Pharmacodynamic Effects Research Articles

Pharmacokinetics and Pharmacodynamics of Inhaled Nicotine Salt and Free-Base Using an E-cigarette: A Randomized Crossover Study.

Popular "pod-style" e-cigarettes commonly use nicotine salt-based e-liquids that cause less irritation when inhaled and can deliver higher nicotine concentrations than free-base nicotine. This study investigated the pharmacokinetic and pharmacodynamic effects of different nicotine formulations (salt vs. free-base) and concentrations that might influence systemic nicotine absorption and appeal of e-cigarettes. In this randomized, double-blind, within-subject crossover study, 20 non-nicotine-naïve participants were switched among three e-liquids (free-base nicotine 20 mg/mL, nicotine salt 20 mg/mL, nicotine salt 40 mg/mL) using a refillable pod system and a standardized vaping protocol (one puff every 30 seconds, 10 puffs total). Serum nicotine concentrations and vital signs were assessed over 180 minutes; direct effects, craving, satisfaction, withdrawal, and respiratory symptoms were measured using questionnaires. CYP2A6 genotypes and the nicotine metabolite ratio were also assessed. Eleven (55%) participants were male and the median age was 23.5 years (range 18-67). All three formulations differed significantly in peak serum nicotine concentration (baseline adjusted Cmax, median (range): 12.0 ng/mL (1.6-27.3), 5.4 ng/mL (1.9-18.7), and 3.0 ng/mL (1.3-8.8) for nicotine salt 40 mg/mL, nicotine salt 20 mg/mL and free-base 20 mg/mL, respectively). All groups reached Cmax 2.0-2.5 minutes (median) after their last puff. Differences in subjective effects were not statistically significant. No serious adverse events were observed. Free-base 20 mg/mL formulations achieved lower blood nicotine concentrations than nicotine salt 20 mg/mL, while 40 mg/mL nicotine salt yielded concentrations similar to cigarette smoking. The findings can inform regulatory policy regarding e-liquids and their potential use in smoking cessation. Nicotine salt formulations inhaled by an e-cigarette led to higher nicotine delivery compared to nicotine-free-base formulations with the same nicotine concentration. These findings should be considered in future regulatory discussions. The 40 mg/mL nicotine salt formulation showed similar nicotine delivery as combustible cigarettes, albeit at concentrations over the maximum limit for e-liquids allowed in the European Union. Nicotine delivery resembling combustible cigarettes might be beneficial for smokers willing to quit to adequately alleviate withdrawal symptoms. However, increased nicotine delivery can also pose a public health risk, raising concerns about abuse liability, especially among youth and nonsmokers.

Abstract CT120: Phase 1 trial of bortezomib and clofarabine combination in adults with refractory solid tumors

Abstract Background/Rationale: The combination of the proteosome inhibitor bortezomib (B) and purine analog clofarabine (C) induced synergy in the NCI-ALMANAC screen of FDA-approved cancer drug combinations; preclinical xenograft studies confirmed this activity and suggested a combination mechanism of action involving greater-than-additive effects on markers of DNA damage response (DDR) and pyroptotic cell death. We conducted a phase 1 clinical trial (NCT02211755) to assess the safety of the B and C combination in patients (pts) with solid tumors and myelodysplastic syndrome (MDS), and to determine the effect of the combination on biomarkers of cell death and DDR. Due to limited MDS pt accrual, this cohort was terminated early, and MDS pt data are not included here.Objectives: The primary objective was to assess safety and maximum tolerated dose (MTD) of B and C in pts with solid tumors and MDS. Secondary objectives were to assess pharmacodynamic (PD) effects using validated assays for cell death and DDR in tumor biopsy tissue and circulating tumor cells (CTCs).Design: The dose escalation followed a 3+3 design, enrolling at least 1 pt from each group (solid tumor and MDS) per dose level until hematologic dose-limiting toxicity (DLT) was observed. Adverse events (AEs) were graded using CTCAE v4.0. Ten planned dose levels (DL) included C ranging from 1 to 10 mg/m2 on D2-5 of cycle 1 and D1-5 from cycle 2 on and B from 0.8 to 1.5 mg/m2 on D1 and D4 of 21-day cycles. Response was assessed by RECIST 1.1 every 2 cycles. Biopsies were performed on the expansion cohort pre-dose, 2-4 hours after C on C1D1, and C2D4; CTCs were collected pre-dose, C1D2, day 1 of subsequent cycles, and at progression.Results: We enrolled 25 pts with advanced solid tumors (15 male, 10 female). Median age was 62 years (range 30-81). DLT occurred in 4 pts (at DL3 [1 pt], DL5 [2], and DL4 [1]) and included Grade 4 neutropenia (3), Grade 3-4 thrombocytopenia (3), and Grade 3 anemia (1). There were no Grade 5 AEs. DL4 (B 1.3 mg/m2 D1 and 4, C 1.5 mg/m2 D1-5, 21-day cycles) was the MTD. Twenty-one pts were evaluable for response; the best response was stable disease (SD) for 10 pts (47.6%). Median duration of response for pts achieving SD was 3.5 months (range 2-7). Of note, 3 out of the 10 colorectal cancer (CRC) pts had SD > 4 months. Four pts with CRC have been enrolled in an expansion cohort for biomarker evaluation; induction of pyroptosis has been measured in a limited number of paired biopsies collected to date. Conclusions: Despite preclinical evidence of synergy, the human equivalent of the efficacious preclinical combination dose could not be achieved clinically, which may account for the lack of antitumor response. Prolonged SD was observed in 3 pts with CRC. PD analyses, including of CTCs and additional cell death biomarkers, are ongoing. Funded by NCI Contract No. HHSN261201500003I. Citation Format: Andre L. De Souza, Naoko Takebe, Alice P. Chen, James H. Doroshow, Ralph E. Parchment, Apurva K. Srivastava, Lawrence Rubistein, Deborah Wilsker, Brandon L. Miller, Murielle Hogu, Geraldine O`Sullivan Coney, Shivaani Kummar, Jeevan Govindharajulu, Robert Meehan, William G. Herrick, Angie Dull, Donna Ketchum, Shaowei Li, Jiuping Ji, Richard Piekarz. Phase 1 trial of bortezomib and clofarabine combination in adults with refractory solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT120.

Abstract CT195: First-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors harboring cancer-associated gene alterations

Abstract Background: WEE1 tyrosine kinase plays a key role in cell cycle regulation and DNA damage responses, acting as a principal gatekeeper of the G1-S and G2-M cell cycle checkpoints. Thus, inhibition of WEE1 can result in high cyclin-dependent kinase 1 and 2 activities, leading to aberrant cell cycle progression. Increasing premature entry into mitosis and subsequent apoptosis via WEE1 inhibition is one potential approach to killing cancer cells effectively. APR-1051 is an orally bioavailable, highly potent, small molecule inhibitor of WEE1 that has demonstrated in vivo anti-proliferative activity in multiple cancer cell lines and high selectivity for WEE1 versus polo-like kinases 1, 2, and 3. Increased selectivity for WEE1 may reduce the myelosuppressive toxicity (e.g., limiting Grade 3 toxicities) reported with other WEE1 inhibitors. Methods: The primary aim of this multi-center, open-label Phase I study is to characterize the safety, dose-limiting toxicities (DLTs), maximum tolerated dose (MTD)/maximum administered dose (MAD) and recommended Phase 2 dose (RP2D) of APR-1051 in patients with advanced solid tumors harboring cancer-associated gene alterations. Secondary objectives include evaluating the pharmacokinetic (PK) properties of APR-1051, assessing the effect of food on its PK, and its preliminary efficacy per RECIST version 1.1. The exploratory objective is to assess the pharmacodynamic effects of APR-1051. For dose escalation, an accelerated titration followed by a BOIN design will be utilized to determine the MAD/MTD. Upon completion of the dose escalation, two suitable doses and schedules of single-agent APR-1051 will be determined for further investigation in dose selection optimization. Key inclusion criteria are age at least 18 years with advanced solid tumor and cancer-associated gene alterations (e.g., amplification/overexpression of CCNE1 or CCNE2, deleterious mutations in FBXW7 or PPP2R1A), ECOG PS 0 or 1, and adequate organ function. Key exclusion criteria are cancer therapy within 3 weeks or at least 5 half-lives, prior radiation therapy at the target lesion except if evidence of disease progression, unresolved therapy-related AEs, investigational agent within 5 half-lives or 30 days of study drug, prior WEE1 inhibitor, CNS metastases or unstable involvement, secondary malignancies that are active and/or require therapy, and concomitant moderate/strong inhibitors/inducers of CYP3A4/5, MDR1, or BCRP. Up to 79 patients will be enrolled at 3 to 5 sites in the United States. Citation Format: Timothy A. Yap, Crystal Miller, David Stenehjem, Eric J. Brown, Mike Carleton, Nadeem Q. Mirza. First-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors harboring cancer-associated gene alterations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT195.

Abstract ND07: BBO-8520, a first-in-class, direct inhibitor of KRASG12C (ON), locks GTP-bound KRASG12C in the state 1 conformation resulting in rapid and complete blockade of effector binding

Abstract The glycine to cysteine mutation on codon 12 of KRAS (KRASG12C) is found in ~15% of non-small cell lung cancers and in a low percentage of colorectal and pancreatic adenocarcinomas. This activating mutation pushes the balance of cellular KRAS towards its active, GTP-bound (ON) state that signals downstream and drives cellular proliferation. Recently approved inhibitors of KRASG12C that bind and sequester the oncogenic protein in its inactive GDP-bound (OFF) state, have demonstrated clinical efficacy; however, median duration of response has been < 9 months. Rapid tumor cell adaptation to KRASG12C (OFF)-only inhibitors like sotorasib and adagrasib has been attributed to reactivation of MAPK signaling through increased RTK flux and KRASG12C gene amplification that result in increased KRASG12C (ON) presence and activity. To block rapid KRASG12C (ON)-driven adaptation to KRASG12C (OFF) inhibitors, we have developed a first-in-class, direct, small molecule covalent inhibitor of both KRASG12C (ON) and (OFF) states. BBO-8520 binds in the switch II pocket and covalently modifies both the (ON) and (OFF) forms of KRASG12C independently of any other partner proteins. Mass spectrometry analysis of KRASG12C covalent engagement by BBO-8520 shows complete modification of both KRASG12C states within 15 minutes, while sotorasib and adagrasib, only modify the (OFF) state. 31P NMR studies demonstrate that BBO-8520 inhibits KRASG12C (ON) by locking the GTP-bound protein in state 1, a conformation where it is unable to bind effectors. The ability to directly bind KRASG12C (ON) leads to potent (~30 nM) inhibition in an effector (Raf1) binding assay where inactive (OFF) inhibitors demonstrate no measurable potency. BBO-8520 displays highly significant binding to KRASG12C in a global cysteine proteome analysis and is 100x more selective for KRASG12C than for WT KRAS and other mutant isoforms, with no measurable activity against N- or H-RAS. Cellular signaling and viability assays show that BBO-8520 has sub-nanomolar potency against KRASG12C mutant cell lines. In effector binding assays, BBO-8520 rapidly and completely blocks the RAS-RAF1 interaction, clearly differentiating it from inactive (OFF) inhibitors that require longer times to allow for cycling to the inactive (OFF) state. Additionally, long-term clonogenic assays that detect the emergence of resistance in the presence of inhibitors show that BBO-8520 is at least 30x more potent than sotorasib and adagrasib at preventing outgrowth. Importantly, the presence of growth factors (e.g., EGF) that push KRASG12C into its (ON) state, and significantly lower the potency of inactive (OFF) inhibitors (>20x), have only minor effects on BBO-8520’s potency. Drug-like pharmacokinetic properties allow BBO-8520 to achieve strong dose- and time-dependent pharmacodynamic effects (>80% inhibition of pERK) following a single, oral dose in KRASG12C mutant tumor bearing mice. In vivo target engagement and pERK inhibition in the MIAPaCa-2 and H358 KRASG12C mutant tumor models resulted in durable tumor regressions at 10 mg/kg. Similarly, daily dosing of 10 mg/kg of BBO-8520 in the KrasG12C-p53 driven GEMM model for 6 weeks resulted in better than 50% lung tumor volume regression. BBO-8520’s potent activity against KRASG12C (ON) presents, for the first time, the potential opportunity to directly target all mutant KRASG12C in cells, including the active form of KRASG12C, enabling efficacy following complete or near-complete target inhibition. Citation Format: Anna E. Maciag, James Stice, Bin Wang, Alok Sharma, Albert Chan, Ken Lin, Devansh Singh, Marcin Dyba, Yue Yang, Saman Setoodeh, Brian P. Smith, Dana Rabara, Zuhui Zhang, Erik K. Larsen, Dom Esposito, John Paul Denson, Michela Ranieri, Mary Meynardie, Sadaf Mehdizadeh, Patrick Alexander, Maria Abreu Blanco, David Turner, Rui Xu, Felice C. Lightstone, Kwok Kin Wong, Dhirendra Simanshu, Keshi Wang, Andrew G. Stephen, Kerstin Sinkevicius, Dwight V. Nissley, Eli Wallace, Frank McCormick, Pedro J. Beltran. BBO-8520, a first-in-class, direct inhibitor of KRASG12C (ON), locks GTP-bound KRASG12C in the state 1 conformation resulting in rapid and complete blockade of effector binding [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr ND07.

Abstract CT191: First-in-human, dose escalation and expansion study of MT-6402, a novel engineered toxin body (ETB) targeting PD-L1, in patients with PD-L1 expressing relapsed/refractory advanced solid tumors: Interim data

Abstract MT-6402 is a PD-L1-targeted ETB capable of directly killing PD-L1 expressing cells by internalization of a de-immunized Shiga-like toxin A subunit (SLTA), resulting in ribosomal destruction. Targeting PD-L1 expressing tumor cells may directly drive tumor regression, whereas targeting PD-L1 expressing immune cells may release immunosuppression and drive tumor immune recognition. MT-6402 also delivers an HLA-A*02 restricted cytomegalovirus (CMV) class I antigen into PD-L1 expressing cells (antigen seeding) that can be recognized by existing CMV-specific cytotoxic T cells. A first-in-human dose escalation (Part A) and expansion (Part B) study with a weekly intravenous administration of MT-6402 in 4-week cycles was initiated in 2021. Safety and tolerability are primary objectives. Efficacy, pharmacokinetics, and pharmacodynamic data are also collected. As of 10Dec2023, 53 total patients (pts) with PD-L1-expressing advanced solid tumors received ≥ 1 dose of MT-6402: 48 pts in Part A ranging in dose 16 to 100 µg/kg and 5 pts in Part B at 63 µg/kg, just below the maximum tolerated dose (MTD) of 83 µg/kg. MT-6402 was well tolerated in Part A, completed Sept2023. 5 dose limiting toxicities have been reported: a Grade (G)3 maculopapular rash at 24 µg/kg, a G3 infusion related reaction at 63 µg/kg, a G1 cardiac troponin T increase leading to dosing hold for ≥2 weeks at 83 µg/kg, a G3 maculopapular rash at 100 µg/kg, and a G1 cardiac troponin T increase at 100 µg/kg. There were no G4 or G5 drug-related adverse events. In Part B, pts with PD-L1 scores of TPS ≥ 50% will be treated at MTD or lower and 5 pts have been treated at 63 µg/kg. Signs of antitumor activity have been reported including a long-lasting PR with 70% tumor reduction have been observed in a pt with CPI-refractory nasopharyngeal carcinoma on treatment 14+ cycles at 63 µg/kg. This pt has a PD-L1 TPS score of 2% indicating immune cell clearance may have driven the response. The most common cancer in Part A is Squamous Cell Carcinoma of the Head and Neck (10 pts). Pharmacodynamic effects include a significant reduction in peripheral PD-L1+ immune cells, indicating a PD-L1 target-specific effect. Substantial alterations in serum cytokines associated with the tumor microenvironment were noted after each dose in most pts in a dose dependent manner. Most pts display increased CD8/CD4 ratios with IL-2 and TNFα cytokine release, indicative of immune activation due to elimination of immune cells. CMV-specific CD8 T-cells exhibited a pattern of extravasation from the periphery in HLA-A*02+/CMV+ pts suggesting antigen seeding. These results describe a novel approach to checkpoint modulation by MT-6402 with targeted cell killing and altered tumor immunophenotype, particularly in HLA-A*02/CMV+ pts. These results provide rationale for continued development of MT-6402. Citation Format: Brian A. Van Tine, Eugene Ahn, Rebecca A. Redman, Minal A. Barve, William J. Edenfield, Julio Peguero, Victoria M. Villaflor, Drew W. Rasco, Steven F. Powell, Admasu T. Mamuye, Chris B. Moore, Joshua M. Pelham, Soratree Charoenthongtrakul, David R. Spigel. First-in-human, dose escalation and expansion study of MT-6402, a novel engineered toxin body (ETB) targeting PD-L1, in patients with PD-L1 expressing relapsed/refractory advanced solid tumors: Interim data [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT191.

Precision Endpoints for Contemporary Precision Oncology Trials.

Traditional endpoints such as progression-free survival and overall survival do not fully capture the pharmacologic and pharmacodynamic effects of a therapeutic intervention. Incorporating mechanism-driven biomarkers and validated surrogate proximal endpoints can provide orthogonal readouts of anti-tumor activity and delineate the relative contribution of treatment components on an individual level, highlighting the limitation of solely relying on aggregated readouts from clinical trials to facilitate go/no-go decisions for precision therapies.

Pharmacodynamic effects following co-administration of cannabinoids and opioids: a scoping review of human experimental studies.

Cannabinoids are increasingly used in the management of chronic pain. Although analgesic potential has been demonstrated, cannabinoids interact with a range of bodily functions that are also influenced by chronic pain medications, including opioids. We performed a scoping review of literature on the pharmacodynamic effects following the co-administration of cannabinoids and opioids. We systematically searched EMBASE, PubMed, and PsycINFO for studies that experimentally investigated the co-effects of cannabinoids and opioids in human subjects. Available evidence was summarized by clinical population and organ system. A risk of bias assessment was performed. A total of 16 studies met the inclusion criteria. Study populations included patients with chronic non-cancer and cancer pain on long-term opioid regimens and healthy young adults without prior exposure to opioids who were subject to experimental nociceptive stimuli. Commonly administered cannabinoid agents included Δ9-tetrahydrocannabinol and/or cannabidiol. Co-administration of cannabinoids and opioids did not consistently improve pain outcomes; however, sleep and mood benefits were observed in chronic pain patients. Increased somnolence, memory and attention impairment, dizziness, gait disturbance, and nauseousness and vomiting were noted with co-administration of cannabinoids and opioids. Cardiorespiratory effects following co-administration appeared to vary according to duration of exposure, population type, and prior exposure to cannabinoids and opioids. The available evidence directly investigating the pharmacodynamic effects following co-administration of cannabinoids and opioids for non-analgesic outcomes is scarce and suffers from a lack of methodological reporting. As such, further research in this area with comprehensive methodologic reporting is warranted.

Autologous human preclinical modeling of melanoma interpatient clinical responses to immunotherapeutics

BackgroundDespite recent advances in immunotherapy, a substantial population of late-stage melanoma patients still fail to achieve sustained clinical benefit. Lack of translational preclinical models continues to be a major challenge...

P2Y12 Inhibition in Patients Requiring Oral Anticoagulation After Percutaneous Coronary Intervention: The SWAP-AC–2 Study

BackgroundAmong patients treated with a novel oral anticoagulant (NOAC) undergoing percutaneous coronary intervention (PCI), combination therapy with clopidogrel (ie, known as dual antithrombotic therapy [DAT]) is the treatment of choice. However, there are concerns for individuals with impaired response to clopidogrel. ObjectivesThe authors sought to assess the pharmacodynamic (PD) effects of clopidogrel vs low-dose ticagrelor in patients with impaired clopidogrel response assessed by the ABCD-GENE score. MethodsThis was a prospective, randomized PD study of NOAC-treated patients undergoing PCI. Patients with an ABCD-GENE score ≥10 (n = 39), defined as having impaired clopidogrel response, were randomized to low-dose ticagrelor (n = 20; 60 mg twice a day) or clopidogrel (n = 19; 75 mg once a day). Patients with an ABCD-GENE score <10 (n = 42) were treated with clopidogrel (75 mg once a day; control cohort). PD assessments at baseline and 30 days post-randomization (trough and peak) were performed to assess P2Y12 signaling (VerifyNow P2Y12 reaction units [PRU], light transmittance aggregometry, and vasodilator-stimulated phosphoprotein); makers of thrombosis not specific to P2Y12 signaling were also assessed. The primary endpoint was PRU (trough levels) at 30 days. ResultsAt 30 days, PRU levels were reduced with ticagrelor-based DAT compared with clopidogrel-based DAT at trough (23.0 [Q1-Q3: 3.0-46.0] vs 154.5 [Q1-Q3: 77.5-183.0]; P < 0.001) and peak (6.0 [Q1-Q3: 4.0-14.0] vs 129.0 [Q1-Q3: 66.0-171.0]; P < 0.001). Trough PRU levels in the control arm (104.0 [Q1-Q3: 35.0–167.0]) were higher than ticagrelor-based DAT (P = 0.005) and numerically lower than clopidogrel-based DAT (P = 0.234). Results were consistent by light transmittance aggregometry and vasodilator-stimulated phosphoprotein. Markers measuring other pathways leading to thrombus formation were largely unaffected. ConclusionsIn NOAC-treated patients undergoing PCI with an ABCD-GENE score ≥10, ticagrelor-based DAT using a 60-mg, twice-a-day regimen reduced platelet P2Y12 reactivity compared with clopidogrel-based DAT. (Tailoring P2Y12 Inhibiting Therapy in Patients Requiring Oral Anticoagulation After PCI [SWAP-AC-2]; NCT04483583)

Evaluate the in vitro effect of anthracycline and alkylating cytophosphane chemotherapeutics on dopaminergic neurons.

Iatrogenesis is an inevitable global threat to healthcare that drastically increases morbidity and mortality. Cancer is a fatal pathological condition that affects people of different ages, sexes, and races around the world. In addition to the detrimental cancer pathology, one of the most common contraindications and challenges observed in cancer patients is severe adverse drug effects and hypersensitivity reactions induced by chemotherapy. Chemotherapy-induced cognitive neurotoxicity is clinically referred to as Chemotherapy-induced cognitive impairment (CICI), chemobrain, or chemofog. In addition to CICI, chemotherapy also causes neuropsychiatric issues, mental disorders, hyperarousal states, and movement disorders. A synergistic chemotherapy regimen of Doxorubicin (Anthracycline-DOX) and Cyclophosphamide (Alkylating Cytophosphane-CPS) is indicated for the management of various cancers (breast cancer, lymphoma, and leukemia). Nevertheless, there are limited research studies on Doxorubicin and Cyclophosphamide's pharmacodynamic and toxicological effects on dopaminergic neuronal function. This study evaluated the dopaminergic neurotoxic effects of Doxorubicin and Cyclophosphamide. Doxorubicin and Cyclophosphamide were incubated with dopaminergic (N27) neurons. Neuronal viability was assessed using an MTT assay. The effect of Doxorubicin and Cyclophosphamide on various prooxidants, antioxidants, mitochondrial Complex-I & IV activities, and BAX expression were evaluated by Spectroscopic, Fluorometric, and RT-PCR methods, respectively. Prism-V software (La Jolla, CA, USA) was used for statistical analysis. Chemotherapeutics dose-dependently inhibited the proliferation of the dopaminergic neurons. The dopaminergic neurotoxic mechanism of Doxorubicin and Cyclophosphamide was attributed to a significant increase in prooxidants, a decrease in antioxidants, and augmented apoptosis without affecting mitochondrial function. This is one of the first reports that reveal Doxorubicin and Cyclophosphamide induce significant dopaminergic neurotoxicity. Thus, Chemotherapy-induced adverse drug reaction issues substantially persist during and after treatment and sometimes never be completely resolved clinically. Consequently, failure to adopt adequate patient care measures for cancer patients treated with certain chemotherapeutics might substantially raise the incidence of numerous movement disorders.

Second-Order Effects of Chemotherapy Pharmacodynamics and Pharmacokinetics on Tumor Regression and Cachexia.

Drug dose response curves are ubiquitous in cancer biology, but these curves are often used to measure differential response in first-order effects: the effectiveness of increasing the cumulative dose delivered. In contrast, second-order effects (the variance of drug dose) are often ignored. Knowledge of second-order effects may improve the design of chemotherapy scheduling protocols, leading to improvements in tumor response without changing the total dose delivered. By considering treatment schedules with identical cumulative dose delivered, we characterize differential treatment outcomes resulting from high variance schedules (e.g. high dose, low dose) and low variance schedules (constant dose). We extend a previous framework used to quantify second-order effects, known as antifragility theory, to investigate the role of drug pharmacokinetics. Using a simple one-compartment model, we find that high variance schedules are effective for a wide range of cumulative dose values. Next, using a mouse-parameterized two-compartment model of 5-fluorouracil, we show that schedule viability depends on initial tumor volume. Finally, we illustrate the trade-off between tumor response and lean mass preservation. Mathematical modeling indicates that high variance dose schedules provide a potential path forward in mitigating the risk of chemotherapy-associated cachexia by preserving lean mass without sacrificing tumor response.

Ianus Bifrons: The Two Faces of Metformin.

The ancient Roman god Ianus was a mysterious divinity with two opposite faces, one looking at the past and the other looking to the future. Likewise, metformin is an "old" drug, with one side looking at the metabolic role and the other looking at the anti-proliferative mechanism; therefore, it represents a typical and ideal bridge between diabetes and cancer. Metformin (1,1-dimethylbiguanidine hydrochloride) is a drug that has long been in use for the treatment of type 2 diabetes mellitus, but recently evidence is growing about its potential use in other metabolic conditions and in proliferative-associated diseases. The aim of this paper is to retrace, from a historical perspective, the knowledge of this molecule, shedding light on the subcellular mechanisms of action involved in metabolism as well as cellular and tissue growth. The intra-tumoral pharmacodynamic effects of metformin and its possible role in the management of different neoplasms are evaluated and debated. The etymology of the name Ianus is probably from the Latin term ianua, which means door. How many new doors will this old drug be able to open?

Abstract 1059: Biomarkers analysis on samples from patients in EVT801 clinical trial: Patient characterization and immunomonitoring

Abstract Introduction: EVT801 is a highly selective small molecule inhibitor of VEGFR3 that acts by inducing tumor (lymph)-angiogenesis normalization in and around the tumor. EVT801 has shown compelling activity in a wide range of cancer models showing a decrease of tumor hypoxia and an increase of CD8pos T-cells infiltration into the tumor micro-environment. EVT801 was well-tolerated in preclinical toxicology studies. A phase I study is underway focusing primarily on understanding the safety, tolerability, and pharmacokinetics of EVT801 across a range of doses (NCT05114668). Methods: The first stage of the phase I trial aims to determine the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) for EVT801. Clinical samples from enrolled patients have been collected to explore preliminary signals of the biological activity of the drug and characterize tumor phenotypes. Patient characterization includes histology and mRNA signature in archival biopsies. Target engagement and pharmacodynamics effects are investigated by immunomonitoring as well as assessment of a defined set of proteins as markers of inflammation and angiogenesis as identified in preclinical in vivo models. Conclusion: Our first biomarkers analyses on a subpopulation of patients with High Grade Serous Ovarian Cancer (HGS-OC) enrolled in the first stage of the study showed that levels of VEGFR3 expression had a negative correlation with CD8 positive T-cells infiltration in the tumor microenvironment and a tendency to positive correlation with a PD1 mAb resistance signature. VEGFR3 expression also tends to be correlated with higher levels of hypoxia (CAIX labelling). Our working hypothesis is that patients with hypoxic HGS-OC tumors with high VEGFR3 expression may benefit from EVT801 treatment; this will need to be reinforced by inclusion of additional patients in dedicated PD biomarkers cohorts during stage 2 of the clinical trial. Citation Format: Lise Davenne, Michael Fitzgerald, Pierre-Benoit Ancey, Oona Delpuech, Céline Poussereau-Pomié, Michael Esquerre, Michael R. Paillasse, Marie Mandron, Philippe Rochaix, Maha Ayyoub, Clara Maria Scarlata, Christine Caux, Christophe Caux, Philippe Cassier, Carlos Gomez-Roca, Jean-Pierre Delord, John Friend, Pierre Fons. Biomarkers analysis on samples from patients in EVT801 clinical trial: Patient characterization and immunomonitoring [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1059.

Abstract 5799: Novel nanoparticle technology targets the delivery of polyIC to EGFR overexpressing cancers and induces a multimodal anti-tumor response

Abstract Aberrant activation of epidermal growth factor receptor (EGFR) signaling pathways is associated with tumor growth and progression. EGFR overexpression occurs in various types of solid cancers and correlates with poor outcome. Unfortunately, the clinical benefit from EGFR-targeted therapies is usually short-lived, due to the development of resistance. TargImmune has developed first-in-class Targeted Apoptotic Immunomodulators (TAIMs), which harness the body’s anti-viral responses to treat solid tumors. Our novel nanoparticle platform technology, Ta:RNA , selectively delivers synthetic dsRNA, polyinosinic:polycytidylic acid (polyIC) to tumor cells that overexpress a target receptor. PolyIC and other pattern recognition receptor (PRR) agonists have been used as adjuvants or for intratumoral administration but have limited efficacy as single agents. TargImmune’s platform allows systemic delivery of dsRNA, tailoring the nanoparticles to various solid cancers by simply changing the targeting moiety. Here we describe EGFR-Ta:RNA, which is targeted to tumors that overexpress EGFR. EGFR-Ta:RNA does not inhibit EGFR per se, and therefore activation of alternative or downstream oncogenes is not expected to cause resistance. The mechanism of action of EGFR-targeted Ta:RNA nanoparticles was extensively studied in vitro and in vivo, using confocal imaging, large-scale RNA sequencing studies, Western blot analysis and ELISA assays. In vitro, EGFR-Ta:RNA potency and selectivity were established by comparing cells with high receptor and low receptor expression. Imaging studies showed that the nanoparticles are internalized selectively into EGFR-overexpressing cancer cells by receptor-mediated endocytosis. RNAseq studies revealed: (i) a common transcriptional signature in EGFR-Ta:RNA-treated tumours and cancer cells; (ii) enrichment in pathways related to anti-viral response, inflammation, type I interferon signaling, and NFΚB signaling; (iii) enrichment in genes coding for cytokines. Western blot analysis and ELISA assays confirmed that the mechanism of action of EGFR-Ta:RNA is mediated via the induction of PRR downstream signaling, which results in cytokine secretion, apoptosis and immune cell activation. The efficacy of EGFR-Ta:RNA was demonstrated in multiple animal models, including both xenograft and immunocompetent models. The pharmacodynamic effect, exemplified by target engagement and activation of PRR signaling in tumors, was verified in vivo. In conclusion, TargImmune’s EGFR-Ta:RNA nanoparticles deliver polyIC in a tumor-targeted manner to evoke PRR signaling, inducing targeted tumor cell apoptosis as well as immune cell recruitment and activation against the heterogenous tumor. EGFR-Ta:RNA represents a novel, multimodal treatment approach for EGFR overexpressing cancers. Citation Format: Derrick Broka, Caroline De Feyter, Shoshana Klein, Meera Saxena, Joerg Schreiber, Alexei Shir, Michal Skowicki, Yaakov Benenson, Alexander Levitzki, Cornelia G. Palivan, Esteban Pombo-Villar, Babette Schade, Maya Zigler. Novel nanoparticle technology targets the delivery of polyIC to EGFR overexpressing cancers and induces a multimodal anti-tumor response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5799.

Abstract 6500: Dependence of EGFR-mutant NSCLC on MET as demonstrated by vebreltinib, a novel and selective brain-penetrating MET kinase inhibitor

Abstract Background: Although EGFR inhibitors (EGFRi), preferably osimertinib, have offered substantial benefit for the classical plus T790M EGFR-mutant NSCLC patients, drug resistance develops and poses a critical challenge for long-term survival. The resistance is rooted to either on-target secondary EGFR mutations or compensatory oncogenic pathways bypassing EGFRi intervention, one of which appears to be treatment-acquired MET amplification (METamp). In this study we set out to understand the conditions when the tumor cells become dependent on MET. Methods: NSCLC patient-derived tumor models (PDX) carrying classical and T790M EGFR driver mutations were selected based on EGFRi history and concurrent MET gene copy numbers or RNA expression levels: Type 1) resistant to osimertinib with METamp; Type 2) partially resistant to osimertinib with METamp; and Type 3) sensitive to osimertinib with low MET expression, no METamp. These PDX xenograft mice were treated with vebreltinib (APL-101) at clinically relevant doses as single agent or in combination with osimertinib. The pharmacodynamic effects on EGFR and MET phosphor (P)- and total proteins were analyzed from tumor samples harvested during and at the end of treatments. Results: Vebreltinib single agent inhibited tumor growth of the type-1 PDX. One such PDX was resistant to chemotherapies, BRAF inhibitor and EGFRi including osimertinib, was inhibited by vebreltinib with ED50 of 3 mg/kg (p.o/q.d.). Another such PDX tumor appeared to be eradicated by vebreltinib treatment at 10 mg/kg (p.o/q.d.) and the mice became tumor-free on Day 18 and remained so after dosing stop on day 21 with last observation at study end (Day 70). In comparison, reference METi savolitinib showed only partial tumor size reduction against the same PDX tumor, not as durable as vebreltinib, and did not eradicate tumor growth at the same dose as vebreltinib or in combo with Osimertinib. Re-grown tumor after savolitinib osimertinib combo dosing stop was inhibited completely by vebreltinib follow-on treatment. In the type-2 PDX, tumor growth was partially inhibited by vebreltinib but was completely inhibited by combo of vebreltinib and osimertinib. The anti-tumor activity of vebreltinib in type-1 and type-2 PDX was associated with pharmacodynamic inhibition of P-MET and P-EGFR and MET protein degradation. In the type-3 PDX, tumor growth appeared to be eradicated by osimertinib and not inhibited by vebreltinib. However, addition of vebreltinib suppressed tumor re-growth after osimertinib dosing stop. Conclusion: EGFR-mutant NSCLC resistance to EGFRi may be dependent on MET pathway regardless of acquired METamp, whereas METamp may dictate the degree of MET dependence. Our data supports the hypothesis that adding vebreltinib to EGFRi overcome MET dependent resistance with durable effect or preventing MET dependent resistance to maximize therapeutic benefits. Citation Format: Xiaoling Zhang, Elaine Liu, Yan Song, Peony Yu, Sanjeev Redkar, Guo-Liang Yu. Dependence of EGFR-mutant NSCLC on MET as demonstrated by vebreltinib, a novel and selective brain-penetrating MET kinase inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6500.

Abstract 3318: GFH375 (VS-7375): An oral, selective KRAS G12D (ON/OFF) inhibitor with potent anti-tumor efficacy

Abstract Background: KRAS is the best-known oncogene but had long been considered ‘undruggable’ until the approval of the first KRAS G12C inhibitor sotorasib in 2021. However, most current clinical-stage KRAS inhibitors target the KRAS G12C mutation. Inhibitors of other KRAS mutants such as KRAS G12D, the most frequent KRAS mutation in human cancer, are needed for patients. We have developed GFH375 (VS-7375), an oral, selective KRAS G12D inhibitor targeting both “ON” (GTP-bound) and “OFF” (GDP-bound) states of KRAS proteins. The in vitro potency, selectivity, and in vivo efficacy of monotherapy and combination therapy with avutometinib, a unique RAF/MEK clamp, were evaluated in preclinical studies. Methods: Biochemical and cellular assays were used to investigate inhibition to KRAS cycling and signaling. CellTiter-Glo assay was performed to determine the effects on proliferation of tumor cell lines. Several KRAS G12D CDX tumor models were employed to study the in vivo pharmacodynamic and anti-tumor effects. Results: GFH375 inhibited both nucleotide exchange on GDP-bound KRAS G12D and interaction between GMPPNP-bound KRAS G12D with RAF1 with single-digit nanomolar IC50 values. GFH375 suppressed phosho-ERK1/2 (p-ERK) level with sub-nanomolar IC50 values and potently inhibited cell proliferation across a panel of KRAS G12D tumor cell lines. GFH375 showed high selectivity for KRAS G12D relative to non-G12D KRAS variants, KRAS wild type cells, and NRAS, HRAS, or BRAF mutated cells. Following a single oral dose, GFH375 produced deep and durable inhibition of p-ERK in KRAS G12D CDX tumors. GFH375 demonstrated dose-dependent anti-tumor activity with tumor regressions at 10 or 30 mg/kg given orally twice daily in multiple KRAS G12D PDAC and CRC CDX tumor models. GFH375 also showed strong anti-tumor efficacy in an intracranial KRAS G12D tumor model starting as low as 10 mg/kg orally twice daily. Strong synergy between GFH375 and avutometinib was observed in vitro and was validated in vivo as anti-tumor activity of GFH375 was further enhanced by avutometinib. Conclusions: GFH375 is a highly potent and selective orally active inhibitor of KRAS G12D (ON/OFF) and demonstrated promising anti-tumor activity in multiple KRAS G12D tumor models. GFH375 was also effective in an intracranial tumor model. GFH375 showed strong synergy with avutometinib in vitro and in vivo. GFH375 is currently in IND-enabling development in preparation for clinical studies of monotherapy and potentially in combination with other agents for patients with KRAS G12D mutant tumors. Citation Format: Feng Yan, Tao Jiang, Tao Liang, Lijian Cai, Leitao Zhang, Xiaoming Xu, Yanhui Zhao, Xiaoling Lan, Xiaohui Zhang, Meng Liu, Qiang Liu, Jinting Gao, Fubo Xie, Xueyan Gao, Li Wang, Jingyang Zhang, Hongcan Ren, Dong Liu, Siyuan Le, Lili Tang, Silvia Coma, Yaofeng Cheng, Nathan Sanburn, Jonathan A. Pachter, Fusheng Zhou, Jiong Lan, Qiang Lu. GFH375 (VS-7375): An oral, selective KRAS G12D (ON/OFF) inhibitor with potent anti-tumor efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3318.

Abstract 1906: UNO-A001 (A001), a clinical candidate CD38 x CD3 bispecific with a novel structure, potently kills multiple myeloma cells in vitro and is highly effective in vivo

Abstract CD38 is a validated target for the treatment of multiple myeloma (MM) as evidenced by the important clinical activity of CD38 targeting monoclonal antibodies. Bispecific T Cell Engagers (TCEs) kill cancer cells by distinct mechanisms as compared to standard format antibody therapeutics and several TCEs have demonstrated impressive clinical activity, and have been approved for clinical use, in hematologic malignancies. Here we describe a novel bispecific leveraging the potent killing mechanism of TCEs to target CD38 bearing cancer cells. UNO-A001 is a TCE binding the cell surface receptor CD38 on target human cancer cells and CD3 on T cells. The molecule has a differentiated format, binding CD38 with a high affinity humanized camelid VHH moiety and CD3 on T cells through a unique antibody Fab arm. The affinities of each arm were optimized so that the CD38 arm bound with high affinity and the CD3 arm with much lower relative binding affinity. This configuration was designed to engage CD38 bearing target cells with multiple TCE molecules at lower doses and concentrations while minimizing T cell binding in the periphery, and in the absence of cell surface CD38. A001 potently and specifically killed human CD38 bearing multiple myeloma cell lines in T cell killing assays in vitro with EC50s in the 2.7-6.6 pM range. This potency, despite the designed lower affinity to CD3, may be due to the unique structure of A001 enabling a productive immunologic synapse between T cells and the target cancer cells, and an optimal TAA/CD3 binding affinity ratio. A001 was also highly effective in inhibiting tumor growth in H929 xenograft models. In a flank model of H929 tumor growth A001 dose dependently inhibited tumor growth with complete growth inhibition of established tumors at the highest dose level tested. In a systemic disease model with NCI-H929-luc cells A001 was also highly effective and improved survival relative to control treated animals. In preparation for clinical studies a robust and high yield production cell line was created and characterized. It achieved high expression levels of quality monodisperse UNO-A001 product that was stable in all relevant storage conditions. A001 has similar affinities for human and cynomolgus macaque CD38 and CD3. Dose ranging studies in cynomolgus macaques demonstrated tolerability consistent with clinically approved TCEs, and the expected dose dependent pharmacodynamic effects on CD38 expressing myeloid and lymphoid cell populations. These data support planned clinical testing of A001 in multiple myeloma and other CD38 bearing hematologic malignancies, including mantle cell lymphoma, T cell lymphoma, and acute myelogenous leukemia. Citation Format: Mark Anderson, Yan Ling, Mark L. Chiu, Peter Cheung. UNO-A001 (A001), a clinical candidate CD38 x CD3 bispecific with a novel structure, potently kills multiple myeloma cells in vitro and is highly effective in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1906.

Abstract 6734: Preclinical impact of pretreatment with CRS mitigation agents on pharmacodynamic response to TAK-500, a systemically delivered CCR2-targeted STING agonist iADC

Abstract Background: Stimulator of interferon genes (STING) agonists elicit potent innate immune enhancement and mobilize robust adaptive immune responses. Given the potential risk of immunotoxicity from associated cytokine release due to STING agonist treatment, there is a need to identify mitigation strategies that minimize immune-related toxicity while offering a therapeutic window for STING-mediated anti-tumor effects. This strategy is particularly relevant for myeloid-targeted immunotherapies, as cytokine release syndrome (CRS) can be myeloid cell-mediated. We utilized preclinical models to evaluate the pharmacological impact of pretreatment with agents routinely used for management of CRS in advance of delivering TAK-500, a novel, systemic, immune-cell directed STING agonist antibody drug conjugate (iADC) that selectively targets CCR2+ myeloid cells. Methods: Dexamethasone and anti-IL-6R antibodies were tested at clinically relevant doses 1 hour prior to treatment with TAK-500 or mTAK-500, a murine surrogate, to study immunomodulatory and anti-tumor effects in preclinical models. Induction of innate and adaptive immune responses and cytokine release was evaluated in human, ex vivo, and in tumor-bearing mouse models to characterize potential impact of premedication strategies on drug pharmacology and anti-tumor efficacy. Results: TAK-500 triggered dose-dependent monocyte activation and cytokine secretion ex vivo. Monocyte activation was minimally impacted by dexamethasone or anti-IL-6R pretreatment. Suppression of IL-6 and IFN-ƴ and increase in IL-10 were observed following dexamethasone pretreatment, whereas anti-IL-6R maintained a more proinflammatory milieu. In syngeneic mouse models, pretreatment with dexamethasone and anti-mouse IL-6R had minimal impact on mTAK-500 anti-tumor efficacy. Key pharmacodynamic effects, including innate immune cell activation in periphery and tumor-draining lymph node and intratumoral CD8+ T cell accumulation, were minimally impacted by either pretreatment agent. Serum cytokine analyses demonstrated suppression of IL-6, IFN-ƴ and increases in IL-10 with dexamethasone, but not with anti-IL-6R, similar to ex vivo findings. Conclusion: Premedication of TAK-500 and mTAK-500 with dexamethasone or anti-IL-6R antibodies does not substantially impact STING-mediated innate immune activation, mobilization of adaptive immune responses or anti-tumor efficacy, despite altered cytokine profiles compared to (m)TAK-500 without premedication. Clinically, these premedication strategies have been effective in mitigating immunotherapy-associated CRS with T cell therapeutics, and here resulted in maintained anti-tumor activity when used in combination with TAK-500, suggesting a viable potential strategy for mitigation of STING-induced immunotoxicities in patients. Citation Format: Emily Rosentrater, Michelle L. Ganno, Tiquella Hatten, Henry Mack, Arjun Reddy Bollampalli, Dong Mei Zhang, Alex Parent, Jeffrey Raizer, Richard C. Gregory, Neil Lineberry, Vicky Appleman. Preclinical impact of pretreatment with CRS mitigation agents on pharmacodynamic response to TAK-500, a systemically delivered CCR2-targeted STING agonist iADC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6734.

Abstract 6512: BPI-501836: A highly potent small molecule inhibitor targeting KRASG12D mutation

Abstract As one of the most notorious un-druggable oncogenes, mutant KRAS impairs the transition of RAS from its active GTP-binding form to the inactive GDP-binding form, leading to sustained activation of downstream MAPK pathway and ultimately tumorigenesis. The recent approved KRASG12C inhibitors have demonstrated clinical benefits in KARSG12C mutant patients. However, the other prevalent KRAS mutations, such as KRASG12D, remain a huge unmet medical challenge. There’s no approved KRASG12D specific inhibitors yet. Here we present BPI-501836, a highly potent and selective small molecular inhibitor for KRASG12D. In vitro, BPI-501836 exhibited very high potency by disrupting the KRASG12D and cRAF interaction in a cell-free assay. In cell-based assays, BPI-501836 inhibited proliferation of KRASG12D mutant cell lines with sub-nanomolar IC50 values, without affecting wide type or non-G12D KRAS mutant cell lines. Moreover, it also attenuated ERK phosphorylation in KRASG12D mutant cells. In vivo, tumor regression was observed following the administration of 6 mg/kg (iv, QW) BPI-501836 in KRASG12D human pancreatic Panc04.03 xenograft mouse models, or in the KRASG12D human pancreatic PK-59 xenograft mouse models with an intraperitoneal injection of 20 mg/kg per week. Noteworthy was the prolonged half-life of BPI-501836 observed across various species, coupled with its high distribution in tumor tissues. Moreover, sustained suppression of ERK phosphorylation in tumor tissues persisted for up to 144 hours after the last dose of BPI-501836 in both xenograft mouse models. This extended pharmacodynamic effect supports the feasibility of a once-weekly dosing schedule in clinical applications. Safety assessments conducted through a 4-week repeated infusion (intravenous, twice weekly) of BPI-501836 in beagle dog demonstrated favorable safety profiles. In conclusion, BPI-501836 emerges as a highly potent and selective KRASG12D inhibitor, exhibiting promising pharmacokinetics, pharmacodynamics, and safety profiles in pre-clinicalstudies. BPI-501836 is currently in IND-enabling stage and holds potential for further development as a therapeutic agent. Citation Format: Xiang Yang, Yuan Lu, Renqi Xu, Xiaoqiang Kong, Yongqing Sun, Xingjie Zhu, Xiaoyun Liu, Zhengyao Zou, Haibo Chen, Yanju Liu, Jialing Sun, Han Han, Cheng Yang, Jing Guo, Hong Lan, Quan Zhou, Lieming Ding, Hao Wu, Jiabing Wang. BPI-501836: A highly potent small molecule inhibitor targeting KRASG12D mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6512.

Abstract 6552: Intratumoral (ITu) delivery of mRNA-2752 encoding human OX40L/IL-23/IL-36γ in combination with durvalumab induces an immunostimulatory effect within the tumor microenvironment (TME) of patients with advanced solid tumors

Abstract Background mRNA-2752 is a first-in-class ITu therapy composed of mRNA encoding human OX40L/IL-23/IL-36γ in a lipid nanoparticle. The combination of T cell costimulation and proinflammatory cytokines were developed to modulate the TME and allow a more robust immune response. Here we show evidence of the pharmacodynamic effect of ITu administration of mRNA-2752 in combination with PD-L1 antibody. Methods In this ongoing phase 1 study (NCT03739931), patients (pts) with advanced solid tumors received 0.25-8 mg mRNA-2752 alone (Arm A) or in combination with 1500 mg IV durvalumab (Arm B)1,2. Pre and on-treatment peripheral and tumor samples were collected to monitor changes in cytokines by ligand binding assays, gene signatures by RNA sequencing, and T cell infiltration by immunohistochemistry. Tumor biopsies were taken at baseline, 24h, 15 and 28 days post treatment. Results mRNA-2752 administration in combination with durvalumab revealed ≥2-fold plasma level increases of IL-23 (34/40, 85%) and IFN-γ (50/65, 77%) at 24h after first injection; exposure was induced in a dose-dependent manner. We observed induction of CD8 T cell abundance (20/49, 41%) and proliferation (23/49, 47%), and OX40L protein expression (28/49, 57%) in pts with evaluable post-treatment injected lesion biopsies. CD8 T cell abundance increased in 2 pts with evaluable post-treatment un-injected lesion biopsies. A positive correlation was observed between T cell abundance and T cell effector genes. All three mRNA (IL-23, IL-36γ, and OX40L) encoded genes were detected post treatment in tumor samples from 43 evaluable patients. In 18 pts with injected lesion biopsy samples at baseline and day 28 samples, the genes related to cytotoxic function (IFNG, GZMB, PRF1), T cell migration (CCL21, CCR7, KLF2), T cell activation/memory phenotype (TCF7, CD69, ITGAE), and conventional type 1 dendritic cells (CLEC9A, XCR1) were induced 28 days post-treatment in pts with complete/partial response or stable disease (CR/PR/SD, n=7) compared to progressive disease (PD, n=11) pts. RNA-Seq transcriptome analysis showed increases in the immune inflamed gene signatures related to antitumor activity in 24/43 (56%) pts post-treatment, and the pre-existing immune inflamed phenotype within the TME was associated with clinical benefit. Conclusions mRNA-2752 ITu injection induced a systemic immunomodulatory effect by elevating effector cytokines. This was associated with pharmacodynamic changes within the TME, including increases in T cell abundance and proliferation, and upregulation of immune gene signatures that correlate with antitumor response.