Glycemic Trends in Patients with Thyroid Eye Disease Treated with Teprotumumab in 3 Clinical Trials.

PURPOSE: Assess incidence, severity, and glucose excursion outcomes in thyroid eye disease (TED) patients receiving the insulin-like growth factor-1 receptor inhibitor teprotumumab from 3 clinical trials. DESIGN: Analysis of pooled glycemic data over time. PARTICIPANTS: Eighty-four teprotumumab- and 86 placebo-treated active TED patients from the phase 2 and phase 3 (OPTIC) controlled clinical trials and 51 teprotumumab-treated patients from the OPTIC extension (OPTIC-X) trial. METHODS: Eight intravenous infusions were given over 21 weeks. Phase 2 serum glucose was measured at weeks 1, 4, 15, and 21, with fasting measurements at weeks 1 and 4. Serum glucose was measured at each study visit in OPTIC and OPTIC-X, with fasting measurements at weeks 1 and 4 (in patients without diabetes) or all visits (in patients with diabetes). In all studies, hemoglobin A1c (HbA1c) was measured at baseline, 12, and 24 weeks plus weeks 36 and 48 in OPTIC-X. MAIN OUTCOME MEASURES: Serum glucose and HbA1c. RESULTS: In the phase 2 and 3 studies, 9 hyperglycemic episodes occurred in 8 teprotumumab patients; mean HbA1c level increased 0.22% from baseline to week 24 (to 5.8%; range, 5.0%-7.9%) versus 0.04% in patients receiving the placebo (to 5.6%; range, 4.6%-8.1%). At study end, 78% (59/76) of teprotumumab patients and 87% (67/77) of patients receiving placebo had normoglycemic findings. Normoglycemia was maintained in 84% (57/68) of patients receiving teprotumumab and 93% (64/69) of patients receiving placebo. Among baseline prediabetic patients, 43% (3/7) remained prediabetic in both groups, and 29% (2/7) of teprotumumab patients and 14% (1/7) of patients receiving placebo had diabetic findings at week 24. OPTIC-X patients trended toward increased fasting glucose and HbA1c whether initially treated or retreated with teprotumumab. Fasting glucose commonly rose after 2 or 3 infusions and stabilized thereafter. Most hyperglycemic incidents occurred in patients with baseline prediabetes/diabetes but were controlled with medication. No evidence was found for progression or increased incidence of hyperglycemia with subsequent doses. CONCLUSIONS: Serious glycemic excursions are uncommon in patients with normoglycemia before teprotumumab therapy. Patients with controlled diabetes or impaired glucose tolerance can be treated safely if baseline screening, regular monitoring of glycemic control, and timely treatment of hyperglycemia are practiced. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Real-time single-base specific detection of the Haemonchus contortus S168T variant associated with levamisole resistance using loop-primer endonuclease cleavage loop-mediated isothermal amplification.

Haemonchus contortus is a parasitic haematophagous nematode that primarily affects small ruminants and causes significant economic loss to the global livestock industry. Treatment of haemonchosis typically relies on broad-spectrum anthelmintics, resistance to which is an important cause of treatment failure. Resistance to levamisole remains less widespread than to other major anthelmintic classes, prompting the need for more effective and accurate surveillance to maintain its efficacy. Loop-primer endonuclease cleavage loop-mediated isothermal amplification (LEC-LAMP) is a recently developed diagnostic method that facilitates multiplex target detection with single nucleotide polymorphism (SNP) specificity and portable onsite testing. In this study, we designed a new LEC-LAMP assay and applied it to detect the levamisole resistance marker S168T in H. contortus. We explored multiplexing probes for both the resistant S168T and the susceptible S168 alleles in a single-tube assay. We then included a generic probe to detect the acr-8 gene in the multiplex assay, which could facilitate the quantification of both resistance markers and overall genetic material from H. contortus in a single step. Our results showed promising application of these technologies, demonstrating a proof-of-concept assay which is amenable to detection of resistance alleles within the parasite population, with the potential for multiplex detection, and point-of-care application enabled by lateral flow end-point detection. However, further optimisation and validation is necessary.

Bridging and Validation of the Specific Graves Ophthalmopathy Quality of Life Questionnaire With Health State Utility Values.

OBJECTIVE: In thyroid eye disease (TED), inflammation and expansion of orbital muscle and periorbital fat result in diplopia and proptosis, severely impacting patient quality of life (QOL). The reported health state utility (HSU) scores, which are QOL measures, allow quantification of TED impact and improvement with therapies; however, no current QOL instrument has been validated with HSU scores for TED. Here, we used the disease-specific Graves Ophthalmopathy Quality of Life (GO-QOL) questionnaire and HSU scores to validate QOL impact. METHODS: The GO-QOL scores from patients in 2 randomized, masked, placebo-controlled teprotumumab trials (N=171) were compared with 6 HSU values based on severity of proptosis/diplopia in those studies. Patient GO-QOL and HSU scores were compared at baseline and after 6-month treatment via regression analyses. GO-QOL and HSU scores were correlated for validation and quantification of QOL impact by severity state and to estimate quality-adjusted life year improvement. RESULTS: GO-QOL scores were correlated with TED severity, indicating that worse severity was associated with lower (worse) GO-QOL scores. Less severe health states were represented by higher (better) GO-QOL scores. Importantly, GO-QOL scores were positively correlated with utility scores of the 6 health states, allowing for conversion of the GO-QOL scores to utility scores. A positive (improved) 0.013 utility change was found for each 1-point (positive) improvement in GO-QOL score produced by teprotumumab versus placebo. CONCLUSION: Patients with moderate-to-severe active TED health states demonstrate increasing TED severity associated with declining utility values and worsening GO-QOL scores. These results indicate that the GO-QOL scores can be used to bridge to the HSU scores for benefit quantification.

Therapeutic IGF-I receptor inhibition alters fibrocyte immune phenotype in thyroid-associated ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) represents a disfiguring and potentially blinding autoimmune component of Graves' disease. It appears to be driven, at least in part, by autoantibodies targeting the thyrotropin receptor (TSHR)/insulin-like growth factor I receptor (IGF-IR) complex. Actions mediated through either TSHR or IGF-IR are dependent on IGF-IR activity. CD34+ fibrocytes, monocyte lineage cells, reside uniquely in the TAO orbit, where they masquerade as CD34+ orbital fibroblasts. Fibrocytes present antigens to T cells through their display of the major histocompatibility complex class II (MHC II) while providing costimulation through B7 proteins (CD80, CD86, and programmed death-ligand 1 [PD-L1]). Here, we demonstrate that teprotumumab, an anti-IGF-IR inhibitor, attenuates constitutive expression and induction by the thyroid-stimulating hormone of MHC II and these B7 members in CD34+ fibrocytes. These actions are mediated through reduction of respective gene transcriptional activity. Other IGF-IR inhibitors (1H7 and linsitinib) and knocking down IGF-IR gene expression had similar effects. Interrogation of circulating fibrocytes collected from patients with TAO, prior to and following teprotumumab treatment in vivo during a phase 2 clinical trial, demonstrated reductions in cell-surface MHC II and B7 proteins similar to those found following IGF-IR inhibitor treatment in vitro. Teprotumumab therapy reduces levels of interferon-γ and IL-17A expression in circulating CD4+ T cells, effects that may be indirect and mediated through actions of the drug on fibrocytes. Teprotumumab was approved by the US Food and Drug Administration for TAO. Our current findings identify potential mechanisms through which teprotumumab might be eliciting its clinical response systemically in patients with TAO, potentially by restoring immune tolerance.

Teprotumumab for the Treatment of Active Thyroid Eye Disease.

BACKGROUND: Thyroid eye disease is a debilitating, disfiguring, and potentially blinding periocular condition for which no Food and Drug Administration-approved medical therapy is available. Strong evidence has implicated the insulin-like growth factor I receptor (IGF-IR) in the pathogenesis of this disease. METHODS: In a randomized, double-masked, placebo-controlled, phase 3 multicenter trial, we assigned patients with active thyroid eye disease in a 1:1 ratio to receive intravenous infusions of the IGF-IR inhibitor teprotumumab (10 mg per kilogram of body weight for the first infusion and 20 mg per kilogram for subsequent infusions) or placebo once every 3 weeks for 21 weeks; the last trial visit for this analysis was at week 24. The primary outcome was a proptosis response (a reduction in proptosis of ≥2 mm) at week 24. Prespecified secondary outcomes at week 24 were an overall response (a reduction of ≥2 points in the Clinical Activity Score plus a reduction in proptosis of ≥2 mm), a Clinical Activity Score of 0 or 1 (indicating no or minimal inflammation), the mean change in proptosis across trial visits (from baseline through week 24), a diplopia response (a reduction in diplopia of ≥1 grade), and the mean change in overall score on the Graves' ophthalmopathy-specific quality-of-life (GO-QOL) questionnaire across trial visits (from baseline through week 24; a mean change of ≥6 points is considered clinically meaningful). RESULTS: A total of 41 patients were assigned to the teprotumumab group and 42 to the placebo group. At week 24, the percentage of patients with a proptosis response was higher with teprotumumab than with placebo (83% [34 patients] vs. 10% [4 patients], P<0.001), with a number needed to treat of 1.36. All secondary outcomes were significantly better with teprotumumab than with placebo, including overall response (78% of patients [32] vs. 7% [3]), Clinical Activity Score of 0 or 1 (59% [24] vs. 21% [9]), the mean change in proptosis (-2.82 mm vs. -0.54 mm), diplopia response (68% [19 of 28] vs. 29% [8 of 28]), and the mean change in GO-QOL overall score (13.79 points vs. 4.43 points) (P≤0.001 for all). Reductions in extraocular muscle, orbital fat volume, or both were observed in 6 patients in the teprotumumab group who underwent orbital imaging. Most adverse events were mild or moderate in severity; two serious events occurred in the teprotumumab group, of which one (an infusion reaction) led to treatment discontinuation. CONCLUSIONS: Among patients with active thyroid eye disease, teprotumumab resulted in better outcomes with respect to proptosis, Clinical Activity Score, diplopia, and quality of life than placebo; serious adverse events were uncommon. (Funded by Horizon Therapeutics; OPTIC ClinicalTrials.gov number, NCT03298867, and EudraCT number, 2017-002763-18.).

Longitudinal Retinal Changes in MOGAD.

OBJECTIVE: Patients with myelin oligodendrocyte glycoprotein antibody (MOG-IgG)-associated disease (MOGAD) suffer from severe optic neuritis (ON) leading to retinal neuro-axonal loss, which can be quantified by optical coherence tomography (OCT). We assessed whether ON-independent retinal atrophy can be detected in MOGAD. METHODS: Eighty patients with MOGAD and 139 healthy controls (HCs) were included. OCT data was acquired with (1) Spectralis spectral domain OCT (MOGAD: N = 66 and HCs: N = 103) and (2) Cirrus high-definition OCT (MOGAD: N = 14 and HCs: N = 36). Macular combined ganglion cell and inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) were quantified. RESULTS: At baseline, GCIPL and pRNFL were lower in MOGAD eyes with a history of ON (MOGAD-ON) compared with MOGAD eyes without a history of ON (MOGAD-NON) and HCs (p < 0.001). MOGAD-NON eyes had lower GCIPL volume compared to HCs (p < 0.001) in the Spectralis, but not in the Cirrus cohort. Longitudinally (follow-up up to 3 years), MOGAD-ON with ON within the last 6-12 months before baseline exhibited greater pRNFL thinning than MOGAD-ON with an ON greater than 12 months ago (p < 0.001). The overall MOGAD cohort did not exhibit faster GCIPL thinning compared with the HC cohort. INTERPRETATION: Our study suggests the absence of attack-independent retinal damage in patients with MOGAD. Yet, ongoing neuroaxonal damage or edema resolution seems to occur for up to 12 months after ON, which is longer than what has been reported with other ON forms. These findings support that the pathomechanisms underlying optic nerve involvement and the evolution of OCT retinal changes after ON is distinct in patients with MOGAD. ANN NEUROL 2022;92:476-485.

Diagnostic value of intereye difference metrics for optic neuritis in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders.

BACKGROUND: The novel optic neuritis (ON) diagnostic criteria include intereye differences (IED) of optical coherence tomography (OCT) parameters. IED has proven valuable for ON diagnosis in multiple sclerosis but has not been evaluated in aquaporin-4 antibody seropositive neuromyelitis optica spectrum disorders (AQP4+NMOSD). We evaluated the diagnostic accuracy of intereye absolute (IEAD) and percentage difference (IEPD) in AQP4+NMOSD after unilateral ON >6 months before OCT as compared with healthy controls (HC). METHODS: Twenty-eight AQP4+NMOSD after unilateral ON (NMOSD-ON), 62 HC and 45 AQP4+NMOSD without ON history (NMOSD-NON) were recruited by 13 centres as part of the international Collaborative Retrospective Study on retinal OCT in Neuromyelitis Optica study. Mean thickness of peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell and inner plexiform layer (GCIPL) were quantified by Spectralis spectral domain OCT. Threshold values of the ON diagnostic criteria (pRNFL: IEAD 5 µm, IEPD 5%; GCIPL: IEAD: 4 µm, IEPD: 4%) were evaluated using receiver operating characteristics and area under the curve (AUC) metrics. RESULTS: The discriminative power was high for NMOSD-ON versus HC for IEAD (pRNFL: AUC 0.95, specificity 82%, sensitivity 86%; GCIPL: AUC 0.93, specificity 98%, sensitivity 75%) and IEPD (pRNFL: AUC 0.96, specificity 87%, sensitivity 89%; GCIPL: AUC 0.94, specificity 96%, sensitivity 82%). The discriminative power was high/moderate for NMOSD-ON versus NMOSD-NON for IEAD (pRNFL: AUC 0.92, specificity 77%, sensitivity 86%; GCIP: AUC 0.87, specificity 85%, sensitivity 75%) and for IEPD (pRNFL: AUC 0.94, specificity 82%, sensitivity 89%; GCIP: AUC 0.88, specificity 82%, sensitivity 82%). CONCLUSIONS: Results support the validation of the IED metrics as OCT parameters of the novel diagnostic ON criteria in AQP4+NMOSD.

Fibrocyte Participation in Thyroid-Associated Ophthalmopathy Suggests New Approaches to Therapy.

PURPOSE: Review the historical context of research and changing therapeutic landscape of thyroid-associated ophthalmopathy (TAO) by focusing on the relationship between TAO, CD34+ fibrocytes, thyrotropin receptor (TSHR), and insulin-like growth factor-I receptor (IGF-IR). METHODS: A literature review using search terms, including fibrocytes, IGF-IR, TSHR, TAO, and thyroid eye disease. RESULTS: The mechanisms involved in TAO have been partially identified. Substantial progress has been made over several decades, including 1) recognizing the interplay between the professional immune system and orbital tissues; 2) TSHR and IGF-IR act interdependently in mediating the pathogenesis of TAO; 3) Multiple cytokines and specific immune cells are involved in activating and remodeling orbital tissue; 4) Recognition of these mechanisms is allowing the development of target therapies such as teprotumumab, a monoclonal antibody IGF-IR inhibitor approved by the US Food and drug administration for treatment of TAO; and 5) It appears that teprotumumab acts on the systemic immune system peripheral to the orbit. CONCLUSION: Additional molecules targeting IGF-IR and other plausible disease mechanisms are currently under development. This activity in the TAO therapeutic space portends even greater improvements in patient care.

Challenges in Orphan Drug Development: Identification of Effective Therapy for Thyroid-Associated Ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease, is a process in which orbital connective tissues and extraocular muscles undergo inflammation and remodeling. The condition seems to result from autoimmune responses to antigens shared by the thyroid and orbit. The thyrotropin receptor (TSHR), expressed at low levels in orbital tissues, is a leading candidate antigen. Recent evidence suggests that another protein, the insulin-like growth factor-I receptor (IGF-IR), is overexpressed in TAO, and antibodies against IGF-IR have been detected in patients with the disease. Furthermore, TSHR and IGF-IR form a physical and functional complex, and signaling initiated at TSHR requires IGF-IR activity. Identification of therapy for this rare disease has proven challenging and currently relies on nonspecific and inadequate agents, thus representing an important unmet need. A recently completed therapeutic trial suggests that inhibiting IGF-IR activity with a monoclonal antibody may be an effective and safe treatment for active TAO.

Teprotumumab Efficacy, Safety, and Durability in Longer-Duration Thyroid Eye Disease and Re-treatment: OPTIC-X Study.

PURPOSE: To evaluate teprotumumab safety/efficacy in patients with thyroid eye disease (TED) who were nonresponsive or who experienced a disease flare. DESIGN: The Treatment of Graves' Orbitopathy to Reduce Proptosis with Teprotumumab Infusions in an Open-Label Clinical Extension Study (OPTIC-X) is a teprotumumab treatment and re-treatment trial following the placebo-controlled teprotumumab Phase 3 Treatment of Graves' Orbitopathy (Thyroid Eye Disease) to Reduce Proptosis with Teprotumumab Infusions in a Randomized, Placebo-Controlled, Clinical Study (OPTIC) trial. PARTICIPANTS: Patients who previously received placebo (n = 37) or teprotumumab (n = 14) in OPTIC. METHODS: OPTIC nonresponders or those who flared (≥2-mm increase in proptosis, ≥2-point increase in clinical activity score [CAS], or both) during follow-up were treated for the first time (previous placebo patients) or re-treated with teprotumumab in OPTIC-X with 8 infusions over 24 weeks. MAIN OUTCOME MEASURES: Proptosis response and safety. Secondary outcomes included proptosis, CAS, subjective diplopia, and quality-of-life. RESULTS: Thirty-three of 37 placebo-treated OPTIC patients (89.2%) became proptosis responders (mean ± standard deviation, -3.5 ± 1.7 mm) when treated with teprotumumab in OPTIC-X. The responses were equivalent to the OPTIC study. In these responders, proptosis, CAS of 0 or 1, and diplopia responses were maintained in 29 of 32 patients (90.6%), 20 of 21 patients (95.2%), and 12 of 14 patients (85.7%), respectively, at follow-up week 48. The median TED duration was 12.9 months versus 6.3 months in those treated with teprotumumab in the OPTIC study. Of the 5 OPTIC teprotumumab nonresponders re-treated in OPTIC-X, 2 responded, 1 showed a proptosis reduction of 1.5 mm from OPTIC baseline, and 2 discontinued treatment early. Of the OPTIC teprotumumab responders who experienced flare, 5 of 8 patients (62.5%) responded when re-treated (mean proptosis reduction, 1.9 ± 1.2 mm from OPTIC-X baseline and 3.3 ± 0.7 mm from OPTIC baseline). Compared with published double-masked trials and their integrated follow-up, no new safety signals were identified. Mild hearing impairment was reported; 4 events occurred during the first course of treatment, and 2 events reoccurred after re-treatment. CONCLUSIONS: Patients with TED of longer disease duration responded similarly to those treated earlier in the disease course. Patients with an insufficient initial response or flare may benefit from additional teprotumumab therapy. No new safety risk was identified; however additional postmarketing pharmacovigilance is ongoing.

Slit2 May Underlie Divergent Induction by Thyrotropin of IL-23 and IL-12 in Human Fibrocytes.

IL-23 and IL-12, two structurally related heterodimeric cytokines sharing a common subunit, divergently promote Th cell development and expansion. Both cytokines have been implicated in the pathogenesis of thyroid-associated ophthalmopathy (TAO), an autoimmune component of Graves disease. In TAO, CD34+ fibrocytes, putatively derived from bone marrow, can be identified in the orbit. There they masquerade as CD34+ orbital fibroblasts (OF) (CD34+ OF) and cohabitate with CD34- OF in a mixed fibroblast population (GD-OF). Slit2, a neural axon repellent, is expressed and released by CD34- OF and dampens the inflammatory phenotype of fibrocytes and CD34+ OF. In this study we report that thyrotropin (TSH) and the pathogenic, GD-specific monoclonal autoantibody, M22, robustly induce IL-23 in human fibrocytes; however, IL-12 expression is essentially undetectable in these cells under basal conditions or following TSH-stimulation. In contrast, IL-12 is considerably more inducible in GD-OF, cells failing to express IL-23. This divergent expression and induction of cytokines appears to result from cell type-specific regulation of both gene transcription and mRNA stabilities. It appears that the JNK pathway activity divergently attenuates IL-23p19 expression while enhancing that of IL-12p35. The shift from IL-23p19 expression in fibrocytes to that of IL-12p35 in their derivative CD34+ OF results from the actions of Slit2. Thus, Slit2 might represent a molecular determinant of balance between IL-23 and IL-12 expression, potentially governing immune responses in TAO.

Teprotumumab in Clinical Practice: Recommendations and Considerations From the OPTIC Trial Investigators.

BACKGROUND: Thyroid eye disease (TED) is a vision-threatening and debilitating condition that until very recently had no Food and Drug Administration (FDA)-approved medical therapies. Teprotumumab has recently been approved to treat TED. We aim to provide guidance for its use, based on the input of the US investigators who participated in Phase 2 and Phase 3 clinical trials. METHODS: An expert panel was convened on October 11th and November 16th of 2019. All panel members had extensive experience as investigators in the Phase 2 and/or Phase 3 clinical trials of teprotumumab. Consensus among those investigators was reached to determine patient characteristics most appropriate for teprotumumab treatment. Safety guidelines were also reviewed and agreed on. RESULTS: The authors recommend that teprotumumab be considered first-line therapy for patients with clinically significant ophthalmopathy, including those with disease duration exceeding 9 months. The clinical activity score (CAS) may be useful for longitudinal monitoring but should not be used to determine treatment eligibility. Criteria will likely be expanded after more experience with the drug. Using teprotumumab for patients with TED with substantial signs, symptoms, or morbidity without a CAS score of >4 (e.g., progressive proptosis, diplopia, and early compressive optic neuropathy) or more, could be considered. Diabetes mellitus and inflammatory bowel disease comorbidities should not be exclusionary, but stringent monitoring in these patients is recommended. Drug dosing, administration interval, and duration should adhere to the study protocol: 8 infusions, separated by 3 weeks. Patients with more severe disease may benefit from additional doses. Corticosteroids can be used before or during teprotumumab therapy. Clinical and laboratory monitoring should be consistent with good clinical practice for patients receiving teprotumumab. CONCLUSIONS: Confirming the efficacy of teprotumumab usage outside the narrow parameters of the completed clinical trials will require rigorous scientific validation. As a step in that direction, we believe its on-label usage is appropriately applied to all patients with TED with substantial symptoms or morbidity, as judged by their physician.

3' Tth Endonuclease Cleavage Polymerase Chain Reaction (3TEC-PCR) Technology for Single-Base-Specific Multiplex Pathogen Detection using a Two-Oligonucleotide System.

Polymerase chain reaction (PCR) is the standard in nucleic acid amplification technology for infectious disease pathogen detection and has been the primary diagnostic tool employed during the global COVID-19 pandemic. Various PCR technology adaptations, typically using two-oligonucleotide dye-binding methods or three-oligonucleotide hydrolysis probe systems, enable real-time multiplex target detection or single-base specificity for the identification of single-nucleotide polymorphisms (SNPs). A small number of two-oligonucleotide PCR systems facilitating both multiplex detection and SNP identification have been reported; however, these methods often have limitations in terms of target specificity, production of variable or false-positive results, and the requirement for extensive optimisation or post-amplification analysis. This study introduces 3' Tth endonuclease cleavage PCR (3TEC-PCR), a two-oligonucleotide PCR system incorporating a modified primer/probe and a thermostable cleavage enzyme, Tth endonuclease IV, for real-time multiplex detection and SNP identification. Complete analytical specificity, low limits of detection, single-base specificity, and simultaneous multiple target detection have been demonstrated in this study using 3TEC-PCR to identify bacterial meningitis associated pathogens. This is the first report of a two-oligonucleotide, real-time multiplex PCR technology with single-base specificity using Tth endonuclease IV.

Teprotumumab for Thyroid-Associated Ophthalmopathy.

BACKGROUND: Thyroid-associated ophthalmopathy, a condition commonly associated with Graves' disease, remains inadequately treated. Current medical therapies, which primarily consist of glucocorticoids, have limited efficacy and present safety concerns. Inhibition of the insulin-like growth factor I receptor (IGF-IR) is a new therapeutic strategy to attenuate the underlying autoimmune pathogenesis of ophthalmopathy. METHODS: We conducted a multicenter, double-masked, randomized, placebo-controlled trial to determine the efficacy and safety of teprotumumab, a human monoclonal antibody inhibitor of IGF-IR, in patients with active, moderate-to-severe ophthalmopathy. A total of 88 patients were randomly assigned to receive placebo or active drug administered intravenously once every 3 weeks for a total of eight infusions. The primary end point was the response in the study eye. This response was defined as a reduction of 2 points or more in the Clinical Activity Score (scores range from 0 to 7, with a score of ≥3 indicating active thyroid-associated ophthalmopathy) and a reduction of 2 mm or more in proptosis at week 24. Secondary end points, measured as continuous variables, included proptosis, the Clinical Activity Score, and results on the Graves' ophthalmopathy-specific quality-of-life questionnaire. Adverse events were assessed. RESULTS: In the intention-to-treat population, 29 of 42 patients who received teprotumumab (69%), as compared with 9 of 45 patients who received placebo (20%), had a response at week 24 (P<0.001). Therapeutic effects were rapid; at week 6, a total of 18 of 42 patients in the teprotumumab group (43%) and 2 of 45 patients in the placebo group (4%) had a response (P<0.001). Differences between the groups increased at subsequent time points. The only drug-related adverse event was hyperglycemia in patients with diabetes; this event was controlled by adjusting medication for diabetes. CONCLUSIONS: In patients with active ophthalmopathy, teprotumumab was more effective than placebo in reducing proptosis and the Clinical Activity Score. (Funded by River Vision Development and others; ClinicalTrials.gov number, NCT01868997 .).

Slit2 Modulates the Inflammatory Phenotype of Orbit-Infiltrating Fibrocytes in Graves' Disease.

Human CD34+ fibrocytes, circulating monocyte lineage progenitor cells, have recently been implicated in thyroid-associated ophthalmopathy (TAO), the ocular manifestation of Graves' disease (GD). Fibrocytes express constitutive MHC class II (MHC-2) and, surprisingly, thyroglobulin (Tg) and functional thyrotropin (TSH) receptor (TSHR). Underlying expression of these thyroid proteins is the autoimmune regulator protein (AIRE). Fibrocytes respond robustly to TSH and thyroid-stimulating Igs by generating extremely high levels of inflammatory cytokines, such as IL-6. In TAO, they appear to infiltrate the orbit, where they transition to CD34+ orbital fibroblasts (OF). There, they coexist with CD34- OF as a mixed fibroblast population (GD-OF). In contrast to fibrocytes, GD-OF express vanishingly low levels of MHC-2, Tg, TSHR, and AIRE. Further, the amplitude of IL-6 induction by TSH in GD-OF is substantially lower. The molecular basis for this divergence between fibrocytes and CD34+ OF remains uncertain. In this article, we report that Slit2, an axon guidance glycoprotein, is constitutively expressed by the CD34- OF subset of GD-OF. Culture conditioned medium (CM) generated by incubating with GD-OF and CD34- OF substantially reduces levels of MHC-2, Tg, TSHR, and AIRE in fibrocytes. Expression can be restored by specifically depleting CM of Slit2. The effects of CD34- OF CM are mimicked by recombinant human Slit2. TSH induces Slit2 levels in GD-OF by enhancing both Slit2 gene transcription and mRNA stability. These findings suggest that Slit2 represents a TSH-inducible factor within the TAO orbit that can modulate the inflammatory phenotype of CD34+ OF and therefore may determine the activity and severity of the disease.

Teprotumumab in Thyroid-Associated Ophthalmopathy: Rationale for Therapeutic Insulin-Like Growth Factor-I Receptor Inhibition.

Thyroid-associated ophthalmopathy (TAO) is an autoimmune component of Graves' disease for which no currently available medical therapy provides reliable and safe benefit. Based on insights generated experimentally over the past several decades, the insulin-like growth factor-I receptor (IGF-IR) has been implicated in the pathogenesis of TAO. Furthermore, an IGF-IR inhibitor, teprotumumab, has emerged from 2 clinical trials as a promising treatment for active, moderate to severe TAO. This brief review intends to provide an overview of the rationale underlying the development of teprotumumab for this disease. It is possible that teprotumumab will soon take its place in our therapeutic armamentarium for active TAO.

De novo triiodothyronine formation from thyrocytes activated by thyroid-stimulating hormone.

The thyroid gland secretes primarily tetraiodothyronine (T4), and some triiodothyronine (T3). Under normal physiological circumstances, only one-fifth of circulating T3 is directly released by the thyroid, but in states of hyperactivation of thyroid-stimulating hormone receptors (TSHRs), patients develop a syndrome of relative T3 toxicosis. Thyroidal T4 production results from iodination of thyroglobulin (TG) at residues Tyr5 and Tyr130, whereas thyroidal T3 production may originate in several different ways. In this study, the data demonstrate that within the carboxyl-terminal portion of mouse TG, T3 is formed de novo independently of deiodination from T4 We found that upon iodination in vitro, de novo T3 formation in TG was decreased in mice lacking TSHRs. Conversely, de novo T3 that can be formed upon iodination of TG secreted from PCCL3 (rat thyrocyte) cells was augmented from cells previously exposed to increased TSH, a TSHR agonist, a cAMP analog, or a TSHR-stimulating antibody. We present data suggesting that TSH-stimulated TG phosphorylation contributes to enhanced de novo T3 formation. These effects were reversed within a few days after removal of the hyperstimulating conditions. Indeed, direct exposure of PCCL3 cells to human serum from two patients with Graves' disease, but not control sera, led to secretion of TG with an increased intrinsic ability to form T3 upon in vitro iodination. Furthermore, TG secreted from human thyrocyte cultures hyperstimulated with TSH also showed an increased intrinsic ability to form T3 Our data support the hypothesis that TG processing in the secretory pathway of TSHR-hyperstimulated thyrocytes alters the structure of the iodination substrate in a way that enhances de novo T3 formation, contributing to the relative T3 toxicosis of Graves' disease.

Duplex recombinase polymerase amplification assays incorporating competitive internal controls for bacterial meningitis detection.

Recombinase polymerase amplification (RPA) is an isothermal nucleic acid amplification technology that provides rapid and robust infectious disease pathogen detection, ideal for point-of-care (POC) diagnostics in disease-prevalent low-resource countries. We have developed and evaluated three duplex RPA assays incorporating competitive internal controls for the detection of leading bacterial meningitis pathogens. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae singleplex RPA assays were initially developed and evaluated, demonstrating 100% specificity with limits of detection of 4.1, 8.5 and 3.9 genome copies per reaction, respectively. Each assay was further developed into internally controlled duplex RPA assays via the incorporation of internal amplification control templates. Clinical performance of each internally controlled duplex RPA assay was evaluated by testing 64 archived PCR-positive clinical samples. Compared to real-time PCR, all duplex RPA assays demonstrated 100% diagnostic specificity, with diagnostic sensitivities of 100%, 86.3% and 100% for the S. pneumoniae, N. meningitidis and H. influenzae assays, respectively. This study details the first report of internally controlled duplex RPA assays for the detection of bacterial meningitis pathogens: S. pneumoniae, N. meningitidis and H. influenzae. We have successfully demonstrated the clinical diagnostic utility of each duplex RPA assay, introducing effective diagnostic technology for POC bacterial meningitis identification in disease-prevalent developing countries.