Terminal Half-life Research Articles

First-in-human Evaluation of a Prostate-specific Membrane Antigen–targeted Near-infrared Fluorescent Small Molecule for Fluorescence-based Identification of Prostate Cancer in Patients with High-risk Prostate Cancer Undergoing Robotic-assisted Prostatectomy

BackgroundMen with high-risk prostate cancer undergoing surgery likely recur due to failure to completely excise regional and/or local disease. ObjectiveThe first-in-human evaluation of safety, pharmacokinetics, and exploratory efficacy of IS-002, a novel near-infrared prostate-specific membrane antigen (PSMA)-targeted fluorescence imaging agent, designed for intraoperative prostate cancer visualization. Design, setting, and participantsA phase 1, single-center, dose-escalation study was conducted in 24 men with high-risk prostate cancer scheduled for robotic-assisted radical prostatectomy with (extended) pelvic lymph node dissection using the da Vinci surgical system. Outcome measurements and statistical analysisAdverse events (AEs), vital signs, complete blood count, complete metabolic panel, urinalysis, and electrocardiogram were assessed over a 14-d period and compared with baseline. The pharmacokinetic profile of IS-002 was determined. Diagnostic accuracy was assessed for exploratory efficacy. Results and limitationsAEs predominantly included discoloration of urine (n = 22/24; expected, related, grade 1). There were no grade ≥2 AEs. IS-002 Cmax and area under the curve increased with increasing dose. Plasma concentrations declined rapidly in a biphasic manner, with the median terminal half-lives ranging from 5.0 to 7.6 h, independent of dose and renal function. At 25 μg/kg, the exploratory efficacy readouts for the negative and positive predictive values were, 97% and 45% for lymph nodes, and 100% and 80% for residual/locoregional disease detection, respectively. ConclusionsIS-002 is safe and well tolerated, and has the potential to enable intraoperative tumor detection that could not be identified using standard imaging. Patient summaryIS-002 is a new imaging agent that specifically targets the prostate-specific membrane antigen receptor. In this study, we tested IS-002 for the first time in men with high-risk prostate cancer undergoing surgery and found that IS-002 is safe, is cleared from the body quickly, and potentially allows identification of prostate cancer in areas that would not be identified by conventional white light imaging.

High-concentration buprenorphine exceeds target plasma concentrations for extended periods following subcutaneous administration in American flamingos (Phoenicopterus ruber).

To determine the pharmacokinetic parameters of a high-concentration buprenorphine formulation after a single SC dose in American flamingos (Phoenicopterus ruber). 6 healthy adult American flamingos (3 males and 3 females). A single dose of high-concentration buprenorphine (1.8 mg/kg) was administered SC to all birds. Blood samples were collected at 0.25, 0.5, 1, 2, 4, 8, 12, 24, 48, 72, and 96 hours after drug administration between October 14 and October 18, 2022. Plasma buprenorphine concentrations were determined by liquid chromatography-tandem mass spectrometry and a noncompartmental analysis was used to determine pharmacokinetic parameters. Mean ± SD peak plasma drug concentration (Cmax) was 195.1 ± 187.4 ng/mL, the mean time to peak plasma concentration (Tmax) was 0.32 ± 0.31 hours, the mean area under the concentration-vs-time curve from time 0 to the last measured concentration (AUC0-last) was 881.4 ± 205.4 ng/mL, and mean terminal half-life (t1/2) was 12.6 ± 3.86 hours. Mean plasma buprenorphine concentrations were >1 ng/mL for at least 48 hours after drug administration. No clinically significant adverse effects were observed. High-concentration buprenorphine dosed at 1.8 mg/kg SC in American flamingos rapidly exceeded plasma drug concentrations reported to have analgesic effects in other avian species and maintained these levels for extended periods. Sedative effects were similar to those reported for other species. Additional studies are needed to evaluate the clinical efficacy of high-concentration buprenorphine at this dose in American flamingos.

Pharmacokinetics of Enrofloxacin and its Metabolite Ciprofloxacin in Badri Cows

Background: Breeds of animals differ with respect to anatomical, physiological and behavioural traits hence the study of inter-breed variation in pharmacokinetics becomes necessary. The aim of the current investigation was to determine the pharmacokinetics of enrofloxacin following intravenous bolus administration to assess the influence of breed on drug pharmacokinetics and availability. Methods: In the present study the pharmacokinetics of a common antimicrobial drug, enrofloxacin and its metabolite, ciprofloxacin was studied in adult, non-pregnant and dry Badri cows, wherein a commercial preparation of enrofloxacin (10% v/v) was administered at a dose rate of 7.5 mg/kg intravenously as a single dose. The plasma samples were collected at regular intervals and subjected to analysis by HPLC after appropriate processing. The results obtained were analysed using a software tool, “PK Solver” to obtain the pharmacokinetic parameters. Result: From the study, it was revealed that the Badri cattle showed a distribution half-life of 0.11 h, a volume of distribution of 7.63 L.kg-1, an elimination half-life of 4.27 h and an MRT of 5.93 h for enrofloxacin. Whereas, a maximum plasma concentration level of 0.12 µg.ml-1 was observed for ciprofloxacin in the current study. According to the results obtained in the pharmacokinetic study, an individualized dosage regimen containing a priming dose of 5 mg/kg and a maintenance dose of 4.5 mg/kg with an interval of 24 hours was suggested for the enrofloxacin in Badri cattle. The results of our current study when compared with the previously available literature on other cattle breeds suggested that the Badri cattle differed with respect to pharmacokinetic properties and further studies will be required to determine the conclusive reason for the differences.

Pharmacokinetics and tolerability of multiple-day oral dosing of mycophenolate mofetil in healthy horses.

Additional efficacious immunomodulatory treatment is needed for the management of immune-mediated disease in horses. Mycophenolate mofetil (MMF) is an immunosuppressive drug that warrants assessment as a viable therapeutic agent for horses. To evaluate the pharmacokinetics (PK) of multiple-day oral dosing of MMF in healthy horses and to determine the tolerability of this dosing regimen. Six healthy Standardbred mares. Horses received MMF 10 mg/kg PO q12h for 7 days in the fed state. Serial sampling was performed over 12 hours on Days 1 and 7 with trough samples collected every 24 hours, immediately before morning drug administration. Noncompartmental PK analyses were performed to determine primary PK parameters, followed by calculation of geometric means and coefficients of variation. A CBC, serum biochemical profile, physical examination, and fecal scoring were used to assess dose tolerability. Seven days of treatment resulted in a mycophenolic acid (MPA) area under the curve (AUC0-12 ) of 12 594 h × ng/mL (8567-19 488 h × ng/mL) and terminal half-life (T1/2 ) of 11.3 hours (7.5-15.9 hours), yielding minor metabolite accumulation in all horses treated. Salmonellosis was detected in the feces of 2 horses by Day 7, and all horses developed myelosuppression, hyperbilirubinemia, hyporexia, decreased gastrointestinal motility, and decreased fecal output by the seventh day of treatment. Administration of MMF at 10 mg/kg PO q12h resulted in hematologic and clinical toxicity within 1 week of treatment. A decreased MMF dose, frequency, or both is needed to avoid colic. Drug monitoring should include frequent hemograms, serum biochemical profiles, and strict biosecurity protocols.

Discovery of Hybrid Thiouracil-Coumarin Conjugates as Potential Novel Anti-SARS-CoV-2 Agents Targeting the Virus's Polymerase "RdRp" as a Confirmed Interacting Biomolecule.

The coronavirus (COVID-19) pandemic, along with its various strains, has emerged as a global health crisis that has severely affected humankind and posed a great challenge to the public health system of affected countries. The replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mainly depends on RNA-dependent RNA polymerase (RdRp), a key enzyme that is involved in RNA synthesis. In this regard, we designed, synthesized, and characterized hybrid thiouracil and coumarin conjugates (HTCAs) by ether linkage, which were found to have anti-SARS-CoV-2 properties. Our in vitro real-time quantitative reverse transcription PCR (RT-qPCR) results confirmed that compounds such as 5d, 5e, 5f, and 5i inhibited the replication of SARS-CoV-2 with EC50 values of 14.3 ± 0.14, 6.59 ± 0.28, 86.3 ± 1.45, and 124 ± 2.38 μM, respectively. Also, compound 5d displayed significant antiviral activity against human coronavirus 229E (HCoV-229E). In addition, some of the HTCAs reduced the replication of SARS-CoV-2 variants such as D614G and B.617.2. In parallel, HTCAs in uninfected Vero CCL-81 cells indicated that no cytotoxicity was noticed. Furthermore, we compared the in silico interaction of lead compounds 5d and 5e toward the cocrystal structure of Suramin and RdRp polymerase with Remdesvir triphosphate, which showed that compounds 5d, 5e, and Remdesvir triphosphate (RTP) share a common catalytical site of RdRp but not Suramin. Additionally, the in silico ADMET properties predicted for the lead HTCAs and RTP showed that the maximum therapeutic doses recommended for compounds 5d and 5e were comparable to those of RTP. Concurrently, the pharmacokinetics of 5d was characterized in male Wistar Albino rats by administering a single oral gavage at a dose of 10 mg/kg, which gave a Cmax value of 0.22 μg/mL and a terminal elimination half-life period of 73.30 h. In conclusion, we established a new chemical entity that acts as a SARS-CoV-2 viral inhibitor with minimal or no toxicity to host cells in the rodent model, encouraging us to proceed with preclinical studies.

THE METABOLISM OF LUFOTRELVIR, A PRODRUG INVESTIGATED FOR THE TREATMENT OF SARS-COV-2, IN HUMANS FOLLOWING INTRAVENOUS ADMINISTRATION.

The metabolism of lufotrelvir, a novel phosphate prodrug of PF-00835231 for the treatment of COVID-19, was evaluated in healthy human volunteers and clinical trial participants with COVID-19 following intravenous infusion. The prodrug was completely converted to PF-00835231 which was subsequently cleared by hydrolysis, hydroxylation, ketoreduction, epimerization, renal clearance, and secretion into the feces. The main circulating metabolite was a hydrolysis product (M7) which was present at concentrations greater than PF-00835231, and this was consistent between healthy volunteers and participants with COVID-19. Upon administration of [14C]lufotrelvir, only 63% of the dose was obtained in excreta over 10 days and total drug-related material demonstrated a prolonged terminal phase half-life in plasma. A considerable portion of the labelled material was unextractable from fecal homogenate and plasma. The position of the carbon-14 atom in the labelled material was at a leucine carbonyl, and pronase digestion of the pellet derived from extraction of the fecal homogenate showed that [14C]leucine was released. Significance Statement Lufotrelvir is an experimental phosphate prodrug intravenous therapy investigated for the potential treatment of COVID-19 in a hospital setting. The overall metabolism of lufotrelvir was determined in human healthy volunteers and clinical trial participants with COVID-19. Conversion of the phosphate prodrug to the active drug PF-00835231 was complete and the subsequent metabolic clearance of the active drug was largely via amide bond hydrolysis. Substantial drug-related material was not recovered due to loss of the carbon-14 label to endogenous metabolism.

UHPLC-MS/MS method for the quantification of ultra-traces of irinotecan and its metabolites in red blood cells and plasma to detect caregivers' contamination.

The occupational exposure of caregivers to antineoplastic agents has been demonstrated since 1979. Since the early 1990s, numerous studies from several countries have demonstrated the contamination of care facilities by antineoplastic drugs. As it is easier to sample, most contamination measurements in workers are carried out in urine sample. The distribution and elimination half-lives of irinotecan suggest that blood can be considered as better than urine for the biomonitoring of a potential contamination of healthcare workers. We describe here the development and the validation of a UHPLC-MS/MS method to simultaneously quantify irinotecan, and two of its main metabolites, APC and SN-38, at ultra-trace levels in plasma and red blood cells (RBC). This method has been applied to blood samples collected from several healthcare services in a French comprehensive cancer center. The results demonstrate that the method is sensitive enough to identify a contamination of healthcare workers by irinotecan and SN-38 at very low concentrations. Moreover, the results show that analysis of RBC is of great interest and complementary to that of serum.

Effect of Fluconazole on the Pharmacokinetics of Pyrotinib Maleate: A Single-Center, Open, Single-Dose, Self-Controlled Study in Healthy Chinese Participants

What Is Known and Objective. Pyrotinib maleate, also known as pyrotinib, is an irreversible dual receptor tyrosine kinase inhibitor that primarily targets the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2). Cytochrome P450 3A4 (CYP3A4) enzyme mainly catalyzes pyrotinib, and its metabolism is influenced apparently by CYP3A4 strong inhibitor, but the effect of CYP3A4 moderate inhibitor is still unclear as a moderate inhibitor of CYP3A4 enzyme. This study evaluated the effect of fluconazole, a widespread antifungal medication, on the pharmacokinetics and safety tolerance of pyrotinib. Methods. This study was an open, single-dose, and self-controlled clinical trial. Eighteen healthy Chinese participants were enrolled in this study. All participants were administered fluconazole on days 6–18 and pyrotinib on days 1 and 9. The maximum plasma concentration (Cmax), time to Cmax (Tmax), area under the concentration–time curve from time 0 to the last measurable concentration (AUC0−t), area under the concentration–time curve from time 0 extrapolated to infinity (AUC0−∞), terminal elimination half-life (t1/2), apparent volume of distribution (Vz/F), and apparent clearance (CL/F) were calculated using WinNonlin software (version 8.1). Safety tolerance was assessed throughout the process. Results and Discussion. Compared with the single administration of pyrotinib, the exposure level was enhanced significantly after the coadministration of pyrotinib and fluconazole. The geometric mean ratios (pyrotinib + fluconazole/pyrotinib alone) of Cmax, AUC0−t, and AUC0−∞ were 2.16, 3.6, and 3.5, respectively. The parameter of t1/2 is 14.16 h and 24.03 h, and CL/F is 275.06 L/h and 78.42 L/h, for pyrotinib alone and with fluconazole. No serious adverse events were reported in this trial, and no participant withdrew from the trial because of adverse events. What Is New and Conclusion. The PK profile of pyrotinib, a CYP3A4 substrate, was significantly influenced by fluconazole, with increased exposure levels and prolonged t1/2. Dosage adjustment is suggested for the clinical application of pyrotinib when coadministered with fluconazole or other CYP3A4 inhibitors/inducers.

#5710 CHARACTERIZATION OF RESPONSE TO TREATMENT WITH RITUXIMAB IN PATIENTS WITH PRIMARY GLOMERULOPATIES

Abstract Background and Aims Rituximab (RTX) is an anti-CD20 monoclonal antibody used in renal diseases with glomerular involvement, which usually present with proteinuria. The doses used in this pathologies are extrapolated from other diseases such as rheumatoid arthritis, but the optimal regimen in this population has not been well defined. Objective To describe the behaviuor of RITUXIMAB in patients with primary glomerulopathies in whom its use is indicated. Method Descriptive low-intervention single-center clinical trial approved by the Spanish Medicines Agency (NEFRTX, EUDRACT 2020-000484-23. Patients treated with rituximab were included according to medical criteria, prior approval by the Pharmacy Commission. The regimen used was 1g every 15 days, or only 1gr dose with premedication according to clinical practice guidelines. 24-hour blood and urine samples were collected on days 1 (post-rituximab), 7, 15 (pre and post-rituximab), 28, and 45. Serum rituximab was determined using ELISA (Lisa-Traker®-Rituximab, Theraradiag®). Clinical and pharmacokinetic data analyzes were performed considering a single compartment model by non-linear regression with Winnolin® to obtain clearance (Cl), half-life (t1/2), maximum concentration (Cmax) and volume of distribution (Vd). Some quantitative results are expressed as mean ± standard deviation. Linear regression was used to establish correlations. Results The results of 5 patients were analyzed, 2 women and 3 men, with a mean age of 68.8 ± 17.02 years of 72 years and a diagnosis of membranous GN (3), ANCA MPO GN (1), focal and segmental GN (1). Renal function CKD EPI: GFR between 45- 60 ml/min N = 2 GFR >60 ml/min N = 3. According to clinical practice guidelines, patients received 1g doses, 2/5 patients received a second dose on day 15. The evaluation parameters were: proteinuria, CD 19+ lymphocyte depletion, Antibodies titers and histological characteristics as appropriate. levels of rituximab in urine samples after the rituximab administration (15, 30, 180, 365 days after) were determinate. All the patients presented proteinuria, with a mean of 11±14.6 g in 24 h urine. Mean Rituximab clearance was 0.676±0.431 ml/h/kg, distribution volume was 222.35±140.52 mL/Kg and Cmax 69.66±26.14 mcg/mL and t1/2 269.66± 229.71 h (11 days approximately). There is a correlation between proteinuria and rituximab half-life (p = 0.077), as well as between proteinuria and clearance creatinine (p = 0.975) suggesting that half life of rituximab is lower if proteinuria increases (Fig. 1). All presented lymphocyte depletion of CD 19 at 45 days. However, those with more proteinuria >2.5 g (N = 3) in those 45 days, after 6 months of exposure to RTX, progressive repopulation of CD19 was observed, which persisted in the year of follow-up. Conclusion In patients with high proteinuria, rituximab has a t1/2 lower than the 21–28 days described in the data sheet, which may suggest that patients with nephrotic syndrome may require higher doses to ensure the effectiveness of treatment with rituximab. Repopulation of CD19 in 45 days could be a reliable indicator of non response in patients with nephrotic proteinuria.

#4328 CHK-336, A FIRST-IN-CLASS ORALLY ADMINISTERED LDH INHIBITOR: SAFETY, PK AND TARGET ENGAGEMENT IN A FIRST-IN-HUMAN PHASE 1 HEALTHY VOLUNTEER STUDY

Abstract Background and Aims CHK-336 is a first-in-class, orally bioavailable, liver-targeted small molecule lactate dehydrogenase (LDH) inhibitor for the treatment of primary hyperoxalurias and other kidney stone disorders caused by oxalate overproduction. The primary objectives of this first-in-human (FIH) study were characterization of the safety and pharmacokinetics (PK) of CHK-336 following single and repeat doses in healthy volunteers (HVs). Exploratory objectives were demonstration of proof of mechanism in HVs based on inhibition of hepatic oxalate production using a stable-label 13C2-glycolate tracer for hepatic LDH target engagement and characterization of the exposure-response relationship. Method This Phase 1, placebo-controlled (6:2 randomization within a cohort), dose escalation study explored single ascending (SAD, 15-500 mg) and multiple ascending (MAD, 30 mg and planned up to 500 mg QD, 14 consecutive days) doses. A total of 104 subjects will be enrolled in this study. A stable-label 13C2-glycolate tracer was administered orally at baseline and following CHK-336 administration to evaluate the inhibition of LDH-mediated production of [13C2]-oxalate by CHK-336, as a measure of hepatic LDH target engagement in HVs. Food-effect was evaluated following a single dose after a standard high fat meal. CHK-336 concentrations were determined in plasma and urine by a validated LC-MS/MS assay. Total oxalate and 13C2-oxalate were determined in urine by validated GC/MS assays. Results CHK-336 was generally well tolerated following single doses from 15 – 500 mg, with no dose-related trends in total adverse events (AEs) or types of AEs. There were no serious AEs, or severe treatment-related AEs (TRAEs). Treatment-emergent AEs were observed in 10 of 56 (17.9%) subjects, 7 (12.5%) of whom experienced TRAEs; all TRAEs were mild or moderate in severity. CHK-336 PK profiles were characterized with a median tmax of 6 hrs following absorption in fasted-state followed by bi-exponential decline and a terminal half-life of 18 ± 8 hrs. Dose-proportional increases in exposure AUC were observed from 15 up to 500 mg. Cmax increase was greater than dose-proportional at ≥60 mg with a concomitant decrease in median tmax from 6hr to 2hr. A high fat meal decreased CHK-336 AUC0-72h by 32% (AUC0-72h) and Cmax by 55%. Renal elimination of unchanged CHK-336 was quantitatively minor (<1% of administered dose). A direct effect inhibitory Imax-IC50 model adequately described the relationship between CHK-336 plasma concentrations and urinary 13C2-oxalate (% of control). Robust target engagement was demonstrated with an exposure-related reduction in urinary 13C2-oxalate from 15 – 60 mg, with maximum inhibition achieved at CHK-336 doses ≥60 mg. Conclusion CHK-336 is a first-in-class, orally administered, liver-targeted LDH inhibitor that was generally well-tolerated following single doses from 15 – 500 mg, with dose proportional increases in AUC exposure. Hepatic oxalate production was robustly reduced by CHK-336, as measured by urinary 13C2-oxalate, thus achieving proof of mechanism in HVs.

Disposition kinetics of robenacoxib following intravenous and oral administration in geese (Anser anser domesticus).

Robenacoxib (RX) is a veterinary cyclooxygenase-2 selective inhibitor drug. It has never been tested on birds and is only labelled for use in cats and dogs. The purpose of this study was to assess its pharmacokinetics in geese after single intravenous (IV) and oral (PO) administrations. Four-month healthy female geese (n = 8) were used. Geese were subjected to a two-phase, single-dose (2 mg/kg IV, 4 mg/kg PO), open, longitudinal study design with a four-month washout period between the IV and the PO phases. Blood was collected from the left wing vein to heparinized tubes at 0, 0.085 (for IV only), 0.25, 0.5, 0.75, 1, 1.5, 2, 4, 6, 8, 10, and 24 h. Plasma RX concentrations were measured using HPLC coupled to an UV detector, and the data were pharmacokinetically analysed using ThothPro™ 4.3 software in a non-compartmental approach. Following IV administration, terminal elimination half-life, volume of distribution, and total clearance were 0.35 h, 0.34 L/kg, and 0.68 L/h/kg, respectively. For the PO route, the mean peak plasma concentration was 6.78 μg/mL at 0.50 h. The t1/2λz was very short and significantly different between the IV and PO administrations (0.35 h IV vs. 0.99 h PO), suggesting the occurrence of a flip-flop phenomenon. The Cl values corrected for the F% were significantly different between IV and PO administrations. It might have been a consequence of the longitudinal study design and the altered physiological and environmental conditions after a 4-month washout period. The absolute oral F% computed with the AUC method surpassed 150%, but after normalizing it to t1/2λz, it was 46%. In conclusion, the administration of RX might not be suitable for geese, due to its short t1/2λz.

Assessing Boron-Pleuromutilin AN11251 for the Development of Antibacterial Agents.

Pleuromutilins are a group of antibiotics derived from the naturally occurring compound. The recent approval of lefamulin for both intravenous and oral doses in humans to treat community-acquired bacterial pneumonia has prompted investigations in modifying the structure to broaden the antibacterial spectrum, enhance the activity, and improve the pharmacokinetic properties. AN11251 is a C(14)-functionalized pleuromutilin with a boron-containing heterocycle substructure. It was demonstrated to be an anti-Wolbachia agent with therapeutic potential for Onchocerciasis and lymphatic filariasis. Here, the in vitro and in vivo PK parameters of AN11251 were measured including PPB, intrinsic clearance, half-life, systemic clearance, and volume of distribution. The results indicate that the benzoxaborole-modified pleuromutilin possesses good ADME and PK properties. AN11251 has potent activities against the Gram-positive bacterial pathogens tested, including various drug-resistant strains, and against the slow-growing mycobacterial species. Finally, we employed PK/PD modeling to predict the human dose for treatment of disease caused by Wolbachia, Gram-positive bacteria, or Mycobacterium tuberculosis, which might facilitate the further development of AN11251.

Development and validation of an ultrahigh-performance liquid chromatography-tandem mass spectrometry method to investigate the plasma pharmacokinetics of a KCa 2.2/KCa 2.3 positive allosteric modulator in mice.

There is currently no treatment for spinocerebellar ataxias (SCAs), which are a group of genetic disorders that often cause a lack of coordination, difficulty walking, slurred speech, tremors, and eventually death. Activation of KCa 2.2/KCa 2.3 channels reportedly exerts beneficial effects in SCAs. Here, we report the development and validation of an analytical method for quantitating a recently developed positive allosteric modulator of KCa 2.2/KCa 2.3 channels (compound 2q) in mouse plasma. Mouse plasma samples (10 μL) containing various concentrations of 2q were subjected to protein precipitation in the presence of a structurally similar internal standard (IS). Subsequently, the analytes were separated on a C18 ultrahigh-performance liquid chromatography column and detected by a tandem mass spectrometer. The method was validated using US Food and Drug Administration (FDA) guidelines. Finally, the validated assay was applied to the measurement of the plasma concentrations of 2q in plasma samples taken from mice after single intravenous doses of 2mg/kg of 2q, and the pharmacokinetic parameters of 2q were determined. The calibration standards were linear (r2 ≥ 0.99) in the range of 1.56-200 nM of 2q with intra- and inter-run accuracy and precision values within the FDA guidelines. The lower limit of quantitation of the assay was 1.56 nM (0.258 pg on the column). The recoveries of 2q and IS from plasma were >94%, with no appreciable matrix effect. The assay showed no significant carryover, and the plasma samples stored at -80°C or the processed samples stored in the autosampler at 10°C were stable for at least 3 weeks and 36 h, respectively. After intravenous injection, 2q showed a bi-exponential decline pattern in the mouse plasma, with a clearance of 30 mL/min/kg, a terminal volume of distribution of 1.93 mL/kg, and a terminal half-life of 45 min. The developed assay is suitable for preclinical pharmacokinetic-pharmacodynamic studies of 2q as a potential drug candidate for ataxias.

A phase 1 study of AGEN2373, a novel CD137 agonist antibody designed to avoid hepatoxicity, in patients with advanced solid tumors.

2524 Background: We present results from the completely enrolled monotherapy arm of the first-in-human dose escalation study of AGEN2373, a novel CD137 agonist antibody engineered to maximize efficacy by circumventing the dose-limiting hepatotoxicity reported for prior CD137 agonists (NCT04121676). AGEN2373 binds to a unique epitope of CD137 on effector T and NK cells in the tumor and tumor-draining lymph nodes, promoting co-engagement of activating Fcγ receptors. CD137 (4-1BB) is a tumor necrosis factor receptor superfamily protein and co-stimulatory receptor that promotes anti-tumor activity of adaptive and innate immune cells, making it an attractive target for immunotherapy. Methods: 46 patients (pts) received AGEN2373 IV every 2 weeks (Q2W), Q3W, or Q4W at doses between 0.03 and 10 mg/kg in a 3+3 design. Key endpoints included safety, tolerability, PK, preliminary efficacy, and PD markers. Imaging was Q8W. Results: Pts were enrolled between Oct 2019 and May 2022 with a median follow-up of 7.2 months. The median age was 64 (range 33-82). The most common tumor types were colorectal cancer, 13 pts (28%) and sarcoma, 8 (17%). Median prior therapies were 4 (range 1-14) including 48% with prior immunotherapy. There were no dose-limiting toxicities (DLTs) and no treatment-related hepatitis. 37% of pts had treatment-related AEs (TRAEs). TRAEs >10% were limited to fatigue (17%) and nausea (15%). There were no G3, 4 or 5 TRAEs. Pharmacokinetic parameters including half-life, clearance, and volume of distribution were consistent with a human IgG1 Fc backbone. Induction of soluble CD137 was dose dependent with 2 mg/kg as the lowest saturating dose and minimum predicted efficacious dose. In 19 pts treated at 2 mg/kg or higher who had at least one post-baseline scan, the overall response rate (ORR) was 11% (n=2); 37% had SD (n=7) resulting in a disease control rate (DCR) (CR, PR or SD) of 47%. Notable responses include: a pt with vulvar SCC who had progressed rapidly on pembrolizumab and had a confirmed partial response (cPR) while remaining on AGEN2373 x 2 mg/kg q2w for ~40 wks, and a pt with ampullary carcinoma with 4 prior regimens had a cPR on AGEN2373 x 6 mg/kg q3w with complete resolution of the pancreatic lesion. A pt with CRPC had a 38% tumor reduction in liver target lesions (confirmed) on AGEN2373 x 10mg/kg q3w but was non-evaluable due to palliative radiation to bone metastases. Conclusions: AGEN2373 showed objective responses as monotherapy in heavily pretreated pts with solid tumors and was well-tolerated with no evidence of hepatotoxicity. This distinguishes AGEN2373 from previous CD137-targeted agents that reported dose-limiting hepatotoxicity. Combination therapy with botensilimab, a novel Fc-enhanced CTLA-4 antagonist, is being studied in pts with PD(L)-1 pretreated melanoma. Clinical trial information: NCT04121676 .

First-in-human phase 1 trial of the safety, tolerability, pharmacokinetics, and preliminary anti-tumor activity of WSD0922-Fu: Initial report from dose escalation cohort.

3109 Background: WSD0922-Fu is an oral, central nervous system (CNS)-penetrant, small molecule, ATP non-competitive, reversible EGFR inhibitor which potently inhibits EGFR aberrations specific to non-small cell lung cancer (NSCLC) and high-grade astrocytoma (HGA). We report initial results of a first-in-human phase 1 dose-escalation trial (NCT04197934) in patients with EGFR aberrant recurrent HGA and NSCLC. Methods: Adult patients with either recurrent EGFR mutant NSCLC with CNS metastases or recurrent EGFR mutant and/or EGFR amplified HGA were enrolled. WSD0922-Fu was orally administered, and dose escalated in cohorts based on a standard 3+3 design to determine the maximum tolerated dose (MTD). Toxicities were graded per CTCAE v5.0 and preliminary efficacy was based on modified RANO criteria or RECIST 1.1 as appropriate. Results: 25 patients (17 HGA, 8 NSCLC) were enrolled and treated in six cohorts (40 mg once daily to 320 mg twice daily, 28-day cycles). The median age was 57 years (range 39-75 years). 24% were female and 36% were ECOG 0. For patients with HGA, all patients were previously treated with radiation and temozolomide; the median number of prior lines of systemic therapy was 1 (range 1-4). For patients with NSCLC, all patients were previously treated with an EGFR inhibitor (prior osimertinib 88%); the median number of prior lines of systemic therapy was 1.5 (range 1-6). The median duration of exposure to WSD0922-Fu among all patients was 54 days (range 2-258 days). The most common (≥25%) treatment-related adverse events included fatigue (68%), acneiform rash (68%), diarrhea (52%), nausea (48%) and pruritis (28%). The frequency of severe AEs was dose dependent. The most common Grade 3+ AEs (≥10%) included lymphopenia (16%), acneiform rash (12%), headache (12%) and diarrhea (12%). The MTD was defined as 160 mg twice daily. At Cycle 1 Day 15 for patients treated at this dose level, the mean terminal elimination half-life (%CV) in the plasma was 31.6 h (102%) (median 14.5 h; range 6.2-78.7 h). The mean Cmax, Tmax, oral clearance at steady state, and AUC (0-12 h) (%CV) were 4513 ng/mL (50%), 2.0 hr (69%), 6.9 L/hr/m2 (42%), and 28084 h*ng/mL (52%), respectively. Oral clearance at steady state was inversely related with dose, suggesting either inhibition or saturation of clearance processes. Among patients treated at MTD or higher dose levels and with available response data, 100% (5/5) of patients with NSCLC demonstrated clinical benefit (SD + PR) while 60% of patients had partial responses (intracranial and extracranial). Furthermore, prolonged stable disease (9 cycles) was observed in a patient with EGFRvIII mutant GBM. Conclusions: The MTD for WSD0922-Fu monotherapy is 160 mg BID. Preliminary efficacy was observed in patients with osimertinib-resistant NSCLC and EGFRvIII mutant HGA. Enrollment to expansion cohorts is ongoing. Clinical trial information: NCT04197934 .

Preliminary pharmacokinetic and safety data after a single intravenous infusion of Voyager-V1 (VV1, VSV-IFNβ-NIS) oncolytic virus in patients with relapsed refractory hematologic malignancies.

e14594 Background: Voyager-V1 (VV1) is an oncolytic vesicular stomatitis virus engineered to express interferon beta (IFNβ) to boost cellular antitumor immunity and sodium iodine symporter (NIS). A phase 1 trial investigating a single infusion of VV1 in patients with relapsed refractory multiple myeloma and T-cell lymphoma (TCL) showed promising and durable clinical activity, primarily in patients with TCL. VV1 infects tumor cells and macrophages in the lymph nodes and spleen, resulting in release of tumor antigens and IFNβ that activates and boost cellular antitumor immunity. We present the preliminary pharmacokinetic analysis in patients given one intravenous (IV) dose of VV1. Methods: Patients received 5e9 to 1.7e11 TCID50 (50% tissue culture infective dose) of VV1 given over 30 minutes. We also explored the impact of infusion duration (0.25, 0.5,1 and 3 hours) in 17 patients with solid tumors. The objectives were to determine the impact of viral dose on pharmacokinetics (PK) of VSV and IFNβ. For VSV and IFNβ PK, whole blood was collected in 30 patients on days 1, 2, 3, and 8. Dose levels were 1.7E10, 5E10, and 1.7E11 TCID50. The plasma concentration-time data were estimated with non-compartmental analysis using WinNonlin 8.3. Results: The half-life of VV1 is comparable (10-12h) between dose levels of 1.7e10, 5e10 and 1.7e11. Ideal infusion rate was found to be 30 minutes and provides the highest Cmax and AUC. Most peak concentrations for viremia and IFNβ were achieved between ‘end of infusion’ and 2.5 hours, 4.5 and 24 hours, respectively. Following infusion, a second concentration peak is found in over half the patients leading to highly variable terminal elimination half-life, specifically where the second peak is at 24 hours. There was no second peak for IFNβ levels. Peak plasma concentration and systemic exposure increased in proportion to increased dose, consistent with linear clearance. Conclusions: The 30 minute infusion rate was considered the best as its PK provides the highest Cmax and AUC with no significant CRS differences among other groups. IL-6 and IFNα markers at hour 4 indicate a likely CRS and hour 24 provides a possible prediction of the grade. Cmax and AUC were also highest at 1.7e11 TCID50. This is the recommended dose that will be used in the expansion arm in patients with TCL. Clinical trial information: NCT03017820 , NCT02923466 . [Table: see text]

A Prospective, Randomized Open-Label Study for Assessment of Antihypertensive Effect of Telmisartan Versus Cilnidipine Using Ambulatory Blood Pressure Monitoring (START ABPM Study).

The antihypertensive agent telmisartan is an angiotensin II receptor blocker with a terminal elimination half-life of 24 h and has a high lipophilicity, thereby enhancing its bioavailability. Another antihypertensive agent, cilnidipine is a calcium antagonist and has dual mode of action on the calcium channels. This study aimed at determining effect of these drugs on ambulatory blood pressure (BP) levels. A randomized, open-label, single-center study was conducted during 2021 - 2022 on newly diagnosed adult patients with stage-I hypertension, in a mega city of India. Forty eligible patients were randomized to telmisartan (40 mg) and cilnidipine (10 mg) groups, with once daily dose administered for 56 consecutive days. Ambulatory blood pressure monitoring (ABPM) (24 h) was performed pre- and post-treatment, and the ABPM-derived parameters were compared statistically. Statistically significant mean reductions were observed in all BP endpoints in telmisartan group but only in 24-h systolic blood pressure (SBP), daytime and nighttime SBP, and manual SBP and diastolic blood pressure (DBP) in cilnidipine group. The mean change from baseline to day 56 between two treatment groups showed statistical significance in last 6-h SBP (P = 0.01) and DBP (P = 0.014), and morning SBP (P = 0.019) and DBP (P = 0.028). The percent nocturnal drop within and between groups was statistically nonsignificant. Also, the between group mean SBP and DBP smoothness index differed nonsignificantly. Telmisartan and cilnidipine once daily were effective and well tolerated in the treatment of newly diagnosed stage-I hypertension. Telmisartan provided sustained 24-h BP control and may offer advantages over cilnidipine in terms of BP reductions, particularly over the 18- to 24-h post-dose period or critical early morning hours.

First-in-human dose-escalation study of NBF-006, a novel investigational siRNA targeting GSTP, in patients with non-small cell lung, pancreatic, or colorectal cancer.

3084 Background: Glutathione S-transferase Pi (GSTP) has an important role in detoxification and anti-oxidative damage response. Additionally, GSTP has a chaperone function which regulates key oncogenic pathways such as the KRAS and JNK pathways. Targeting multiple pathways could lead to more effective therapy than agents inhibiting single downstream kinase pathways (i.e., a MEK inhibitor), as alternative or redundant pathways could compensate for the inhibition of a single kinase. NBF-006 is a novel drug product containing a GSTP siRNA encapsulated within a lipid nanoparticle. It has been designed to deliver siRNA to tumors of the lung and common sites of metastatic spread (liver and marrow) which has been demonstrated in preclinical efficacy models. Methods: NBF-006-001 is a first-in-man (FIM) dose escalation study evaluating safety, tolerability, and PK of NBF-006 administered intravenously over 70 minutes, QW4 followed by a 2-week rest period in patients with advanced non-small cell lung (NSCLC), pancreatic (PANC), or colorectal cancer (CRC). Results: Twenty-one patients (11 NSCLC, 5 CRC, and 5 PANC) received treatment in a standard 3+3 dose escalation design (0.15 mg/kg [n=2], 0.3 mg/kg [n=3], 0.6 mg/kg [n=3], 1.2 mg/kg [n=6], and 1.6 mg/kg [n=7]). NBF-006 was well tolerated with no treatment-related grade 4-5 AEs, SAEs nor DLTs. Only one grade 3 event (WBC decrease) was assessed as possibly related. The most common NBF-006-related AEs were Grade 1 or 2 arthralgia, diarrhea, fatigue, and vomiting (11% each). There was no dose relationship in the number of AEs or any observed AEs. No meaningful complement activation, cytokine elevation nor ADA response has been observed to date (20 patients). One patient had 2 infusion related reactions (Grade 1 and 2). PK analysis indicated a terminal half-life ranging from 26 to 55 hours with no accumulation. Cmax and AUC demonstrated dose-proportionality up to 1.2 mg/kg and no additional increase in exposure at 1.6 mg/kg. NSCLC patients had an average and median number of prior lines of therapy of 4 and 3, respectively, with a range from 1-7 prior lines. One patient with NSCLC (treated at 1.6 mg/kg) experienced a durable partial response and progressed after ten months on the study. Four additional patients with NSCLC experienced stable disease, and two of these stayed on study treatment for >6 months (both treated at 1.2 mg/kg). One patient remains on treatment. CRC and PANC patients had an average/median of 4 and 3 prior lines, respectively. In CRC and PANC, stable disease for 24 weeks was the best response (n=1 each). Conclusions: This FIM study with NBF-006 demonstrated a favorable safety profile with early signs of antitumor activity in NSCLC. No DLTs or treatment-related SAEs were observed. Dose expansion in NSCLC is ongoing and will not be presented. Clinical trial information: NCT03819387 .

IMPORT-201 (IMP-MEL): A phase 1 first-in-human dose finding/randomized phase 2 study of a novel iNKT agonist IMM60 and pembrolizumab for advanced melanoma and metastatic non-small cell lung cancer (NSCLC).

2575 Background: Invariant natural killer T-cells (iNKTs) share features of NK-like cells and T-cells, playing a role in both innate and adaptive immune responses. The importance of this relatively rare lymphocyte subset has generated interest due to its dual ability to have a direct cytotoxic effect on CD1d expressing tumors as well as to induce long-lasting antitumor CD8 T cell responses mediated by cross-priming and licensing of dendritic cells. While many current clinical approaches involve the use of allogeneic iNKT cells, here we describe initial clinical studies with IMM60, a synthetically derived agonist of iNKT cells formulated in a liposome (PORT-2). In preclinical studies, IMM60 treatment results in maturation of DCs and B cells and a potent stimulation of iNKT cell-derived IFN-g. In murine efficacy studies, IMM60 demonstrated monotherapy activity in multiple PD-1 resistant models (e.g., B16-F10), as well as upregulation of PD-L1 expression on cancer cells and re-sensitization to PD-1 inhibition. Methods: The IMPORT-201 trial is a multicenter, international expansion of an open-label first-in-human phase I/II investigator initiated study (IMP-MEL). Ph 1 is currently enrolling patients with NSCLC or melanoma. IMM60-containing liposomes are administered IV Q3W at 3 escalating dose levels for 6 doses as monotherapy or with pembrolizumab 200mg Q3W. The Ph I portion of the study seeks to establish the recommended Ph 2 dose of IMM60 alone and in combination with pembrolizumab. The Ph 2 evaluates IMM60 monotherapy, PD-1 monotherapy, and the combination. Results: Eight patients with melanoma (n=4) or NSCLC (n=4) have been enrolled in the IMM60 monotherapy dose cohorts. These patients were heavily pretreated, having a median of 3.5 prior therapies (range 2-7). One patient with NSCLC has been enrolled to the IMM60 + pembrolizumab combination cohort. IMM60 was well tolerated with no treatment-related SAEs or G3-5 AEs, and no MTD was determined. The most common related AE is G1-2 fatigue, reported in 2 patients. In the monotherapy cohort, a preliminary review of individual target lesions showed 2 lesions that completely resolved, 1 lesion with 69% decrease in size, 10 lesions that were stable, and 6 lesions with >20% increase in size. Serum biomarker analysis demonstrated evidence of iNKT and NK activation, as well as increases in dendritic and CD86+ B cells. Pharmacokinetics demonstrate dose proportionality with a terminal half-life of ~8 hours. Conclusions: IMM60 is well tolerated as monotherapy and in combination with pembrolizumab at the doses tested. These data show that a single agent iNKT agonist can be safely administered in a heavily pre-treated population and initiate immune activation. The combination with pembrolizumab is ongoing, and updated results of the Ph 1 portion of the study will be reported. Clinical trial information: NCT05709821 .

A first-in-human, open-label, phase I trial of daily oral PCLX-001, an NMT inhibitor, in patients with relapsed/refractory B-cell lymphomas and advanced solid tumors.

e15094 Background: Myristoylation, the N-terminal modification of proteins with the fatty acid myristate, regulates multiple membrane-bound signal transduction pathways driving cancer cell biology. This modification is catalyzed by two N-myristoyltransferases (NMT), NMT1 and NMT2. Aberrant NMT expression has been identified in cancer cells and inhibition of myristoylation represents a novel anticancer treatment strategy. PCLX-001 is an oral, highly bioavailable, small molecule NMT inhibitor with strong affinity for both NMT1 and NMT2 proteins (IC50 of 5nM and 8nM, respectively). In vitro, hematologic cancer cell lines were exquisitely sensitive to PCLX-001. PCLX-001 regressed subcutaneous tumors in xenograft models derived from lymphoma cell lines, as well as in a refractory DLBCL patient derived xenograft model. PCLX-001 also demonstrated anticancer activity in multiple solid tumor xenograft models. Based on pre-clinical data, we hypothesized that PCLX-001 would be safe, tolerable, and active as a novel oral cancer therapeutic. Methods: Patients with relapsed/refractory B-cell lymphomas and advanced solid tumors are being enrolled in a multicenter, open label, standard phase I dose escalation design to determine feasibility, maximum tolerated dose (MTD), and pharmacokinetics of PCLX-001 monotherapy. Seven dose levels are being studied: 20 mg, 40 mg, 70 mg, 100 mg, 140 mg, 200 mg, and 280 mg. Dose limiting toxicity (DLT) is defined as: grade (Gr) 4 platelets, Gr 3 platelets with bleeding, Gr 4 ANC ≥ 7 days, febrile neutropenia, or clinically significant > Gr 3 non-hematologic toxicity. Results: Eighteen evaluable patients (3 relapsed B-cell lymphoma; 15 advanced solid tumor) have been accrued through dose level six (200 mg cohort) without DLT. No attributable Gr 3 or 4 toxicities have been identified. Noncompartmental pharmacokinetic (PK) analyses demonstrate rapid oral absorption, a terminal half-life of approximately 10 hours, rapid achievement of steady state, and no induction of metabolism. PCLX-001 trough plasma concentrations at higher dose cohorts exceed the EC90 required to inhibit cultured cancer cells. Conclusions: PCLX-001 is safe and well tolerated up to the 200 mg daily dose. Our results support the ongoing development of PCLX-001 as an oral daily therapy for the treatment of patients with cancer. Updated study results will be presented, summarizing the safety, MTD, and PK outcomes in PCLX-001 treated patients. Preliminary clinical activity will be determined in 20 patient dose expansion cohorts of relapsed/refractory B-cell lymphomas, and selected advanced solid tumors following the identification of PCLX-001 MTD. Clinical trial information: NCT04836195 .