Transient MEK inhibitor-associated retinopathy in metastatic melanoma.

BACKGROUND: Melanoma is one of the most aggressive skin cancers. Recently, selective MEK inhibitors have shown efficacy in patients with advanced BRAF- and NRAS-mutant melanoma. Soon after the initiation of clinical oncology trials with MEK inhibitors, it was observed that some participants developed an eye condition resembling central serous chorioretinopathy. The present article addresses the clinical features and management of these MEK inhibitor-associated retinal syndromes. PATIENTS AND METHODS: Thirty-two patients with advanced cutaneous melanoma were treated with the selective MEK inhibitor binimetinib (MEK162) in three different Phase 1b or 2 clinical trials. Twenty patients on binimetinib monotherapy and 12 on binimetinib plus RAF inhibitor [pan-kinase RAF inhibitor RAF265 (n = 7) or selective BRAF inhibitor encorafenib (LGX818) (n = 5)] combination therapy underwent ophthalmological examinations at regular intervals, including determination of best corrected visual acuity, perimetry, colour vision testing, dilated fundus examination, and multimodal imaging. RESULTS: Grade 1-2 bilateral retinopathies with multiple lesions were observed in 13 of 20 patients on binimetinib monotherapy, 4 of 7 patients on binimetinib plus RAF265 combination therapy, and 2 of 5 patients on binimetinib plus encorafenib combination therapy. In this study population, the rate ranged from 40% to 65%. Retinopathy events appeared during the first 4 weeks, and in some cases, during the first few days of treatment. Patients reported mild and only short-lived visual symptoms. Optical coherence tomography revealed neuroretinal elevations. Central retinal thickness and volume showed dose-dependent increases after the start of treatment, followed by a marked decrease despite continued treatment, which was associated with symptom resolution. No vascular abnormalities were found with fluorescein and indocyanine green angiography. CONCLUSIONS: Treatment with the selective MEK inhibitor binimetinib as a single agent or in combination with RAF inhibitors induced transient retinopathy with multiple bilateral lesions in some patients. Binimetinib-induced retinopathy was usually mild, self-limiting, and tolerable as visual function was not seriously impaired.

N,N'-dialkylimidazolium chloroplatinate(II), chloroplatinate(IV), and chloroiridate(IV) salts and an N-heterocyclic carbene complex of platinum(II): synthesis in ionic liquids and crystal structures.

The first imidazole-type carbene complex of platinum(II), cis-(C2H4)(1-ethyl-3-methylimidazol-2-ylidene)PtCl2, has been obtained by reacting PtCl2 and PtCl4 with ethylene in the basic [EMIM]Cl/AlCl3 (1.3:1) ionic liquid (where [EMIM]+ = 1-ethyl-3-methylimidazolium) at 200 degrees C and structurally characterized (monoclinic P21/c space group, a = 10.416(2) A, b = 7.3421(9) A, c = 15.613(2) A, beta = 101.53(2) degrees, Z = 4). This complex can be regarded as a stable analogue of the pi-alkene-Pd(II)-carbene intermediate in the Heck reaction. In addition, a series of new N,N'-dialkylimidazolium salts of platinum group metals of the type [RMIM]2[MCln], where [RMIM+] = 1-alkyl-3-methylimidazolium and M = Pt(II), Pt(IV), or Ir(IV), have been prepared and characterized. The salts [EMIM]2[PtCl6] (1) and [EMIM]2[PtCl4] (2) were prepared in the ionic liquid [EMIM]Cl/AlCl3 and the salts [BMIM]2[PtCl4] (3) and [BMIM]2[PtCl6] (4) (where [BMIM]+ = 1-n-butyl-3-methylimidazolium) and [EMIM]2-[IrCl6] (5) in aqueous or acetonitrile media. From TGA measurements, salts 1-5 decompose in air in several steps eventually to form the corresponding metal, the onset of decomposition being observed at (degree C) 260 (1), 220 (2), 200 (3), 215 (4), and 210 (5). The structures of 1, 2, and 5 were determined by single-crystal X-ray analysis. The three salts crystallize in the monoclinic P21/n space group (1, a = 7.6433(9) A, b = 16.353(2) A, c = 9.213(1) A, beta = 113.56(1) degrees, Z = 2; 2, a = 8.601(1) A, b = 8.095(2) A, c = 13.977(2) A, beta = 91.75(2) degrees, Z = 2; 5, a = 10.353(2) A, b = 9.759(2) A, c = 10.371(2) A, beta = 92.98(3) degrees, Z = 2).