Oral Hypoxia-Inducible Factor 2α Inhibitor Belzutifan in Ocular von Hippel-Lindau Disease: Subgroup Analysis of the Single-Arm Phase 2 LITESPARK-004 Study.

PURPOSE: To report the efficacy of the oral hypoxia-inducible factor 2α inhibitor belzutifan in participants with von Hippel-Lindau disease-associated retinal hemangioblastomas in the LITESPARK-004 study. DESIGN: Subgroup analysis of the phase 2, single-arm, open-label LITESPARK-004 study. PARTICIPANTS: Adults with 1 or more von Hippel-Lindau disease-associated measurable renal cell carcinoma tumors not requiring immediate surgical intervention were eligible. METHODS: Participants received oral belzutifan 120 mg once daily until disease progression or unacceptable treatment-related toxicity. MAIN OUTCOME MEASURES: Efficacy of belzutifan in retinal hemangioblastomas was a secondary end point, measured as response (improved, stable, or progressed) by independent reading center-certified graders based on color fundus imaging performed every 12 weeks using the investigator's preferred imaging standards. Additional assessments, where available, included OCT and ultra-widefield fluorescein angiography. RESULTS: Among 61 participants in LITESPARK-004, 12 had 1 or more evaluable active retinal hemangioblastomas in 16 eyes at baseline per independent reading center. As of April 1, 2022, the median follow-up for participants with ocular von Hippel-Lindau disease at baseline was 37.3 months. All 16 eyes were graded as improved, with a response rate of 100.0% (95% confidence interval, 79.4%-100%). No new retinal hemangioblastomas or ocular disease progression were reported as of data cutoff date. Eight participants underwent additional multimodal eye assessments performed at the National Institutes of Health study site. Among this subgroup, 10 of 24 hemangioblastomas in 8 eyes of 6 participants measured 500 µm or more in greatest linear dimension at baseline and were analyzed further. All 10 hemangioblastomas had a mean area reduction of 15% or more by month 12 and of 30% or more by month 24. CONCLUSIONS: Belzutifan showed promising activity against ocular von Hippel-Lindau disease, including capacity to control retinal hemangioblastomas, with effects sustained for more than 2 years while treatment is ongoing. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Belzutifan for von Hippel-Lindau Disease: Pancreatic Lesion Population of the Phase 2 LITESPARK-004 Study.

PURPOSE: Primary analysis of the ongoing, single-arm, phase 2 LITESPARK-004 study (NCT03401788) showed clinically meaningful antitumor activity in von Hippel-Lindau (VHL) disease-associated renal cell carcinoma (RCC) and other neoplasms with belzutifan treatment. We describe results of belzutifan treatment for VHL disease-associated pancreatic lesions [pancreatic neuroendocrine tumors (pNET) and serous cystadenomas]. PATIENTS AND METHODS: Adults with VHL diagnosis based on germline VHL alteration, ≥1 measurable RCC tumor, no renal tumor >3 cm or other VHL neoplasm requiring immediate surgery, Eastern Cooperative Oncology Group performance status of 0 or 1, and no prior systemic anticancer treatment received belzutifan 120 mg once daily. End points included objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), and linear growth rate (LGR) in all pancreatic lesions and pNETs per RECIST version 1.1 by independent review committee, and safety. RESULTS: All 61 enrolled patients (100%) had ≥1 pancreatic lesion and 22 (36%) had ≥1 pNET measurable at baseline. Median follow-up was 37.8 months (range, 36.1-46.1). ORR was 84% [51/61; 17 complete responses (CR)] in pancreatic lesions and 91% (20/22; 7 CRs) in pNETs. Median DOR and median PFS were not reached in pancreatic lesions or pNETs. After starting treatment, median LGR for pNETs was -4.2 mm per year (range, -7.9 to -0.8). Eleven patients (18%) had ≥1 grade 3 treatment-related adverse event (AE). No grade 4 or 5 treatment-related AEs occurred. CONCLUSIONS: Belzutifan continued to show robust activity and manageable safety in VHL disease-associated pNETs.

Small cell bladder cancer: should we consider prophylactic cranial irradiation?

ABSTRACT Purpose: To describe the clinical characteristics, treatment patterns, and outcomes in patients with small cell bladder cancer at our institution, including those who received prophylactic cranial irradiation (PCI) for the prevention of intracranial recurrence. Materials and Methods: Patients with small cell bladder cancer treated at a single institution between January 1990 and August 2015 were identified and analyzed retrospectively for demographics, tumor stage, treatment, and overall survival. Results: Of 44 patients diagnosed with small cell bladder cancer, 11 (25%) had metastatic disease at the time of presentation. Treatment included systemic chemotherapy (70%), radical surgery (59%), and local radiation (39%). Six patients (14%) received PCI. Median overall survival was 10 months (IQR 4 - 41). Patients with extensive disease had worse overall survival than those with organ confined disease (8 months vs. 36 months, respectively, p = 0.04). Among those who received PCI, 33% achieved 5 - year survival. Conclusion: Outcomes for patients with small cell bladder cancer remain poor. Further research is indicated to determine if PCI increases overall survival in small call bladder cancer patients, especially those with extensive disease who respond to chemotherapy.