Pharmacokinetics and Pharmacodynamics The Journal of Clinical Pharmacology Utilizing Pharmacokinetics/Pharmacodynamics 53(10) 1020–1027 ©2013, The American College of Modeling to Simultaneously Examine Clinical Pharmacology DOI: 10.1002/jcph.140 Free CCL2, Total CCL2 and Carlumab (CNTO 888) Concentration Time Data Gerald J. Fetterly, PhD1, Urvi Aras, PhD1, Patricia D. Meholick, MS1, Chris Takimoto, MD, PhD2, Shobha Seetharam, PhD2, Thomas McIntosh, MS2, Johann S. de Bono, MD, PhD3, Shahneen K. Sandhu, MD3, Anthony Tolcher, MD4, Hugh M. Davis, PhD2, Honghui Zhou, PhD, FCP2, and Thomas A. Puchalski, PharmD2 Abstract The chemokine ligand 2 (CCL2) promotes angiogenesis, tumor proliferation, migration, and metastasis. Carlumab is a human IgG1k monoclonal antibody with high CCL2 binding affinity. Pharmacokinetic/pharmacodynamic data from 21 cancer patients with refractory tumors were analyzed. The PK/PD model characterized the temporal relationships between serum concentrations of carlumab, free CCL2, and the carlumab–CCL2 complex. Dose‐dependent increases in total CCL2 concentrations were observed and were consistent with shifting free CCL2. Free CCL2 declined rapidly after the initial carlumab infusion, returned to baseline within 7 days, and increased to levels greater than baseline following subsequent doses. Mean predicted half‐lives of carlumab and carlumab–CCL2 complex were approximately 2.4 days and approximately 1 hour for free CCL2. The mean dissociation constant (KD), 2.4 nM, was substantially higher than predicted by in vitro experiments, and model‐based simulation revealed this was the major factor hindering the suppression of free CCL2 at clinically viable doses. Keywords soluble ligand, PK/PD modeling, cytokine CC‐chemokine ligand 2 (CCL2), also known as monocyte chemoattractant protein‐1, is a CC‐chemokine which acts through chemokine receptor 2.1–3 CCL2 promotes tumor inflammation, survival, angiogenesis, and metastasis in a variety of cancer types, including breast,4,5 lung,6 esophageal,7,8 and gastric9 carcinomas, as well as 1PK/PD Core Facility, Department of Medicine, Roswell Park Cancer melanoma,10,11 squamous cell carcinoma of the head Institute, Buffalo, New York 2 and neck,12 and hemangiomas.13,14 CCL2 is an important Janssen Research & Development, LLC, Spring House, Pennsylvania 3Drug Development Unit, Royal Marsden NHS Foundation Trust and stimulator in a model of human tumor cell angiogene- The Institute of Cancer Research, Sutton, UK 4,5,15 sis, and it has been proven to be a potent attractor for 4START (South Texas Accelerated Research Therapeutics), San monocytes and macrophages, especially tumor‐associated Antonio, Texas macrophages that have been implicated in the promotion of tumor growth and metastasis.4,5,16 In malignant tumors, Submitted for publication 29 January 2013; accepted 23 June 2013. high levels of CCL2 have been correlated with active Corresponding Author: angiogenesis, stimulated cancer cell proliferation, en- Thomas Puchalski, PharmD, Biologics Clinical Pharmacology, Janssen hanced metalloproteinase production, tumor aggres- Research & Development, LLC, 1400 McKean Road, PO Box 776, siveness, poor prognosis, and early relapse in patients.4,5 Spring House, PA 19477. Email: [email protected] Carlumab (formerly CNTO 888) is a human immuno- Author disclosures: Chris Takimoto, Shobha Seetharam, Thomas globulin G1 kappa monoclonal antibody with activity McIntosh, Hugh M. Davis, Honghui Zhou, and Thomas A. Puchalski against the soluble ligand CCL2 and is currently being are or were employees of Janssen Research & Development, LLC. at the evaluated as a potential therapeutic agent for the treatment time of the study and own(ed) stock in Johnson & Johnson. Gerald J. of solid tumors. Carlumab can neutralize CCL2 activity in Fetterly declares no conflicts of interest. Urvi Aras is an employee of 17 Bristol Myers Squibb. Patricia D. Zagst declares no conflicts of interest. vivo by binding to free CCL2 in the blood. It also Johann S. de Bono declares no conflicts of interest. Anthony Tolcher inhibits macrophage infiltration, prevents tumor angio- serves as an uncompensated consultant to Janssen Research & genesis, and decreases tumor vessel density.18 Inhibiting Development, LLC. Shahneen K. Sandhu declares no conflicts of interest. Fetterly et al 1021 CCL2 has the potential to reduce the number of provided informed written consent before any study drug macrophages and monocytes infiltrating tumor tissue, was administered. thereby modulating tumor inflammation and potentially Carlumab was measured in serum using an electro- decreasing tumor cell proliferation. chemiluminescence‐based immunoassay (ECLIA) with a Twenty‐five percent of US Food and Drug Adminis- lower limit of quantification (LLOQ) of 0.078 mg/ml. The tration‐approved antibody products fall into an important carlumab–CCL2 complex was measured in serum using subclass of agents that target soluble ligands.19 In the an ECLIA with a LLOQ of 300 pg/ml. Free serum CCL2 oncology field, little data characterizing the effects of was assayed using an initial Protein A‐based separation antibody on the target ligand are available. Utilizing a method followed by analysis using a commercial CCL2 pharmacokinetics/pharmacodynamics (PK/PD) modeling ELISA assay kit with a LLOQ of 78 pg/ml. approach to examine the interaction between the antibody Samples were collected for carlumab PK analysis prior and the target can provide insight into the turnover of the to and immediately after completion of the IV infusion. target and the binding affinity of the antibody. Additionally, for the first and fourth infusion, samples The overall goal of this modeling exercise was to were collected at 4 and 24 hours post‐infusion, and on devise a carlumab dosing strategy that would optimally Days 8, 15, 18, 22, and 25 post‐infusion. decrease CCL2 concentrations and prolong the length of For determination of serum concentrations of free time that free CCL2 concentrations are suppressed. The CCL2 and the carlumab–CCL2 complex, samples were specific objectives of our analyses were (1) to develop a collected prior to the infusion, 24 hours post‐infusion, and mechanistic PK/PD model to simultaneously characterize on Days 8, 15, and 22 post‐infusion following the first the serum concentration‐time profiles of carlumab, free administration of carlumab. For the second and third CCL2, and the carlumab–CCL2 complex and (2) to administrations, samples were only collected prior to the simulate free CCL2 concentrations following administra- infusion. For the fourth administration, samples were tion of various carlumab dose regimens in order to gain a collected prior to the infusion and 24 hours post‐infusion. better understanding of the effects of carlumab on free Additional samples were collected during follow‐up visits CCL2 and the carlumab–CCL2 complex. at Weeks 8, 12, and 18. Modeling Software Methods Population PK/PD modeling and simulation were per- Phase 1 Study of Carlumab in Malignant Solid Tumors formed using the maximum likelihood estimation method Details of the study design and results will be reported (MLEM) in ADAPT 5. Statistical analyses and graphing elsewhere.20 In brief, this first‐in‐human study of were performed using SAS Version 9.1, and Prism 5 was carlumab was an open‐label, multiple administration, used for plotting model‐based simulations. ascending‐dose study designed to determine the safety and PK of carlumab. Patients received a 90‐minute IV PK/PD Model infusion of carlumab, followed by a 4‐week monitoring A PK/PD model that incorporated target binding was used period to assess the single‐dose PK profile of carlumab. to simultaneously characterize the concentration‐time Three subsequent doses of carlumab were administered profiles of carlumab, the soluble ligand target, CCL2, every 2 weeks following the end of the monitoring period. and the carlumab–CCL2 complex in serum (Figure 1). In the dose‐escalation phase of the study, a total of 5 Several models were tested that incorporated the cohorts were evaluated at doses of 0.3, 1, 3, 10, or 15 mg/ relationship between the drug and the drug–receptor kg. Three patients were included in each cohort dosed at complex, but ultimately a quasi‐equilibrium model of 3 mg/kg, and 6 patients were included in each of the 10 target‐mediated drug disposition (TMDD) was used to and 15 mg/kg dose cohorts. The dose‐expansion phase analyze the available data.21 consisted of patients receiving either 10 or 15 mg/kg of Based on the pharmacological mechanism of action of carlumab at 2‐week intervals. Data from only the dose‐ drug–receptor complexes described by TMDD, IV escalation phase were used to develop the PK/PD model administered carlumab may distribute to and from tissue due to the robust amount of carlumab, free CCL2, and binding sites (k3 and k4) or may be eliminated from the carlumab–CCL2 complex serum concentration‐time central compartment by degradation (kdeg). Carlumab, information available from this phase of the study. Key which has a half‐life of approximately 2.4 days, binds to patient eligibility criteria included the presence of type‐ free CCL2 ligands, which have half‐lives of approximately specific solid tumors that had progressed after all 1 hour when present in the blood. Free CCL2 is assumed to available standard therapy, and measurable or evaluable be produced at a zero‐order rate of Ksyn and has a baseline metastatic disease. The study was conducted in accor- value of Rss. Free CCL2 also is assumed to distribute dance with the principles of the Declaration of Helsinki between tumor tissue and blood, and is eliminated from the and was approved by institutional review boards. Patients blood at a rate of Kdeg,free ligand. The formed complex is 1022 The Journal of Clinical Pharmacology / Vol 53 No 10 (2013) Ksyn carlumab CCL2 Tumor / Tissue K K K Blood 3 4 2 KD carlumab CCL2 complex Drug Admin 1 mole of carlumab binds 1 mole of CCL2 Kdeg, Kdeg, Kdeg, carlumab-CCL2 carlumab free CCL2 complex Figure 1. Simultaneous PK/PD model of carlumab, free CCL2, and carlumab–CCL2 complex.