First-in-human Trials Research Articles

Risky first-in-human clinical trials on medically fragile persons: owning the moral cost.

The purpose of a first-in-human (FIH) clinical trial is to gather information about how the drug or device affects and interacts with the human body: its safety, side effects, and (potential) dosage. As such, the primary goal of a FIH trial is not participant benefit but to gain knowledge of drug or device efficacy, i.e., baseline human safety knowledge. Some FIH clinical trials carry significant foreseeable risk to participants with little to no foreseeable participant benefit. Participation in such trials would be a bad deal for participants, and the research is considered justifiable because of the promise of significant potential social benefit. I argue that there is an ethical tension inherent in risky FIH research and that researchers should fairly compensate risky FIH trial participants. This does not make the risk-benefit outcome more favorable for participants; rather, it amounts to a collective reckoning with the ethical tension inherent in the research.

Erythrocyte-αPD-1 conjugates overcome resistance to checkpoint blockade immunotherapy: A first-in-human study.

2557 Background: While the immune checkpoint blockade (ICB) therapy has revolutionized the field of tumor therapy. the resistance remains a major challenge. We have previously developed WTX-212, an erythrocyte-antibody conjugate covalently linking anti-PD-1 antibody to erythrocyte membranes. Unlike conventional antibodies, WTX-212 exhibits natural accumulation in the spleen and remodels the splenic immune landscape in tumor-bearing mice. WTX-212 treatment efficiently activates CD8+ T cells in the spleen, which subsequently infiltrate into tumors and exhibit anti-tumor cytotoxicity. Additionally, activated T cells reduce the splenic reservoir of Myeloid-derived suppressor cells (MDSC) and those within tumors, further enhancing overall anti-tumor responses. Pre-clinical studies have demonstrated that WTX-212 can significantly suppress tumor growth in xenograft tumor models resistant to anti-PD-1 immunotherapies. A first-in-human (FIH) clinical trial is now investigating its potential in human cancer patients. Methods: The FIH trial (NCT05707325) is aimed to investigate the safety, pharmacokinetics and preliminary efficacy of WTX-212 in cancer patients with advanced malignancies. All of patients had previously received anti-PDs therapies and developed resistance to these treatments. By Feb 5th, 2024, the tumor lesions were assessed using RECIST v1.1 criteria. Blood and tumor samples were collected for correlative analysis. Results: 7 metastasized patients with various solid tumors, having undergone a median of 3.1 prior lines of therapy (ranging from 1-6), received WTX-212 monotherapy. None of patients treated with WTX-212 experienced treatment-related adverse events greater than Grade 3, indicating a high safety profile. WTX-212 was detectable in peripheral blood at the end of cycle in a dose dependent manner. Disease control was achieved in 5/7 patients (DCR=71%). Specifically, a patient with esophageal cancer, achieved a confirmed complete remission after 6-cycle treatment. Additionally, two patients, one with esophageal cancer (3L) and another with HPV-negative cervical cancer (4L), maintained stable disease for over 40 and 30 weeks, respectively. Consistent with our pre-clinical findings, a substantial reduction in MDSCs were observed in 6/7 patients (ranging from 24%-82%). Furthermore, a median 1.5-fold increase in T cells was noted in all patients in the peripheral blood after the 1st cycle of the treatment. Conclusions: WTX-212 treatment is safe and tolerable and shows promising clinical signs in cancer patients resistant to anti-PD-1 immunotherapy, supporting further investigation and exploration of WTX-212 monotherapy and combination therapy. Clinical trial information: NCT05707325 .

Clinical pharmacology considerations for first-in-human clinical trials for enzyme replacement therapy.

Inborn errors of metabolism (IEM) such as lysosomal storage disorders (LSDs) are conditions caused by deficiency of one or more key enzymes, cofactors, or transporters involved in a specific metabolic pathway. Enzyme replacement therapy (ERT) provides an exogenous source of the affected enzyme and is one of the most effective treatment options for IEMs. In this paper, we review the first-in-human (FIH) protocols for ERT drug development programs supporting 20 Biologic License Applications (BLA) approved by the Center for Drug Evaluation and Research (CDER) at the US Food and Drug Administration (FDA) in the period of May 1994 to September 2023. We surveyed study design elements across these FIH protocols including study population, dosage form, dose selection, treatment duration, immunogenicity, biomarkers, and study follow-up. A total of 18 FIH trials from 20 BLAs were identified and of those, 72% (13/18) used single ascending dose (SAD) and/or multiple ascending dose (MAD) study design, 83% (15/18) had a primary objective of assessing the safety and tolerability, 72% (13/18) included clinical endpoint assessments, and 94% (17/18) included biomarker assessments as secondary or exploratory endpoints. Notably, the majority of ERT products tested the approved route of administration and the approved dose was tested in 83% (15/18) of FIH trials. At last, we offer considerations for the design of FIH studies.

A review of dose escalation for FDA-approved products treating solid tumors and hematological malignancies in first-in-human trials.

First-in-human (FIH) dose-escalation trials on oncology should prioritize safety and emphasize efficacy. We reviewed the FIH trials of 67 anti-tumor products approved by the Food and Drug Administration between 2018 and 2023 and found that the "3 + 3" design remains the predominant dose-escalation method (66.2%). The number of patients receiving sub-therapeutic doses is positively correlated with the maximum tolerated dose (MTD) or maximum dose (MD) to starting dose ratio (P = 0.056) and the number of dose levels in trials (P < 0.001). In addition, the proportion of products with a high ratio in antibody drugs is higher than that in small molecules (P < 0.001). The MTD or MD exceeded the label dose by three or more doses in 22.03% of the products. In conclusion, optimizing the starting dose selection method, refining the way of determining doses, and finding alternative indicators to replace toxicity as the endpoints will increase the effectiveness and broaden the beneficiary scope.

Abstract 3186: An Erythrocyte-αPD-1 conjugate suppresses cancers resistant to checkpoint blockade immunotherapy: A first-in-human study

Abstract Background: Immune checkpoint blockade (ICB) therapy has revolutionized cancer treatment, yet resistance to this therapy can lead to immune escape and disease progression. Here, we introduce WTX-212, an erythrocyte-antibody conjugate covalently linking anti-PD-1 antibody to erythrocyte membranes. Unlike conventional antibodies, WTX-212 naturally accumulates in the spleen and remodels the splenic immune landscape in tumor-bearing mice. Pre-clinical studies have demonstrated that T cells activated by WTX-212 reduce the splenic reservoir of immunosuppressive myeloid cells, including those within tumors. This results in a systemic anti-tumor immune response and suppression of tumor growth in xenograft tumor models resistant to anti-PD-1 immunotherapies. A first-in-human (FIH) clinical trial is now investigating its potential in human cancer patients. Methods: The FIH trial (NCT05707325) is aimed to investigate the safety, pharmacokinetics, mechanisms and preliminary efficacy of WTX-212 in cancer patients with advanced malignancies. All of patients had previously received anti-PDs therapies and developed resistance to these treatments. By November 15th, 2023, 7 patients across two cohorts had received WTX-212 monotherapy (1 × 1011-2 × 1011 cells, Q3W IV). The tumor lesions were assessed using RECIST v1.1 criteria. Blood and tumor samples were collected for correlative analysis. Results: 7 patients with various solid tumors, having undergone a median of 3.1 prior lines of therapy (ranging from 1-6), received WTX-212 monotherapy. No dose-limiting toxicities or treatment-related adverse events greater than Grade 3 were reported. WTX-212 was detectable in peripheral blood at the end of cycle in a dose dependent manner. Disease control, including partial remission (PR) and stable disease (SD), was observed in 5/7 patients (DCR, 71%). One patient with esophageal cancer achieved a PR with a significant 44% reduction in target lesion size after two cycles of treatment. Two patients, one with esophageal cancer (3 lines prior therapies) and another with HPV-negative cervical cancer (4 lines prior therapies), maintained disease control for over 30 weeks after WTX-212 treatment. Consistent with preclinical findings, WTX-212 systemically induced anti-tumor responses, leading to a reduction of myeloid-derived suppressor cells (MDSCs) particularly the PMN-MDSC subset in 6/7 patients (reductions ranging from 24%-82% compared to baseline), and a median 1.5-fold increase of T cells in 7/7 patients in the peripheral blood after the 1st cycle of treatment. Conclusion: The initial promising data support further investigation and exploration of the combination therapy strategies to expand the therapeutic potential of WTX-212 in cancer patients. Erythrocyte-drug conjugation may serve as a unique strategy for targeting the peripheral immune system to treat cancers. Citation Format: Liu Yang, Xiaoqian Nie, Zheling Chen, Yuehua Liu, Jiawei Zheng, Xiaofei Gao. An Erythrocyte-αPD-1 conjugate suppresses cancers resistant to checkpoint blockade immunotherapy: A first-in-human study [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 3186.

Abstract C162: Assessment of the potential for QTc prolongation by the investigational ATR inhibitor tuvusertib in patients with advanced solid tumors using integrated nonclinical and clinical assessments

Abstract Background: Tuvusertib (M1774) is a potent, selective, orally administered inhibitor of ataxia telangiectasia and Rad3-related protein kinase (ATR) with demonstrated antitumor activity in preclinical models. Tuvusertib is currently being evaluated in phase I and II trials as monotherapy and in combination with other DNA damage response inhibitors and immune checkpoint inhibitors. Assessment of an investigational agent’s potential to cause delayed ventricular repolarization (QTc prolongation) is essential in drug development. QTc prolongation is assessed using nonclinical studies and concentration-QTc (c-QTC) analysis of phase I clinical data across a wide dose range and/or a thorough QT/QTc (TQT) clinical study. Here, we assess tuvusertib’s potential to cause QTc prolongation by integrating nonclinical evaluations and clinical c-QTc analyses. Methods: Nonclinical evaluations included in vitro binding of tuvusertib to the ether-a-go-go-related gene (hERG) channel and telemetry of tuvusertib in male beagle dogs and minipigs. Pharmacokinetics-time-matched triplicate electrocardiograms were collected in patients with advanced solid tumors from the first-in-human (FIH) trial (NCT04170153) for tuvusertib 5−270 mg QD along with intermittent dosing regimens. Based on exploratory analyses, a linear mixed-effect model (Garnett C, et al. J Pharmacokinet Pharmacodyn 2018;45:383–97) was chosen to describe the relationship between tuvusertib plasma concentrations and selected heart rate (HR)-corrected QT using the Fridericia correction (QTcF). Results: In vitro hERG channel binding potency for tuvusertib 0.3–10.0 µM was calculated with a half-maximal inhibitory concentration (IC50) of 2.8 µM. Nonclinical telemetry studies showed no treatment effect on QT/QTc prolongation at doses of up to 3 mg/kg in male beagle dogs and minipigs. c-QTc analyses in 55 patients from the FIH trial revealed a small positive slope of drug effect (slope estimate [95% CI] = 0.00244 [0.000708, 0.00417] ms/(ng/mL)). This increase in model-predicted QTcF from baseline was not considered to be clinically meaningful (&amp;lt;20 ms threshold) at steady-state maximum concentration (Cmax) achieved with the recommended dose for expansion (RDE) of 180 mg QD 2w on/1w off (mean [upper bound of 95% CI] = 3.4 [5.5] ms) and up to 3 times the RDE (10.3 [16.5] ms). Concentration-HR modeling found no relationship between tuvusertib concentration and HR, suggesting the absence of an effect. Conclusions: Integrating nonclinical and clinical assessments revealed no clinically meaningful effect of tuvusertib on QTc at concentrations achieved with the RDE and up to 3-times higher concentrations. Citation Format: Jatinder Kaur Mukker, Timothy A. Yap, Anthony W. Tolcher, Johann S. de Bono, Ruth Plummer, Rohan Kulkarni, Han Witjes, Paul Matthias Diderichsen, Axel Krebs-Brown, Rainer Strotmann, Zoltan Szucs, Ioannis Gounaris, Karthik Venkatakrishnan. Assessment of the potential for QTc prolongation by the investigational ATR inhibitor tuvusertib in patients with advanced solid tumors using integrated nonclinical and clinical assessments [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C162.

Abstract 15137: microRNA-132 Inhibition Improves Cardiac Function and Reduces Remodeling in Patients With Heart Failure With Reduced Ejection Fraction (HFrEF): An Exploratory Subgroup Analysis of the CDR132L First-in-Human Study

Background: The CDR132L first-in-human (FiH) study examined safety, tolerability, pharmacokinetic, and exploratory pharmacodynamic effects of different ascending doses of the novel antisense oligonucleotide CDR132L targeting microRNA-132-3p (miR-132) in patients with stable heart failure (HF) of ischemic origin receiving standard-of-care (n=28). The study population was not stratified according to their left-ventricular ejection fraction (LVEF), and therefore heterogenous, but equally distributed among heart failure with reduced or preserved ejection fraction (HFrEF or HFpEF). Research question: In an exploratory post-hoc analysis of pharmacodynamic parameters we specifically focused on patients with HFrEF (with a LVEF&lt;45% at baseline, n=14) and, based on our predictive PK/PD modeling, categorized patients into ‘non-pharmacodynamically active’ (non-PD active; placebo and 0.32 mg/kg CDR132L group) and 'pharmacodynamically active' (PD active; patients receiving 1, 3, or 10 mg/kg CDR132L). Results: The PD active group showed a significant median reduction in NT-proBNP by 37.1% between baseline and study endpoint (day 112) while this HF biomarker was increased by 17.7% in the non-PD active group (p=0.0152, Mann-Whitney U test). CDR132L treatment provoked a trend towards 6.1% improvement in LVEF. For the non-PD active group only +1.4% were noted. An additional biomarker related to HF and cardiac fibrosis, lipocalin-2 (NGAL), tended to decrease in the PD active, but not in the non-PD active group. Conclusion: Analysis of the HFrEF subgroup in this FiH trial, although limited by the small patient numbers, indicatively underlines the encouraging benefits of CDR132L, a novel antisense drug, on LV function and cardiac remodeling as established in previous large animal HF models.

A review of clinical trials registered in India from 2008 to 2022 to describe the first-in-human trials.

This analysis was conducted to review the number, and describe the characteristics of first-in-human (FIH) Phase 1 clinical trials registered in India from 2008 to 2022. The data were extracted from the Clinical Trials Registry - India database for all FIH Phase 1 clinical trials registered between 2008 and 2022. Early-phase trials that were not FIH trials (e.g., pharmacokinetic studies and drug-drug interaction studies) were excluded from the study. A total of 1891 trials were retrieved and 220 were included in the analysis. Most of the investigational products were drugs (55%) followed by vaccines (38.2%). The most common therapeutic class of drugs was cancer chemotherapy (19.8%), followed by antimicrobial chemotherapy and endocrinology (18.2% each). The most common vaccine was the influenza vaccine (21.4%), followed by the measles-mumps-rubella vaccine (15.5%). The pharmaceutical industry was the predominant sponsor for most (91%) of the Phase 1 trials. Of the top five sites where most of the Phase 1 trials were conducted, three were private nonacademic centers (cumulatively 31%) and two were tertiary care medical colleges (cumulatively 9%). Phase 1 clinical trials seem to be conducted in India predominantly with industry sponsorship. There is a need to have an alternate ecosystem to take forward molecules that do not receive adequate attention from the industry and molecules that are of national health priority other than areas such as chemotherapy, antimicrobials, and endocrinology. The Indian Council of Medical Research is setting up Phase 1 clinical trial capacity for molecules that predominantly may arise from nonindustry channels.

The role of WTX212, an erythrocyte-anti-PD1 antibody conjugate, in anti-tumor activities in tumor models and cancer patients with acquired resistance to immunotherapy.

29 Background: Despite the success of immune-checkpoint blockade (ICB) treatments, a considerable proportion of patients cannot benefit from ICB therapy due to acquired resistance. Recent studies have revealed that successful immunotherapy drives new immune responses arising from peripheral immune system instead of reinvigorating the pre-existing responses in the tumor. Here we designed WTX212, autologous engineered red blood cells (RBCs) conjugated with anti-PD1 antibodies capable of activating the peripheral immune system. We also evaluated its anti-cancer activities in anti-PD1 non-responsive tumor models and a first-in-human (FIH) trial. Methods: The anti-tumor efficacy of WTX212 was evaluated in both PD1 responsive (MC38 colorectal cancer) and non-responsive (KP lung cancer and pB3 breast cancer) mouse tumor models (n=7 / group). Mice were monitored twice a week for clinical signs and tumor sizes. The mechanism of action was investigated in splenectomized mice and by analyzing the biodistribution of WTX212 using a radiolabeling method. The immune landscape was also profiled through cytof mass and scRNA-seq analyses in the spleen, tumor and peripheral blood. The FIH trial (NCT05707325) explores safety, pharmacokinetics and mechanism in cancer patients with acquired resistance to ICB. WTX212 was manufactured by covalently engineering anti-PD1 antibody with RBCs isolated from patients. By 11th April 2023, 3 patients have been enrolled and received at least one dose of WTX212 (20*1010 cells, IV, Q3W). Results: Treatment of WTX212 significantly suppressed tumor growth up to 100% in anti-PD1 responsive and non-responsive tumor models. Unlike antibodies, WTX212 primarily distributed to the spleen and vascular system. The anti-tumor effect of WTX212 was abrogated in corresponding splenectomized mice. Compared to anti-PD1 antibody, single-cell analysis identified the immune landscape remodeling in the spleen from WTX212-treated mice, with down-regulation of PD-L1+ myeloid-derived suppressor cells (MDSCs) and up-regulation of effector CD8+ T cells. In the FIH trial, 3 patients have been administered with total thirteen cycles of WTX212. No treatment-related AEs greater than Grade 2 were observed. WTX212 remained in the peripheral blood day 21 post transfusion. WTX212 rapidly activates peripheral immune systems with decreased MDSCs, Tregs and increased effector T cells in peripheral blood from all patients. The first patient who received six cycles of WTX212 treatment demonstrated stable disease with a 20% reduction at the target lesion. Conclusions: WTX212 demonstrated anti-tumor activities by activating the peripheral immune system to overcome resistance to immunotherapy in both preclinical models and human patients. WTX212 is well-tolerated supporting the future clinical trials. Clinical trial information: NCT05707325 .

WTX212, an erythrocyte-anti-PD1 antibody conjugate, to demonstrate anti-tumor activities in tumor models and patients with cancer with acquired resistance to immunotherapy.

e14529 Background: Despite the success of immune-checkpoint blockade (ICB) treatments, a considerable proportion of patients cannot benefit from ICB therapy due to acquired resistance. One major challenge is the systemic suppression of immune cells induced by the tumor. Recent studies have revealed that successful immunotherapy drives new immune responses arising from peripheral immune system instead of reinvigorating the pre-existing responses in the tumor. Here we designed WTX212, autologous engineered red blood cells (RBCs) conjugated with anti-PD1 antibodies capable of activating the peripheral immune system. We also evaluated its anti-cancer activities in anti-PD1 non-responsive tumor models and a first-in-human (FIH) trial. Methods: The anti-tumor efficacy of WTX212 was evaluated in both PD1 responsive (MC38 colorectal cancer) and non-responsive (KP lung cancer and pB3 breast cancer) mouse tumor models (n=7 / group). Mice were monitored twice a week for clinical signs and tumor sizes. The mechanism of action was investigated in splenectomized mice and by analyzing the biodistribution of WTX212 using a radiolabeling method. The immune landscape was also profiled through cytof mass and scRNA-seq analyses in the spleen, tumor and peripheral blood. The FIH trial (NCT05707325) explores safety, pharmacokinetics and mechanism in cancer patients with acquired resistance to ICB. WTX212 was manufactured by covalently engineering anti-PD1 antibody with RBCs isolated from patients. By 6th Feb 2023, 3 patients have been enrolled and received at least one dose of WTX212 (20*1010 cells, IV, Q3W). Results: Treatment of WTX212 significantly suppressed tumor growth up to 100% in anti-PD1 responsive and non-responsive tumor models and activated tumor microenvironment with increased infiltrated T cells. Unlike antibodies, WTX212 primarily distributed to the spleen and vascular system. The anti-tumor effect of WTX212 was abrogated in corresponding splenectomized mice. Compared to anti-PD1 antibody, single-cell analysis identified the immune landscape remodeling in the spleen from WTX212-treated mice, with down-regulation of PD-L1+ myeloid-derived suppressor cells (MDSCs) and up-regulation of effector CD8+ T cells. In the FIH trial, 3 patients have been administered with total eight cycles of WTX212. No treatment-related AEs greater than Grade 2 were observed. WTX212 remained in the peripheral blood day 21 post transfusion. WTX212 rapidly activates peripheral immune systems with decreased MDSCs, Tregs and increased effector T cells in peripheral blood from all patients. Conclusions: WTX212 demonstrated anti-tumor activities by activating the peripheral immune system to overcome resistance to immunotherapy in both preclinical models and human patients. WTX212 is well-tolerated supporting the future clinical trials.

Abstract ND04: BAY 2965501: A highly selective DGK- ζ inhibitor for cancer immuno-therapy with first-in-class potential

Abstract The second messenger diacyl glycerol (DAG) plays a key role in T cell receptor downstream signaling and thereby in T-cell activation. Diacylglycerol kinase zeta (DGK-ζ) is a lipid kinase that can down-modulate T-cell activation by catalyzing the conversion of DAG to phosphatidic acid, thereby acting as a ligand independent, intracellular immune checkpoint. Inhibition of DGK- ζ offers the potential to enhance T cell priming against suboptimal tumor antigens and to overcome multiple immune-suppressive mechanisms in the tumor microenvironment. Bayer AG in collaboration with the German Cancer Research Center (DKFZ) have developed BAY 2965501, a highly selective, orally available DGK-ζ inhibitor which shows a unique binding mode and good DMPK profile. The compound enhances the reactivity of human and mouse T-cells, both in the priming and the effector phase, and overcomes the inhibitory impact of suppressive factors, such as adenosine and prostaglandin E2. Oral dosing of BAY 2965501 shows T cell dependent efficacy in syngeneic, murine tumor models. Furthermore, this results in reactivation of exhausted T cells in vivo. Preclinical safety studies showed only mild findings, so that good clinical tolerability is expected. Collectively, the preclinical data support first in human (FiH) phase I testing of therapeutic potential. A FiH trial with BAY 2965501 in patients with advanced solid tumors including NSCLC, gastric/GEJ AdCa, ccRCC, and melanoma patients, is currently enrolling patients (NCT05614102). This study will evaluate the safety, tolerability, maximum tolerated or administered dose, pharmacokinetics, pharmacodynamics, and tumor response profile of BAY 2965501. Citation Format: Rienk Offringa, Catherine Olesch, Frederik Cichon, Mareike Grees, Norbert Schmees, Ulrike Roehn, Florian Prinz, Judith Guenther, Detlef Stoeckigt, Michael Erkelenz, Thi Thanh Uyen Nguyen, Ulf Boemer, Nicolas Werbeck, Marc Kunze, Kirstin Petersen, Dennis Kirchhoff. BAY 2965501: A highly selective DGK- ζ inhibitor for cancer immuno-therapy with first-in-class potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr ND04.

Clearance as an Early Indicator of Efficacy for Therapeutic Monoclonal Antibodies: Circumventing Dose Selection Challenges in Oncology.

The designs of first-in-human (FIH) studies in oncology (e.g., 3+3 dose escalation design) usually do not provide a sufficient sample size to determine the dose-response relationship for efficacy. This study aimed to assess the feasibility of using monoclonal antibody (mAb) clearance as a biomarker for efficacy to facilitate the identification of potentially efficacious doses across cancer types and drug targets. We performed electronic searches of the Drugs@FDA website, the European Medicines Agency website, and PubMed to identify reports of FIH trials of approved mAbs in oncology. The clearance, half-life, and overall response rate (ORR) data for the mAbs at different dose levels were extracted. Twenty-five approved mAbs were included in this study. As expected, due to the small sample sizes in FIH studies, there was no clear dose-response for ORR. However, we found a clear negative association between mAb clearance and ORR across tumors/drug targets, and a clear negative dose-clearance relationship, with clearance decreasing and saturated at high dose levels. The approved mAb doses (1-25 mg/kg) are approximately 2-fold the saturation doses (1-10 mg/kg). The associated clearance values at the approved doses vary across different cancers and drug targets (0.17-1.56 L/day), while tend to be similar within a disease/drug target. Anti-CD20 mAbs for B-cell lymphomas show a higher clearance (~ 1 L/day) than other cancers and targets (e.g., ~0.3 L/day for anti-PD-1). Clearance of mAbs can be a tumor/drug target-agnostic biomarker for potential anti-tumor activity as clearance decreases with increasing ORR. Our findings shed important insights into target clearance values that may lead to desired efficacy for different cancers and drug targets, which can be used to guide dose selection for the future development of mAbs during FIH oncology studies.

SY07-4 History and future of oncology early phase global clinical development in Asia

First-in-human (FIH) clinical trials in oncology are highly complex and can only be conducted at a globally small number of highly specialized and qualified hospitals. Historically, early clinical data on new drugs oftentimes had to be generated in national trials, conducted after the global FIH trial. This led to unnecessary delays in getting access to new innovative drugs for patients in Asian countries.

Design and rationale of a phase 1 dose-escalation study of AMG 193, a methylthioadenosine (MTA)-cooperative PRMT5 inhibitor, in patients with advanced methylthioadenosine phosphorylase (MTAP)-null solid tumors.

TPS3167 Background: Protein arginine methyltransferase 5 (PRMT5) is an emerging target for cancer treatment. MTAP homozygous deletion occurs in 15% of cancers and often coincides with deletion of the tumor suppressor gene CDKN2A, leading to buildup of its substrate MTA. MTA shares close structural similarity to S-adenosyl methionine (SAM), the substrate methyl donor for PRMT5. By competing with SAM, MTA partially inhibits PRMT5. Thus, MTAP-null cancers are susceptible to further PRMT5 inhibition (Kryukov Science 2016). Current direct/indirect PRMT5 inhibitors (PRMT5i) showed preliminary anticancer activity, albeit with considerable toxicities due to their indiscriminate activities. AMG 193 is an MTA-cooperative PRMT5i that preferentially targets the MTA-bound state of PRMT5 that is enriched in MTAP-null tumors and represents a novel strategy to increase the therapeutic margin of this class of inhibitors. AMG 193 potently inhibits MTAP-null cancer cell lines and patient-derived xenografts. Methods: NCT05094336 is a first-in-human (FIH), multicenter, open-label, phase 1/1b/2 trial evaluating the safety, tolerability, pharmacokinetics (PK), pharmacodynamics, and efficacy of AMG 193 in patients with advanced MTAP-null solid tumors. Eligible patients (≥ 18 years) with histologically confirmed locally advanced/metastatic solid tumors not amenable to curative treatment with surgery and/or radiation, homozygous MTAP and/or CDKN2A deletion (by local next generation sequencing), or MTAP protein loss in tumors (by central immunohistochemistry), measurable disease, ECOG PS 0‒1, adequate hematopoietic, renal, liver, pulmonary, cardiac, coagulation function and glucose control will be included. The study will be conducted in 3 parts, each with subparts. Here, we describe Part 1a/b (dose exploration). Five dose levels are planned. Treatment continues until progression or withdrawal. The primary objectives are to evaluate the safety and tolerability of AMG 193 monotherapy; endpoints include dose-limiting toxicities, treatment-emergent adverse events, serious adverse events, electrocardiograms, laboratory abnormalities, and vital signs. Secondary objectives include the characterization of the PK parameters of AMG 193 including Cmax, Tmax, and AUC after single or multiple doses. This study is expected to enroll approximately 30 patients in Part 1a/b. This is the first FIH trial open for enrollment for this new class of PRMT5i and enrollment is ongoing. Clinical trial information: NCT05094336.

Phase I study of intratumoral administration of CF33-HNIS-antiPDL1 in patients with metastatic triple negative breast cancer.

e13070 Background: Despite recent FDA approval of immune checkpoint inhibitor pembrolizumab and drug-antibody conjugate in the treatment of metastatic triple negative breast cancer (mTNBC), the overall survival benefit of these therapies remains modest. Oncolytic virotherapy (OV) utilizes genetically modified viruses to infect and kill cancer cells while sparing healthy cells. CF33-hNIS-anti-PD-L1 (CHECKvacc) is a novel chimeric orthopoxvirus with robust anti-cancer activity in TNBC xenografts. Cells infected with CHECKvacc were shown to express functional human sodium-iodide symporter (hNIS) and anti-PD-L1 proteins. hNIS gene transfer allows tracking of virus by 99mTc single-photon emission computed tomography (SPECT). Our preliminary animal studies demonstrated that tumor cells infected with CHECKvacc successfully secrete functional hNIS and anti-PD-L1. CHECKvacc is safe and well-tolerated, and detects and effectively kills TNBC at doses several magnitudes lower than other OVs in xenograft models. Methods: This study is a first-in-human (FIH) phase I, single center, single arm clinical trial evaluating the safety and tolerability of CHECKvacc intratumoral injection in patients with mTNBC. Key eligibility criteria include patients with unresectable or metastatic TNBC; progressed on at least 2 prior chemotherapies including immune checkpoint inhibitor-containing regimen; ECOG 0-1; RECIST 1.1 measurable disease; and at least one tumor amenable to repeated intratumoral injections. Eligible patients receive CHECKvacc intratumorally at one of 8 assigned dose levels (1 × 105 PFU, 3 × 105 PFU, 1 × 106 PFU, 3× 106 PFU, 1 × 107 PFU, 3 × 107 PFU, 1 × 108 PFU, 3 x 108 PFU) on Days 1 and 15 of each 28-day cycle for a total of 3 cycles of treatment. Primary objectives are to evaluate the safety and tolerability of CHECKvacc (DLTs and other toxicities by CTCAE v5.0). Secondary objectives are to determine optimal biological dose (OBD), recommended phase II dose (RP2D), and response rate by RECIST1.1. Results: The first 3 subjects of dose level 1 will be enrolled sequentially for safety monitoring. Once the initial 3 subjects are treated sequentially, the study will follow the Phase I Queue 3+3 (IQ 3+3) design which expands a dose level up to 8 subjects after a single DLT has been observed. Enrollment to the final RP2D may be expanded to include up to 12 patients for efficacy assessment. The estimated targeted accrual is 33 patients (minimum) to 78 patients (maximum). Correlative aims include assessing viral kinetics, viral plaque assay, 99mTc SPECT imaging for virus tracking, peripheral blood and tumor tissue for antiviral immune activation, and tumor microenvironment changes in association with response to therapy. Conclusions: This FIH trial of CF33-hNIS-antiPD-L1 intratumoral injection in patients with mTNBC is currently underway. Clinical trial information: NCT05081492.

Practical consideration for successful sequential tumor biopsies in first-in-human trials

In first-in-human (FIH) trials, sequential tumor biopsies, i.e., two consecutive tumor biopsies, the first performed at baseline (pretreatment) and the second during the early treatment period (on-treatment), provide proof of concept in investigational new drugs. We evaluated the success of sequential tumor biopsies in FIH trials, and explored approaches for improved success rates. We retrospectively reviewed the sequential tumor biopsies required in 17 of 52 FIH trials conducted from 2015 to 2020. One hundred and thirty-eight patients were identified. Success of either pretreatment or on-treatment biopsy alone, and of sequential tumor biopsies, was defined as the acquisition of viable tumor cells and as obtaining tumor cells from both biopsy specimens, respectively. The success rates of pretreatment and on-treatment biopsy were 98.6% and 94.2%, respectively, and of sequential tumor biopsies was 70.3%. Adverse events associated with the pretreatment biopsies (33.3% positive; 72.0% negative) and timing of the first imaging assessment (before on-treatment biopsy = 40.0%; after on-treatment biopsy = 82.7%) correlated with successful sequential tumor biopsies. The reasons for unsuccessful sequential tumor biopsies could be categorized into two groups: 1) patient refusal of the on-treatment biopsy (most frequently due to early disease progression); and 2) absence of tumor cells in the pretreatment or on-treatment biopsy specimen. We propose an approach to achieving greater success in sequential tumor biopsies in FIH trials; the first imaging assessment during the study should be scheduled after on-treatment biopsy. (Registration number UMIN000042487, Date of registration November 18, 2020).

A translational model-based approach to inform the choice of the dose in phase 1 oncology trials: the case study of erdafitinib.

Erdafitinib (JNJ-42756493, BALVERSA) is a tyrosine kinase inhibitor indicated for the treatment of advanced urothelial carcinoma. In this work, a translational model-based approach to inform the choice of the doses in phase 1 trials is illustrated. A pharmacokinetic (PK) model was developed to describe the time course of erdafitinib plasma concentrations in mice and rats. Data from multiple xenograft studies in mice and rats were analyzed using the Simeoni tumor growth inhibition (TGI) model. The model parameters were used to derive a range of erdafitinib exposures that might inform the choice of the doses in oncology phase 1 trials. Conversion of exposures to doses was based on preliminary PK assessments from the first-in human (FIH) study. A one-compartment PK disposition model, with linear absorption and dose-dependent clearance, adequately described the PK data in both mice and rats via an allometric scaling approach. The TGI model was able to describe tumor growth dynamics, providing quantitative measurements of erdafitinib antitumor potency in mice and rats. Based on these estimates, ranges of efficacious unbound concentration were identified for erdafitinib in mice (0.642-5.364μg/L) and rats (0.782-2.565μg/L). Based on the FIH data, it was possible to transpose exposures into doses and doses of above 4mg/day provided erdafitinib exposures associated with significant TGI in animals. The findings were in agreement with the results of the FIH trial, in which the first hints of clinical activities were observed at 6mg. The successful modeling exercise of erdafitinib preclinical data showed how translational PK-PD modeling might be a tool to help to inform the choice of the doses in FIH studies.

Phase II, Multiple-Dose Study of Anti-FcRn Antibody, Rozanolixizumab (UCB7665), in Patients with Primary Immune Thrombocytopenia: Interim Analysis

Phase II, Multiple-Dose Study of Anti-FcRn Antibody, Rozanolixizumab (UCB7665), in Patients with Primary Immune Thrombocytopenia: Interim Analysis

Improving consent forms for first-in-human trials through participant feedback.

e13563 Background: Risks and benefits of investigational agents that have not been tested in humans are, at best, incompletely characterized in nonclinical investigations. Despite the growing emphasis to include patient voices in clinical trial design, no published research has explored patient preferences on how best to convey the information that the agent has not been tested in humans. This study established that First in Human (FIH) consent forms present this information in different locations and queried participants for their input on the preferable FIH consent form structure. Methods: Consent forms for FIH oncology trials open to accrual at Winship Cancer Institute in 2019-2020 were analyzed for (1) the location of the mention that the study drug has not been used in humans before (FIH information), (2) the location of animal and other nonclinical data, and (3) placement of the risks section. Patients offered enrollment in a FIH trial were eligible for this study. Participants were interviewed during a clinic visit after consent was obtained. An ethics researcher asked questions about the participant’s opinions on the wording and placement of the FIH, nonclinical, and risk information in the specific trial consent form. All interviews were audio-recorded and double coded by two independent coders. The location of FIH and nonclinical data in the consent forms was compared to the patient’s suggested location for this information. Results: Saturation of themes was reached after interviewing 17 (17/19, 89% accrual) participants who were enrolled in 9 different FIH trials. Twenty FIH consents were qualitatively analyzed. Preferred placement compared to actual consent placement is listed in the table. 82% (14/17) of participants thought that nonclinical data on risks and efficacy was important to mention. 95% (19/20) of consents listed nonclinical data and most participants thought the placement in the consent was appropriate but 18% (3/17) of participants wanted the information earlier in the consent. No consent forms that were analyzed had the risks section before the study schedule; however, 47% (8/17) of participants wanted to move the risks sections before the study schedule. Conclusions: There is considerable variation in the layout of FIH consent forms that does not align with patient preferences. Standardization of FIH consent forms to better reflect patient input is essential in order to promote understandability of these important yet sometimes misunderstood clinical trials and to ensure ethical informed consent.[Table: see text]

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