Core Viewpoint - Fortress Biotech and its subsidiary Cyprium Therapeutics received a Complete Response Letter from the FDA regarding the New Drug Application for CUTX-101, intended for treating Menkes disease in pediatric patients [1][3]. Group 1: Company Developments - In December 2023, Sentynl Therapeutics assumed full responsibility for the development and commercialization of CUTX-101 from Cyprium [2]. - Sentynl expects to address the FDA's concerns and pursue resubmission of the CUTX-101 NDA promptly [2][3]. - The CRL highlighted cGMP deficiencies at the manufacturing facility, but did not raise concerns regarding the efficacy and safety data of CUTX-101 [3]. Group 2: Financial and Regulatory Aspects - Sentynl will transfer a Rare Pediatric Disease Priority Review Voucher to Cyprium upon approval and Cyprium is eligible for royalties on net sales of CUTX-101, along with up to $129 million in development and sales milestones [4]. - The CUTX-101 NDA was initially granted Priority Review by the FDA, supported by positive clinical efficacy results showing significant improvement in overall survival for Menkes disease patients receiving early treatment [5]. Group 3: Disease Background - Menkes disease is a rare X-linked recessive pediatric condition caused by mutations in the copper transporter ATP7A, with a birth prevalence estimated between 1 in 34,810 and 1 in 8,664 live male births [6]. - The disease is characterized by severe neurological symptoms and high mortality rates in untreated cases, with many patients not surviving past the age of 2-3 years [6]. Group 4: Company Overview - Cyprium Therapeutics focuses on developing therapies for Menkes disease and related disorders, having entered into a Cooperative Research and Development Agreement with the NIH to advance CUTX-101 [7]. - Fortress Biotech is an innovative biopharmaceutical company with a diverse portfolio, including eight marketed products and multiple development programs across various therapeutic areas [8][9].