Biogen announced Thursday it will acquire Alcyone Therapeutics for $85 million upfront plus development and regulatory milestones, securing full rights to an implantable drug delivery system that could transform how patients receive neurological therapies. The acquisition centers on ThecaFlex DRx, an investigational subcutaneous port and catheter device designed to provide easier access to the cerebrospinal fluid for drug administration.
The two companies have collaborated since 2023 on developing ThecaFlex DRx as an alternative delivery method for SPINRAZA (nusinersen), Biogen's blockbuster treatment for spinal muscular atrophy that generated almost $1.6 billion in revenue last year. Currently, SPINRAZA must be administered through repeated lumbar punctures directly into the central nervous system, a procedure that can be challenging for patients and families.
Clinical Development and Regulatory Status
Two clinical studies, PIERRE and PIERRE-PK, are currently underway testing the ThecaFlex DRx system's delivery of nusinersen. The device has received CE Mark approval in Europe and Investigational Device Exemption (IDE) from the U.S. Food and Drug Administration to conduct clinical investigations. Additionally, ThecaFlex has been granted Breakthrough Device Designation from the FDA, recognizing its potential to address unmet medical needs.
Biogen plans to introduce the new drug delivery system for SPINRAZA in early 2028, contingent upon successful completion of clinical trials and regulatory approval. The company expects the current testing will "inform pathways" for broader applications across its neurological medicine portfolio.
Technology and Manufacturing
ThecaFlex DRx, part of Alcyone's Falcon Delivery Platform, consists of an implantable intrathecal catheter, catheter fixation device, and subcutaneous port system. The technology has been in development since 2019 and is manufactured locally at Alcyone's Lowell, Massachusetts facility. The system is designed to enable routine administration of therapies through intrathecal bolus administration while avoiding the need for repeated lumbar punctures.
Strategic Implications for Antisense Oligonucleotides
The acquisition strengthens Biogen's position in antisense oligonucleotide therapies, building on its successful partnership with Ionis Pharmaceuticals. Beyond SPINRAZA, which is approved in more than 71 countries and has treated over 14,000 individuals worldwide, Biogen and Ionis have brought Qalsody to market for ALS and are developing additional treatments for Alzheimer's disease and spinal muscular atrophy.
SPINRAZA works as an antisense oligonucleotide that targets the underlying cause of motor neuron loss by continuously increasing the amount of full-length survival motor neuron (SMN) protein produced in the body. It has demonstrated efficacy across ages and SMA types with a well-established safety profile based on data in patients treated up to 10 years.
Transaction Structure and Future Operations
Under the acquisition terms, Biogen will account for the transaction as an asset acquisition, with substantially all of the upfront payment recorded as acquired in-process research and development expense in the fourth quarter of 2025. The transaction is subject to customary closing conditions.
Following the acquisition, Biogen expects to oversee end-to-end development, manufacturing, and commercialization of ThecaFlex DRx. Alcyone's remaining therapeutic assets, along with its Falcon precision intra-cerebrospinal fluid drug transport modeling and intraparenchymal delivery technologies, will be divested into a new independent company called Neela Therapeutics, Inc. The transaction will include convertible debt financing in Neela Therapeutics from existing investors, including Biogen.
