Clinical Development Strategies and Outcomes in First-in-Human Trials of Monoclonal Antibodies

Optimal biological dose selection in dose-finding trials with model-assisted designs based on efficacy and toxicity: a simulation study

With the emergence of molecular targeted agents and immunotherapies in anti-cancer treatment, a concept of optimal biological dose (OBD), accounting for efficacy and toxicity in the framework of dose-finding, has been widely introduced into phase I oncology clinical trials. Various model-assisted designs with dose-escalation rules based jointly on toxicity and efficacy are now available to establish the OBD, where the OBD is generally selected at the end of the trial using all toxicity and efficacy data obtained from the entire cohort. Several measures to select the OBD and multiple methods to estimate the efficacy probability have been developed for the OBD selection, leading to many options in practice; however, their comparative performance is still uncertain, and practitioners need to take special care of which approaches would be the best for their applications. Therefore, we conducted a comprehensive simulation study to demonstrate the operating characteristics of the OBD selection approaches. The simulation study revealed key features of utility functions measuring the toxicity-efficacy trade-off and suggested that the measure used to select the OBD could vary depending on the choice of the dose-escalation procedure. Modelling the efficacy probability might lead to limited gains in OBD selection.

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

BACKGROUND AND OBJECTIVE

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Early change in the clearance of pembrolizumab reflects the survival and therapeutic response: A population pharmacokinetic analysis in real-world non-small cell lung cancer patients

OBJECTIVES

The dosing pattern of pembrolizumab is based on population pharmacokinetic (Pop-PK) analysis of clinical trials. Data for Japanese patients or patient populations with poor conditions such as cachexia are scarce. In this study, we performed a Pop-PK analysis of Japanese non-small cell lung cancer patients and analyzed the relationship between exposure, treatment effect, and survival.

MATERIALS AND METHODS

A total of 270 blood samples from 76 patients who received 200 mg pembrolizumab every 3 weeks between March 2017 and December 2018 were included. Blood concentrations of pembrolizumab were measured using mass spectrometry, and Pop-PK analysis was conducted using the Phoenix NLME software with a one-compartment model.

RESULTS

The estimated median of clearance (CL) in this analysis population was 0.104 L/day, about half of the historical data for Western data. Overall, pembrolizumab CL decreased over time, with some populations showing increased CL early in the treatment and others showing decreased CL over time. When the time-varying CL was stratified by quartile, the group with decreasing CL showed significantly better treatment response and survival than the group with increasing CL, even though the group included more patients with cachexia. Detailed analysis suggested that the patient population that responded to pembrolizumab treatment had an improved general condition and reduced protein catabolism, further decreasing CL.

CONCLUSION

In populations that benefit from pembrolizumab treatment, CL may be reduced early in their treatment, which may be a predictive and prognostic factor. However, further prospective validation of our findings is needed.

Improving Biologics' Effectiveness in Clinical Oncology: From the Combination of Two Monoclonal Antibodies to Oligoclonal Antibody Mixtures

Simple Summary

The approval of the two antibody combinations trastuzumab/pertuzumab and ipilimumab/nivolumab in oncology has paved the way for novel antibody combinations or oligoclonal antibody mixtures to improve their efficacy in cancer. The underlying biological mechanisms and challenges of these strategies will be discussed using data from clinical trials listed in databases. These therapeutic combinations also lead to questions on how to optimize their formulation and delivery to induce a therapeutic polyclonal response in patients with cancer.

Abstract

Monoclonal antibodies have revolutionized the treatment of many diseases, but their clinical efficacy remains limited in some other cases. Pre-clinical and clinical trials have shown that combinations of antibodies that bind to the same target (homo-combinations) or to different targets (hetero-combinations) to mimic the polyclonal humoral immune response improve their therapeutic effects in cancer. The approval of the trastuzumab/pertuzumab combination for breast cancer and then of the ipilimumab/nivolumab combination for melanoma opened the way to novel antibody combinations or oligoclonal antibody mixtures as more effective biologics for cancer management. We found more than 300 phase II/III clinical trials on antibody combinations, with/without chemotherapy, radiotherapy, small molecules or vaccines, in the ClinicalTrials.gov database. Such combinations enhance the biological responses and bypass the resistance mechanisms observed with antibody monotherapy. Usually, such antibody combinations are administered sequentially as separate formulations. Combined formulations have also been developed in which separately produced antibodies are mixed before administration or are produced simultaneously in a single cell line or a single batch of different cell lines as a polyclonal master cell bank. The regulation, toxicity and injection sequence of these oligoclonal antibody mixtures still need to be addressed in order to optimize their delivery and their therapeutic effects.

A Phase I, First-in-Human Study of GSK2849330, an Anti-HER3 Monoclonal Antibody, in HER3-Expressing Solid Tumors

BACKGROUND

GSK2849330, an anti-HER3 monoclonal antibody that blocks HER3/Neuregulin 1 (NRG1) signaling in cancer cells, is engineered for enhanced antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. This phase I, first-in-human, open-label study assessed the safety, pharmacokinetics (PK), pharmacodynamics, and preliminary activity of GSK2849330 in patients with HER3-expressing advanced solid tumors.

PATIENTS AND METHODS

Patients with various tumor types were prospectively selected for HER3 expression by immunohistochemistry; a subset was also screened for NRG1 mRNA expression. In the dose-escalation phase, patients received GSK2849330 1.4-30 mg/kg every 2 weeks, or 3 mg/kg or 30 mg/kg weekly, intravenously (IV). In the dose-expansion phase, patients received 30 mg/kg GSK2849330 IV weekly.

RESULTS

Twenty-nine patients with HER3-expressing cancers, of whom two expressed NRG1, received GSK2849330 (dose escalation: n = 18, dose expansion: n = 11). GSK2849330 was well tolerated. No dose-limiting toxicities were observed. The highest dose, of 30 mg/kg weekly, expected to provide full target engagement, was selected for dose expansion. Treatment-emergent adverse events (AEs) were mostly grade 1 or 2. The most common AEs were diarrhea (66%), fatigue (62%), and decreased appetite (31%). Dose-proportional plasma exposures were achieved, with evidence of HER3 inhibition in paired tissue biopsies. Of 29 patients, only 1 confirmed partial response, lasting 19 months, was noted in a patient with CD74-NRG1-rearranged non-small cell lung cancer (NSCLC).

CONCLUSION

GSK2849330 demonstrated a favorable safety profile, dose-proportional PK, and evidence of target engagement, but limited antitumor activity in HER3-expressing cancers. The exceptional response seen in a patient with CD74-NRG1-rearranged NSCLC suggests further exploration in NRG1-fusion-positive cancers.

IMPLICATIONS FOR PRACTICE

This first-in-human study confirms that GSK2849330 is well tolerated. Importantly, across a variety of HER3-expressing advanced tumors, prospective selection by HER3/NRG1 expression alone was insufficient to identify patients who could benefit from treatment with this antibody-dependent cell-mediated cytotoxicity- and complement-dependent cytotoxicity-enhanced anti-HER3 antibody. The only confirmed durable response achieved was in a patient with CD74-NRG1-rearranged lung cancer. This highlights the potential utility of screening for NRG1 fusions prospectively across tumor types to enrich potential responders to anti-HER3 agents in ongoing trials.

Which factors matter the most? Revisiting and dissecting antibody therapeutic doses

Factors such as antibody clearance and target affinity can influence antibodies' effective doses for specific indications. However, these factors vary considerably across antibody classes, precluding direct and quantitative comparisons. Here, we apply a dimensionless metric, the therapeutic exposure affinity ratio (TEAR), which normalizes the therapeutic doses by antibody bioavailability, systemic clearance and target-binding property to enable direct and quantitative comparisons of therapeutic doses. Using TEAR, we revisited and dissected the doses of up to 60 approved antibodies. We failed to detect a significant influence of target baselines, turnovers or anatomical locations on antibody therapeutic doses, challenging the traditional perceptions. We highlight the importance of antibodies' modes of action for therapeutic doses and dose selections; antibodies that work through neutralizing soluble targets show higher TEARs than those working through other mechanisms. Overall, our analysis provides insights into the factors that influence antibody doses, and the factors that are crucial for antibodies' pharmacological effects.

Pivotal Dose of Pembrolizumab: A Dose-Finding Strategy for Immuno-Oncology

Despite numerous publications emphasizing the value of dose finding, drug development in oncology is dominated by the mindset that higher dose provides higher efficacy. Examples of dose finding implemented by biopharmaceutical firms can change this mindset. The purpose of this article is to outline a pragmatic dose selection strategy for immuno-oncology (IO) and other targeted monoclonal antibodies (mAbs). The approach was implemented for pembrolizumab. Selecting a recommended phase II dose (RP2D) with a novel mechanism of action is often challenging due to uncertain relationships between pharmacodynamics measurements and clinical end points. Additionally, phase I efficacy and safety data are generally inadequate for RP2D selection for IO mAbs. Here, the RP2D was estimated based on phase I (clinical study KN001 A and A2) pharmacokinetics data as the dose required for target saturation, which represents a surrogate for maximal pharmacological effect for antagonist mAbs. Due to limitations associated with collecting and analyzing tumor biopsies, characterizing intratumoral target engagement (TE) is challenging. To overcome this gap, a physiologically-based pharmacokinetic model was implemented to predict intratumoral TE. As tumors are spatially heterogeneous, TE was predicted in well-vascularized and poorly vascularized tumor regions. Additionally, impact of differences in target expression, for example, due to interindividual variability and cancer type, was simulated. Simulations showed that 200 mg every 3 weeks can achieve ≥ 90% TE in clinically relevant scenarios, resulting in the recommendation of 200 mg every 3 weeks as the RP2D. Randomized dose comparison studies (KN001 B2 and D) showing similar efficacy over a fivefold dose/exposure range confirmed the RP2D as the pivotal dose.

Optimal biological dose: a systematic review in cancer phase I clinical trials

BACKGROUND

Classical phase 1 dose-finding designs based on a single toxicity endpoint to assess the maximum tolerated dose were initially developed in the context of cytotoxic drugs. With the emergence of molecular targeted agents and immunotherapies, the concept of optimal biological dose (OBD) was subsequently introduced to account for efficacy in addition to toxicity. The objective was therefore to provide an overview of published phase 1 cancer clinical trials relying on the concept of OBD.

METHODS

We performed a systematic review through a computerized search of the MEDLINE database to identify early phase cancer clinical trials that relied on OBD. Relevant publications were selected based on a two-step process by two independent readers. Relevant information (phase, type of therapeutic agents, objectives, endpoints and dose-finding design) were collected.

RESULTS

We retrieved 37 articles. OBD was clearly mentioned as a trial objective (primary or secondary) for 22 articles and was traditionally defined as the smallest dose maximizing an efficacy criterion such as biological target: biological response, immune cells count for immunotherapies, or biological cell count for targeted therapies. Most trials considered a binary toxicity endpoint defined in terms of the proportion of patients who experienced a dose-limiting toxicity. Only two articles relied on an adaptive dose escalation design.

CONCLUSIONS

In practice, OBD should be a primary objective for the assessment of the recommended phase 2 dose (RP2D) for a targeted therapy or immunotherapy phase I cancer trial. Dose escalation designs have to be adapted accordingly to account for both efficacy and toxicity.

Efficacy and safety of anticancer drug combinations: a meta-analysis of randomized trials with a focus on immunotherapeutics and gene-targeted compounds

Hundreds of trials are being conducted to evaluate combination of newer targeted drugs as well as immunotherapy. Our aim was to compare efficacy and safety of combination versus single non-cytotoxic anticancer agents. We searched PubMed (01/01/2001 to 03/06/2018) (and, for immunotherapy, ASCO and ESMO abstracts (2016 through March 2018)) for randomized clinical trials that compared a single non-cytotoxic agent (targeted, hormonal, or immunotherapy) versus a combination with another non-cytotoxic partner. Efficacy and safety endpoints were evaluated in a meta-analysis using a linear mixed-effects model (guidelines per PRISMA Report).We included 95 randomized comparisons (single vs. combination non-cytotoxic therapies) (59.4%, phase II; 41.6%, phase III trials) (29,175 patients (solid tumors)). Combinations most frequently included a hormonal agent and a targeted small molecule (23%). Compared to single non-cytotoxic agents, adding another non-cytotoxic drug increased response rate (odds ratio [OR]=1.61, 95%CI 1.40-1.84)and prolonged progression-free survival (hazard ratio [HR]=0.75, 95%CI 0.69-0.81)and overall survival (HR=0.87, 95%CI 0.81-0.94) (all p<0.001), which was most pronounced for the association between immunotherapy combinations and longer survival. Combinations also significantlyincreased the risk of high-grade toxicities (OR=2.42, 95%CI 1.98-2.97) (most notably for immunotherapy and small molecule inhibitors) and mortality at least possibly therapy related (OR: 1.33, 95%CI 1.15-1.53) (both p<0.001) (absolute mortality = 0.90% (single agent) versus 1.31% (combinations)) compared to single agents. In conclusion, combinations of non-cytotoxic drugs versus monotherapy in randomized cancer clinical trials attenuated safety, but increased efficacy, with the balance tilting in favor of combination therapy, based on the prolongation in survival.

[Determining the dose to be injected in the first clinical trials with monoclonal antibodies: not so easy!]

Monoclonal antibodies are a therapeutic tool frequently used in oncology, as they allow the specific targeting of molecules expressed by cancer cells and, in most cases, induce minimal toxic effects on healthy tissues. Because monoclonal antibodies frequently lack significant toxicity and are not associated to a direct relationship between dose and effect, the methods of clinical development traditionally used for chemotherapy agents are scarcely useful for this class of drugs. In addition, no consensus exists on the definition of parameters different from toxicity that could assist the process of dose selection of monoclonal antibody in early clinical trials.

Setting the Dose of Checkpoint Inhibitors: The Role of Clinical Pharmacology

Cancer immunotherapy is based on checkpoint inhibitors (CPIs) that significantly improve the clinical outcome of several malignant diseases. These inhibitors are monoclonal antibodies (mAbs) directed at cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed cell death 1 (PD-1), or programmed death-ligand 1 (PD-L1), sharing most of the clinical pharmacokinetic characteristics of mAb targeted therapies, all of which differ from those of cytotoxics and small molecules. Establishing the labeled dose of mAbs, and particularly of the CPIs, represents a true challenge. This review therefore examines the main criteria used for dose selection, along with their limits. The relationships between CPI pharmacokinetic parameters and treatment outcome (efficacy and/or toxicity) differ somewhat among the various drugs, but general features can be identified. Nevertheless, the interpretation of these relationships remains quite controversial. A first interpretation asserts that inter-individual pharmacokinetic variability in clearance has an impact on outcome and should be taken into consideration for dosing individualization. The second considers that higher clearance values observed in some patients result from characteristics associated with poor predictive factors of efficacy. Finally, the schedule, and particularly its frequency of administration, merits rethinking.

Tutorial on Monoclonal Antibody Pharmacokinetics and Its Considerations in Early Development

The tutorial introduces the readers to the fundamentals of antibody pharmacokinetics (PK) in the context of drug development. Topics covered include an overview of antibody development, PK characteristics, and the application of antibody PK/pharmacodynamics (PD) in research and development decision-making. We also discuss the general considerations for planning a nonclinical PK program and describe the types of PK studies that should be performed during early development of monoclonal antibodies.

Strategies for clinical development of monoclonal antibodies beyond first-in-human trials: tested doses and rationale for dose selection

BACKGROUND

Our previous survey on first-in-human trials (FIHT) of monoclonal antibodies (mAbs) showed that, due to their limited toxicity, the recommended phase II dose (RP2D) was only tentatively defined.

METHODS

We identified, by MEDLINE search, articles on single-agent trials of mAbs with an FIHT included in our previous survey. For each mAb, we examined tested dose(s) and dose selection rationale in non-FIHTs (NFIHTs). We also assessed the correlation between doses tested in the registration trials (RTs) of all FDA-approved mAbs and the corresponding FIHT results.

RESULTS

In the 37 dose-escalation NFIHTs, the RP2D indication was still poorly defined. In phase II-III NFIHTs (n=103 on 37 mAbs), the FIHT RP2D was the only dose tested for five mAbs. For 16 mAbs, only doses different from the FIHT RP2D or the maximum administered dose (MAD) were tested and the dose selection rationale infrequently indicated. In the 60 RTs on 27 FDA-approved mAbs with available FIHT, the FIHT RP2D was tested only for two mAbs, and RT doses were much lower than the FIHT MAD.

CONCLUSIONS

The rationale beyond dose selection in phase II and III trials of mAbs is often unclear in published articles and not based on FIHT data.

Cancer Immunotherapy Trials Underutilize Immune Response Monitoring

Immune-related radiological and biomarker monitoring in cancer immunotherapy trials permits interrogation of efficacy and reasons for therapeutic failure. We report the results from a cross-sectional analysis of response monitoring in 685 T-cell checkpoint-targeted cancer immunotherapy trials in solid malignancies, as registered on the U.S. National Institutes of Health trial registry by October 2016. Immune-related radiological response criteria were registered for only 25% of clinical trials. Only 38% of trials registered an exploratory immunological biomarker, and registration of immunological biomarkers has decreased over the last 15 years. We suggest that increasing the utilization of immune-related response monitoring across cancer immunotherapy trials will improve analysis of outcomes and facilitate translational efforts to extend the benefit of immunotherapy to a greater proportion of patients with cancer.

89Zr-Lumretuzumab PET Imaging before and during HER3 Antibody Lumretuzumab Treatment in Patients with Solid Tumors

Purpose: We evaluated biodistribution and tumor targeting of ⁸⁹Zr-lumretuzumab before and during treatment with lumretuzumab, a human epidermal growth factor receptor 3 (HER3)-targeting monoclonal antibody.Experimental Design: Twenty patients with histologically confirmed HER3-expressing tumors received ⁸⁹Zr-lumretuzumab and underwent positron emission tomography (PET). In part A, ⁸⁹Zr-lumretuzumab was given with additional, escalating doses of unlabeled lumretuzumab, and scans were performed 2, 4, and 7 days after injection to determine optimal imaging conditions. In part B, patients were scanned following tracer injection before (baseline) and after a pharmacodynamic (PD)-active lumretuzumab dose for saturation analysis. HER3 expression was determined immunohistochemically in skin biopsies. Tracer uptake was calculated as standardized uptake value (SUV).Results: Optimal PET conditions were found to be 4 and 7 days after administration of ⁸⁹Zr-lumretuzumab with 100-mg unlabeled lumretuzumab. At baseline using 100-mg unlabeled lumretuzumab, the tumor SUVmax was 3.4 (±1.9) at 4 days after injection. SUVmean values for normal blood, liver, lung, and brain tissues were 4.9, 6.4, 0.9 and 0.2, respectively. Saturation analysis (n = 7) showed that 4 days after lumretuzumab administration, tumor uptake decreased by 11.9% (±8.2), 10.0% (±16.5), and 24.6% (±20.9) at PD-active doses of 400, 800, and 1,600 mg, respectively, when compared with baseline. Membranous HER3 was completely downregulated in paired skin biopsies already at and above 400-mg lumretuzumab.Conclusions: PET imaging showed biodistribution and tumor-specific ⁸⁹Zr-lumretuzumab uptake. Although, PD-active lumretuzumab doses decreased ⁸⁹Zr-lumretuzumab uptake, there was no clear evidence of tumor saturation by PET imaging as the tumor SUV did not plateau with increasing doses. Clin Cancer Res; 23(20); 6128-37. ©2017 AACR.

Drug Development of Therapeutic Monoclonal Antibodies

Monoclonal antibodies (MAbs) have become a substantial part of many pharmaceutical company portfolios. However, the development process of MAbs for clinical use is quite different than for small-molecule drugs. MAb development programs require careful interdisciplinary evaluations to ensure the pharmacology of both the MAb and the target antigen are well-understood. Selection of appropriate preclinical species must be carefully considered and the potential development of anti-drug antibodies (ADA) during these early studies can limit the value and complicate the performance and possible duration of preclinical studies. In human studies, many of the typical pharmacology studies such as renal or hepatic impairment evaluations may not be needed but the pharmacokinetics and pharmacodynamics of these agents is complex, often necessitating more comprehensive evaluation of clinical data and more complex bioanalytical assays than might be used for small molecules. This paper outlines concerns and strategies for development of MAbs from the early in vitro assessments needed through preclinical and clinical development. This review focuses on how to develop, submit, and comply with regulatory requirements for MAb therapeutics.

Determination of the starting dose in the first-in-human clinical trials with monoclonal antibodies: a systematic review of papers published between 1990 and 2013

A systematic review was performed to evaluate how the maximum recommended starting dose (MRSD) was determined in first-in-human (FIH) studies with monoclonal antibodies (mAbs). Factors associated with the choice of each MRSD determination method were also identified. PubMed was searched for FIH studies with mAbs published in English between January 1, 1990 and December 31, 2013, and the following information was extracted: MRSD determination method, publication year, therapeutic area, antibody type, safety factor, safety assessment results after the first dose, and number of dose escalation steps. Seventy-nine FIH studies with mAbs were identified, 49 of which clearly reported the MRSD determination method. The no observed adverse effects level (NOAEL)-based approach was the most frequently used method, whereas the model-based approach was the least commonly used method (34.7% vs 16.3%). The minimal anticipated biological effect level (MABEL)- or minimum effective dose (MED)-based approach was used more frequently in 2011–2013 than in 1990–2007 (31.6% vs 6.3%, P=0.036), reflecting a slow, but steady acceptance of the European Medicines Agency’s guidance on mitigating risks for FIH clinical trials (2007). The median safety factor was much lower for the MABEL- or MED-based approach than for the other MRSD determination methods (10 vs 32.2–53). The number of dose escalation steps was not significantly different among the different MRSD determination methods. The MABEL-based approach appears to be safer and as efficient as the other MRSD determination methods for achieving the objectives of FIH studies with mAbs faster.

Approaches to modernize the combination drug development paradigm

Recent advances in genomic sequencing and omics-based capabilities are uncovering tremendous therapeutic opportunities and rapidly transforming the field of cancer medicine. Molecularly targeted agents aim to exploit key tumor-specific vulnerabilities such as oncogenic or non-oncogenic addiction and synthetic lethality. Additionally, immunotherapies targeting the host immune system are proving to be another promising and complementary approach. Owing to substantial tumor genomic and immunologic complexities, combination strategies are likely to be required to adequately disrupt intricate molecular interactions and provide meaningful long-term benefit to patients. To optimize the therapeutic success and application of combination therapies, systematic scientific discovery will need to be coupled with novel and efficient clinical trial approaches. Indeed, a paradigm shift is required to drive precision medicine forward, from the traditional "drug-centric" model of clinical development in pursuit of small incremental benefits in large heterogeneous groups of patients, to a "strategy-centric" model to provide customized transformative treatments in molecularly stratified subsets of patients or even in individual patients. Crucially, to combat the numerous challenges facing combination drug development-including our growing but incomplete understanding of tumor biology, technical and informatics limitations, and escalating financial costs-aligned goals and multidisciplinary collaboration are imperative to collectively harness knowledge and fuel continual innovation.

A Phase I, First-in-Human Study of AMG 780, an Angiopoietin-1 and -2 Inhibitor, in Patients with Advanced Solid Tumors

PURPOSE

To assess the toxicity, pharmacokinetics, tumor vascular response, tumor response, and pharmacodynamics of AMG 780, a mAb designed to inhibit the interaction between angiopoietin-1 and -2 and the Tie2 receptor.

EXPERIMENTAL DESIGN

This was a phase I dose-escalation study of patients with advanced solid tumors refractory to standard treatment without previous antiangiogenic treatment. AMG 780 was administered by intravenous infusion every 2 weeks in doses from 0.1 to 30 mg/kg. The primary endpoints were incidences of dose-limiting toxicity (DLT) and adverse events (AE), and pharmacokinetics. Secondary endpoints included tumor response, changes in tumor volume and vascularity, and anti-AMG 780 antibody formation.

RESULTS

Forty-five patients were enrolled across nine dose cohorts. Three patients had DLTs (0.6, 10, and 30 mg/kg), none of which prevented dose escalation. At 30 mg/kg, no MTD was reached. Pharmacokinetics of AMG 780 were dose proportional; median terminal elimination half-life was 8 to 13 days. No anti-AMG 780 antibodies were detected. At week 5, 6 of 16 evaluable patients had a >20% decrease in volume transfer constant (K(trans)), suggesting reduced capillary blood flow/permeability. The most frequent AEs were hypoalbuminemia (33%), peripheral edema (29%), decreased appetite (27%), and fatigue (27%). Among 35 evaluable patients, none had an objective response; 8 achieved stable disease.

CONCLUSIONS

AMG 780 could be administered at doses up to 30 mg/kg every 2 weeks in patients with advanced solid tumors. AMG 780 treatment resulted in tumor vascular effects in some patients. AEs were in line with toxicity associated with antiangiopoietin treatment. Clin Cancer Res; 22(18); 4574-84. ©2016 AACR.