Effect of antigen-dependent clearance on pharmacokinetics of anti-heparin-binding EGF-like growth factor (HB-EGF) monoclonal antibody

Discovery of an Heparin-Binding Epidermal Growth Factor Domain Antibody from a Phage Library and Analysis of Its Inhibitory Effects in SKOV3 Cells

Objective: Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF), which binds to the EGF receptor, plays an important role in the occurrence and development of inflammation in various diseases. HB-EGF mediates the progression of ovarian cancer and is associated with disease prognosis. Thus, a specific humanized antibody to HB-EGF with high affinity is important. Methods: In this study, a humanized domain antibody (VH) against HB-EGF was discovered through phage display technology. The domain antibody was expressed in HB2151 cells and purified from the supernatant using protein L, and were used to test the its effect in invasion and migration of ovarian cancer SKOV3. Results: A domain antibody against HB-EGF was discovered, with a dissociation constant of ∼30 nM. Functional assays indicated that the domain antibody inhibited the functions of HB-EGF in promoting invasion and migration of SKOV3 cells. Conclusions: The selected domain antibody is a potential tool for developing novel drugs or therapies to combat ovarian cancer.

Rapid Elimination of Broadly Neutralizing Antibodies Correlates with Treatment Failure in the Acute Phase of Simian-Human Immunodeficiency Virus Infection

Early human immunodeficiency virus type 1 (HIV-1) treatment during the acute period of infection can significantly limit the seeding of viral reservoirs and modify the course of disease. However, while a number of HIV-1 broadly neutralizing antibodies (bnAbs) have demonstrated remarkable efficacy as prophylaxis in macaques chronically infected with simian-human immunodeficiency virus (SHIV), intriguingly, their inhibitory effects were largely attenuated in the acute period of SHIV infection. To investigate the mechanism for the disparate performance of bnAbs in different periods of SHIV infection, we used LSEVh-LS-F, a bispecific bnAb targeting the CD4 binding site and CD4-induced epitopes, as a representative bnAb and assessed its potential therapeutic benefit in controlling virus replication in acutely or chronically SHIV-infected macaques. We found that a single infusion of LSEVh-LS-F resulted in rapid decline of plasma viral loads to undetectable levels without emergence of viral resistance in the chronically infected macaques. In contrast, the inhibitory effect was robust but transient in the acutely infected macaques, despite the fact that all macaques had comparable plasma viral loads initially. Infusing multiple doses of LSEVh-LS-F did not extend its inhibitory duration. Furthermore, the pharmacokinetics of the infused LSEVh-LS-F in the acutely SHIV-infected macaques significantly differed from that in the uninfected or chronically infected macaques. Host SHIV-specific immune responses may play a role in the viremia-dependent pharmacokinetics. Our results highlight the correlation between the fast clearance of infused bnAbs and the treatment failure in the acute period of SHIV infection and may have important implications for the therapeutic use of bnAbs to treat acute HIV infections.IMPORTANCE Currently, there is no bnAb-based monotherapy that has been reported to clear the virus in the acute SHIV infection period. Since early HIV treatment is considered critical to restricting the establishment of viral reservoirs, investigation into the mechanism for treatment failure in acutely infected macaques would be important for the therapeutic use of bnAbs and eventually towards the functional cure of HIV/AIDS. Here we report the comparative study of the therapeutic efficacy of a bnAb in acutely and chronically SHIV-infected macaques. This study revealed the correlation between the fast clearance of infused bnAbs and treatment failure during the acute period of infection.

First-in-human study of the anti-HB-EGF antibody U3-1565 in subjects with advanced solid tumors

U3-1565 is a monoclonal antibody directed against heparin-binding epidermal growth factor-like growth factor (HB-EGF), which mediates angiogenesis via induction of vascular endothelial growth factor (VEGF-A). This first-in-human study characterized the safety, tolerability, efficacy, pharmacokinetics, and pharmacodynamics of U3-1565 in subjects with advanced solid tumors. In Part 1 (dose escalation following a modified 3 + 3 design), Cohorts 1-4, U3-1565 was administered at 2, 8, 16, and 24 mg/kg every 3 weeks for Cycle 1 and every 2 weeks thereafter. In Part 1, Cohort 5, and in Part 2 (dose expansion), U3-1565 was administered at 24 mg/kg every week. Thirty-six subjects were enrolled and treated (15 in Part 1; 21 in Part 2). No subject experienced dose limiting toxicity and maximum tolerated dose was not reached. All drug-related events were Grade 1 or 2 in severity, with fatigue and rash predominating. Following treatment with U3-1565, 1 subject with metastatic colorectal cancer experienced partial response and 6 subjects achieved stable disease. Four subjects completed the study main phase (first 12 cycles) and entered the extension phase. Of the 6/36 subjects with high (> 1500 pg/ml) baseline VEGF-A levels, all showed a decrease in VEGF-A (median - 60% [-22% to -97%]). Of the remaining subjects, only 19/30 showed a decrease (median - 18% [-2% to -82%]). Subjects with high VEGF-A baseline levels remained on treatment longer (3/6 entered study extension phase versus 1/30), and were more likely to show disease control (3/6 versus 4/30). In conclusion, U3-1565 demonstrates both proof of mechanism and clinical activity across different tumor types.

Phase 1 Study of Monotherapy with KHK2866, an Anti-Heparin-Binding Epidermal Growth Factor-Like Growth Factor Monoclonal Antibody, in Patients with Advanced Cancer

BACKGROUND

KHK2866 is a recombinant, humanized, non-fucosylated, monoclonal antibody directed at heparin-binding epidermal growth factor-like growth factor (HB-EGF).

OBJECTIVE

To determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, potential immunogenicity, and preliminary clinical efficacy of KHK2866 monotherapy in patients with advanced and refractory cancer in a first-in-human, phase 1 study.

MATERIALS AND METHODS

Using a standard 3 + 3 dose-escalation design, 20 patients received KHK2866 (0.3, 1, and 3 mg/kg) intravenously once weekly. Two additional patients received 0.1 mg/kg in a cohort which was subsequently added following protocol amendment.

RESULTS

The first three patients enrolled experienced grade 2 hypersensitivity (acute infusion reactions) after the first dose of KHK2866. After prophylactic treatment with an H1-blocker and corticosteroids in subsequently recruited patients, two grade 2 hypersensitivity reactions were observed in the remaining 19 patients. Grade 2/3 neurotoxicity appeared to be dose-limiting at 3 mg/kg in the original dose-escalation cohorts (n = 2), at 1 mg/kg in the MTD dose expansion cohort (n = 1), and at 0.1 mg/kg (n = 1). Neurotoxicity was manifested as complex partial seizure activity, aphasia, and confusion after first-dose administration. Pharmacokinetic exposure to KHK2866 increased proportionally to dose. Mean elimination half-life was 71.9-118 h over the dose range from 0.3 to 3 mg/kg. All KHK2866 doses decreased serum free HB-EGF levels, generally below the lower limit of quantification.

CONCLUSIONS

The study was terminated because of neuropsychiatric toxicity. The only predictive factor for neuropsychiatric toxicity was administration of KHK2866. These effects were reversible, but were not predictable. Their etiology is not presently understood. [Study registered at ClinicalTrials.gov #NCT0179291].

Targeting hepatic heparin-binding EGF-like growth factor (HB-EGF) induces anti-hyperlipidemia leading to reduction of angiotensin II-induced aneurysm development

Objective

The upregulated expression of heparin binding EGF-like growth factor (HB-EGF) in the vessel and circulation is associated with risk of cardiovascular disease. In this study, we tested the effects of HB-EGF targeting using HB-EGF-specific antisense oligonucleotide (ASO) on the development of aortic aneurysm in a mouse aneurysm model.

Approach and results

Low-density lipoprotein receptor (LDLR) deficient mice (male, 16 weeks of age) were injected with control and HB-EGF ASOs for 10 weeks. To induce aneurysm, the mice were fed a high fat diet (22% fat, 0.2% cholesterol; w/w) at 5 week point of ASO administration and infused with angiotensin II (AngII, 1,000ng/kg/min) for the last 4 weeks of ASO administration. We confirmed that the HB-EGF ASO administration significantly downregulated HB-EGF expression in multiple tissues including the liver. Importantly, the HB-EGF ASO administration significantly suppressed development of aortic aneurysms including thoracic and abdominal types. Interestingly, the HB-EGF ASO administration induced a remarkable anti-hyperlipidemic effect by suppressing very low density lipoprotein (VLDL) level in the blood. Mechanistically, the HB-EGF targeting suppressed hepatic VLDL secretion rate without changing heparin-releasable plasma triglyceride (TG) hydrolytic activity or fecal neutral cholesterol excretion rate.

Conclusion

This result suggested that the HB-EGF targeting induced protection against aneurysm development through anti-hyperlipidemic effects. Suppression of hepatic VLDL production process appears to be a key mechanism for the anti-hyperlipidemic effects by the HB-EGF targeting.

Preclinical Pharmacokinetics Evaluation of Anti-heparin-binding EGF-like Growth Factor (HB-EGF) Monoclonal Antibody Using Cynomolgus Monkeys via (89)Zr-immuno-PET Study and the Determination of Drug Concentrations in Serum and Cerebrospinal Fluid

PURPOSE

Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family and is an important therapeutic target in some types of human cancers. KHK2866 is a humanized anti-HB-EGF monoclonal antibody IgG that neutralizes HB-EGF activity by inhibiting the binding of HB-EGF to its receptors. The phase I study of KHK2866 was discontinued because of neuropsychiatric toxicity. In this study, the pharmacokinetics of KHK2866 was evaluated by (89)Zr-immuno-PET study and the determination of drug concentrations in serum and cerebrospinal fluid using cynomolgus monkeys was performed in order to predict neurotoxicity in a reverse-translational manner.

METHODS

KHK2866 was radiolabeled with (89)Zr for preclinical evaluations in normal cynomolgus monkeys and its distribution was analyzed. Furthermore, as a separate study, KHK2866 concentrations in serum and cerebrospinal fluid were determined after administration of a single dose.

RESULTS

PET studies with monkeys revealed (89)Zr-KHK2866 accumulation in the liver, spleen and joints of multiple parts, but not in brain. In addition, the pharmacokinetic analyses in serum and CSF demonstrated a low penetration of KHK2866 into the brain.

CONCLUSIONS

These studies indicate the difficulty of prediction for neuropsychiatric toxicity of monoclonal antibodies in human by means of pharmacokinetic evaluations using cynomolgus monkeys.