Heterochromia following intravitreal chemotherapy in two cases

Safety of intravitreal chemotherapy in the management of retinoblastoma: A systematic review of the literature

Intravitreal chemotherapy is used as a salvage therapy for retinoblastoma with persistent or recurrent vitreous seeding after primary treatment. To assess the safety of this technique, we conducted a systematic review of all studies reporting ocular toxicity data. Forty-eight trials involving 2751 eyes were included. The most common complications were cataract, retinal toxicity, and vitreous hemorrhage. However, severe and permanent adverse events were limited, while the risk of extraocular dissemination, a significant concern, was practically eliminated through preventive techniques. Globe salvage rates ranged from 29 % to 100 %. In conclusion, intravitreal chemotherapy seems to improve prognosis of eyes with advanced disease, with an acceptable safety profile. Nevertheless, most relevant studies are retrospective, and no randomized trials have been performed. Recognizing the challenges regarding the conduct of randomized studies for such a rare pediatric cancer, we believe that multicenter trials through international collaborations can significantly enhance the available information.

A real-world data analysis of topotecan in the FDA Adverse Event Reporting System (FAERS) database

OBJECTIVES

The objective of this study was to monitor and identify adverse events (AEs) associated with topotecan, a medication used for the treatment of solid tumors, in order to improve patient safety and guide medication usage.

METHODS

To assess the disproportionality of topotecan-related AEs in real-world data, four algorithms (ROR, PRR, BCPNN, and EBGM) were employed as measures to detect signals of topotecan-associated AEs.

RESULTS

A statistical analysis was conducted using data from the FAERS database, encompassing 9,511,161 case reports from 2004Q1 to 2021Q4. Among these reports, 1,896 were identified as primary suspected (PS) AEs related to topotecan, and 155 topotecan-related adverse drug reactions (ADRs) at the preferred terms (PTs) level were selected. The occurrence of topotecan-induced ADRs was analyzed across 23 organ systems. The analysis revealed several expected ADRs, such as anemia, nausea, and vomiting, which were consistent with the drug labels. Additionally, unexpected significant ADRs associated with eye disorders at the system organ class (SOC) level were identified, indicating potential adverse effects not currently mentioned in the drug instructions.

CONCLUSION

This study identified new and unexpected signals of adverse drug reactions (ADRs) related to topotecan, providing valuable insights into the relationship between ADRs and topotecan usage. The findings highlight the importance of ongoing monitoring and surveillance to detect and manage AEs effectively, ultimately improving patient safety during topotecan treatment.

Functional genomics identifies new synergistic therapies for retinoblastoma

Local intravitreal or intra-arterial chemotherapy has improved therapeutic success for the pediatric cancer retinoblastoma (RB), but toxicity remains a major caveat. RB initiates primarily with RB1 loss or, rarely, MYCN amplification, but the critical downstream networks are incompletely understood. We set out to uncover perturbed molecular hubs, identify synergistic drug combinations to target these vulnerabilities, and expose and overcome drug resistance. We applied dynamic transcriptomic analysis to identify network hubs perturbed in RB versus normal fetal retina, and performed in vivo RNAi screens in RB1^null and RB1^wt;MYCN^amp orthotopic xenografts to pinpoint essential hubs. We employed in vitro and in vivo studies to validate hits, define mechanism, develop new therapeutic modalities, and understand drug resistance. We identified BRCA1 and RAD51 as essential for RB cell survival. Their oncogenic activity was independent of BRCA1 functions in centrosome, heterochromatin, or ROS regulation, and instead linked to DNA repair. RAD51 depletion or inhibition with the small molecule inhibitor, B02, killed RB cells in a Chk1/Chk2/p53-dependent manner. B02 further synergized with clinically relevant topotecan (TPT) to engage this pathway, activating p53-BAX mediated killing of RB but not human retinal progenitor cells. Paradoxically, a B02/TPT-resistant tumor exhibited more DNA damage than sensitive RB cells. Resistance reflected dominance of the p53-p21 axis, which mediated cell cycle arrest instead of death. Deleting p21 or applying the BCL2/BCL2L1 inhibitor Navitoclax re-engaged the p53-BAX axis, and synergized with B02, TPT or both to override resistance. These data expose new synergistic therapies to trigger p53-induced killing in diverse RB subtypes.