Teprotumumab-Related Hyperglycemia

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.

A case of rapidly declining glycemic control and diabetic ketoacidosis in a newly diagnosed diabetes patient after starting teprotumumab for thyroid eye disease

PURPOSE

Teprotumumab for thyroid eye disease has a known hyperglycemic adverse effect through its impact on the insulin-like growth factor-1 receptor. While most cases are mild and easily managed by adjusting diabetes medications, it appears some patients have a more dramatic response. The purpose of this case report is to highlight an example of rapidly declining glycemic control and diabetic ketoacidosis (DKA) in a patient with newly diagnosed diabetes after starting teprotumumab for thyroid eye disease.

METHODS

This was a single-patient case report assessing a severe episode of hyperglycemia leading to new-onset diabetes. The case report was approved by Atrium Health Wake Forest Baptist's IRB committee. The patient was closely monitored by a pharmacist-led pharmacotherapy clinic after initial diagnosis and periodically since then to adjust therapy and assess glucose and hemoglobin A1c (HbA1c) trends.

RESULTS

After the acute episode of DKA was managed inpatient, the patient was discharged with insulin outpatient, but this was ultimately weaned off, and the patient's glucose and HbA1c are stable on metformin alone. This patient decided to not continue teprotumumab due to extensive side effects including but not limited to severe hyperglycemia.

CONCLUSION

While additional research is needed as to the cause of severe hyperglycemia in select patients, providers should consider proactively monitoring glucose throughout treatment with teprotumumab by ensuring that patients have baseline labs and labs at every visit and access to a glucometer with education for its use.

Severe Hyperglycemia with Teprotumumab for Treatment of Thyroid Eye Disease

Introduction

Thyroid eye disease (TED) is a rare condition involving autoimmune-mediated inflammation of the orbit and periocular structures, which can result in many debilitating symptoms. Teprotumumab, a monoclonal antibody that targets the insulin-like growth factor 1 receptor, is gaining popularity for the treatment of TED. In fact, owing to its efficacy and side effect profile, some recommend that it be considered as a first-line therapy for patients with TED. While teprotumumab is often chosen due to its efficacy and relatively favorable side effect profile compared to other treatments, there is a known risk of hyperglycemia with this mechanism of action, which is well described through clinical trials in the oncology literature. Though all cases in the clinical trial study of teprotumumab were mild, there is growing evidence that its effect on blood sugar can be more profound.

Case Presentation

We present a case of a well-controlled, recently diagnosed type 2 diabetic placed on teprotumumab for treatment of TED who developed life-threatening hyperglycemia. The case report provides evidence of hyperglycemic risk, as it highlights a patient's significant increase in hemoglobin A1C to 15.4 in addition to elevated serum glucose of 954 mg/dL while receiving teprotumumab.

Conclusion

This case of severe hyperglycemia accentuates the need for more diligent, if not universal, glucose monitoring during teprotumumab treatment.

Efficacy and Safety of Teprotumumab in Patients With Thyroid Eye Disease of Long Duration and Low Disease Activity

CONTEXT

Early inflammatory thyroid eye disease (TED) can lead to symptomatic chronic disease, including disabling proptosis. Teprotumumab, an insulin-like growth factor-1 receptor (IGF-1R) inhibitor, previously demonstrated efficacy in acute, high-inflammation TED trials.

OBJECTIVE

We present data from the first placebo-controlled trial with teprotumumab in chronic/low disease activity TED.

METHODS

This randomized double-masked, placebo-controlled trial, conducted at 11 US centers, enrolled adult participants with TED duration of 2 to 10 years, Clinical Activity Score (CAS) ≤ 1 or no additional inflammation or progression in proptosis/diplopia for ≥1 year, proptosis ≥3 mm from before TED and/or from normal, euthyroid/mildly hypo/hyperthyroid, no prior teprotumumab, and no steroids within 3 weeks of baseline. Patients received (2:1) intravenous teprotumumab or placebo once every 3 weeks (total 8 infusions). The primary endpoint was proptosis (mm) improvement at Week 24. Adverse events (AEs) were assessed.

RESULTS

A total of 62 (42 teprotumumab and 20 placebo) patients were randomized. At Week 24, least squares mean (SE) proptosis improvement was greater with teprotumumab (-2.41 [0.228]) than with placebo (-0.92 [0.323]), difference -1.48 (95% CI -2.28, -0.69; P = .0004). Proportions of patients with AEs were similar between groups. Hyperglycemia was reported in 6 (15%) vs 2 (10%) and hearing impairment in 9 (22%) vs 2 (10%) with teprotumumab and placebo, respectively. AEs led to discontinuation in 1 teprotumumab (left ear conductive hearing loss with congenital anomaly) and 1 placebo patient (infusion-related). There were no deaths.

CONCLUSION

Teprotumumab significantly improved proptosis vs placebo in longstanding/low inflammation TED, demonstrating efficacy regardless of disease duration/activity. The safety profile was comparable to that previously reported.

Thyroid Eye Disease and Its Association With Diabetes Mellitus: A Major Review

PURPOSE

Thyroid eye disease (TED) associated with diabetes mellitus (DM) presents unique challenges. DM is a risk factor for TED. Standard management of TED with glucocorticoids (GC), orbital radiation, or teprotumumab can cause adverse events in poor glycemic control. The authors reviewed the literature on the relationship between TED and DM and the management of co-existing diseases.

METHODS

The authors searched PubMed with keywords "thyroid eye disease," "diabetes mellitus," and similar terms from 2013 to 2022. The authors included relevant studies after screening the abstracts. Additional references to the selected studies were included where applicable. Data were extracted from the final articles according to the preplanned outline of the review.

RESULTS

The initial search yielded 279 abstracts. The final review included 93 articles. TED and DM interact at multiple levels-genetic, immunologic, cellular, nutritional, and metabolic. Both DM and thyroid dysfunction exacerbate the morbidity caused by the other. Metabolic factors also affect the inflammatory pathway for TED. Patients with DM develop TED with greater frequency and severity, necessitating interventions for vision salvage. Agents (GC, teprotumumab, or radiation) used for TED are often unsuitable for treatment with DM, especially if there is poor glycemic control or diabetic retinopathy. There were no studies on using steroid-sparing agents in TED with DM.

CONCLUSION

TED and DM co-exist because of multiple intersections in the pathophysiology. Challenges in the treatment include increased TED severity and risk of hyperglycemia and retinopathy. Multidisciplinary teams best undertake treatment of TED with DM.

Teprotumumab for the Treatment of Recalcitrant Thyroid Eye Disease

PURPOSE

Teprotumumab, an insulin-like growth factor 1 receptor monoclonal antibody, is FDA-approved to treat thyroid eye disease (TED). The initial clinical trials excluded patients with previous orbital irradiation, surgery, glucocorticoid use (cumulative dose >1 gm), or prior biologic treatment. Information on the use of teprotumumab for patients who failed prior therapy is limited. Our purpose is to characterize the efficacy of teprotumumab for the treatment of recalcitrant TED.

METHODS

This is a multicenter retrospective study of all patients treated with teprotumumab for moderate-to-severe TED after failing conventional therapy with corticosteroids, orbital radiation, surgical decompression, biologics, or other steroid-sparing medications. Treatment failure was defined as an incomplete response to or reactivation after previous treatment. Only patients who received at least 4 infusions of teprotumumab were included in the analysis. Primary outcome measures comprised proptosis response (≥2 mm reduction in the study eye without a similar increase in the other eye), clinical activity score (CAS) response (≥2-point reduction in CAS), and diplopia response (≥1 point improvement in Gorman diplopia score in patients with baseline diplopia) following treatment. Adverse events and risk factors for recalcitrant disease were also evaluated.

RESULTS

Sixty-six patients were included in this study, 46 females and 20 males. Average age was 59.3 years (range 29-93). The mean duration of disease from TED diagnosis to first infusion was 57.8 months. The proptosis, CAS, and diplopia responses in this recalcitrant patient population were 85.9%, 93.8%, and 69.1%, respectively. Patients experienced a mean reduction in proptosis of 3.1 ± 2.4 mm and a mean improvement in CAS of 3.8 ± 1.6. Patients who underwent prior decompression surgery experienced a statistically significant decrease in diplopia response (46.7% vs. 77.5%, p = 0.014) and proptosis response (75.0% vs. 90.9%, p = 0.045) when compared with nondecompression patients. Additionally, there were no significant differences in proptosis, CAS, and diplopia responses between patients with acute (defined as disease duration <1 year) versus chronic (disease duration ≥1 year) TED. While most adverse events were mild to moderate, 4 patients reported serious adverse events related to persistent hearing loss.

CONCLUSIONS

Patients with recalcitrant TED demonstrated a significant improvement after teprotumumab in each of the primary study outcomes. The degree of proptosis reduction, diplopia response, and CAS improvement in the recalcitrant group were similar to those of treatment-naïve patients from the pivotal clinical trials. Patients with a prior history of orbital decompression, however, demonstrated poor improvement in diplopia and less reduction in proptosis than surgery naïve patients. These results indicate that teprotumumab is a treatment option for the treatment of patients with TED recalcitrant to prior medical therapies.

The Adverse Effects Profile of Teprotumumab

CONTEXT

Teprotumumab therapy for thyroid eye disease (TED) patients represents a major step forward. It targets and inhibits the insulin-like growth factor-1 receptor (IGF-1R), and its effectiveness is based on its interconnectedness with the thyrotropin receptor. However, IGF-1R has a ubiquitous expression and several adverse effects have been reported with teprotumumab use.

OBJECTIVE

Describing these adverse effects for better understanding is the purpose of this review.

METHODS

We reviewed the oncological studies in which teprotumumab was initially used. Subsequently we reviewed the clinical trials for TED and then the case series and case reports associated with teprotumumab use since it is US Food and Drug Administration approval (January 2020). We focused on common and/or serious adverse effects reported with the use of teprotumumab.

RESULTS

We described the common occurrence of hyperglycemia (10%-30% incidence), its risk factors and suggested management. Hearing changes are described, a broad spectrum from mild ear pressure to hearing loss (sensorineural mechanism). Risk factors, suggested monitoring, and possible upcoming therapies are reviewed. We also reviewed data on fatigue, muscle spasms, hair loss, weight loss, gastrointestinal disturbances, menstrual changes, and infusion reactions. We noted some discrepancies between adverse effects in oncological studies vs studies focused on TED, and we aimed to explain these differences.

CONCLUSION

The use of teprotumumab should consider patient's values and preferences in balancing the expected benefit with these potential risks. Future drugs targeting IGF-1R should investigate these adverse effects for a possible class effect. Combination therapies with different agents hopefully will be identified that maximize benefits and minimize risks.