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Schlereth B, Quadt C, Dreier T, Kufer P, Lorenczewski G, Prang N, Brandl C, Lippold S, Cobb K, Brasky K, Leo E, Bargou R, Murthy K, Baeuerle PA. T-cell activation and B-cell depletion in chimpanzees treated with a bispecific anti-CD19/anti-CD3 single-chain antibody construct. Cancer Immunol Immunother 2006; 55:503-14. [PMID: 16032400 PMCID: PMC11030059 DOI: 10.1007/s00262-005-0001-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Accepted: 03/30/2005] [Indexed: 10/25/2022]
Abstract
BscCD19xCD3 is a bispecific single-chain antibody construct with exceptional cytotoxic potency in vitro and in vivo. Here, we have investigated the biological activity of bscCD19xCD3 in chimpanzee, the only animal species identified in which bscCD19xCD3 showed bispecific binding, redirected B-cell lysis and cytokine production comparable to human cells. Pharmacokinetic analysis following 2-h intravenous infusion of 0.06, 0.1 or 0.12 mug/kg of bscCD19xCD3 as part of a dose escalation study in a single female chimpanzee revealed a half-life of approximately 2 h and elimination of the bispecific antibody from circulation within approximately 8 h after the end of infusion. This short exposure to bscCD19xCD3 elicited a transient increase in serum levels of IFNgamma, IL-6, IL-2, soluble CD25, and transiently upregulated expression of CD69 and MHC class II on CD8-positive cells. Cytokine release and upregulation of T-cell activation markers were not observed with vehicle controls. A multiple-dose study using 5 weekly doses of 0.1 mug/kg in two animals also showed transient cytokine release and an activation of peripheral T cells with a first-dose effect, accompanied by a transient lymphopenia. While oscillations of T-cell counts were relatively even during repeated treatments, the amplitudes of peripheral B cells declined with every infusion, which was not observed in a vehicle control animal. Our data show that bscCD19xCD3 can be safely administered to chimpanzees at dose levels that cause fully reversible T-cell activation and, despite a very short exposure time, cumulative loss of peripheral B lymphocytes. A clinical trial testing prolonged administration of bscCD19xCD3 (MT103) for improving efficacy is currently ongoing.
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Affiliation(s)
| | - Cornelia Quadt
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
- Present Address: Oncology Business Unit, Novartis AG, WKL-490.1.50, 4002 Basel, Switzerland
| | - Torsten Dreier
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
- Present Address: Ablynx NV, Technologiepark 4, 9052 Zwijnaarde, Belgium
| | - Peter Kufer
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
| | | | - Nadja Prang
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
| | | | | | - Kathy Cobb
- Southwest Foundation of Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549 USA
| | - Kathleen Brasky
- Southwest Foundation of Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549 USA
| | - Eugen Leo
- Micromet AG, Staffelseestr. 2, 81477 Munich, Germany
| | - Ralf Bargou
- Robert-Rössle-Clinic, University Medical Center Charité, Humboldt University of Berlin, and Helios Kliniken Berlin, Lindenberger Weg 80, 13122 Berlin-Buch, Germany
| | - Krishna Murthy
- Southwest Foundation of Biomedical Research, P.O. Box 760549, San Antonio, TX 78245-0549 USA
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Rogatko A, Babb JS, Tighiouart M, Khuri FR, Hudes G. New Paradigm in Dose-Finding Trials: Patient-Specific Dosing and Beyond Phase I. Clin Cancer Res 2005; 11:5342-6. [PMID: 16061846 DOI: 10.1158/1078-0432.ccr-05-0458] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We propose a new paradigm for the clinical evaluation of new cancer therapies. It entails adjusting the search for the optimal dose on the basis of measurable patient characteristics that may be predictive of adverse responses to treatment, and extending this search beyond phase I and into phases II and III. We provide examples of (a) how the fine-tuning of dose may involve utilization of patient-specific attributes to obtain a personalized treatment regimen, and (b) how novel methods for phase I design can be used to update the working dose for the conduct of phase II and III cancer clinical trials. These examples should be interpreted as an enticement for the development of new methods to implement the proposed new paradigm.
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Affiliation(s)
- André Rogatko
- Winship Cancer Institute, Atlanta, Georgia 30322, USA.
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