A typical anterior retinoblastoma: diagnosis by aqueous humor cell-free DNA analysis.

BACKGROUND: Aqueous humor from eyes with active retinoblastoma contains tumor-derived cell-free DNA. MATERIALS AND METHODS: Single retrospective case report. RESULTS: A 13-year-old girl with acute right eye pain and redness was diagnosed with hypertensive anterior uveitis. Following initial management, she was referred to ocular oncology for an atypical clinical picture. Multiple seeds were noted 360 degrees in the anterior chamber, at the equator of the lens and canal of Petit, and ultrasound biomicroscopy identified a temporal pars plana lesion. While aqueous humor cytology was inconclusive for malignancy, targeted next-generation sequencing of aqueous cell-free DNA identified biallelic RB1 full gene deletion, confirming the diagnosis of retinoblastoma. Partial regression followed three cycles of systemic carboplatin, etoposide, and vincristine and three intracameral melphalan injections. Four months later, she had recurrence of the primary tumor and increase in seeding and received the investigational sustained release episcleral topotecan chemoplaque. Stable regression was achieved to 28-month follow-up, with no detectable aqueous cell-free DNA. CONCLUSIONS: RB1 sequencing analysis of tumor-derived cell-free DNA from aqueous humor can confirm the diagnosis of retinoblastoma in cases of diagnostic uncertainty.

EMPOWER Retinoblastoma: Engaging Patient Partners in Solving the Top 10 Priorities for Eye Cancer Research in Canada.

While it is recognized that research priorities should reflect and integrate the perspectives and needs of patients along with those of health professionals and researchers, it remains challenging to actualize such priorities into tangible research projects. Targeted dissemination is required to catalyze research on these priorities. To create awareness of and inspire action toward actualizing the top 10 retinoblastoma research priorities in Canada, Canadian Retinoblastoma Research Advisory Board (CRRAB) members developed a wide range of dissemination tools and processes. These resources, co-produced with patients, were instrumental to CRRAB sharing the top 10 priorities internationally to mobilize action toward solving them.

The Retinoblastoma Research Booklet: A Catalyst for Patient Involvement in Retinoblastoma Research.

Peer-to-peer recruitment efforts are important in generating interest and participation of patients as partners in research but difficult to sustain when face-to-face interactions are limited. The Retinoblastoma Research and You! booklet, co-developed by patients, researchers and health professionals, serves as a guide for patient engagement in research while retaining an element of personalization. The Retinoblastoma Research and You! booklet was developed through two virtual workshops to iterate and finalize the booklet design and content. The booklet outlines how individual patients' lived experiences and skills can influence retinoblastoma research and highlights real-world examples of patient-partnered research activities at different stages of the research process.

Pediatric Cataract Surgery Following Treatment for Retinoblastoma: A Case Series and Systematic Review.

PURPOSE: To determine the visual and refractive outcomes and the ocular and systemic complications of cataract surgery in eyes treated for retinoblastoma. DESIGN: Retrospective consecutive case series and systematic review. METHODS: Children <18 years of age with retinoblastoma who underwent surgery for secondary cataract between 2000 and 2020 were reviewed. Medline (OVID), Embase, Web of Science, and the Cochrane database were searched from inception to August 2020. RESULTS: A total of 15 eyes of 15 children were included. The mean age at retinoblastoma diagnosis was 12 months (median, 14; interquartile range [IQR], 4-19). Cataract developed at a mean age of 39 months (median, 31; IQR, 20-52), secondary to multiple treatments (n = 7), pars-plana vitrectomy (n = 3), external-beam radiotherapy (n = 2), laser (n = 2), and retinal detachment (n = 1). The mean preoperative quiescent interval was 44 months (median, 28; IQR, 15-64). Primary intraocular lens implantation was performed in 93%, posterior capsulotomy in 40%, and anterior vitrectomy in 33% of participants. Postoperatively, 100% had improved fundus visibility and 73% had improved vision. Complications included visual axis opacification (11 of 15), capsular phimosis (5 of 15), and zonulopathy (3 of 15). No patient developed intraocular recurrence, extraocular extension, or metastasis at a mean of 76 months (median, 78; IQR, 29-128) follow-up. The systematic review identified 852 studies, with 18 meeting inclusion criteria. Across all studies (n = 220 children), intraocular recurrence occurred in 6%, globe salvage in 91%, and extraocular extension and metastasis in <1%. CONCLUSIONS: Modern retinoblastoma therapies, including intravitreal chemotherapy and vitrectomy, cause secondary cataract. Following cataract surgery, intraocular recurrence risk is low and extraocular spread is rare. Although surgery improves tumor visualization, visual prognosis may be limited by several factors. Challenges include biometry limitations and a high incidence of zonulopathy.

Patients presenting with metastases: stage IV uveal melanoma, an international study.

OBJECTIVE: To analyse ocular and systemic findings of patients presenting with systemic metastasis. METHODS AND ANALYSIS: It is an international, multicentre, internet-enabled, registry-based retrospective data analysis. Patients were diagnosed between 2001 and 2011. Data included: primary tumour dimensions, extrascleral extension, ciliary body involvement, American Joint Committee on Cancer (AJCC)-tumour, node, metastasis staging, characteristics of metastases. RESULTS: Of 3610 patients with uveal melanoma, 69 (1.9%; 95% CI 1.5 to 2.4) presented with clinical metastasis (stage IV). These melanomas originated in the iris, ciliary body and choroid in 4%, 16% and 80% of eyes, respectively. Using eighth edition AJCC, 8 (11%), 20 (29%), 24 (35%), and 17 (25%) belonged to AJCC T-categories T1-T4. Risk of synchronous metastases increased from 0.7% (T1) to 1.5% (T2), 2.6% (T3) and 7.9% (T4). Regional lymph node metastases (N1a) were detected in 9 (13%) patients of whom 6 (67%) had extrascleral extension. Stage of systemic metastases (known for 40 (59%) stage IV patients) revealed 14 (35%), 25 (63%) and 1 (2%) had small (M1a), medium-sized (M1b) and large-sized (M1c) metastases, respectively. Location of metastases in stage IV patients were liver (91%), lung (16%), bone (9%), brain (6%), subcutaneous tissue (4%) and others (5%). Multiple sites of metastases were noted in 24%. Compared with the 98.1% of patients who did not present with metastases, those with synchronous metastases had larger intraocular tumours, more frequent extrascleral extension, ciliary body involvement and thus a higher AJCC T-category. CONCLUSIONS: Though higher AJCC T-stage was associated with risk for metastases at diagnosis, even small T1 tumours were stage IV at initial presentation. The liver was the most common site of metastases; however, frequent multiorgan involvement supports initial whole-body staging.

Clinical audit of retinoblastoma management: a retrospective single-institution study.

OBJECTIVE: The primary aim of this study was to identify the frequency of death, metastasis, enucleation, and use of external beam radiation therapy (EBRT) among retinoblastoma patients. The secondary aim was to determine whether any events were associated with suboptimal clinical management to identify areas for clinical care improvement. METHODS: Patients diagnosed with retinoblastoma between January 1, 2000, and December 31, 2015, at The Hospital for Sick Children were included. Medical records of eligible patients underwent a comprehensive 2-part review. First, a chart review collected diagnostic details, treatment course, and occurrence of 4 events: death, metastasis, use of EBRT, and enucleation. Next, events were reviewed in detail, and a multidisciplinary committee reached consensus on cases managed suboptimally. RESULTS: The study included 209 patients (292 eyes). There were 8 deaths, 11 metastases, 177 enucleations (143 primary, 34 secondary), and 8 uses of EBRT. Thirteen patients were reviewed by the multidisciplinary committee, which confirmed that 5 of these patients had events associated with suboptimal clinical management. Three patients developed metastases leading to death (misdiagnosis and mismanagement of trilateral retinoblastoma [1], parental refusal of enucleation [1], and inaccurate histopathology after primary enucleation [1]). One patient developed extraocular extension related to scleral invasion following aggressive focal therapy. One patient underwent secondary enucleation for a Group B eye related to mismanagement of a treatment complication. DISCUSSION: Deaths, metastases, and enucleations with documented instances of suboptimal care highlighted a need to enhance medical team and patient communication, histopathology interpretation, laser treatment guidelines, and trilateral retinoblastoma management. Routine clinical audit of retinoblastoma management can identify areas for clinical practice change.

Retinoblastoma Survival Following Primary Enucleation by AJCC Staging.

Primary enucleation of the eye with retinoblastoma is a widely accessible, life-saving treatment for retinoblastoma. This study evaluated the survival of patients following primary enucleation based on AJCC 8th edition staging. Included were 700 consecutive patients (700 eyes) treated with primary enucleation at 29 Chinese treatment centers between 2006 and 2015. Excluded were patients with less than one year follow-up, bilateral retinoblastoma, clinical evidence of extraocular disease at diagnosis, or prior focal or systemic therapy. The 5-year overall survival was 95.5%, and 5-year disease-specific survival (DSS) was 95.7%. Survival was better when enucleation was <26 days from diagnosis than delayed >26 days (96.1% vs. 86.9%; p = 0.017). Patients with eyes presenting with raised intraocular pressure with neovascularization and/or buphthalmos (cT3c) had worse 5-year DSS (87.1%) than those without (cT2b, 99.1%; cT3b, 98.7%; cT3d, 97.2%) (p < 0.05). The 5-year DSS based on pathological staging was pT1 (99.5%), pT2a (95.5%), pT3a (100%), pT3b (93.0%), pT3c/d (92.3%), and pT4 (40.9%). Patients with pT3 pathology who received six cycles of adjuvant chemotherapy had better 5-year DSS (97.7%) than those with no chemotherapy (88.1%; p = 0.06) and those who underwent 1-3 cycles (86.9%, p = 0.02) or 4-5 cycles (89.3%, p = 0.06). Patients with pT4 pathology who received six cycles of chemotherapy had better 5-year DSS than those with 0-5 cycles (63.6% vs. 16.7%; p = 0.02). Prompt primary enucleation yielded high long-term survival for children with retinoblastoma. The AJCC 8th edition staging is predictive of survival.

Tylectomy Safety in Salvage of Eyes with Retinoblastoma.

Intraocular surgery is tabooed in retinoblastoma management, due to the concern of lethal extraocular spread. We reviewed the outcomes of consecutive children with intraocular retinoblastoma diagnosed at 29 Chinese centers between 2012-2014. We compared the outcomes of three categories of treatment: eye salvage including tylectomy (Group I), eye salvage without tylectomy (Group II), and primary enucleation (Group III). A total of 960 patients (1243 eyes) were diagnosed: 256 in Group I, 370 in Group II, and 293 in Group III; 41 patients abandoned treatment upfront. The estimated 5-year overall survivals (OS) were, for Group I, 94%, for Group II 89%, and for Group III 95%. The estimated 5-year disease-specific survivals (DSS) were, for Group I, 96%, for Group II 90%, and for Group III 95%. Patients in Group I had a significantly higher 5-year DSS than patients in Group II (p = 0.003) and not significantly different than patients in Group III (p = 0.367). Overall survival was not compromised by the inclusion of tylectomy in eye salvage therapy compared to eye salvage without tylectomy or primary enucleation. Disease-specific survival was better when tylectomy was included in eye salvage treatments. Tylectomy as part of multimodal treatment may contribute to the care of retinoblastoma patients with chemotherapy-resistant tumor, eyes with concomitant ocular complications, or at the risk of treatment abandonment.

Natural History of Untreated Retinoblastoma.

Treatment abandonment is a leading cause of death in children with retinoblastoma worldwide. We studied children who abandoned treatment upfront at diagnosis to delineate the natural history of untreated retinoblastoma. Studied were children who received no treatment, diagnosed between 2007 and 2017 at 29 Chinese centers. Data were retrospectively collected from medical chart reviews and interviews with each patient's family. During the study period, 44 children received no treatment after diagnosis of retinoblastoma. Clinical or radiologic evidence of orbital extension was available for 25 children, and radiologic evidence of systemic metastasis was available for 12 children. Median times from diagnosis of intraocular tumor to orbital disease was 13.7 months, orbital disease to metastasis was 2.6 months, and metastasis to death was 2.0 months. Children with brain metastasis had shorter survival than those with metastasis to other sites (median 1.0 vs. 3.1 months; p = 0.015). Overall, 36% of patients died within 12 months of diagnosis, 77% within 24 months, 95% within 36 months and 100% within 48 months. While multiple factors influence refusal of treatment, insights into the natural history of retinoblastoma derived from real-world evidence can inform clinicians and parents that retinoblastoma is life-threatening and encourage urgent treatment at diagnosis.

RB1 germline mutation spectrum and clinical features in patients with unilateral retinoblastomas.

Background: Retinoblastoma is the most common intraocular cancer in children in which above 90% of bilateral cases and 10-25% of unilateral cases have germline RB1 mutations. We summarized the spectrum of RB1 germline mutations and the clinical manifestations of unilateral retinoblastomas to guide clinical treatments.Methods: Two hundred and sixty-three unrelated patients with unilateral retinoblastoma and their parents were included between February 2014 and August 2020. Next-generation sequencing and Sanger sequencing analysis of the core promoter region and exons 1-27 including flanking intronic regions of the RB1 gene were performed. If a germline mutation was identified in a retinoblastoma patient, the parental blood sample was requested to test for the identified mutation.Results: RB1 germline mutations were identified in 39/263 (14.8%) unilateral retinoblastoma patients and 11 (28.2%) had a missense mutation, 10 (25.6%) had nonsense mutations, 2 (5.1%) had frameshifts, 1 (2.6%) had synonymous mutation, and 7 (17.9%) had a large deletion, 2 (5.1%) had splice site mutations, 6 (15.4%) had variant of uncertain significance. Moreover, 27 (69.2%) of 39 patients identified RB1 mutations were predicted to have pathogenic mutation. The median age at diagnosis of patients with identified RB1 pathogenic mutations was 16.9 months and the patients with the wild-type allele was 21.1 months (P = .323).Conclusion: The rate of germline RB1 mutations is 14.8% in our cohort of unilateral retinoblastomas. The high incidence of germline mutations indicates that genetic testing and counseling for families of unilateral retinoblastoma patients would be beneficial.

Response criteria for intraocular retinoblastoma: RB-RECIST.

Standardized guidelines for assessing tumor response to therapy are essential for designing and conducting clinical trials. The Response Evaluation Criteria In Solid Tumors (RECIST) provide radiological standards for assessment of solid tumors. However, no such guidelines exist for the evaluation of intraocular cancer, and ocular oncology clinical trials have largely relied on indirect measures of therapeutic response-such as progression-free survival-to evaluate the efficacy of treatment agents. Herein, we propose specific criteria for evaluating treatment response of retinoblastoma, the most common pediatric intraocular cancer, and emphasize a multimodal imaging approach for comprehensive assessment of retinoblastoma tumors in clinical trials.

Applications of iodine-125 plaque radiotherapy for residual or recurrent retinoblastoma.

OBJECTIVE: To determine the role of iodine-125 plaque radiotherapy (IPR) as a secondary treatment for localized (solitary or multiple) residual (partially regressed) or recurrent (regrowth after ≥6 months stability) retinoblastoma in the era of systemic and/or regional chemotherapy. DESIGN: A single-institute retrospective, noncomparative, interventional case series managed between July 2014 and June 2019. PARTICIPANTS: Thirteen consecutive eyes of 12 patients with 14 residual or recurrent retinoblastoma tumors treated with IPR. Patients who had to follow up <1 year post-IPR were excluded except for those who had enucleation. METHODS: Data collected included pre-IPR treatments, tumor characteristics at IPR, and post-IPR anatomical outcome (local tumor control and globe salvage) and functional outcome (radiation complications). RESULTS: Local tumor control was achievable in 12 of 14 tumors. Local recurrences were observed in 2 of 5 tumors that exhibited fish-flesh regression after IPR (p = 0.04). Globe salvage was possible in 11 eyes (12 tumors). Only 2 eyes were legally blind and the remaining 9 eyes had vision >20/125. Radiation-induced complications included radiation retinopathy (4/11), radiation papillopathy (1/11), diffuse vitreous hemorrhage (4/11). Eyes with fish-flesh-regressed tumours tended to show more complications, but were statistically insignificant (p = 0.09, Fisher exact test). There was no association of time to IPR (early <6 months vs late >6 months) with occurrence of tumor recurrence or complications (p > 0.05). CONCLUSION: IPR offers satisfactory local tumor control and globe salvage in localized recurrent/residual retinoblastoma. Fish-flesh tumor regression after IPR should be closely monitored for further recurrences.

Impact of Systemic Chemotherapy and Delayed Enucleation on Survival of Children with Advanced Intraocular Retinoblastoma.

PURPOSE: Primary enucleation is a well-established method to achieve cure for advanced intraocular retinoblastoma. Recent treatment advances have induced a trend toward trial eye salvage using chemotherapy or other modalities. We investigated how pre-enucleation/postenucleation systemic chemotherapy and the resulting delayed enucleation affect patient survival after failed trial eye salvage. DESIGN: Multicenter, retrospective cohort study. PARTICIPANTS: Children with Group D and E retinoblastoma primarily or secondarily enucleated at 29 Chinese treatment centers. METHODS: Data reviewed included clinical staging, time from diagnosis to enucleation, numbers of cycles of carboplatin, etoposide/teniposide and vincristine chemotherapy, disease-specific survival (DSS), histopathology, and follow-up. MAIN OUTCOME MEASURES: Primary outcome was DSS. Secondary outcome was histopathology of enucleated eyes. RESULTS: Primarily enucleated eyes had significantly shorter delay from diagnosis to enucleation than eyes treated with pre-enucleation chemotherapy (P < 0.001). Delay between diagnosis and enucleation >3.5 months (Group D) and >2 months (Group E) decreased survival (Group D: P = 0.018; Group E: P = 0.017). Compared with primarily enucleated children, children with 1 to 3 cycles of pre-enucleation chemotherapy for Group E eyes had no significant difference in survival (P = 0.74), but those who received ≥4 cycles had worse survival (P = 0.025). After pre-enucleation chemotherapy, more children with Group E (but not Group D) eyes had high-risk histopathology (pT3/pT4) (Group D: P = 0.076; Group E: P < 0.001) and worse survival than those primarily enucleated (P < 0.001). Postenucleation chemotherapy improved survival of children with high-risk histopathology (pT3/pT4) (P = 0.001) but did not change survival of children with low-risk histopathology (pT1/pT2) (P = 0.52). CONCLUSIONS: We observed that pre-enucleation chemotherapy offered no survival benefit and timely enucleation minimized risk of metastatic death. Postenucleation chemotherapy improved survival of children with high-risk histopathology but was not useful for those with low-risk histopathology. These findings facilitate informed discussion on the risks and benefits of delayed enucleation, the use of systemic chemotherapy for trial salvage of eyes with advanced intraocular retinoblastoma, and the specific children who benefit from postenucleation chemotherapy.

Secondary Prevention of Retinoblastoma Revisited: Laser Photocoagulation of Invisible New Retinoblastoma.

PURPOSE: Invisible retinoblastoma tumors are now detected with screening for retinal tumors in at-risk neonates (those inheriting RB1 pathogenic alleles from affected parents) using handheld OCT. Laser photocoagulation is challenging, requiring exact localization of a tumor invisible to indirect ophthalmoscopy and standard imaging. We describe OCT-guided localization and photocoagulation of these invisible tumors with 1-year follow-up. DESIGN: Retrospective, noncomparative, single-institutional, observational case series. PARTICIPANTS: Children with any clinically invisible retinoblastoma tumor that was detected on OCT posterior pole screening. METHODS: OCT revealed round homogeneous invisible tumors within the inner nuclear layer. Software calipers placed beside anatomic retinal landmarks (branched/curved vessels, fovea, or optic disc) mapped the tumor location and extent. A single laser (532 nm) burn flagged the location, and OCT evaluated the tumor-laser burn relationship; laser treatment was then continued in the correct location. Post-laser OCT ensured complete treatment. MAIN OUTCOME MEASURES: Accuracy (frequency of geographic miss and skip areas), effectiveness (recurrence rate), and burden (scar size and characteristics at final follow-up) of laser treatment. RESULTS: Eleven new invisible posterior pole tumors in 7 eyes of 5 children were treated by this technique. Localization and tumor-laser burn relationships were accurate in 11 of 11 tumors (100%, 95% confidence interval [CI], 49.9-100), and all showed swelling and hyper-reflectiveness of the tumor in post-laser OCT. Two photocoagulation sessions (2 weeks apart) were sufficient to successfully manage 9 of 11 tumors (82%, 95% CI, 37.4-100) with resulting permanent flat scars. One tumor (9%, 95% CI, 0.2-50.6) developed OCT-detected subclinical recurrences within 3 months, treated by 1 laser session. No treatment scar showed gliosis, foveal involvement, or retinal traction at 1-year follow-up. Scar expansion occurred in 1 tumor (9%, 95% CI, 0.2-50.6), and all scars (100%, 95% CI, 49.9-100) showed pigmentary changes. CONCLUSIONS: The OCT-guided localization and photocoagulation technique is valuable in achieving precision results in managing invisible new retinoblastoma tumors. This technique shows a potential to improve outcomes of secondary prevention screening for retinoblastoma.

The RB1 Story: Characterization and Cloning of the First Tumor Suppressor Gene.

The RB1 gene is the first described human tumor suppressor gene and plays an integral role in the development of retinoblastoma, a pediatric malignancy of the eye. Since its discovery, the stepwise characterization and cloning of RB1 have laid the foundation for numerous advances in the understanding of tumor suppressor genes, retinoblastoma tumorigenesis, and inheritance. Knowledge of RB1 led to a paradigm shift in the field of cancer genetics, including widespread acceptance of the concept of tumor suppressor genes, and has provided crucial diagnostic and prognostic information through genetic testing for patients affected by retinoblastoma. This article reviews the long history of RB1 gene research, characterization, and cloning, and also discusses recent advances in retinoblastoma genetics that have grown out of this foundational work.

Clinical Predictors at Diagnosis of Low-Risk Histopathology in Unilateral Advanced Retinoblastoma.

PURPOSE: Attempted eye salvage for unilateral (cT2b/group D) retinoblastoma may risk tumor spread compared with primary enucleation. Identification of clinical features predictive of low histopathologic risk support safe trial salvage. DESIGN: Retrospective, noncomparative single-institutional observational case series. PARTICIPANTS: Children with unilateral cT2b/group D retinoblastoma managed with primary enucleation at the Hospital for Sick Children, Toronto, Canada, January 2008 through February 2018. METHODS: Data included clinical features (intraocular pressure, optic nerve obscuration, macular involvement, tumor seeding, and serous retinal detachment [RD] >1 quadrant), timing to enucleation, histopathologic features, and follow-up. MAIN OUTCOME MEASURES: Primary outcome was low-risk (LR; pT1/pT2) versus high-risk (HR; pT3/pT4) histopathologic features with clinicopathologic correlations. Secondary outcomes were positive predictive (probability that certain clinical features would predict LR histopathologic features) and negative predictive values (probability that absence of these clinical features would predict HR histopathologic features). RESULTS: Thirty-eight eyes were eligible and showed vitreous seeding and normal intraocular pressure. The median diagnosis to enucleation interval was 4 days (range, 0-14 days). Histopathologic analysis diagnosed 4 (10.5%) HR and 34 (89.5%) LR eyes. High-risk eyes demonstrated massive choroidal invasion (4/38) or trans-scleral, extraocular, and postlaminar optic nerve invasion (1/38). Clinical findings included macular involvement (31/38), complete optic nerve obscuration (27/38), and RD (28/38). The proportion of eyes with HR histopathologic features was 13% (4/31; 95% confidence interval [CI], 1%-25%) with macular involvement, 15% (4/27; 95% CI, 1%-28%) with complete optic nerve obscuration, and 14% (4/28; 95% CI, 1%-27%) with RD. The predictability of LR histopathologic features was 100% with macular sparing (7/7; 95% CI, 47%-100%), optic nerve visibility (10/10; 95% CI, 63%-100%), and less than 1 quadrant of RD (10/10; 95% CI, 63%-100%). In 1 child lacking all 3 clinical LR predictive features with HR histopathologic features (pT3a), metastases developed and the patient died; other children are alive and well (mean follow-up, 65 months). CONCLUSIONS: Presence of macular sparing, optic nerve visibility, less than 1 quadrant of RD, or a combination thereof predicted LR histopathologic features at primary enucleation, suggesting safe trial eye salvage. No clinical sign predicted HR histopathologic features.

Single-center retrospective study of the effectiveness and toxicity of the oral iron chelating drugs deferiprone and deferasirox.

BACKGROUND: Iron overload, resulting from blood transfusions in patients with chronic anemias, has historically been controlled with regular deferoxamine, but its parenteral requirement encouraged studies of orally-active agents, including deferasirox and deferiprone. Deferasirox, licensed by the US Food and Drug Administration in 2005 based upon the results of randomized controlled trials, is now first-line therapy worldwide. In contrast, early investigator-initiated trials of deferiprone were prematurely terminated after investigators raised safety concerns. The FDA declined market approval of deferiprone; years later, it licensed the drug as "last resort" therapy, to be prescribed only if first-line drugs had failed. We undertook to evaluate the long-term effectiveness and toxicities of deferiprone and deferasirox in one transfusion clinic. METHODS AND FINDINGS: Under an IRB-approved study, we retrospectively inspected the electronic medical records of consented iron-loaded patients managed between 2009 and 2015 at The University Health Network (UHN), Toronto. We compared changes in liver and heart iron, adverse effects and other outcomes, in patients treated with deferiprone or deferasirox. RESULTS: Although deferiprone was unlicensed in Canada, one-third (n = 41) of locally-transfused patients had been switched from first-line, licensed therapies (deferoxamine or deferasirox) to regimens of unlicensed deferiprone. The primary endpoint of monitoring in iron overload, hepatic iron concentration (HIC), increased (worsened) during deferiprone monotherapy (mean 10±2-18±2 mg/g; p < 0.0003), exceeding the threshold for life-threatening complications (15 mg iron/g liver) in 50% patients. During deferasirox monotherapy, mean HIC decreased (improved) (11±1-6±1 mg/g; p < 0.0001). Follow-up HICs were significantly different following deferiprone and deferasirox monotherapies (p < 0.0000002). Addition of low-dose deferoxamine (<40 mg/kg/day) to deferiprone did not result in reductions of HIC to <15 mg/g (baseline 20±4 mg/g; follow-up, 18±4 mg/g; p < 0.2) or in reduction in the proportion of patients with HIC exceeding 15 mg/g (p < 0.2). During deferiprone exposure, new diabetes mellitus, a recognized consequence of inadequate iron control, was diagnosed in 17% patients, most of whom had sustained HICs exceeding 15 mg/g for years; one woman died after 13 months of a regimen of deferiprone and low-dose deferasirox. During deferiprone exposure, serum ALT increased over baseline in 65% patients. Mean serum ALT increased 6.6-fold (p < 0.001) often persisting for years. During deferasirox exposure, mean ALT was unchanged (p < 0.84). No significant differences between treatment groups were observed in the proportions of patients estimated to have elevated cardiac iron. CONCLUSIONS: Deferiprone showed ineffectiveness and significant toxicity in most patients. Combination with low doses of first-line therapies did not improve the effectiveness of deferiprone. Exposure to deferiprone, over six years while the drug was unlicensed, in the face of ineffectiveness and serious toxicities, demands review of the standards of local medical practice. The limited scope of regulatory approval of deferiprone, worldwide, should restrict its exposure to the few patients genuinely unable to tolerate the two effective, first-line therapies.