Pharmacokinetics and Exposure-Response Relationship of Teprotumumab, an Insulin-Like Growth Factor-1 Receptor-Blocking Antibody, in Thyroid Eye Disease

Background and Objective

Thyroid eye disease (TED) is characterized by inflammation/expansion of orbital tissues, proptosis, and diplopia. Teprotumumab is the first US Food and Drug Administration-approved therapy for TED, administered as an initial intravenous infusion of 10 mg/kg followed by 20 mg/kg every 3 weeks for an additional seven infusions. The objective of this article is to discuss the pharmacokinetics and exposure-response profile for teprotumumab in patients with TED.

Methods

A population pharmacokinetic analysis was performed to characterize pharmacokinetics and select dosing in patients with TED. Exposure-response was evaluated for efficacy (proptosis response, clinical activity score categorical response, and diplopia response) and safety (hyperglycemia, muscle spasms, and hearing impairment) parameters.

Results

Teprotumumab pharmacokinetics was linear in patients with TED, with low systemic clearance (0.334 L/day), low volume of distribution (3.9 and 4.2 L for the central and peripheral compartment, respectively), and a long elimination half-life (19.9 days). The approved dosing regimen provided > 20 µg/mL for > 90% insulin-like growth factor 1 receptor saturation throughout the dosing interval. Model-predicted mean (± standard deviation) steady-state area under the concentration-time curve, peak, and trough concentrations in patients with TED were 131 (± 30.9) mg∙h/mL, 643 (± 130) µg/mL, and 157 (± 50.6) µg/mL, respectively. Female patients had a 15% higher steady-state peak concentration but a similar steady-state area under the concentration-time curve vs male patients. No other covariates affected teprotumumab pharmacokinetics. No meaningful correlations between teprotumumab exposures and efficacy or safety parameters were observed.

Conclusions

Teprotumumab pharmacokinetics was well characterized in patients with TED, and generally consistent with other IgG1 antibodies. Efficacy was consistent across the exposure range with a well-tolerated safety profile supporting the current dose regimen for patients with TED.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-021-01003-3.

Teprotumumab (Tepezza): from the discovery and development of medicines to USFDA approval for active thyroid eye disease (TED) treatment

Teprotumumab (TPT) is a type I insulin-like growth factor receptor inhibitor, marketed as Tepezza; recently USFDA approved it for the treatment of thyroid eye disease (thyroid-associated ophthalmopathy (TAO), Graves ophthalmopathy/orbitopathy) in the USA. It is a monoclonal antibody although it was initially developed in collaboration with Genmab and Roche for the treatment of the tumour, but later it was investigated by River Vision Development Corporation and Horizon Therapeutics for its ophthalmic use. The drug has been designated as an orphan drug, breakthrough designation and fast-track designation. This review summarizes the milestones in the research and development including ongoing, clinical trial of TPT till now, foremost to this primary approval for thyroid-associated ophthalmopathy (TAO).

The insulin receptor/insulin-like growth factor receptor family as a therapeutic target in oncology

Over the past decade, encouraging preclinical and early clinical data concerning the relevance of the insulin receptor/insulin-like growth factor (IGF) receptor family to neoplasia led to ambitious clinical trial programs of more than a dozen drug candidates that target these receptors. These candidates include antireceptor antibodies, antiligand antibodies, receptor-specific tyrosine kinase inhibitors, and agents such as picropodophyllin and metformin that have novel mechanisms of action. Several recently reported phase III clinical trials of anti-IGF-I receptor antibodies have been disappointing and are sufficient to disprove the hypothesis that the antibodies tested have large favorable impacts on unselected patients with cancer. However, many of these trials were designed prior to recent insights concerning pathophysiology and predictive biomarkers. Future studies are required, but it will be important to optimize their design rather than simply repeat the approaches taken to date.

Targeting the insulin-like growth factor receptor pathway in lung cancer: problems and pitfalls

The insulin-like growth factor (IGF) pathway is a complex pathway involving interactions between membrane-bound receptors, ligands, binding proteins, downstream effectors, and other receptor tyrosine kinase signaling cascades. The IGF pathway has been identified as a potential therapeutic target in non-small cell lung cancer (NSCLC) based on the following provocative factors. Preclinical observations in NSCLC have shown that this pathway is involved in tumor cell proliferation, survival, and invasiveness. In addition, IGF-1R protein expression is found in a significant number of non-small cell tumor specimens. Initial therapeutic efforts involved the development of monoclonal antibodies and tyrosine kinase inhibitors that target IGF-1R, a transmembrane receptor tyrosine kinase. Enthusiasm for targeting this pathway increased when a randomized phase II study showed that combining an anti-IGF-1R monoclonal antibody (figitumumab) with a platinum doublet resulted in a higher response rate and trends for superior progression-free survival and overall survival. Subsequently, a phase III study failed to confirm the promising results observed in the phase II trial. Currently, investigators are studying different monoclonal antibodies and tyrosine kinases targeting IGF-1R. In unselected patients, results presented thus far do not suggest efficacy of this agent. However, retrospective subgroup analyses suggest that circulating IGF-1 levels might identify patients who could benefit from treatment with an IGF-1R monoclonal antibody and may warrant further exploratory studies for predictive molecular markers. The purpose of this paper is to briefly discuss the IGF pathway and its relationship with other signaling pathways in lung cancer and to review the ongoing IGF clinical trials and efforts to identify predictive molecular markers.

Randomized phase II study of erlotinib in combination with placebo or R1507, a monoclonal antibody to insulin-like growth factor-1 receptor, for advanced-stage non-small-cell lung cancer

PURPOSE

R1507 is a selective, fully human, recombinant monoclonal antibody (immunoglobulin G1 subclass) against insulin-like growth factor-1 receptor (IGF-1R). The strong preclinical evidence supporting coinhibition of IGF-1R and epidermal growth factor receptor (EGFR) as anticancer therapy prompted this study.

PATIENTS AND METHODS

Patients with advanced-stage non-small-cell lung cancer (NSCLC) with progression following one or two prior regimens, Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2, and measurable disease were eligible. Patients were randomly assigned to receive erlotinib (150 mg orally once a day) in combination with either placebo, R1507 9 mg/kg weekly, or R1507 16 mg/kg intravenously once every 3 weeks. Treatment cycles were repeated every 3 weeks. The primary end point was comparison of the 12-week progression-free survival (PFS) rate.

RESULTS

In all, 172 patients were enrolled: median age, 61 years; female, 33%; never-smokers, 12%; and performance status 0 or 1, 88%. The median number of R1507 doses was six for the weekly arm and 3.5 for the every-3-weeks arm. Grades 3 to 4 adverse events occurred in 37%, 44%, and 48% of patients with placebo, R1507 weekly, and R1507 every 3 weeks, respectively. The 12-week PFS rates were 39%, 37%, and 44%, and the median overall survival was 8.1, 8.1, and 12.1 months for the three groups, respectively, with statistically nonsignificant hazard ratios. The 12-week PFS rate in patients with KRAS mutation was 36% with R1507 compared with 0% with placebo.

CONCLUSION

The combination of R1507 with erlotinib did not provide PFS or survival advantage over erlotinib alone in an unselected group of patients with advanced NSCLC. Predictive biomarkers are essential for further development of combined inhibition of IGF-1R and EGFR.

Plasma and tissue insulin-like growth factor-I receptor (IGF-IR) as a prognostic marker for prostate cancer and anti-IGF-IR agents as novel therapeutic strategy for refractory cases: a review

Cancer database analysis indicates that prostate cancer is one of the most seen cancers in men meanwhile composing the leading cause of morbidity and mortality among developed countries. Current available therapies are surgery, radiotherapy and androgene ablation for prostate carcinoma. The response rate is as high nearly 90% however, most of these recur or become refractory and androgene independent (AI). Therefore recent studies intensified on molecular factors playing role on development of prostate carcinoma and novel treatment strategies targetting these factors and their receptors. Insulin-like growth factor-I (IGF-I) and its primary receptor insulin-like growth factor receptor-I (IGF-IR) are among these factors. Biologic functions and role in malign progression are primarily achieved via IGF-IR which is a type 2 tyrosine kinase receptor. IGF-IR plays an important role in mitogenesis, angiogenesis, transformation, apoptosis and cell motility. It also generates intensive proliferative signals leading to carcinogenesis in prostate tissue. So IGF-IR and its associated signalling system have provoked considerable interest over recent years as a novel therapeutic target in cancer. In this paper it is aimed to sum up the lately published literature searching the relation of IGF-IR and prostate cancer in terms of incidence, pathologic features, and prognosis. This is followed by a discussion of the different possible targets within the IGF-1R system, and drugs developed to interact at each target. A systems-based approach is then used to review the in vitro and in vivo data in the published literature of the following compounds targeting IGF-1R components using specific examples: growth hormone releasing hormone antagonists (e.g. JV-1-38), growth hormone receptor antagonists (e.g. pegvisomant), IGF-1R antibodies (e.g. CP-751,871, AVE1642/EM164, IMC-A12, SCH-717454, BIIB022, AMG 479, MK-0646/h7C10), and IGF-1R tyrosine kinase inhibitors (e.g. BMS-536942, BMS-554417, NVP-AEW541, NVP-ADW742, AG1024, potent quinolinyl-derived imidazo (1,5-a)pyrazine PQIP, picropodophyllin PPP, nordihydroguaiaretic acid Insm-18/NDGA). And the other end point is to yield an overview on the recent progress about usage of this receptor as a novel anticancer agent of targeted therapies in treatment of prostate carcinoma.

Management options in triple-negative breast cancer

Notorious for its poor prognosis and aggressive nature, triple-negative breast cancer (TNBC) is a heterogeneous disease entity. The nature of its biological specificity, which is similar to basal-like cancers, tumors arising in BRCA1 mutation carriers, and claudin-low cancers, is currently being explored in hopes of finding the targets for novel biologics and chemotherapeutic agents. In this review, we aim to give a broad overview of the disease's nomenclature and epidemiology, as well as the basic mechanisms of emerging targeted therapies and their performance in clinical trials to date.

The insulin-like growth factor signaling pathway as a target for treatment of colorectal carcinoma

The insulin-like growth factors (IGFs), IGF1 and IGF2, are peptide hormones that bind to the insulin-like growth factor 1 receptor (IGF1R) and cause intracellular signaling that ultimately results in cellular growth and proliferation. Evidence from epidemiologic and preclinical studies suggests that IGF signaling may be of importance in the pathogenesis of colorectal cancer (CRC). In recent years, agents that target the IGF1R pathway have been developed. These agents are currently under evaluation for the treatment of CRC.

From targets to treatments: a review of molecular targets in pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (pancreatic NET) are relatively rare, slowly growing tumors, although their incidence is increasing, and patients may survive for several years with metastatic disease. Apart from symptomatic relief, there have been few treatment options for these tumors in the past. More recently, investigators have explored the potential of molecularly targeted agents in treating pancreatic NET, with some success. In this review, we consider the data supporting exploitation of different targets in pancreatic NET, including peptide receptors, receptor tyrosine kinases (involved in tumor angiogenesis and more directly supporting tumor growth), and intracellular targets, such as the mammalian target of rapamycin (mTOR), which has a central role in regulating cell growth, metabolism, and apoptosis. Probably due to the paucity of pancreatic NET, many clinical trials to date have included heterogeneous NET populations, and there are few randomized studies of this specific patient population. Very recently, promising results have been achieved in placebo-controlled, phase III trials with the multitargeted tyrosine kinase inhibitor, sunitinib, and the mTOR inhibitor, everolimus. These agents have been approved or are currently being reviewed by authorities for use in patients with pancreatic NET. Here we review potential molecular targets in pancreatic NET and summarize the available data for targeted agents from phase II and III trials open to patients with this tumor.

Biological rationale and current clinical experience with anti-insulin-like growth factor 1 receptor monoclonal antibodies in treating sarcoma: twenty years from the bench to the bedside

Two decades have elapsed since insulin-like growth factor-1 receptor (IGF-1R) signaling was initially implicated in sarcoma biology to the first clinical experience of IGF-1R blockade in sarcoma. During these 21 years, the IGF pathway and its key mediator IGF-1R have been implicated in the genesis, growth, proliferation, metastasis, and resistance to conventional treatment in several sarcoma subtypes. In addition, IGF-1R has been validated, both in vitro and in vivo, as a target for the treatment of sarcoma. Several radiologic and clinical responses to IGF-1R monoclonal antibodies have been reported in Ewing sarcoma patients enrolled in early clinical studies. Furthermore, these therapies were well tolerated, and thus far severe toxicity has been rare. The early clinical evidence of antitumor activity has supported the initiation of various phase II clinical trials in Ewing and other sarcoma subtypes, the results of which are eagerly awaited, as well as studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies. Despite these encouraging results, not all patients benefit from IGF-1R inhibition and consequently there is an urgent need for the identification of predictive markers of response.

Insulin-like growth factor receptor 1 (IGF1R) gene copy number is associated with survival in operable non-small-cell lung cancer: a comparison between IGF1R fluorescent in situ hybridization, protein expression, and mRNA expression

PURPOSE

The purpose of this study was to characterize insulin-like growth factor-1 receptor (IGF1R) protein expression, mRNA expression, and gene copy number in surgically resected non-small-cell lung cancers (NSCLC) in relation to epidermal growth factor receptor (EGFR) protein expression, patient characteristics, and prognosis.

PATIENTS AND METHODS

One hundred eighty-nine patients with NSCLC who underwent curative pulmonary resection were studied (median follow-up, 5.3 years). IGF1R protein expression was evaluated by immunohistochemistry (IHC) with two anti-IGF1R antibodies (n = 179). EGFR protein expression was assessed with PharmDx kit. IGF1R gene expression was evaluated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) from 114 corresponding fresh-frozen samples. IGF1R gene copy number was assessed by fluorescent in situ hybridization using customized probes (n = 181).

RESULTS

IGF1R IHC score was higher in squamous cell carcinomas versus other histologies (P < .001) and associated with stage (P = .03) but not survival (P = .46). IGF1R and EGFR protein expression showed significant correlation (r = 0.30; P < .001). IGF1R gene expression by qRT-PCR was higher in squamous cell versus other histologies (P = .006) and did not associate with other clinical features nor survival (P = .73). Employing criteria previously established for EGFR copy number, patients with IGF1R amplification/high polysomy (n = 48; 27%) had 3-year survival of 58%, patients with low polysomy (n = 87; 48%) had 3-year survival of 47% and patients with trisomy/disomy (n = 46; 25%) had 3-year survival of 35%, respectively (P = .024). Prognostic value of high IGF1R gene copy number was confirmed in multivariate analysis.

CONCLUSION

IGF1R protein expression is higher in squamous cell versus other histologies and correlates with EGFR expression. IGF1R protein and gene expression does not associate with survival, whereas high IGF1R gene copy number harbors positive prognostic value.

A phase I study of weekly R1507, a human monoclonal antibody insulin-like growth factor-I receptor antagonist, in patients with advanced solid tumors

PURPOSE

A phase I study was conducted to evaluate the pharmacokinetics, pharmacodynamics, safety, and tolerability of R1507-a fully human IgG1 type monoclonal antibody directed against the human insulin-like growth factor-I receptor.

EXPERIMENTAL DESIGN

Patients with advanced solid tumors were assigned to receive i.v. R1507 weekly (qW), starting with 1 mg/kg. Subsequent cohorts were dosed at 3 and then 9 mg/kg. An additional 12 patients received 9 mg/kg R1507 qW. Patients remained on the study until the development of a dose-limiting toxicity or progressive disease.

RESULTS

In total, 37 patients were treated with R1507 qW. No dose-limiting toxicities were identified and the maximum tolerated dose was not reached. The pharmacokinetics of R1507 were characterized by a slow clearance and limited volume of distribution, with an estimated elimination half-life justifying weekly administration. Serum IGF-I ligand levels increased proportionally to dose during the first 72 hours in all cohorts. R1507 was well tolerated. Two patients diagnosed with Ewing's sarcoma had partial responses of 11.5 and >26 months (ongoing at time of submission); 13 patients had stable disease; and 16 had progressive disease as best response by the Response Evaluation Criteria in Solid Tumors.

CONCLUSION

R1507 is well tolerated and shows antitumor activity in patients with solid neoplasms, in particular Ewing's sarcoma. The recommended dose for the weekly schedule is 9 mg/kg qW.

Effect of type 1 insulin-like growth factor receptor targeted therapy on chemotherapy in human cancer and the mechanisms involved

INTRODUCTION

Chemotherapy is administered only to patients with advanced cancers, typically to modest avail. Hence, the search for innovative approaches to treat cancer is growing rapidly. One such approach involves targeting molecular pathways identified as encouraging tumor growth and maintenance, particularly the type 1 insulin-like growth factor (IGF-1) and its receptor (IGF-1R) pathway that is important in conferring chemoresistance.

MATERIALS AND METHODS

This study focuses on IGF-1R targeted therapy, which will enhance chemotherapy efficacy, through reviewing recent literature from PubMed and Medline databases.

CONCLUSION

This review examines data and strategies addressing an approach conquering chemoresistance through the combination of IGF-1R targeted therapy and chemotherapy in cancer patients, as well as the mechanisms by which IGF-1R acts as a target. This will impact on future research on treatment selection, thereby improving patient prognosis.

Targeting insulin-like growth factor type 1 receptor in cancer therapy

It is believed that the insulin-like growth factor receptor type 1 (IGF-1R) signaling pathway plays a pivotal role in cancer growth, progression, and resistance to anticancer therapies. Strategies are being developed to block IGF-1R as an anticancer treatment. We reviewed several potential strategies for disrupting the IGF axis. We also reviewed the effects of two drugs that target the IGF-1R: monoclonal antibodies and tyrosine kinase inhibitors. Preliminary results of studies involving these agents provided a foundation for ongoing clinical trials, whose results in the near future will help us understand how to incorporate anti IGF-1R strategies into the current anticancer armamentarium.

Novel therapeutic agents for osteosarcoma

Osteosarcoma is the most common malignant primary bone tumor in childhood. Despite multiagent chemotherapy and aggressive surgical resection, 30% of patients with localized disease and 80% of patients with metastatic disease at diagnosis will relapse. Survival for these patients has remained unchanged over the past 20 years. A number of novel agents in various stages of development hold promise for improving therapy for patients with osteosarcoma. This article will focus on novel therapeutic approaches, including agents targeting signal-transduction pathways, inhibitors of the tumor microenvironment and immunomodulatory agents, as well as overcoming resistance mechanisms and the use of novel delivery mechanisms.

Emerging role of insulin-like growth factor receptor inhibitors in oncology: early clinical trial results and future directions

Preclinical evidence that targeting the insulin-like growth factor receptor (IGF-IR) is effective in cancer treatment has been accumulating for almost two decades. Efforts to develop drugs began in the late 1990s, and initial data from clinical trials were reported in 2006. The biological rationale for IGF-IR targeting has potential relevance to many tumor types, and early results have justified expanded programs to evaluate IGF-IR-targeting agents in many areas of clinical need. More than two dozen drug candidates have been developed and clinical trials are underway for at least 12 of these. Early clinical trials reveal an acceptable safety profile together with pharmacodynamic evidence that the receptor can be successfully targeted. It is premature to draw conclusions regarding efficacy, but well-documented instances of single-agent activity were noted during phase I evaluations, and recent evidence from a phase II study suggests that co-administration of an anti-IGF-IR antibody with chemotherapy for non-small-cell lung cancer improves objective response rate and progression-free survival. With more than 70 trials involving a variety of drug candidates underway, the IGF-IR is becoming one of the most intensively investigated molecular targets in oncology. Early results justify the continuation of ongoing research across a broad range of cancer indications.

The role of IGF-1R in pediatric malignancies

The insulin-like growth factor (IGF) family consists of ligands (IGF-I, IGF-II, insulin), several receptors (including IGF-1R), and six binding proteins (IGFBP-1 through IGFBP-6). Members of this family regulate key cellular activities and they also play an important role in the development and progression of both adult and childhood cancers. Binding of a ligand to the receptor leads to its activation, followed by signal transduction along several pathways. In some childhood malignancies, IGF-1R can be activated by endocrine, autocrine, or paracrine mechanisms. Although mutations in IGF-1R have not been identified, this signaling pathway is upregulated in many childhood cancers. These findings have led to the development of a host of IGF-1R signaling modulators that are currently being tested in clinical trials. This review explores the role of IGF-1R in a range of childhood malignancies.

Insulin and insulin-like growth factor signalling in neoplasia

Insulin and insulin-like growth factors (IGFs) are well known as key regulators of energy metabolism and growth. There is now considerable evidence that these hormones and the signal transduction networks they regulate have important roles in neoplasia. Epidermiological, clinical and laboratory research methods are being used to investigate novel cancer prevention and treatment strategies related to insulin and IGF signalling. Pharmacological strategies under study include the use of novel receptor-specific antibodies, receptor kinase inhibitors and AMP-activated protein kinase activators such as metformin. There is evidence that insulin and IGF signalling may also be relevant to dietary and lifestyle factors that influence cancer risk and cancer prognosis. Recent results are encouraging and have justified the expansion of many translational research programmes.

IGF-1 receptor inhibitors in clinical trials--early lessons

The insulin-like growth factor pathway plays a major role in cancer cell proliferation, survival and resistance to anti-cancer therapies in many human malignancies, including breast cancer. As a key signaling component of IGF system, the IGF-1 receptor is the target of several investigational agents in clinical and pre-clinical development. This review will focus on the rationale for targeting the IGF-1 receptor and other components of the IGF-1 system. In addition, we will examine the role of IGF-1 signaling in resistance to clinically important breast cancer therapies, including cytotoxic chemotherapy, hormonal therapy and erbB targeted agents. We will also review the completed and ongoing clinical investigations with IGF-1 receptors inhibitors to date and the utility of these early data in designing future breast cancer studies with IGF-1 signaling inhibition strategies.

Early drug development of inhibitors of the insulin-like growth factor-I receptor pathway: lessons from the first clinical trials

The insulin-like growth factor-I receptor (IGF-IR) was first cloned in 1986. Since then, intense work has defined classic phosphorelays activated via the IGF-IR, which regulate cell proliferation, apoptosis, motility, and fate. The understanding of the roles of hormones in cancer and the growth hormone-IGF-IGF-binding protein axis specifically has yield to a second wave of development: the design of specific inhibitors that interrupt the signaling associated with this axis. The ability to manipulate these pathways holds not only significant therapeutic implications but also increase the chance of deeper insight about the role of the axis in carcinogenesis and metastasis. Nowadays, >25 molecules with the same goal are at different stages of development. Here, we review the clinical and preclinical experience with the two most-investigated strategies, tyrosine kinase inhibitors and monoclonal antibodies, and the advantages and disadvantages of each strategy, as well as other alternatives and possible drug combinations. We also review the biomarkers explored in the first clinical trials, the strategies that have been explored thus far, and the clinical trials that are going to explore their role in cancer treatment.

Activation of growth factor receptors in esophageal cancer--implications for therapy

Esophageal cancer is a highly aggressive disease and is the seventh most common cause of cancer-related death in the western world. Worldwide, it ranks as the sixth most frequent cause of cancer death. Despite advances in surgical techniques and treatment, the prognosis of esophageal cancer remains poor, with very few long-term survivors. The need for novel strategies to detect esophageal cancer earlier and to improve current therapy is urgent. It is well established that growth factors and growth factor receptor-mediated signaling pathways are important components of the transformation process in many forms of cancer, including esophageal cancer. With the recent advances in drug development, there are emerging possibilities to use growth factor signal transduction pathways in targeted therapy. This review provides a summary of the role of growth factors and their receptors in esophageal cancer and discusses their potential roles as biomarkers and as targets in therapy.

Role of insulin-like growth factor-1R system in colorectal carcinogenesis

The insulin-like growth factor (IGF) system is comprised of receptors, ligands (IGF-I and IGF-II), and a family of binding proteins (IGFBPs). It plays an important role in growth and development and in the maintenance of normal homeostasis. We present a review of the current laboratory and epidemiologic evidence that suggests an important role of the IGF system in colorectal carcinogenesis. Due to the complexity of this system, we have focused the review on the role of the IGF-1 receptor and its ligands in colorectal carcinogenesis and the strategies to block this pathway as a potential anti-cancer therapy.