary antitumor activity and a tolerable safety profile in patients (pts) with advanced malignancies including UC (Baldini 2023). This global, open label, phase 2/3 multicenter adaptive study aims to evaluate the safety and efficacy of BT8009 as monotherapy, or combined with pembrolizumab (pembro), vs chemotherapy in pts with locally advanced or metastatic UC (la/mUC) (NCT06225596/BT8009-230; Duravelo-2). Methods: The trial will enroll up to 956 adult pts in 2 cohorts. Cohort 1 will include n≤641 previously untreated pts eligible for platinum-based chemotherapy. Cohort 2 will include n≤315 pts with ≥1 prior systemic therapy, excluding enfortumab vedotin or other MMAE-based therapy. Pts must have la/mUC of the renal pelvis, ureter, bladder, or urethra, ECOG performance status ≤2 (Cohort 1) or ≤1 (Cohort 2), and adequate organ function. Cohort 1 will be randomized 1:1:1 to receive: 1) BT8009 5 mg/m2 on days (D)1, 8, and 15 + pembro 200 mg on D1; 2) BT8009 6 mg/m2 on D1 and 8 + pembro 200 mg on D1; or 3) chemotherapy (gemcitabine + cisplatin / carboplatin, followed by avelumab maintenance). Cohort 2 will be randomized 1:1 to receive: 1) BT8009 5 mg/m2 on D1, 8, and 15 or 2) BT8009 6 mg/m2 on D1 and 8. Cycle lengths will be 21D (28D for avelumab). After 30 pts in each dose arm have 9 weeks follow-up, an interim analysis will determine the optimal dose of BT8009 + pembro (Cohort 1) or BT8009 monotherapy (Cohort 2) to be used for the rest of the study. An additional Cohort 2 arm, optimal dose of BT8009 + pembro, will open after completion of the interim analysis. Discontinuation criteria include planned completion of therapy, progressive disease, and intolerable toxicity. Primary endpoints are progression-free survival (PFS; Cohort 1) and objective response rate (ORR; Cohort 2) assessed by blinded independent central review. Secondary endpoints are ORR (Cohort 1), PFS (Cohort 2), and overall survival, duration of response, disease control rate, safety/tolerability, and health-related quality of life (Cohorts 1 and 2). Pharmacokinetics, incidence/titers of antidrug antibodies, and tumor/peripheral biomarkers are exploratory endpoints. Efficacy endpoints will be assessed per RECIST v1.1. This study is actively recruiting. Clinical trial information: NCT06225596 .

IMM2510, an anti-PD-L1/VEGF bispecific antibody fusion protein, in patients with advanced solid tumors: A phase I dose-escalation study.

e14506 Background: IMM2510 is a novel bispecific antibody fusion protein targeting PD-L1 and VEGF. The preclinical study demonstrated that IMM2510 induced significantly stronger anti-tumor activity than either monotherapy or combination of PD-L1 inhibitor and anti-VEGF antibody through blocking the PD-1/PD-L1 pathway and thus activate T cells and reducing VEGF-mediated tumor angiogenesis as well as an enhanced ADCC effect. We previously disclosed the preliminary clinical data of IMM2510, and here we further report safety and efficacy results of IMM2510 in the phase I dose escalation study. Methods: A phase I, multicenter, open-label, dose-escalation study, was designed to evaluate the safety, efficacy, recommended phase II dose (RP2D), and pharmacokinetics (PK) of IMM2510 in patients (pts) with advanced solid tumors. The study was designed with an accelerated titration followed by a standard 3+3 design. IMM2510 (0.007, 0.03, 0.1, 0.3, 1.0, 3.0, 6.0, 10.0, 20.0 mg/kg) was administered intravenously Q2W as monotherapy. Results: As of Dec 21, 2023, 33 pts had received IMM2510 at 9 dose levels (0.007-20.0 mg/kg), the median age was 57 years (range 36-74), the median prior line of therapy was 3 (range 1-13), and 27.3% pts received prior anti PD-1/PD-L1 inhibitor therapies. Treatment-related adverse events (TRAEs) occurred in 32 pts (97.0%). Most TRAEs were grade 1 or 2. The most common TRAEs (≥ 20%) of all grades were infusion related reaction (IRR) (72.7%), platelet count decreased (39.4%), anemia (33.3%) and diarrhea (21.2%). Grade ≥3 TRAEs occurred in 11 pts (33.3%). Grade ≥3 TRAEs (≥5%) were IRR (9.1%), platelet count decreased (6.1%), lymphocyte count decreased (6.1%) and diarrhea (6.1%). TRAEs leading to treatment discontinuation occurred in 3 pts (9.1%) which were IRR, hypersensitivity and pyrexia, respectively. No DLT occurred. In 25 response evaluable pts, 3 pts had confirmed PR: 1 pt with sq-NSCLC (onco-driver gene negative, previous IO treatment failure) at 3 mg/kg with tumor shrinkage 46% and still on the treatment with treatment duration over 20 months; 1 pt with sq-NSCLC at 10 mg/kg with tumor shrinkage about 32% along with treatment duration 9.4 months; 1 pt with thymus adeno-squamous carcinoma (PD-L1 CPS 80) at 20 mg/kg with tumor shrinkage over 53% and still remains on the treatment along with treatment duration 8.1 months. In addition, 7 pts with BOR SD and 4 of them had over 15% decreased tumor burden (1 cervical cancer at 3 mg/kg, 2 non-sq NSCLC at 10 and 20 mg/kg respectively, 1 ovarian cancer at 20 mg/kg). The half-life of IMM2510 in 20.0mg/kg dose group was around 6.8 days. The RP2D was determined to be 20.0 mg/kg. Conclusions: IMM2510 is well tolerated in general and preliminary anti-tumor activity in solid tumors is encouraging. The phase Ib/II is ongoing to enroll patients. Clinical trial information: NCT05972460 .

Phase 1 study of BDTX-1535, an oral 4th generation covalent EGFR inhibitor, in patients with recurrent glioblastoma: Preliminary dose escalation results.

2068 Background: Epidermal growth factor receptor ( EGFR) gene is the most frequently altered oncogenic driver in glioblastoma (GBM). In-frame deletion alterations (e.g., EGFRvIII) and missense mutations co-occur in the setting of EGFR gene amplification and are characterized as a hallmark of disease pathogenesis in GBM. BDTX-1535 is an oral, highly potent, brain penetrant, selective, irreversible 4th generation tyrosine kinase inhibitor that targets EGFR alterations in GBM and NSCLC. Preliminary results of the Phase 1 dose escalation study (NCT05256290) of patients with recurrent GBM (rGBM) are presented here. Methods: BDTX-1535-101 is a first-in-human study that enrolled patients with either rGBM harboring EGFR alterations following standard of care or patients with locally advanced or metastatic EGFR mutated NSCLC that progressed on prior EGFR TKIs. Using an adaptive Bayesian optimal interval design in the Phase 1 part, patients were enrolled at increasing dose cohorts and were treated daily for 21-day cycles until treatment discontinuation. The primary objective was to determine the BDTX-1535 recommended Phase 2 dose based on the overall safety, PK, pharmacodynamics, and preliminary antitumor activity. Results: Twenty-seven patients with rGBM were enrolled in the Phase 1 cohort that consisted of 54 patients in total including 27 patients with NSCLC. Patients were treated across seven dose levels (15mg – 400mg QD). The mean age of patients with rGBM was 58.7 years (range 41-85) with 96% of patients with previous temozolomide (TMZ) treatment and a median of 2 lines of prior therapy (range 1-4). The most common all-grade treatment-related AEs across all cohorts were rash (78%), diarrhea (41%), fatigue (15%), stomatitis (11%), decreased appetite (11%), nausea (11%) and paronychia (11%). Gr 3 TRAEs ≥ 10% included rash (19%) reported at 300 or 400 mg QD doses. Plasma exposure of BDTX-1535 increased dose proportionally and had a half-life of ~15h, supporting once daily dosing. The maximum tolerated dose (MTD) is 300 mg QD. Among 19 evaluable patients for response based on RANO criteria, 1 confirmed partial response was observed and 8 patients achieved stable disease. Five patients remained on BDTX-1535 with stable disease for an extended period (>5 months) who previously performed poorly on TMZ with short treatment duration, and 1 patient continues on BDTX-1535 after 16 months of treatment. Conclusions: BDTX-1535 was well-tolerated up to 300mg daily, which is the MTD, and promising preliminary clinical activity was observed in patients with rGBM after relapse on standard of care treatment. Given the inability to reconfirm EGFR status at the time of treatment with BDTX-1535 in this Phase 1 trial, further exploration of BDTX-1535 in a “window of opportunity” study is ongoing (NCT06072586). Clinical trial information: NCT05256290 .

BC3195, a novel ADC targeting CDH3: Preliminary results of a first-in-human phase I study in patients with advanced solid malignancies.

e15008 Background: Cadherin-3 (CDH3), a calcium-dependent cell-cell adhesion glycoprotein, is overexpressed on lung, breast, ovarian, colorectal, pancreatic, head and neck and other malignancies, but with negligible expression on nonmalignant tissues, and associated with cancer aggressiveness, invasiveness, and poor prognosis. BC3195 is known as the only antibody drug conjugate (ADC) in clinical stage, targeting CDH3 with payload of monomethyl auristatin E (MMAE). Methods: A phase I, open-label, first in human study to evaluate the safety, tolerability, PK, and preliminary antitumor activity of BC3195 is being performed in subjects with advanced solid malignancies. Disease assessments are performed every 6 weeks using RECIST v1.1. BC3195 is administered as 1 hour (h) IV infusion every 3 weeks. An evaluation of seven dose levels is planned: 0.3, 0.6, 1.2, 2.4, 3.0 and 3.6 mg/kg with a BOIN design guiding dose escalation. Results: Up to January 1st, 2024, nine patients (median age, 59; male, 56%) have been enrolled and treated with BC3195, with 3 patients each in the 0.3, 0.6 and 1.2 mg/kg dose cohorts. No DLT was observed across all the 3 dose cohorts. Treatment emergent adverse events (TEAEs) occurring in ≥3 patients included: aspartate aminotransferase increased (5/9, 55.6%), conjugated bilirubin increased (5/9, 55.6%), triglycerides increased (4/9, 44%), uric acid increased (3/9, 33.3%), heart rate increased (3/9, 33%), and hypoalbuminemia (5/9, 55.6%), cough (4/9, 44.4%), hyponatraemia (4/9, 44.4%), anemia (4/9, 44.4%), asthenia (3/9, 33.3%), rash (3/9, 33.3%), vomiting (3/9, 33.3%) and back pain (3/9, 33.3%). Two subjects experienced ≥ Grade 3 TEAEs unrelated to study drug. Six subjects were evaluable for tumor assessment, and 3 subjects (3/6, 50%) show stable disease (SD) as the best response (2 subjects with target lesion reduction). PK results demonstrated that exposure for the ADC and total antibody (TA) increased with dose, the relationship between AUC0-last and dose was greater than dose-proportional, while Cmax was linear. Free MMAE was highest at the 1.2 mg/kg dose level. Median Tmax values for ADC and TA were 1 h (end of infusion), and median Tmax for free MMAE was 25-169 h. In addition, elimination t1/2 values averaged 27-48 h, 31-68 h and 63-76 h for the ADC, TA, and MMAE, respectively. Conclusions: BC3195 exhibited favorable safety profile and PK characteristics up to 1.2mg/kg. Given BC31095’s safety and PK behavior, as well as preliminary activity at the 0.6 mg/kg dose level, patient enrollment at higher dose levels is ongoing. Clinical trial information: NCT05957471 .

A first-in-human phase 1, multicenter, open-label study of CB-012, a next-generation CRISPR-edited allogeneic anti-CLL-1 CAR-T cell therapy for adults with relapsed/refractory acute myeloid leukemia (AMpLify).

TPS6586 Background: CAR-T cell therapies have shown significant clinical benefit in treating adults with many hematologic malignancies. In acute myeloid leukemia (AML), a challenge in the development of CAR-T cell therapies has been the limitation of suitable target antigens since many are also expressed on hematopoietic stem cells (HSCs). The target antigen C-type lectin-like molecule-1 (CLL-1) has emerged as an attractive therapeutic target due to its expression on AML mature blasts and leukemic stem cells and its absence on HSCs. CB-012 is an allogeneic CAR-T cell therapy that targets CLL-1. CB-012 is derived from healthy donor T cells by using Cas12a CRISPR hybrid RNA-DNA (chRDNA) technology to introduce 5 genome edits: (1) TRAC gene knockout (KO), which eliminates T cell receptor expression to reduce the risk of graft-versus-host disease, (2) site-directed insertion of a fully human anti-CLL-1 CAR into the TRAC locus, (3) KO of PD-1 to enhance antitumor activity by reducing T cell exhaustion, (4) β2-microgobulin ( B 2M) gene KO, which eliminates HLA class I presentation to mitigate host T cell-mediated rejection, and (5) site-directed insertion of a B2M–HLA-E-peptide fusion into the B 2M locus to reduce NK cell-mediated rejection. In murine xenograft models of AML, CB-012 significantly reduced the tumor burden and increased the survival of mice bearing CLL-1+PD-L1+ tumors. Methods: CB-012 is being evaluated in a multicenter, Phase 1 clinical trial in patients with relapsed/refractory (r/r) AML. A 3+3 dose escalation design is being utilized with the primary objectives to determine the safety and tolerability of CB-012 and the recommended Phase 2 dose (RP2D). An expansion phase will follow dose escalation at the recommended dose(s) for expansion. Additional objectives include preliminary antitumor activity and pharmacokinetics. Key inclusion criteria include nonproliferative disease defined as ≤25% blasts in the bone marrow and peripheral blood, ECOG performance status ≤1, and adequate organ function. After receiving lymphodepletion therapy with cyclophosphamide (750 mg/m2/d) and fludarabine (30 mg/m2/d) administered concurrently for 3 days followed by a 2-day break, patients receive a single-dose infusion of CB-012 and are followed for safety and efficacy. The dose escalation portion of the study is actively enrolling patients. The AMpLify trial is registered at clinicaltrials.gov (NCT06128044). Clinical trial information: NCT06128044 .

An open-label, phase 1, multicenter study to evaluate the safety and preliminary anti-tumor activity of NT-112 in human leukocyte antigen-C*08:02–positive adult patients with unresectable, advanced, and/or metastatic solid tumors that are positive for the KRAS G12D mutation.

TPS2677 Background: The landscape of cancer treatment is evolving with the emergence of innovative immunotherapies. Among these, T cell receptor-engineered T cell (TCR-T) therapy has shown promise for patients with solid tumor malignancies. Targeting driver mutations, such as KRAS, may offer novel therapeutic options for patients with limited treatment options. Oncogenic driver mutations in KRAS typically involve single-base mutations at genomic hotspot locations. The KRAS isoform is mutated in 84% of RAS-driven cancers and in nearly 100% of pancreatic ductal adenocarcinoma (PDAC). The KRAS G12D mutation is the most frequent mutation in PDAC (28%), followed by colorectal cancers (12%). Despite its well-established target role in tumorigenesis, there is no FDA-approved therapy targeting the G12D variant. NT-112 is an autologous TCR-T cell therapy targeting the KRAS G12D mutation presented by HLA-C*08:02, armored by disruption of the gene encoding the transforming growth factor beta receptor type 2 (TGFBR2) in order to reduce the immunosuppressive effect of TGF-β in the tumor microenvironment. Methods: This first-in-human, open label, multicenter, Phase 1, dose escalation study aims to assess the safety, identify the MTD and evaluate potential anti-tumor activities of NT-112 in subjects with solid tumors. The study will enroll up to 24 adult subjects harboring the KRAS G12D mutation that are HLA-C*08:02 positive, who exhibit progressive or recurrent disease after at least one line of standard of care treatment. Enrolled patients will undergo leukapheresis, from which, CD4 and CD8 T cells will be enriched and activated ex vivo. The genes encoding the TGFBR2 and the endogenous TCR α and β chains are knocked out from the activated T cells utilizing clustered regularly interspaced short palindromic repeats (CRISPR-Cas9). The HLA-C*08:02-restricted TCR specific to the KRAS G12D mutation is knocked-in in the TCR α locus. Subjects will undergo standard lymphodepletion followed by a single infusion of NT-112 and concurrent, daily, subcutaneous, recombinant IL-2 for up to 8 days. Dose escalation will occur across 3 ascending dose levels following the BOIN design. Subjects will be monitored for dose-limiting toxicities for 28 days following NT-112 infusion. Disease response will be assessed according to the RECIST v1.1 criteria. Comprehensive translational analysis will be conducted to gain insights into the mechanism of action, biomarkers associated with treatment response, and potential mechanisms of resistance. All subjects will be followed for up to 15 years. Clinical trial information: NCT06218914 .

A phase I trial of intratumoral STX-001: A novel self-replicating mRNA expressing IL-12 alone or with pembrolizumab in advanced solid tumors.

TPS2696 Background: STX-001 is a multi-mechanistic lipid nanoparticle encapsulated synthetic self-replicating mRNA, engineered to express the IL-12 cytokine for an extended duration when administered intratumorally. A murine surrogate of STX-001 induces deep durable responses in multiple preclinical solid tumor models. This Phase 1 open-label, multi-center first-in-human dose-escalation trial evaluates the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antitumor activity of STX-001 alone, or in combination with pembrolizumab in patients with treatment refractory advanced cancers. Methods: Approximately 30 adults ≥18 years of age with histologically confirmed advanced solid tumors that are refractory to standard treatments will be enrolled. The study will consist of two arms, an STX-001 monotherapy arm and an STX-001 + pembrolizumab combination arm, enrolling approximately 15 patients each. Key eligibility criteria include ECOG status 0 or 1, a tumor lesion amendable to injection, and confirmed prior disease progression. STX-001 will be administered every 3 weeks (q3w) for 3 doses and then every 6 weeks (q6w) for a further 3 doses. Tumor biopsies will be obtained at baseline and after the first STX-001 administration. Primary endpoints will include safety and maximum tolerated dose (MTD), with secondary endpoints encompassing pharmacokinetics and preliminary efficacy as measured by RECIST 1.1. To determine the MTD, this study will employ the Bayesian optimal interval (BOIN) design, with the 3 + 3 design run-in and a recommended phase 2 dose (RP2D) will be determined. Tumor response will be assessed using RECIST 1.1 criteria. Exploratory pharmacodynamic analyses will assess tumor-infiltrating lymphocytes and STX-001 mRNA in baseline and on-treatment biopsies, evaluate inflammatory cytokine profiles in plasma, determine immune activation in circulating immune cells, and measure circulating tumor DNA (ctDNA) for molecular response assessment. Clinical trial information: NCT06249048 .