Citations

Précis: This study reports 12-month outcomes of combined phacoemulsification and Hydrus Microstent implantation in Asian eyes with moderate-to-severe normal tension glaucoma (NTG), demonstrating a significant reduction in glaucoma medications with an excellent intra and postoperative safety profile. Objective: To evaluate the 12-month safety and efficacy outcomes of combined phacoemulsification and Hydrus Microstent (Ivantis Inc.) implantation in Asian eyes with moderate to severe NTG. Methods: Retrospective study of consecutive surgeries performed from August 2019 to August 2021 in a single tertiary eye centre in Singapore. Outcome measures included a reduction in intraocular pressure (IOP), number of glaucoma medications, and intra and postoperative complications. Results: Data from 21 eyes of 21 subjects were analyzed. All subjects were ethnic Chinese, and the majority were males (14, 66.7%). At baseline, the mean IOP was 13.3 (2.3) mm Hg, all eyes had a Humphrey visual field mean deviation of ≥−6 dB [mean: −13.9 (4.3) dB], and all eyes were on at least one glaucoma medication. There was no statistically significant reduction in IOP at all time points compared with baseline (all P > 0.05). However, the median number of medications was reduced from 2 to 0 at all time points, up to postoperative month (POM) 12 (all P < 0.001). There were no intraoperative complications. No eyes underwent secondary glaucoma procedures nor lost any Snellen line of visual acuity by POM12. One (4.8%) eye experienced numerical hypotony at postoperative day 1, which resolved conservatively. Two (9.5%) eyes underwent laser iridoplasty for stent occlusion by iris. There was no deterioration in Humphrey visual field mean deviation at POM12 compared with baseline (n = 20, P > 0.05). Conclusion: Combined phacoemulsification and Hydrus Microstent implantation were effective in reducing medication burden in Asian eyes with moderate to severe NTG, up to 12 months postoperatively.

e14507 Background: Regorafenib, an oral multikinase inhibitor of VEGFR2/3, PDGFRb, KIT, FGFR, RET, RAF and TIE2, is efficacious in refractory mCRC but its mechanism of action is unclear and predictive biomarkers are lacking. Methods: We assessed tumor and circulatory biomarkers in a phase 2 study of regorafenib in refractory mCRC patients. Regorafenib was administered orally at 160mg/d for 3 out of 4 weeks. Post cycle 2 response was assessed by RECIST 1.1. Subjects were scheduled for FDG PET-CT scans (pre + D15) and paired core needle tumor biopsies for IHC analysis (pre + D21) in cycle 1. Archival tumor mutations were evaluated using Sequenom MassARRAY OncoCarta Panel V1.0 assay. Results: 35 patients were treated; 49% received > 4 prior therapies and 43% had prior bevacizumab. Median PFS was 3.45 mths (95% CI: 3.40-3.49), ORR was 3% and disease control rate [DCR] (PR + SD at 8 wks) was 57%. Early PET responses (EORTC criteria) were seen in 49%, but did not predict for DCR (p=1.0). Fatigue, hand foot skin reaction (HFSR), voice change and diarrhea occurred in > 30% of subjects. Grade 3-5 toxicities occurred in 46%, the commonest being HFSR and rash (17% each). Median relative dose intensity was 92%; 43% required > 1 dose reduction, 60% required > 1 dose interruption. KRAS (29%), BRAF (9%), EGFR (9%), NRAS (6%) KIT (3%), PIK3CA (3%), PDGFRA (3%) and CDK (3%) mutations were detected in archival tumors. None predicted for ORR or DCR; PFS was identical in KRAS mutant vs wt patients (3.45 mths, p=0.39) and similar in BRAF mutant vs wt patients (3.48 vs 3.45 mths, p=0.10). The patient with the longest PFS (12.6 mths) had a BRAF mutation. Amongst the 10 paired tumor samples available, IHC markers upregulated in >50% cases were pMEK, pERK, pJun and pJNK, whilst those downregulated/ unchanged in >50% were pKIT, pVEGFR2, CD31 [vascular endothelial cells (ECs)] and podoplanin (lymphatic ECs). The greatest change was observed in podoplanin expression, corresponding to a 60% reduction in lymphatic vessel density. Conclusions: FDG-PET responses in cycle 1 did not predict for regorafenib clinical benefit in mCRC patients. Targeting lymphatic/vascular ECs in the tumor microenvironment may be a more significant antitumor mechanism of regorafenib than MAP kinase pathway inhibition. Clinical trial information: NCT01189903.