Corneal in vivo confocal microscopy to detect belantamab mafodotin-induced ocular toxicity early and adjust the dose accordingly: a case report

PLL-g-PEG Polymer Inhibits Antibody-Drug Conjugate Uptake into Human Corneal Epithelial Cells In Vitro

Purpose: Antibody-drug conjugates (ADCs) are a relatively recent advance in the delivery of chemotherapeutics that improve targeting of cytotoxic agents. However, despite their antitumor activity, severe ocular adverse effects, including vision loss, have been reported for several ADCs. The nonspecific uptake of ADCs into human corneal epithelial cells (HCECs) and their precursors via macropinocytosis has been proposed to be the primary mechanism of ocular toxicity. In this study, we evaluated the ability of a novel polymer, poly(l-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG), to decrease the ADC rituximab-mc monomethylauristatin F (MMAF) (RIX) uptake into human corneal epithelial (HCE-T) cells. Methods: HCE-T cells were exposed to increasing concentrations of RIX to determine inhibition of cell proliferation. HCE-T cells were treated with PLL-g-PEG, the macropinocytosis inhibitor 5-(N-ethyl-N-isopropyl) amiloride (EIPA), or vehicle. After 30 min of incubation, RIX was added. ADC was detected by fluorescent anti-human immunoglobulin G and fluorescently conjugated dextran as viewed by microscopy. Results: RIX caused dose-dependent inhibition of HCE-T cell proliferation. EIPA significantly reduced RIX uptake and decreased macropinocytosis as assessed by direct quantification of RIX using a fluorescently conjugated anti-human antibody as well as quantification of macropinocytosis using fluorescently conjugated dextran. PLL-g-PEG resulted in a dose-dependent inhibition of RIX uptake with half-maximal inhibitory concentrations of 0.022%-0.023% PLL-g-PEG. Conclusion: The data show PLL-g-PEG to be a potent inhibitor of RIX uptake by corneal epithelial cells and support its use as a novel therapeutic approach for the prevention of ocular adverse events associated with ADC therapy.

Corneal Toxicity in Patients Treated by BELANTAMAB MAFODOTIN: How to Improve and Facilitate Patients Follow-Up Using Refractive Shift?

Purpose: Multiple myeloma (MM) is the second most common neoplastic blood disease worldwide. Belantamab mafodotin is a new antibody conjugate anti-B-cell maturation antigen effective against refractory myelomas. It induces intracorneal microcysts leading to refractive fluctuations. The aim of this study is to assess the value of monitoring refractive fluctuations based on the location of microcystic-like epithelial changes (MECs) to facilitate patient follow-up. Methods: This observational and multicentric study was conducted using data collected from several French centers contacted through secure email through a standardized data collection table. Results: The fluctuation of objective refraction in spherical equivalent confirms a significant myopic shift from peripheral to central forms. A decrease in the best-corrected visual acuity (BCVA), an increase in keratometry, and an increase in central epithelial pachymetry have also been observed when MECs migrate toward the center. Conclusion: The myopization found in our study in patients with central and paracentral MECs is consistent with current literature. Fluctuations in BCVA, keratometry, and epithelial pachymetry are also consistent. This study is the first real-world study and highlights heterogeneity in follow-up, emphasizing the need to establish multidisciplinary follow-up strategies. The analysis of refractive fluctuations appears to be a reproducible and noninvasive screening method that could facilitate patient follow-up without the need for consultation focused on corneal diseases.

Visualization of Keratopathy Associated With the Antibody-Drug Conjugate Belantamab Mafodotin Using Infrared Imaging in Patients With Multiple Myeloma

PURPOSE

The treatment of patients with relapsed/refractory multiple myeloma (RRMM) with the antibody-drug conjugate belantamab mafodotin is affected by ocular adverse effects, most frequently keratopathy with corneal microcyst-like epithelial changes (MECs). To assess ocular side effects, the "Keratopathy and Visual Acuity (KVA) scale," based on the extent of keratopathy subjectively graded on slit-lamp examination and the change in best corrected visual acuity from baseline, was created. Advanced corneal imaging techniques have been explored to further characterize MECs and identify objective imaging biomarkers. We examined whether infrared reflectance imaging of the anterior segment (AS-IR) could contribute to the assessment, monitoring, and documentation of corneal toxicity in patients treated with belantamab mafodotin.

METHODS

In addition to the KVA examination, AS-IR imaging was performed. AS-IR images were evaluated for presence of visible hyporeflective lesions and their spatial and temporal distribution between visits and compared with keratopathy identified on slit-lamp examination. To standardize the assessment, a scoring system for lesions on AS-IR was implemented for additional analysis.

RESULTS

Nine patients undergoing treatment with belantamab mafodotin for up to 9 months were examined. All patients exhibited hyporeflective lesions on AS-IR imaging, indicative of corneal toxicity corresponding to MECs observed on slit-lamp examination. AS-IR lesions showed early occurrence, variable quantity and size, and distinct distribution patterns, correlating with clinical findings during treatment.

CONCLUSIONS

As shown for belantamab mafodotin, AS-IR imaging represents a fast, noninvasive, supplemental method for documentation, monitoring, and assessment of corneal adverse effects during treatment with antibody-drug conjugates, which may enable more standardized analyses.

Incidence and Mitigation of Corneal Pseudomicrocysts Induced by Antibody-Drug Conjugates (ADCs)

Purpose of Review

This study is to highlight the incidence of corneal pseudomicrocysts in FDA-approved antibody-drug conjugates (ADCs), and success of preventive therapies for pseudomicrocysts and related ocular surface adverse events (AEs).

Recent Findings

ADCs are an emerging class of selective cancer therapies that consist of a potent cytotoxin connected to a monoclonal antibody (mAb) that targets antigens expressed on malignant cells. Currently, there are 11 FDA-approved ADCs with over 164 in clinical trials. Various AEs have been attributed to ADCs, including ocular surface AEs (keratitis/keratopathy, dry eye, conjunctivitis, blurred vision, corneal pseudomicrocysts). While the severity and prevalence of ADC-induced ocular surface AEs are well reported, the reporting of corneal pseudomicrocysts is limited, complicating the development of therapies to prevent or treat ADC-related ocular surface toxicity.

Summary

Three of 11 FDA-approved ADCs have been implicated with corneal pseudomicrocysts, with incidence ranging from 41 to 100% of patients. Of the six ADCs that reported ocular surface AEs, only three had ocular substudies to investigate the benefit of preventive therapies including topical steroids, vasoconstrictors, and preservative-free lubricants. Current preventive therapies demonstrate limited efficacy at mitigating pseudomicrocysts and other ocular surface AEs.

Antibody-Drug Conjugates and Ocular Toxicity

Antibody-drug conjugates (ADCs) are a growing class of chemotherapeutic agents for the purpose of treating cancers that often have relapsed or failed first- and second-line treatments. ADCs are composed of extremely potent cytotoxins with a variety of side effects, one of the most significant being ocular toxicity. The available literature describes these toxicities as varying in severity and in incidence, although with disparate methods of evaluation and management. Some of the most common toxicities include microcyst-like epithelial keratopathy and dry eye. We discuss proposed mechanisms of ocular toxicity and describe the reports that mention these toxicities. We focus on ADCs with the most published literature and the most significant effects on ocular tissue. We propose areas for further investigation and possible ideas of future management. We provide a comprehensive look at the reports of ADCs in current literature to better inform clinicians on an expanding drug class.

Ocular surface toxicities associated with modern anticancer therapies

Cancer treatments have recently shifted from broad-spectrum cytotoxic therapies to more focused treatments, maximizing anti-cancerous activity while reducing toxicity to healthy cells. These modern anticancer therapies (MATs) encompass a wide range of innovative molecules that mainly include immune checkpoint inhibitors (ICIs) and targeted anticancer therapies (TATs), comprising antibody drug conjugates (ADCs) and inhibitors of signal transduction (IST). Some MATs are associated with ocular surface (OS) adverse events (AEs) that can cause severe discomfort and even lead to loss of vision. While these complications remain rare, they're probably underreported. It is likely that both oncologists and ophthalmologists will come across MATs-associated OS-AEs in their practices, due to the increasing number of patients being treated with MATs. Rapid identification of OS-AEs is crucial, as early intervention can manage these conditions to avoid vision loss and reduce negative impacts on quality of life (QoL). We discuss characteristics of OS pathologies attributed to MATs, describe the suspected underlying pathophysiological mechanisms, and outline the main lines of treatment.

Management of Belantamab Mafodotin-Associated Keratopathy With Rigid Gas-Permeable Corneal Contact Lenses

ABSTRACT

Belantamab mafodotin is a relatively new drug used in the treatment of relapsed or refractory multiple myeloma. Clinical studies have shown promising responses, but ocular toxicity remains a major challenge with dose reduction or therapy discontinuation being the only available treatment option. We report a clinical case of a patient with severe keratopathy under therapy with belantamab. The use of rigid gas-permeable corneal contact lenses led to a major visual improvement and enabled therapy continuation at full dose over several months. Although this strategy may not be suitable for all patients, it provides an additional option for the treatment of ocular toxicity of this promising agent.

Dupilumab-Induced, Tralokinumab-Induced, and Belantamab Mafodotin-Induced Adverse Ocular Events-Incidence, Etiology, and Management

ABSTRACT

Emerging monoclonal antibody therapies are assuming greater importance in the management of severe and refractory forms of immunity-driven and oncological disorders. However, some have been found to induce adverse ocular events (AOEs) leading to discontinuation of treatment or additional multidisciplinary management. We present the current knowledge concerning AOEs associated with 3 monoclonal antibody therapies: dupilumab, tralokinumab, and belantamab mafodotin. We examine the manifestations of their AOEs, proposed pathophysiological mechanisms, and current treatment recommendations. We identified and reviewed all studies for dupilumab, tralokinumab, and belantamab mafodotin using the keywords "dupilumab," "tralokinumab," "belantamab mafodotin," "conjunctivitis," and "keratopathy" from January 2016 to November 2021. Conjunctivitis was the most frequently reported AOE in patients with atopic dermatitis receiving dupilumab or tralokinumab. Mild cases were managed with warm compresses for associated meibomian gland dysfunction, artificial tears, and antihistamine/mast cell stabilizer eye drops. In more severe cases, additional anti-inflammatory therapy, with corticosteroid eye drops or ointments, or topical calcineurin inhibitors-such as tacrolimus or ciclosporin-were required. Patients with resistant or refractory multiple myeloma treated with belantamab mafodotin often developed keratopathy, which could necessitate contact lens fitting, or for cycles of belantamab mafodotin to be delayed.

Strategies for Prevention and Management of Ocular Events Occurring With Mirvetuximab Soravtansine

Mirvetuximab soravtansine (MIRV) is a first-in-class antibody-drug conjugate (ADC) targeting folate receptor alpha (FRα) and is indicated for the treatment of adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1 to 3 prior systemic treatment regimens. MIRV has demonstrated single-agent anticancer activity in clinical trials, with a differentiated safety profile comprising primarily low-grade, resolvable gastrointestinal and ocular adverse events (AEs). Pooled safety analysis of 464 MIRV-treated patients across 3 trials, including the phase 2 SORAYA study, found that 50% of patients had ≥1 ocular AEs of interest (AEIs) of blurred vision or keratopathy, the majority being grade ≤2. Grade 3 ocular AEIs occurred in 5% of patients, and 1 patient (0.2%) had a grade 4 event of keratopathy. All grade ≥2 AEIs of blurred vision and keratopathy resolved to grade 1 or 0 in patients with complete follow-up data. MIRV-associated ocular AEs were primarily characterized by resolvable changes to the corneal epithelium, with no cases of corneal ulcers or perforations. This reflects the distinctive, milder ocular safety profile for MIRV compared with that of other ADCs with ocular toxicities in clinical use. To maintain a generally low incidence of severe ocular AEs, patients should follow recommendations for maintaining ocular surface health, including daily use of lubricating eye drops and periodic use of corticosteroid eye drops, and should undergo an eye examination at baseline, at every other cycle for the first 8 cycles of treatment, and as clinically indicated. Dose modification guidelines should be followed to maximize patients' ability to remain on therapy. Close collaboration between all care team members, including oncologists and eye care professionals, will help patients benefit from this novel and promising anticancer agent. This review focuses on the etiology, rates, prevention, and management of MIRV-associated ocular events.

Corneal toxicity associated with belantamab mafodotin is not restricted to the epithelium: neuropathy studied with confocal microscopy

PURPOSE

The purpose of this study was to investigate epithelial and neuronal changes in patients with refractory/relapsed multiple myeloma (RRMM) before/during belantamab mafodotin (belamaf) treatment using confocal microscopy.

DESIGN

Retrospective case series.

METHODS

RRMM patients underwent best corrected visual acuity (BCVA) testing and slit-lamp examination/photography, followed by corneal confocal microscopy (CCM) to evaluate the epithelium and subbasal nerve plexus (SNP) to measure corneal nerve fiber density (CNFD), -branch density (CNBD), and -fiber length (CNFL) before and during belamaf treatment.

RESULTS

In 14 eyes of 7 patients (4 female, 68±10 years) with complete follow-up (4±2 months), the median BCVA dropped from 20/25 (20/25-20/20) to 20/40 (20/200-20/32) in the worse eye at the end of follow-up. Microcystic epithelial changes and ocular surface disease were demonstrated biomicroscopically. CCM showed "grape-like" hyperreflective spots in the central basal epithelium that changed to polymorphous-structured cysts in the superficial epithelium, with no pathology detected at the(peri-)limbal structures. The baseline, normal SNP morphology with a mean CNFD, CNBD, and CNFL of 20.25±7.06/mm², 19.49±12.34/mm², and 11.8±3.74mm/mm² respectively, showed severe fiber fragmentation during follow-up, and an observed complete loss of the SNP at the end of follow-up in all eyes.

CONCLUSIONS

This study is the first to illustrate neurotoxic effects of belamaf on the human cornea.

Corneal Findings Associated to Belantamab-Mafodotin (Belamaf) Use in a Series of Patients Examined Longitudinally by Means of Advanced Corneal Imaging

Belantamab mafodotin (belamaf) is a novel antibody–drug conjugate developed for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). Although the drug has demonstrated a good efficacy, corneal adverse events have been reported. In this prospective study, consecutive patients with RRMM who received belamaf infusions were included. The standard ophthalmological visit was implemented with anterior segment (AS)-optical coherence tomography (OCT) and in vivo confocal microscopy (IVCM). Five patients (three males, two females; mean age 66 ± 6.0 years) with MMRR and unremarkable ocular findings at baseline who received belamaf infusion were included. After a median time of 28 days from the first infusion, four of them developed corneal alterations with transient vision reduction to a variable extent. In particular, corneal deposits of microcyst-like epithelial changes (MECs) were detected centrally in one patient and peripherally in three patients. AS-OCT scans showed a bilateral heterogeneous increase in signal intensity, together with hyper-reflective lesions confined within the epithelium in all cases, except for one case in which they also involved the stroma. Corneal maps showed a transient increase in epithelial thickness in the first phase that was followed by a diffuse decrease in the subsequent phase. IVCM scans showed MECs as hyper-reflective opacities located at the level of corneal epithelium, largely intracellular. Multimodal corneal imaging may implement the current clinical scale, helping us to detect corneal abnormalities in patients under belamaf therapy. This workup provides useful data for monitoring over time corneal findings and for optimizing systemic therapy.