Effect of inhibition of the FGFR–MAPK signaling pathway on the development of ocular toxicities

Retinopathy Associated With Hair Dye

This case report describes a woman who presented with bilateral blurry vision a few days after dyeing her hair with hair dye containing aromatic amines.

Early Optical Coherence Tomography Signs of Erdafitinib-Induced Retinopathy

A 64-year-old male presented for a baseline ophthalmic exam before beginning erdafitinib, a fibroblast growth factor receptor (FGFR) inhibitor, for stage 4 papillary urothelial cancer. Baseline optical coherence tomography (OCT) and ophthalmic examination were unremarkable. After one month of treatment, his OCT demonstrated a significant thickening of the ellipsoid zone and prominence of the interdigitation zones along with a small amount of subretinal fluid. Two months after discontinuation of the medication, the OCT returned to baseline. Erdafitinib is a Food and Drug Administration (FDA)-approved treatment for unresectable or metastatic urothelial cancer with FGFR2 or FGFR3 mutations. However, retinal toxicity can ensue with the initiation of the drug and cause subjective vision changes and OCT abnormalities. The drug may exert toxic effects on retinal pigment epithelium, which may be seen through interval OCTs and visualization of the interdigitation zone. Therefore, pronunciation of the ellipsoid and interdigitation zone on OCT may allow for surveillance of early manifestations of erdafitinib-induced retinal toxicity.

Safety and Efficacy of Encorafenib, Binimetinib, and Cetuximab for BRAFV600E-Mutant Metastatic Colorectal Cancer: Results of the Japanese Expanded Access Program

BACKGROUND

The phase 3 BEACON CRC study demonstrated the survival benefits of encorafenib and cetuximab, with or without binimetinib (the BEACON triplet or doublet regimen), for BRAFV600E-mutant metastatic colorectal cancer (mCRC). This expanded access program (EAP) and subsequent follow-up study assessed the efficacy and safety of the BEACON triplet regimen in Japanese patients with BRAFV600E-mutant mCRC.

MATERIALS AND METHODS

The EAP was an open-label, single-arm study including Japanese patients with BRAFV600E-mutant mCRC whose disease progressed after 1 to 2 prior regimens. The patients received the BEACON triplet regimen with 28-day cycles. The subsequent follow-up study assessed the survival outcomes following EAP completion. Safety was assessed only during the EAP.

RESULTS

Among the 86 enrolled patients, 81 received the BEACON triplet regimen. The objective response rate and median progression-free survival were 27.6% (95% confidence interval [CI], 18.0%-39.1%) and 5.26 (95% CI, 4.14-5.52) months, respectively. Grade 3 to 4 adverse events and treatment-related adverse events occurred in 43.2% and 28.4% of patients, respectively. No new safety signals were observed during the EAP. Among 58 patients with confirmed survival at EAP completion, 57 were included in the follow-up study. With a median observation period of 9.17 months through the EAP and follow-up study, the median overall survival was 10.38 (95% CI, 9.00-16.16) months.

CONCLUSION

The efficacy and safety of the BEACON triplet regimen in Japanese patients with BRAFV600E-mutant mCRC were consistent with those reported in the BEACON CRC trial, supporting its use as a standard treatment for pretreated patients with BRAFV600E-mutant mCRC.

Erdafitinib-associated retinal alterations and rapid onset bilateral white cataracts

Purpose

This report aims to highlight the wide spectrum of ophthalmic adverse events associated with erdafitinib, a fibroblast growth factor inhibitor that blocks activation of the mitogen-activated protein kinase kinase (MAPK/MEK) cascade. The purpose of this report is to describe a case of erdafitinib-associated bilateral outer retinal alterations in the MEK-associated retinopathy spectrum and rapid onset bilateral total cataracts following a 20-month course of erdafitinib therapy.

Observations

A 69 year old male with metastatic bladder cancer presented 47 days following treatment initiation with daily erdafitinib (8-mg) with mild new subretinal fluid and minimal associated subretinal debris in the left eye and accentuation/thickening of the interdigitation zone in the right eye. Over the course of treatment, improvements were noted, particularly with erdafitinib dose reduction. At 20 months, both eyes developed rapidly progressive mature cataracts with significant visual changes, necessitating bilateral cataract extraction.

Conclusions and importance

The potential stability of moderate outer retinal changes (i.e., ellipsoid zone/interdigitation zone, subretinal fluid) while continuing erdafitinib therapy is highlighted in this report. In addition, the importance of continued ophthalmic surveillance is emphasized given the possible association of anterior segment adverse events with long-term erdafitinib use.

Pan fibroblast growth factor receptor inhibitor associated retinopathy

PURPOSE

To report a case of Fibroblast Growth Factor Receptor inhibitor (FGFRi) associated retinopathy in a patient treated with Erdafitinib.

CASE REPORT

A patient with a history of non-muscle invasive urothelial carcinoma treated with Erdafitinib developed symptomatic unifocal bilateral serous retinal detachments (SRD) eight weeks after starting this new treatment. Six months after discontinuing the drug, the SRDs resolved and visual acuity recovered to baseline. However, hyper and hypo auto fluorescent lesions were still visible on fundus autofluorescence, suggesting a still ongoing retinal pigment epithelium (RPE) impairment.

CONCLUSIONS

Cancer treatments using FGFRi are showing promising results but their ocular toxicity is not well reported nor fully understood. Oncologists should be aware of the potential risks associated with FGFRi and involve ophthalmologists for the follow-up of their patients. The toxicity of FGFRi seems to resolve after drug continuation, but a certain degree of infra clinical RPE impairment may persist. Longer term follow-ups are warranted to further understand the effects of FGFRi on the RPE.

Safety Profile and Adverse Event Management for Futibatinib, An Irreversible FGFR1-4 Inhibitor: Pooled Safety Analysis of 469 Patients

PURPOSE

Futibatinib, a covalently-binding inhibitor of fibroblast growth factor receptor (FGFR)1-4 gained approval for the treatment of refractory, advanced intrahepatic cholangiocarcinoma (iCCA) harboring an FGFR2 fusion/other rearrangement. An integrated analysis was performed to evaluate safety and provide guidance on the management of futibatinib-associated adverse events (AEs) in patients with unresectable/metastatic tumors, including iCCA.

PATIENTS AND METHODS

Data from three global phase I or II studies of futibatinib (NCT02052778; JapicCTI-142552) were pooled. AEs were graded per NCI CTCAE v4.03, where applicable. Safety was analyzed for patients receiving any futibatinib starting dose (overall population) and in those receiving the approved starting dose of 20 mg once every day.

RESULTS

In total, 469 patients with one of 33 known tumor types were analyzed, including 318 patients who received futibatinib 20 mg every day. AEs of clinical interest (AECI; any grade/grade ≥3) in the overall population included hyperphosphatemia (82%/19%), nail disorders (27%/1%), hepatic AEs (27%/11%), stomatitis (19%/3%), palmar-plantar erythrodysesthesia syndrome (PPES; 13%/3%), rash (9%/0%), retinal disorders (8%/0%), and cataract (4%/1%). Median time to onset of grade ≥3 AECIs ranged from 9 days (hyperphosphatemia) to 125 days (cataract). Grade ≥3 hyperphosphatemia, hepatic AEs, PPES, and nail disorders resolved to grade ≤2 within a median of 7, 7, 8, and 28 days, respectively. Discontinuations due to treatment-related AEs were rare (2%), and no treatment-related deaths occurred. AE management included phosphate-lowering medication and dose adjustments.

CONCLUSIONS

Futibatinib showed a consistent and manageable safety profile across patients with various tumor types. AECIs were mostly reversible with appropriate clinical management.

IRREVERSIBLE RETINAL PIGMENT EPITHELIUM TOXICITY ASSOCIATED WITH FIBROBLAST GROWTH FACTOR RECEPTOR INHIBITOR THERAPY

PURPOSE

Erdafitinib is a fibroblast growth factor receptor inhibitor indicated for the treatment of cancer. A case of fibroblast growth factor receptor inhibitor-associated retinopathy that resulted in significant visual symptoms and chronic subretinal abnormalities is reported.

METHODS

A 73-year-old man with a history of relapsed multiple myeloma was treated with erdafitinib. Soon after his fourth treatment cycle, he developed blurred vision in both eyes. Therapy with erdafitinib was subsequently discontinued.

RESULTS

Funduscopic examination and optical coherence tomography of both eyes revealed multifocal subretinal fluid in the macula of both eyes. Eleven weeks after cessation of the erdafitinib, the visual acuity improved but the patient reported bilateral annular scotomas. Evaluation was notable for resolution of the subretinal fluid with the development irregular subfoveal thickening in both eyes. The patient's symptoms improved, but the subfoveal abnormalities were persistent at 14 months follow-up.

CONCLUSION

Erdafitinib may be associated with permanent retinal pigment epithelium toxicity.

Case report: Pemigatinib-induced retinopathy: a serial examination of subretinal fluid secondary to an FGFR inhibitor

Background

Modern chemotherapeutic agents continue to evolve as modern monoclonal antibody treatments are designed to directly target proteins, enzymes, and focal loci. A particular class of these medications, fibroblast growth factor (FGFR) inhibitors, specifically pemigatinib (Pemazyre®; Incyte), has been approved by the US Food and Drug Administration since April 2020 for the treatment of advanced or metastatic cholangiocarcinoma. As it is a relatively new medication, its side-effect profile is manifesting in active clinical practice. The presence of FGFR receptors in the retinal pigment epithelium makes the retina susceptible to potential adverse effects secondary to pemigatinib use.

Case presentation

A 69-year-old African-American male with a tumor mutation burden 3 (TMB-3) metastatic adenocarcinoma of the liver from primary cholangiocarcinoma, who was undergoing chemotherapy with pemigatinib, was found to have asymptomatic bilateral subretinal fluid accumulation. Serial monitoring with optical coherence tomography (OCT) demonstrated complete resolution of the subretinal fluid while off-cycle and asymptomatic re-accumulation of subretinal fluid while on-cycle, with no significant changes in visual acuity.

Conclusions

Subretinal fluid accumulation secondary to pemigatinib may develop during the active treatment cycles without causing any significant visual symptoms for the patient. Serial monitoring demonstrates fluctuations of subretinal fluid during the patient's on- and off-cycles. This case strengthens the current guidelines for continuing pemigatinib in asymptomatic patients found to have subretinal fluid. Further studies are warranted to identify patients who may be at higher risk for developing subretinal fluid.

Dissimilar Effect of P-Glycoprotein and Breast Cancer Resistance Protein Inhibition on the Distribution of Erlotinib to the Retina and Brain in Humans and Mice

P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are two ATP-binding cassette efflux transporters that are coexpressed at the human blood-brain barrier (BBB) and blood-retina barrier (BRB). While pharmacological inhibition of P-gp and/or BCRP results in increased brain distribution of dual P-gp/BCRP substrate drugs, such as the tyrosine kinase inhibitor erlotinib, the effect of P-gp and/or BCRP inhibition on the retinal distribution of such drugs has hardly been investigated. In this study, we used positron emission tomography (PET) imaging to assess the effect of transporter inhibition on the distribution of [11C]erlotinib to the human retina and brain. Twenty two healthy volunteers underwent two PET scans after intravenous (i.v.) injection of a microdose (<5 μg) of [11C]erlotinib, a baseline scan, and a second scan either with concurrent i.v. infusion of tariquidar to inhibit P-gp (n = 5) or after oral intake of single ascending doses of erlotinib (300 mg, 650 mg, or 1000 mg, n = 17) to saturate erlotinib transport. In addition, transport of [3H]erlotinib to the retina and brain was assessed in mice by in situ carotid perfusion under various drug transporter inhibition settings. In comparison to the baseline PET scan, coadministration of tariquidar or erlotinib led to a significant decrease of [11C]erlotinib total volume of distribution (VT) in the human retina by -25 ± 8% (p ≤ 0.05) and -41 ± 16% (p ≤ 0.001), respectively. In contrast, erlotinib intake led to a significant increase in [11C]erlotinib VT in the human brain (+20 ± 16%, p ≤ 0.001), while administration of tariquidar did not result in any significant changes. In situ carotid perfusion experiments showed that both P-gp and BCRP significantly limit the distribution of erlotinib to the mouse retina and brain but revealed a similar discordant effect at the mouse BRB and BBB following co-perfusion with tariquidar and erlotinib as in humans. Co-perfusion with prototypical inhibitors of solute carrier transporters did not reveal a significant contribution of organic cation transporters (e.g., OCTs and OCTNs) and organic anion-transporting polypeptides (e.g., OATP2B1) to the retinal and cerebral distribution of erlotinib. In conclusion, we observed a dissimilar effect after P-gp and/or BCRP inhibition on the retinal and cerebral distribution of [11C]erlotinib. The exact mechanism for this discrepancy remains unclear but may be related to the function of an unidentified erlotinib uptake carrier sensitive to tariquidar inhibition at the BRB. Our study highlights the great potential of PET to study drug distribution to the human retina and to assess the functional impact of membrane transporters on ocular drug distribution.

Challenges in posterior uveitis-tips and tricks for the retina specialist

PURPOSE

Posterior uveitis is a common chorioretinal pathology affecting all ages worldwide and is a frequent reason for referral to the retina clinic. The spectrum of etiologies for uveitis is very broad and includes infectious and auto-immune diseases. Inflammation can be confined to the eye or may be a part of systemic disease. A useful outline is therefore proposed to aid in the correct diagnosis of these challenging entities. The situation is further complicated by the fact that many neoplastic conditions resemble features of posterior uveitis; they are known as "masqueraders of uveitis". Here, we summarize different posterior uveitides that present with rare findings, along with masqueraders that can be difficult to distinguish. These conditions pose a diagnostic dilemma resulting in delay in treatment because of diagnostic uncertainty.

METHODS

An extensive literature search was performed on the MEDLINE/PUBMED, EBSCO and Cochrane CENTRAL databases from January 1985 to January 2022 for original studies and reviews of predetermined diagnoses that include posterior uveitic entities, panuveitis and masquerade syndromes.

RESULTS

We described conditions that can present as mimickers of posterior uveitis (i.e., immune check-points inhibitors and Vogt-Koyanagi-Harada-like uveitis; leukemia and lymphoma associated posterior uveitis), inflammatory conditions that present as mimickers of retinal diseases (i.e., Purtscher-like retinopathy as a presentation of systemic lupus erythematosus; central serous chorioretinopathy masquerading inflammatory exudative retinal detachment), and uveitic conditions with rare and diagnostically challenging etiologies (i.e., paradoxical inflammatory effects of anti-TNF-α; post vaccination uveitis; ocular inflammation after intravitreal injection of antiangiogenic drugs).

CONCLUSION

This review of unique posterior uveitis cases highlights the overlapping features of posterior uveitis (paradoxical inflammatory effects of anti -TNF α and uveitis; Purtscher-like retinopathy as a presentation of systemic lupus erythematosus, …) and the nature of retinal conditions (ischemic ocular syndrome, or central retinal vein occlusion, amyloidosis, inherited conditions like retinitis pigmentosa, autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV), etc.…) that may mimic them is represented. Careful review of past uveitis history, current medications and recent vaccinations, detailed examination of signs of past or present inflammation, eventually genetic testing and/ or multimodal retinal imaging (like fluorescein angiography, EDI-OCT, OCT-angiography for lupus Purtscher-like retinopathy evaluation, or ICG for central serous retinopathy, or retinal amyloid angiopathy) may aid in correct diagnosis.

Serous Retinopathy Associated With Combination MEK and Fibroblast Growth Factor Receptor Inhibitor

Purpose: To present a case of a chemotherapy regimen combining a fibroblast growth factor receptor (FGFR) and mitogen-activated protein kinase kinase (MEK) inhibitor leading to serous retinopathy. Methods: A retrospective chart review of a single case was performed. Results: A 67-year-old man with pancreatic and prostate cancer developed bilateral multifocal pockets of subretinal fluid while on an experimental chemotherapy regimen combining an MEK inhibitor (trametinib) and an FGFR inhibitor (erdafitinib). Conclusions: Given that FGFR lies upstream to the mitogen-activated protein kinase signaling pathway, retinal toxicity may be more severe and more common with FGFR-MEK combination therapy. Future studies are necessary to guide ophthalmic surveillance.

Past, present, and future of FGFR inhibitors in cholangiocarcinoma: from biological mechanisms to clinical applications

INTRODUCTION

Biliary tract carcinoma (BTC) is a heterogenous group of aggressive hepatic malignancies, second to hepatocellular carcinoma per prevalence. Despite clinical research advancement, the overall 5-year survival rate is just above 2%. With the identification of somatic core mutations in half of cholangiocarcinomas. In the intrahepatic subtype (iCCA), it is possible to target mutational pathways of pharmacological interest.

AREAS COVERED

Major attention has been drawn to fibroblast growth factor receptor (FGFR), especially the type 2 (FGFR2), found mutated in 10-15% of iCCAs. FGFR2 fusions became the target of novel tyrosine-kinase inhibitors investigated in clinical studies, showing promising results so as to gain regulatory approval by American and European committees in recent years. Such drugs demonstrated a better impact on the quality of life compared to standard chemotherapy; however, side effects including hyperphosphatemia, gastrointestinal, eye, and nail disorders are common although mostly manageable.

EXPERT OPINION

As FGFR inhibitors may soon become the new alternative to standard chemotherapy in FGFR-mutated cholangiocarcinoma, accurate molecular testing and monitoring of acquired resistance mechanisms will be essential. The possible application of FGFR inhibitors in first-line treatment, as well as in combination with current standard treatments, remains the next step to be taken.

Ocular adverse events associated with BRAF and MEK inhibitor combination therapy: a pharmacovigilance disproportionality analysis of the FDA adverse event reporting system

BACKGROUND

BRAF and MEK inhibitor combination therapy have significantly improved the outcome of several BRAF-mutation tumors, but it also confers the risk of drug-induced ocular adverse events (oAEs). However, very few studies focused on this risk.

METHODS

The United States Food and Drug Administration Adverse Event Reporting System (FAERS) data from Quarter 1-2011 to Quarter 2-2022 were searched to detect signs of oAEs of three marketed BRAF and MEK inhibitor combination therapies: vemurafenib plus cobimetinib (V + C), dabrafenib plus trametinib (D + T), and encorafenib plus binimetinib (E + B). Disproportionality analyses were performed by calculating the proportional reporting ratio (PRR), χ2 (chi-square), and reporting odds ratios (RORs) with a 95% confidence interval (CI).

RESULTS

A series of oAEs were identified, including 42 preferred terms, which could be classified into 8 aspects. In addition to previously reported oAEs, several unexpected oAE signals were detected. Moreover, differences in oAE profiles were found among three combination therapies (V + C, D + T, and E + B).

CONCLUSIONS

Our findings support an association between several oAEs and BRAF and MEK inhibitor combination therapies, including several new oAEs. In addition, oAEs profiles may vary across the treatment regimens. Further studies are needed to better quantify these oAEs.

Encorafenib, binimetinib, and cetuximab in BRAF V600E-mutated colorectal cancer: an early post-marketing phase vigilance study

BACKGROUND

Triplet and doublet regimens of encorafenib plus cetuximab with and without binimetinib, respectively, were approved in Japan for unresectable, metastatic, BRAF V600E-mutated colorectal cancer (mCRC) that had progressed after 1-2 prior chemotherapies. This early post-marketing phase vigilance (EPPV) study collected adverse drug reactions (ADRs) from Japanese patients to ensure safety measures as appropriate.

METHODS

Patients with BRAF V600E mCRC who received the triplet or doublet regimens in Japan were selected for this study. ADRs were collected as spontaneous reports between November 27, 2020 and May 26, 2021. Serious ADRs were evaluated according to guidelines of the International Council for Harmonisation and the EudraVigilance list of Important Medical Event Terms.

RESULTS

An estimated 550 Japanese patients with mCRC received the triplet or doublet regimens during the 6-month EPPV period. Overall, 101 and 42 patients reported ADRs and serious ADRs, respectively. No ADRs leading to death were reported. The most frequently reported ADRs were nausea (17 patients), serous retinal detachment (16), decreased appetite (12), diarrhea (11), and vomiting (11). Among the important identified/potential risks that are defined in the risk management plans for encorafenib and binimetinib, eye disorder-related ADRs were observed in 32 patients, rhabdomyolysis-related ADRs in 12, hemorrhage-related ADRs in 7, and hepatic dysfunction-related ADRs in 7. Of 22 patients with serious eye disorders, 20 recovered or were recovering during the EPPV period.

CONCLUSION

The safety profile in this EPPV study was similar to that from the phase III BEACON CRC study and no new safety concerns were identified.

DCZ19931, a novel multi-targeting kinase inhibitor, inhibits ocular neovascularization

Neovascularization is a prominent cause of irreversible blindness in a variety of ocular diseases. Current therapies for pathological neovascularization are concentrated on the suppression of vascular endothelial growth factors (VEGF). Despite the remarkable efficacy of anti-VEGF drugs, several problems still exist, including ocular complications and drug resistance. Thus, it is still required to design novel drugs for anti-angiogenic treatment. This study aimed to investigate the anti-angiogenic effects of a small molecule multi-target tyrosine kinase inhibitor, DCZ19931, on ocular neovascularization. The results showed that administration of DCZ19931 at the tested concentrations did not cause obvious cytotoxicity and tissue toxicity. DCZ19931 could reduce the size of choroidal neovascularization (CNV) lesions in laser-induced CNV model and suppress ocular neovascularization in oxygen-induced retinopathy (OIR) model. DCZ19931 could suppress VEGF-induced proliferation, migration, and tube formation ability of endothelial cells, exhibiting similar anti-angiogenic effects as Ranibizumab. DCZ19931 could reduce the levels of intercellular cell adhesion molecule-1 (ICAM-1) expression in vivo and in vitro. Network pharmacology prediction and western blots revealed that DCZ19931 exerted its anti-angiogenic effects through the inactivation of ERK1/2-MAPK signaling and p38-MAPK signaling. In conclusion, this study indicates that DCZ19931 is a promising drug for anti-angiogenic therapy for ocular diseases.

Phase I study of the irreversible fibroblast growth factor receptor 1-4 inhibitor futibatinib in Japanese patients with advanced solid tumors

This phase I study was designed to: (1) determine the maximum tolerated dose (MTD) and recommended dose (RD) of the fibroblast growth factor receptor (FGFR) inhibitor futibatinib in Japanese patients with advanced solid tumors, and (2) examine the antitumor activity of the RD in patients with gastric cancer (GC) or other advanced solid tumors who have FGFR or FGF/FGFR abnormalities, respectively. In the dose-escalation phase, patients were assigned to 21-day cycles of oral futibatinib 8-160 mg three times a week (TIW) or 16 or 20 mg once daily (QD). In the expansion phase, patients received oral futibatinib 56, 80, or 120 mg TIW, or 16 or 20 mg QD. Eighty-three patients received futibatinib TIW (n = 40) or QD (n = 43). No dose-limiting toxicities were observed according to the final study protocol definition, and the MTD was not reached. The most common adverse events with both regimens were hyperphosphatemia (TIW, 82.5%; QD, 100.0%) and decreased appetite (TIW, 40.0%; QD, 58.1%). Hyperphosphatemia was asymptomatic, not leading to futibatinib discontinuation. The overall response rate (ORR) was 11.5% in patients with FGF/FGFR abnormalities. Notably, in GC patients harboring FGFR2 copy number (CN) ≥10, the ORR was 36.4% versus 0 in patients with CN <10. Therefore, futibatinib had a generally predictable and manageable safety profile in patients with advanced solid tumors. Antitumor activity was seen in patients with FGF/FGFR abnormalities, particularly those with GC and high FGFR2 CNs. Thus, futibatinib 20 mg QD was chosen as the RD for phase II studies.

Characterization of Serous Retinopathy Associated with Cobimetinib: Integrated Safety Analysis of Four Studies

INTRODUCTION AND OBJECTIVE

Serous retinopathy can be associated with MEK inhibitors, including cobimetinib. We present results of an integrated safety analysis to further characterize ocular functional and structural changes due to serous retinopathy.

METHODS

Four studies evaluating cobimetinib at the approved dose and schedule in combination with other oncology drugs were included. Study CO39721 incorporated standardized ophthalmologic assessments to fully characterize serous retinopathy events over time and was the primary study for analysis. Supporting information was provided by studies GO28141, WO29479, and GO30182.

RESULTS

In total, 655 patients received one or more doses of cobimetinib and comprised the safety-evaluable population. Overall, 117 patients (17.9%) had one or more serous retinopathy events, 24 (3.7%) had two or more events, and four (0.6%) had three or more events. Grade 3 events occurred in < 2.5% of patients. In CO39721, the median time to onset was 15 days (range 7-111); median time to resolution of first occurrence was 26 days (range 6-591 + days). Twelve of 25 patients (48.0%) recovered without a dose modification and 4/25 (16.0%) were recovered/recovering following a dose modification. The most frequent presentation of serous retinopathy was focal subretinal fluid on optical coherence tomography (62.8% of cases); in some instances (25.7% of cases), subretinal fluid was multifocal. There was no loss of visual function or visual acuity at serous retinopathy onset or resolution.

CONCLUSIONS

Results from this integrated safety analysis indicate that cobimetinib-associated serous retinopathy can be managed with or without a dose modification of cobimetinib at the discretion of the treating physician. No visual loss or permanent retinal damage was identified on comprehensive ophthalmologic assessments.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT03178851, NCT01689519, NCT02322814, and NCT02788279.

A Case of Bilateral Multifocal Choroiditis Associated with BRAF/MEK Inhibitor Use for Metastatic Cutaneous Melanoma

PURPOSE

To report a case of BRAF/MEK inhibitor-associated multifocal choroiditis that recurred after medication re-exposure and resolved after discontinuing BRAF/MEK inhibition and administering local steroid therapy.

CASE REPORT

A 32-year-old woman with metastatic cutaneous melanoma on dabrafenib/trametinib presented with bilateral anterior uveitis and new bilateral multifocal chorioretinal scars. The anterior uveitis resolved after a course of topical steroids. She presented 18 months later with reactivation of bilateral multifocal choroiditis after starting encorafenib/binimetinib 1 month prior. The chorioretinal lesions appeared elevated with associated vitreous cell. Indocyanine angiography showed numerous foci of new choroiditis, more pronounced in the left eye. Encorafenib/binimetinib was discontinued and a subtenon triamcinolone injection was administered to the left eye. Her symptoms improved and the choroiditis resolved.

CONCLUSION

BRAF/MEK inhibitors may be associated with ocular toxicity manifesting as multifocal choroiditis. The increasing use of these agents and risk of visual impairment warrants early detection and management.

Central retinal vein occlusion in the setting of fibroblast growth factor receptor inhibition

Purpose

To report a case of central retinal vein occlusion (CRVO) in a patient being treated with a fibroblast growth factor receptor (FGFR) inhibitor.

Observations

A 54-year-old female patient with endometrial cancer presented with CRVO and cystoid macular edema while receiving lenvatinib/pembrolizumab combination therapy. The patient received treatment with intravitreal bevacizumab, after which her visual acuity improved markedly, permitting the continuation of her chemotherapy regimen without recurrence of ocular adverse events.

Conclusions and Importance

Like mitogen-activated protein kinase inhibitors, FGFR inhibitors have the potential to be associated with retinal vein occlusion. In this case, visual recovery was possible with intravitreal anti-vascular endothelial growth factor therapy, and toxicity did not recur with drug reinitiation and continuation over five years of follow-up.

Favorable Management of Repeated Serous Retinal Detachment with Continued Tumor Response in a Patient with Intrahepatic Cholangiocarcinoma During Treatment with Pemigatinib: A Case Report

Pemigatinib is a fibroblast growth factor receptor inhibitor (FGFRi) approved for the treatment of patients with previously treated biliary tract cancer with FGFR2 fusion. Although infrequent, ocular toxicity manifested as serous retinal detachment (SRD) has been observed and is regarded as a serious side effect. We herein report the case of a 54-year-old woman with unresectable cholangiocarcinoma-initiated pemigatinib after failure of gemcitabine plus S-1 (GS). Although the patient experienced repeated SRD after pemigatinib, dose interruption and dose reduction of pemigatinib from 13.5 mg to 9 mg, and from 9 mg to 4.5 mg led to complete recovery of SRD, and continued tumor shrinkage.

Effects of systemic targeted immunosuppressive therapy on ocular surface

PURPOSE OF REVIEW

The purpose of this review is to give an overview of the corneal manifestations of targeted systemic immunotherapies and provide guidelines for management when applicable.

RECENT FINDINGS

The advent of newer systemic immunosuppressive therapy has resulted in the need for more awareness of potential ocular side effects. Side effects can range from vortex keratopathy as seen with the tyrosine kinase inhibitors, to epithelial microcysts as reported in the use of cytarabine and belantamab mafodotin, spontaneous corneal perforations have been reported with programmed death 1 inhibitors, while eyelid cicatrization has been reported epidermal growth factor inhibitors. Several immunomodulatory therapies result in conjunctivitis which tends to respond to topical lubrication and corticosteroid treatment. Most manifestations listed in the review are limited to the anterior segment; however, some may lead to retinal and optic nerve changes which can be permanently damaging.

SUMMARY

Ocular surface and corneal changes secondary to systemic immunosuppression can affect main components of the ocular surface. Although most adverse effects are reversible, few changes can be permanent and therefore close ophthalmologic monitoring is necessary.

Erdafitinib-Induced Secondary Maculopathy

Purpose:

This work presents a case of secondary maculopathy associated with the use of erdafitinib (Balversa) for the management of bladder urothelial carcinoma with bony metastasis.

Methods:

A case report is presented.

Results:

A 58-year-old Hispanic man presented with blurry vision 3 weeks after starting erdafitinib for the management of bony metastases associated with urothelial carcinoma. A comprehensive evaluation identified multiple areas of subretinal fluid induced by erdafitinib. Throughout treatment, the ocular condition progressed, causing worsening of vision; this led to discontinuation of the drug. Discontinuation was associated with visual and anatomic function improvement.

Conclusions:

Fibroblast growth factor receptor (FGFR) plays a major role in maintaining mature and premature retinal pigment epithelium cells. Drugs that inhibit the FGFR pathway block the activation of the mitogen-activated protein kinase pathway, leading to synthesis of antiapoptotic proteins. Erdafitinib is associated with ocular toxicity and leads to multifocal pigment epithelial detachments associated with secondary subretinal fluid.

Bilateral Serous Retinal Detachment Associated with a Mitogen-activated Protein KinaseKinase Inhibitor in a Patient with BRAF-mutant Colorectal Cancer

We herein report a 73-year-old woman with BRAF V600E-mutated colon cancer treated with encorafenib plus cetuximab with binimetinib as standard salvage therapy for patients with advanced colorectal cancer. She developed bilateral serous retinal detachment the next day, and the regimen was discontinued, resulting in complete resolution by the third day. Doublet therapy without binimetinib was initiated along with a weekly ophthalmologic examination for 10 weeks without recurrence of retinal detachment. Thus, binimetinib was presumed to have been the cause of the retinal detachment. This clinical course suggests the need for close monitoring of patients for vision impairment and close collaboration with ophthalmologists.

Differential gene expression analysis using RNA sequencing: retinal pigment epithelial cells after exposure to continuous-wave and subthreshold micropulse laser

PURPOSE

Subthreshold micropulse laser (SMPL) is more clinically efficient for the treatment of diabetic macular edema (DME) than the conventional continuous-wave (CW) laser. We aimed to characterize transcriptome changes after the application of these lasers and to compare the transcripts.

METHODS

Human pluripotent stem cell-derived retinal pigment epithelial cells were exposed to laser irradiation. Differentially expressed genes (DEGs), distribution of heat shock protein (Hsp) family, gene expression profile, and gene ontology (GO) enrichment analysis based on RNA sequencing data were investigated at 3 h and 24 h after irradiation.

RESULTS

CW laser induced more DEGs than SMPL (1771 vs. 520 genes). The expression of the Hsp family was confirmed in both groups: however, the induction patterns was different for different genes. GO enrichment analysis revealed that CW laser upregulated the expression of DEGs involved in vasculature development (GO: 0001944), related to apoptosis and repair after cell injury whereas SMPL upregulated the expression of DEGs involved in photoreceptor cell maintenance (GO: 0045494), photoreceptor cell development (GO: 0042461), and sensory perception of light stimuli (GO: 0050953).

CONCLUSIONS

The results provide insights into the genetic responses and may contribute to the understanding of the molecular mechanisms of laser-induced thermal effects.

HAIR DYE-INDUCED RETINOPATHY MIMICKING MEK-INHIBITOR RETINOPATHY

PURPOSE

To report a new toxic retinopathy related to the use of hair dye.

METHODS

Case reports of three patients with follow-up after exposure and until resolution.

RESULTS

There were three middle-aged women (32-66 year old) all of whom had bilateral moderate to severe vision loss and normal slit-lamp examination at presentation. Fundus examination showed bilateral multiple serous retinal detachments predominantly located in the posterior pole, with some pigment epithelial hypertrophy in chronic cases. Optical coherence tomography showed similar features as in MEK-inhibitor retinopathy. Electrooculogram performed in one patient showed abnormal Arden ratio. During follow-up, visual acuity improved with regression of the serous retinal detachments. The speed of resolution was proportional to the acuteness of the exposure to aromatic amines.

CONCLUSION

Hair dyes containing aromatic amines can be responsible for bilateral toxic retinopathy mimicking MEK-inhibitor retinopathy.

Ibrutinib-related uveitis: A case series

Purpose

Four cases of ibrutinib-related uveitis are presented, which are to the best of our knowledge the first in the literature. Possible mechanisms of ibrutinib-mediated uveitis are explored.

Observations

Case 1 is a 60-year-old female who had been stable on 1 year of ibrutinib for chronic lymphocytic leukaemia. She was diagnosed with ibrutinib-related uveitis, which responded well to topical steroids. Case 2 is a 63-year-old male diagnosed with uveitis after 2 years of ibrutinib treatment for chronic lymphocytic leukaemia. He responded well to topical and oral steroids; however, he continued to have uveitis relapses after weaning steroids. Case 3 is a 69-year-old male diagnosed with uveitis after 18 months of ibrutinib treatment. He was trialed on topical and intravenous steroids, and restarted ibrutinib without worsening of symptoms. Case 4 is a 66-year-old female who developed uveitis after being stable on ibrutinib for 3 years. She responded well to topical steroids.

Conclusions and Importance

Inflammatory complications of tyrosine kinase inhibitors are well described. While ibrutinib, and other kinase inhibitors, are generally well-tolerated, there are increasing reports of ocular toxicities, including uveitis. It is recommended to monitor patients for potential ocular adverse effects and facilitate rapid ophthalmologic assessment.

Choroidal and Choriocapillaris Morphology in Pan-FGFR Inhibitor-Associated Retinopathy: A Case Report

Emerging anticancer agents such as the pan-FGFR Inhibitor have achieved remarkable improvements in the survival of patients with metastatic malignancies. Nevertheless they are still associated with specific ophthalmic toxicities. Understanding their pathophysiology can lead us to better clinical practice of life-threatening and vision-threatening circumstances. To investigate choroidal alterations as a potential pathophysiological mechanism of a serous detachment in bilateral pan-FGFR Inhibitor-Associated Retinopathy (FGFRAR), the morphology of the choroid and choriocapillaris were assessed. The choroidal thickness (ChT) and choriocapillaris flow void were measured by macular optical coherence tomography (OCT) and angiography (OCT-A), respectively. Data were collected at the baseline, then at one-month and two-months follow-ups after starting erdafitinib, in a single case of pulmonary angiosarcoma. Choroidal and choriocapillaris morphology showed stable ChT and choriocapillaris flow void at FGFRAR onset and relapse. To the best of our knowledge, this is the first analyzed case reported with flow-void OCT-angiography. Considering these results, FGFRAR in this patient does not seem to match the pachychoroid spectrum disorder definition; rather, an intracellular mechanism based on intracellular transduction pathways may be at work.

[Pharmacological characteristics and clinical study results of Pemigatinib (Pemazyre® Tablets), a selective fibroblast growth factor receptor (FGFR) inhibitor]

Pemigatinib (Pemazyre^® Tablets 4.5 mg) is a novel fibroblast growth factor receptor (FGFR) inhibitor, created by Incyte Corporation. The product was approved in March 2021 and was launched in June 2021 for the treatment of patients with locally advanced or metastatic biliary tract cancer (BTC) with a fibroblast growth factor receptor 2 (FGFR2) fusion or rearrangement that has progressed after at least one prior line of systemic therapy. Pemigatinib was shown to selectively inhibit kinase activity of FGFR1～3 (IC₅₀; 0.39～1.2 nM). In cultured cells, pemigatinib inhibited the phosphorylation of FGFR1 and its downstream signals, ERK1/2 and STAT5 in a concentration-dependent manner. Pemigatinib also potently inhibited the growth of various types of cell lines with FGFR 1～3 gene alteration. Pemigatinib was shown to induce concentration-dependent tumor regression in a tumor xenograft model mice in which tumor tissue sections from patients with cholangiocarcinoma (CCA) harboring FGFR2 gene fusions were transplanted. Pemigatinib was well tolerated in Japanese and overseas Phase1 studies (INCB 54828-101 and 202). In the global phase2 study (INCB 54828-202) conducted in CCA patients with FGFR2 gene fusions or rearrangements, significant improvement in the overall response rate was observed. Although several adverse reactions were observed which was based on the mechanism of action of pemigatinib, the safety profile and management of the adverse reactions were favorable. Pemigatinib is expected to contribute to second-line drug treatment after failure of standard therapies in biliary tract cancer.

Quality of Life and Symptom Management in Advanced Biliary Tract Cancers

Biliary tract carcinomas (BTCs) account for less than 1% of all cancers but are increasing in incidence. Prognosis is poor for BTC patients, with 5-year survival rates of less than 10%. While chemotherapy has been the mainstay treatment for patients with advanced BTC, immunotherapy and targeted therapies are being evaluated in numerous clinical trials and rapidly incorporated into clinical practice. As patients with BTC have reduced health-related quality of life (HRQoL) due to both tumor- and treatment-related symptoms, it is important for clinicians to recognize and manage these symptoms early. This review will highlight the anticipated complications from BTC and its systemic treatment, as well as their effects on HRQoL.

Clinical and Morphologic Characteristics of Fibroblast Growth Factor Receptor Inhibitor-Associated Retinopathy

Importance

Fibroblast growth factor receptor (FGFR) 1 to 4 inhibitors are approved by the US Food and Drug Administration and suppress the mitogen-activated protein kinase (MAPK) pathway, with a potential for treatment-related retinopathy. To date, implications of FGFR inhibitor-associated ocular toxic effects are poorly described. Therefore, more detailed clinical descriptions of this ocular toxic effect could help explain visual symptoms while receiving drug therapy.

Objective

To describe the clinical and morphologic characteristics of serous retinal disturbances associated with FGFR inhibitors.

Design, Setting, and Participants

In this retrospective case series, 146 patients receiving FGFR inhibitors as cancer treatment at a single tertiary referral center were included. This study included 40 eyes of 20 patients with retinopathy by optical coherence tomography (OCT). OCTs were obtained on the remaining patients and the results were judged normal. Patients were recruited from March 2012 to January 2021.

Main Outcomes and Measures

Characteristics of treatment-emergent choroidal and retinal OCT abnormalities as compared with baseline OCT, associated with visual acuity at presentation and at fluid resolution.

Results

A total of 20 of 146 patients (13.7%) exhibited FGFR inhibitor-associated retinopathy. Of these 20 patients, 11 (55%) were female, and the median (range) age was 62.6 (42.7-86.0) years. The median (range; mean) time from medication start to initial subretinal fluid detection was 21 (5-125; 32) days. The median (interquartile range [IQR]) baseline logMAR best-corrected visual acuity (BCVA) was 0 (0-0.1). At fluid accumulation, 11 eyes had decreased vision: the median (IQR) subgroup baseline BCVA was 0 (0-0.1); and the median (IQR) BCVA change from baseline to accumulation was -0.1 (-0.2 to -0.1). For 26 eyes (65%) with follow-up, the subretinal fluid resolved without medical intervention or drug interruption in all but 1 patient. At fluid resolution, the median (IQR) BCVA was 0.1 (0-0.1), and the change in median (IQR) BCVA from baseline to fluid resolution was 0 (-0.03 to 0). No patient discontinued drug therapy on account of their retinopathy.

Conclusions and Relevance

FGFR inhibitors result in subretinal fluid foci similar to other drugs that inhibit the MAPK pathway. In this series, FGFR inhibitors did not cause irreversible loss of vision; the retinopathy was self-limited and did not require medical intervention. These results may explain visual symptoms while taking the drug, although the precise frequency or magnitude of this adverse effect cannot be determined with certainty from this retrospective investigation.

FGFR Inhibitors: Clinical Activity and Development in the Treatment of Cholangiocarcinoma

PURPOSE OF REVIEW

Cholangiocarcinoma is an aggressive cancer with a poor prognosis and limited treatment. Gene sequencing studies have identified genetic alterations in fibroblast growth factor receptor (FGFR) in a significant proportion of cholangiocarcinoma (CCA) patients. This review will discuss the FGFR signaling pathway's role in CCA and highlight the development of therapeutic strategies targeting this pathway.

RECENT FINDINGS

The development of highly potent and selective FGFR inhibitors has led to the approval of pemigatinib for FGFR2 fusion or rearranged CCA. Other selective FGFR inhibitors are currently under clinical investigation and show promising activity. Despite encouraging results, the emergence of resistance is inevitable. Studies using circulating tumor DNA and on-treatment tissue biopsies have elucidated underlying mechanisms of intrinsic and acquired resistance. There is a critical need to not only develop more effective compounds, but also innovative sequencing strategies and combinations to overcome resistance to selective FGFR inhibition. Therapeutic development of precision medicine for FGFR-altered CCA is a dynamic process of involving a comprehensive understanding of tumor biology, rational clinical trial design, and therapeutic optimization. Alterations in FGFR represent a valid therapeutic target in CCA and selective FGFR inhibitors are treatment options for this patient population.

Increased interdigitation zone visibility on optical coherence tomography following systemic fibroblast growth factor receptor 1-3 tyrosine kinase inhibitor anticancer therapy

BACKGROUND

To describe ocular adverse events and retinal changes during fibroblast growth factor receptor (FGFR) inhibitor (AZD4547) anticancer therapy.

METHODS

This is a sub-study examining ocular adverse effects from AZD4547 therapy (single-centre, open-label, single arm phase II clinical trial). Comprehensive ocular examinations were performed 3 weekly in 24 patients. Macular optical coherence tomography (OCT) scan (30⁰  × 25⁰ ) was obtained at each visit and OCT parameters [central 1 mm retinal thickness (CRT) and total macular volume in central 6 mm] extracted. OCT scans were subdivided into outer (ELM to RPE) and inner (ELM to ILM) layers to compare outer and inner retinal changes.

RESULTS

In 24 patients, AZD4547 was associated with eyelash elongation (n = 5, 21%) and punctate corneal erosion (n = 2, 8%). One patient developed clinically significant posterior capsular opacification during the study. OCT data were available in 23 patients, retinal changes ranged from an asymptomatic increased visibility of the interdigitation zone (IDZ) (n = 10, 43%) to multilobular subretinal fluid pockets (n = 5, 22%), which was associated with mild visual acuity loss. In a subset of patients (n = 9) with pre-AZD4547 dosing OCT baseline, CRT increased by mean (SD) of 9 (4) μm in those with IDZ change only compared with 64 (38) μm in those with other retinal changes. Retinal changes tended to be bilateral, self-limiting and improved over time without medical intervention.

CONCLUSIONS

The ocular signs and symptoms did not result in dose cessation. Posteriorly, FGFR inhibition leads to outer retinal changes ranging from increased visibility of IDZ to distinct, multiple fluid pockets.

Retinal toxicities of systemic anticancer drugs

Newer anticancer drugs have revolutionized cancer treatment in the last decade, but conventional chemotherapy still occupies a central position in many cancers, with combination therapy and newer methods of delivery increasing their efficacy while minimizing toxicities. We discuss the retinal toxicities of anticancer drugs with an emphasis on the mechanism of toxicity. Uveitis is seen with the use of v-raf murine sarcoma viral oncogene homolog B editing anticancer inhibitors as well as immunotherapy. Most of the cases are mild with only anterior uveitis, but severe cases of posterior uveitis, panuveitis, and Vogt-Koyanagi-Harada-like disease may also occur. In the retina, a transient neurosensory detachment is observed in almost all patients on mitogen-activated protein kinase kinase (MEK) inhibitors. Microvasculopathy is often seen with interferon α, but vascular occlusion is a more serious toxicity caused by interferon α and MEK inhibitors. Crystalline retinopathy with or without macular edema may occur with tamoxifen; however, even asymptomatic patients may develop cavitatory spaces seen on optical coherence tomography. A unique macular edema with angiographic silence is characteristic of taxanes. Delayed dark adaptation has been observed with fenretinide. Interestingly, this drug is finding potential application in Stargardt disease and age-related macular degeneration.

Ocular Safety Profile of BRAF and MEK Inhibitors: Data from the World Health Organization Pharmacovigilance Database

PURPOSE

BRAF inhibitors (BRAFi) and MEK inhibitors (MEKi) significantly improved metastatic melanoma prognosis. Ocular adverse effects (OAEs) represent an uncommon but disabling toxicity of these drugs. We aimed to characterize the ocular safety profile of BRAFi or MEKi and to detect possible safety signals.

METHODS

We performed a retrospective, observational, pharmacovigilance study using VigiBase, the World Health Organization global safety database. Ocular adverse effects were classified according to the eye segments and the inflammatory pattern based on the Standardization of Uveitis Nomenclature. Associations among BRAFi monotherapy, MEKi monotherapy, and BRAFi+MEKi combination therapy and OAE reporting were assessed using disproportionality analysis. Results were expressed with the reporting odds ratio (ROR) and its 95% confidence interval (CI).

RESULTS

From January 2010 to October 2019, 1568 OAE cases were reported with BRAFi or MEKi. Among them, 1006 cases with sufficient data were included, corresponding to 310 (30.8%), 124 (12.3%), and 572 (56.9%) cases reported with BRAFi, MEKi, or BRAFi+MEKi combination therapy, respectively. BRAF inhibitor monotherapy was significantly associated with the reporting of iris and ciliary body abnormalities (ROR, 8.7; 95% CI, 6.0-12.5), diffuse abnormalities (ROR, 7.1; 95% CI, 5.4-9.4), anterior uveitis (ROR, 8.6; 95% CI, 6.0-12.1), and panuveitis (ROR, 7.1; 95% CI, 5.4-9.4). MEK inhibitor monotherapy was associated with the reporting of retinal and choroid abnormalities (ROR, 9.5; 95% CI, 7.4-12.2), diffuse abnormalities (ROR, 2.5; 95% CI, 1.1-6.1), and panuveitis (ROR, 2.5; 95% CI, 1.1-6.1). Combinations of BRAFi and MEKi therapies were associated with OAEs from both drugs, with a possible synergistic or additive effect for diffuse abnormalities and panuveitis.

CONCLUSIONS

Our study characterizes the ocular safety profile of BRAFi and MEKi. We identify possible safety signals for several OAEs not previously reported with BRAFi and MEKi. Our data provide the rationale for a personalized management of OAE in patients with BRAFi+MEKi combination therapy according to the type of ocular reaction.

Multifocal serous retinopathy with pemigatinib therapy for metastatic colon adenocarcinoma

Background

Pemigatinib is an inhibitor of the fibroblast growth factor receptor (FGFR), recently approved for the treatment of cholangiocarcinoma. FGFR retinopathy is a newly recognized entity, with only two other FGFR inhibitors reported to cause serous retinopathy. Herein, we describe the first published report of a multifocal serous retinopathy secondary to pemigatinib.

Case presentation

A 67-year-old male with stage 4A metastatic colon adenocarcinoma undergoing systemic therapy with pemigatinib was found to have developed bilateral multifocal serous retinopathy. Fundus autofluorescence showed corresponding multifocal hypoautofluorescent foci, whereas fluorescein angiography and indocyanine green angiography were unremarkable. Subretinal fluid resolved rapidly after discontinuation of pemigatinib.

Conclusions

Multifocal serous retinopathy appears to be a class effect of FGFR inhibitors. FGFR retinopathy clinically resembles MEK retinopathy—both feature multifocal subretinal fluid, low visual significance, and quick resolution. However, given that FGFR inhibitors have a broader molecular range than MEK inhibitors, further characterization of FGFR retinopathy is necessary to generate management guidelines.

Serous business: Delineating the broad spectrum of diseases with subretinal fluid in the macula

A wide range of ocular diseases can present with serous subretinal fluid in the macula and therefore clinically mimic central serous chorioretinopathy (CSC). In this manuscript, we categorise the diseases and conditions that are part of the differential diagnosis into 12 main pathogenic subgroups: neovascular diseases, vitelliform lesions, inflammatory diseases, ocular tumours, haematological malignancies, paraneoplastic syndromes, genetic diseases, ocular developmental anomalies, medication-related conditions and toxicity-related diseases, rhegmatogenous retinal detachment and tractional retinal detachment, retinal vascular diseases, and miscellaneous diseases. In addition, we describe 2 new clinical pictures associated with macular subretinal fluid accumulation, namely serous maculopathy with absence of retinal pigment epithelium (SMARPE) and serous maculopathy due to aspecific choroidopathy (SMACH). Differentiating between these various diseases and CSC can be challenging, and obtaining the correct diagnosis can have immediate therapeutic and prognostic consequences. Here, we describe the key differential diagnostic features of each disease within this clinical spectrum, including representative case examples. Moreover, we discuss the pathogenesis of each disease in order to facilitate the differentiation from typical CSC.

Targeted Cancer Therapy and Its Ophthalmic Side Effects: A Review

Targeted cancer therapy agents are the latest development in cancer therapeutics. Although the spectrum of their use continues to expand, ocular side effects are frequently encountered with the use of cancer therapeutics. This review describes the ocular side effects of targeted cancer therapy agents.

Fibroblast Growth Factor Receptor (FGFR) Inhibitors in Urothelial Cancer

Dysregulated fibroblast growth factor receptor (FGFR) signaling is associated with several cancers, including urothelial carcinoma. Preclinical studies with FGFR inhibitors have shown significant antitumor activity, which has led to clinical evaluation of multiple FGFR inhibitors. Recently, erdafitinib was approved by the U.S. Food and Drug Administration for advanced urothelial carcinoma with FGFR gene alterations as the first molecularly targeted therapy. Additional ongoing clinical trials with other types of FGFR inhibitors have shown encouraging results. This review summarizes the oncogenic signaling of FGFR alterations, completed and ongoing clinical trials of FGFR inhibitors, and resistance patterns. IMPLICATIONS FOR PRACTICE: Dysregulated fibroblast growth factor receptor (FGFR) signaling is associated with several cancers, including urothelial carcinoma. Preclinical studies with FGFR inhibitors have shown significant antitumor activity, which has led to clinical evaluation of multiple FGFR inhibitors. Most recently, erdafitinib was approved by the U.S. Food and Drug Administration for advanced urothelial carcinoma with FGFR gene alterations as the first molecularly targeted therapy. Additional ongoing clinical trials with other types of FGFR inhibitors have shown encouraging results. This review summarizes the oncogenic signaling of FGFR alterations, completed and ongoing clinical trials of FGFR inhibitors, and resistance patterns.

OCULAR ADVERSE EVENTS ASSOCIATED WITH MEK INHIBITORS

PURPOSE

Mitogen-activates protein kinase (MAPK) inhibitors, particularly MEK inhibitors, have shifted the treatment paradigm for metastatic BRAF-mutant cutaneous melanoma; however, oncologists, ophthalmologists, and patients have noticed different toxicities of variable importance. This review aims to provide an update of the ocular adverse events (OAEs), especially retinal toxicity, associated with the use of MEK inhibitors.

METHODS

We conducted a scientific literature search using the PubMed database up to July 2018 with the terms "MEK inhibitors" with a "review" filter and "MEK inhibitors" with a "clinical trials" filter. Phase I-III experimental studies and reviews were selected. Current principles and techniques for diagnosing and managing MEK inhibitor retinopathy and other OAEs are discussed.

RESULTS

In patients treated with MEK inhibitors, including asymptomatic patients, OAEs occur with an incidence of up to 90%. Mild to severe ophthalmic toxicities are described, including visual disturbances, a 2-line decrease in Snellen visual acuity, dry eye symptoms, ocular adnexal abnormalities, visual field defects, panuveitis, and retinal toxicities, such as different degrees of MEK-associated retinopathy, vascular injury, and retinal vein occlusion.

CONCLUSION

MEK inhibitors can lead to different degrees of retinal, uveal, and adnexal OAE, causing visual disturbances or discomfort. One of the most relevant OAE of MEK therapy is MEK inhibitor-associated retinopathy (MEKAR), which is usually mild, self-limited, and may subside after continuous use of the drug for weeks or months, or discontinuation, thereby restoring the normal visual function of the retina, with some exceptions. Ocular adverse events are often associated with other systemic adverse effects that can modify the dosage of treatment, so the communication with the oncologist is fundamental.

Drug-induced maculopathy

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of drug-induced maculopathies including their clinical presentations, diagnostic findings, and treatment options. With the increasing pace of development and arrival of drugs to the market, this review aims to inform retina specialists of relevant side effects that may be encountered in a clinical practice setting.

RECENT FINDINGS

The major themes visited in this article focus on relevant findings of drugs that cause pigmentary and crystalline maculopathy, photoreceptor dysfunction, cystoid macular edema, central serous choroidopathy, uveitis, and vascular damage.

SUMMARY

The current review reports updated findings and discusses the pathophysiologic mechanisms, presentations, and treatments of drug-induced maculopathies.

Risk factors for MEK-associated retinopathy in patients with advanced melanoma treated with combination BRAF and MEK inhibitor therapy

BACKGROUND

Retinopathy is a common adverse event with mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors. Little is known about the pathophysiology of MEK inhibitor-associated retinopathy (MEKAR). Since MEKAR has many similarities to central serous chorioretinopathy (CSCR), they may share common risk factors. The aim of this study was to evaluate the association between baseline characteristics and MEKAR in melanoma patients initiating MEK inhibitor treatment.

METHODS

Data from patients treated with cobimetinib and vemurafenib for advanced melanoma in the coBRIM trial were subjected to secondary analysis. Consistent with CSCR risk factors, assessed baseline characteristics included: age, gender, past ocular disease, weight, hypertension, diabetes, dyslipidemia, glomerular filtration rate (eGFR) and corticosteroid use. Associations between characteristics and retinopathy events (any grade and symptomatic) were evaluated using univariate logistic regression and represented as odds ratios (OR).

RESULTS

A total of 247 patients were treated with cobimetinib and vemurafenib, of whom 72 (29%) had retinopathy of any grade and 33 (13%) had symptomatic retinopathy. Patients with a history of ocular disease were at significantly higher risk of retinopathy (any grade, 44%; symptomatic, 22%) than those with no ocular disease history (any grade, 22%; symptomatic, 10%). Individuals with a history of ocular inflammation or infection were at highest risk: 4 of 5 developed symptomatic retinopathy during MEK inhibitor therapy. Increased age was associated with a higher risk of any grade retinopathy {decade increase OR [95% confidence interval (CI)] = 1.03 (1.01-1.05); p = 0.009}, while increasing eGFR was significantly associated with a decreased risk of any grade retinopathy [0.98 (0.96-0.99); p = 0.004]; the associations were not statistically significant with symptomatic retinopathy. Other assessed CSCR risk factors were not significantly associated with MEKAR.

CONCLUSION

Age, glomerular filtration rate and history of ocular disease (particularly inflammatory eye disease) were associated with a risk of MEK inhibitor induced retinopathy. Patients who are at increased risk of MEKAR may benefit from more regular ophthalmologic assessment during treatment.

Clinical Development of BRAF plus MEK Inhibitor Combinations

Genomic profiling shows that many solid tumors are characterized by specific driver aberrations, and this has expanded the therapeutic options for many patients. The mitogen-activated protein kinase (MAPK) pathway is a key cell signaling pathway involved in regulating cellular growth, proliferation, and survival. Driver mutations in the BRAF gene, a key player in the MAPK pathway, are described in multiple tumor types, including subsets of melanoma, non-small cell lung cancer (NSCLC), and anaplastic thyroid cancer (ATC), making BRAF a desirable target for inhibition. BRAF inhibitors have shown efficacy in several cancers; however, most patients eventually develop resistance. To delay or prevent resistance, combination therapy targeting BRAF and MEK, a downstream signaling target of BRAF in the MAPK pathway, was evaluated and demonstrated synergistic benefit. BRAF and MEK inhibitor combinations have been approved for use in various cancers by the US FDA. We review the clinical data for various BRAF plus MEK combination regimens in three cancer types with underlying BRAF driver mutations: melanoma, NSCLC, and ATC. We also discuss practical treatment considerations and management of selected combination therapy toxicities.

MiR-3116 sensitizes glioma cells to temozolomide by targeting FGFR1 and regulating the FGFR1/PI3K/AKT pathway

Glioma is a brain tumour that is often diagnosed, and temozolomide (TMZ) is a common chemotherapeutic drug used in glioma. Yet, resistance to TMZ is a chief hurdle towards curing the malignancy. The current work explores the pathways and involvement of miR-3116 in the TMZ resistance. miR-3116 and FGFR1 mRNA were quantified by real-time PCR in malignant samples and cell lines. Appropriate assays were designed for apoptosis, viability, the ability to form colonies and reporter assays to study the effects of the miR-3116 or FGFR1. The involvement of PI3K/AKT signalling was assessed using Western blotting. Tumorigenesis was evaluated in an appropriate xenograft mouse model in vivo. This work revealed that the levels of miR-3116 dipped in samples resistant to TMZ, while increased miR-3116 caused an inhibition of the tumour features mentioned above to hence augment TMZ sensitivity. miR-3116 was found to target FGFR1. When FGFR1 was overexpressed, resistance to TMZ was augmented and reversed the sensitivity caused by miR-3116. Our findings further confirmed PI3K/AKT signalling pathway is involved in this action. In conclusion, miR-3116 sensitizes glioma cells to TMZ through FGFR1 downregulation and the PI3K/AKT pathway inactivation. Our results provide a strategy to overcome TMZ resistance in glioma treatment.

The cardenolides ouabain and reevesioside A promote FGF2 secretion and subsequent FGFR1 phosphorylation via converged ERK1/2 activation

Na⁺/K⁺-ATPase α1 was reported to directly interact with and recruit FGF2 (fibroblast growth factor 2), a vital cell signaling protein implicated in angiogenesis, to the inner plasma membrane for subsequent secretion. Cardenolides, a class of cardiac glycosides, were reported to downregulate FGF2 secretion upon binding to Na⁺/K⁺-ATPase α1 in a cell system with ectopically expressed FGF2 and Na⁺/K⁺-ATPase α1. Herein, we disclose that the cardenolides ouabain and reevesioside A significantly enhance the secretion/release of FGF2 and the phosphorylation of FGFR1 (fibroblast growth factor receptor 1) in a time- and dose-dependent manner, in A549 carcinoma cells. A pharmacological approach was used to elucidate the pertinent upstream effectors. Only the ERK1/2 inhibitor U0126 but not the other inhibitors examined (including those inhibiting the unconventional secretion of FGF2) was able to reduce ouabain-induced FGF2 secretion and FGFR1 activation. ERK1/2 phosphorylation was increased upon ouabain treatment, a process found to be mediated through upstream effectors including ouabain-induced phosphorylated EGFR and a reduced MKP1 protein level. Therefore, at least two independent lines of upstream effectors are able to mediate ouabain-induced ERK1/2 phosphorylation and the subsequent FGF2 secretion and FGFR1 activation. These finding constitute unprecedent insights into the regulation of FGF2 secretion by cardenolides.

BILATERAL VISUAL FIELD DEFECTS IN A PATIENT TREATED WITH THE MEK AND BRAF INHIBITORS TRAMETINIB AND DABRAFENIB FOR MELANOMA OF UNKNOWN ORIGIN

INTRODUCTION

Although the introduction of BRAF and MEK inhibitors has greatly enhanced treatment possibilities in advanced BRAFV600-mutated melanoma, class-related toxicities are rather frequent and often involve the eye. Ophthalmologic side effects most commonly include central/diffuse serous retinopathy and retinal vein occlusion. Affection of the optic nerve head however has not been described clinically.

CASE REPORT

A 29-year-old man presented in our eye clinic with bilateral blurred vision. Seventeen days earlier, he had been started on trametinib and dabrafenib combination therapy for metastasized melanoma of unknown origin. Visual field testing revealed diffuse bilateral defects, which regressed spontaneously on pause of MEK and BRAF inhibitor treatment.

DISCUSSION

In addition to the widely known class-related retinal toxicity, MEK and BRAF inhibitor-associated adverse events may also involve the optic nerve head, causing visual field defects probably regressing spontaneously after discontinuation of targeted oncologic therapy. In such cases, repeat brain imaging and exclusion of melanoma-associated retinopathy is recommended. Reinitiation of treatment and subsequent dose escalation seem to be feasible, but should be monitored by an ophthalmologist.

Cobimetinib in malignant melanoma: how to MEK an impact on long-term survival

Approximately 50% of cutaneous melanomas harbor activating mutations of the BRAF-oncogene, making BRAF inhibitors (BRAFi) the standard treatment for this disease. However, disease responses are limited in duration mainly due to acquired resistance. Dual MAPK pathway inhibition with addition of a MEK inhibitor (MEKi) to a BRAFi improved the efficacy and tolerability compared with BRAFi alone. Cobimetinib (Cotellic®) is an orally bioavailable, potent and selective MEKi, which significantly improved response rates when combined with BRAFi vemurafenib (median overall survival: 22.3 months). The toxicity profile of cobimetinib is manageable and treatment discontinuation due to adverse events is uncommon. Present efforts are addressed to overcome resistance and improve long-term outcomes: based on the evidence of the immunomodulatory properties of BRAFi and MEKi, current clinical trials of combined targeted and immunotherapy are investigating the role of cobimetinib in the context of combination or as sequential treatments.

FREQUENT SUBCLINICAL MACULAR CHANGES IN COMBINED BRAF/MEK INHIBITION WITH HIGH-DOSE HYDROXYCHLOROQUINE AS TREATMENT FOR ADVANCED METASTATIC BRAF MUTANT MELANOMA: Preliminary Results From a Phase I/II Clinical Treatment Trial

PURPOSE

To assess the potential ocular toxicity of a combined BRAF inhibition (BRAFi) + MEK inhibition (MEKi) + hydroxychloroquine (HCQ) regime used to treat metastatic BRAF mutant melanoma.

METHODS

Patients with stage IV metastatic melanoma and BRAF V600E mutations (n = 11, 31-68 years of age) were included. Treatment was with oral dabrafenib, 150 mg bid, trametinib, 2 mg/day, and HCQ, 400 mg to 600 mg bid. An ophthalmic examination, spectral domain optical coherence tomography, near-infrared and short-wavelength fundus autofluorescence, and static perimetry were performed at baseline, 1 month, and q/6 months after treatment.

RESULTS

There were no clinically significant ocular events; there was no ocular inflammation. The only medication-related change was a separation of the photoreceptor outer segment tip from the apical retinal pigment epithelium that could be traced from the fovea to the perifoveal retina noted in 9/11 (82%) of the patients. There were no changes in retinal pigment epithelium melanization or lipofuscin content by near-infrared fundus autofluorescence and short-wavelength fundus autofluorescence, respectively. There were no inner retinal or outer nuclear layer changes. Visual acuities and sensitivities were unchanged.

CONCLUSION

BRAFi (trametinib) + MEKi (dabrafenib) + HCQ causes very frequent, subclinical separation of the photoreceptor outer segment from the apical retinal pigment epithelium without inner retinal changes or signs of inflammation. The changes suggest interference with the maintenance of the outer retinal barrier and/or phagocytic/pump functions of the retinal pigment epithelium by effective MEK inhibition.