This week’s Rare Diseases update highlights clinical progress, manufacturing partnerships, rare-disease dealmaking, pipeline reprioritization, and treatment optimization.
In Today’s Newsletter
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🧬 CRENESSITY glucocorticoid-reduction guidance [1] [US • 06 May 2026]
https://neurocrine.gcs-web.com/news-releases/news-release-details/neurocrine-biosciences-announces-publication-expert
Context: Neurocrine Biosciences published pediatric and adult expert recommendations in The Journal of Clinical Endocrinology & Metabolism.
Key point: The algorithms guide glucocorticoid dose reduction after CRENESSITY (crinecerfont) initiation in classic CAH.
Implication: May influence prescriber choice and payer reviews pending full data.
👁️ BioCryst ends avoralstat DME program [2] [06 May 2026]
https://www.fiercebiotech.com/biotech/biocryst-culls-eye-disease-candidate-after-second-attempt-find-indication
Context: Avoralstat was being studied in diabetic macular edema after earlier hereditary angioedema development was discontinued.
Key point: BioCryst Pharmaceuticals ended avoralstat development to focus its pipeline on rare diseases.
Implication: Signals pipeline investment and modality expansion.
🧫 AGC Biologics joins OTXL ClinDevNet [3] [US • 11 May 2026]
https://www.globenewswire.com/news-release/2026/05/11/3291817/0/en/agc-biologics-joins-orphan-therapeutics-accelerator-s-clinical-development-network-as-a-manufacturing-partner-to-advance-cell-and-gene-therapies-for-ultra-rare-diseases.html
Context: OTXL’s Orphan ClinDevNet supports development and commercial access for stalled ultra-rare disease therapies.
Key point: AGC Biologics joined the network as a manufacturing partner for cell and gene therapies, including ex vivo gene-therapy work.
Implication: Signals pipeline investment and modality expansion.
🏢 BioMarin consolidates Amicus workforce [4] [US • 12 May 2026]
https://www.fiercepharma.com/pharma/biomarin-consolidates-staff-amicus-hq-after-closing-48b-deal-rare-disease-peer
Context: BioMarin closed its $4.8B acquisition of Amicus Therapeutics, adding Galafold, Pombiliti-Opfolda, and DMX-200.
Key point: BioMarin is removing 58 roles tied to Amicus’ Princeton, New Jersey headquarters, with cuts scheduled from August to late October.
Implication: Signals pipeline investment and modality expansion.
⚡ Actio starts KYRON Phase 1b/2 trial [5] [US • 08 May 2026]
https://www.biospace.com/press-releases/actio-biosciences-announces-initiation-of-kyron-phase-1b-2-trial-of-abs-1230-for-the-treatment-of-kcnt1-related-epilepsy-and-acceptance-into-fdas-rare-disease-evidence-principles-process
Context: ABS-1230 is an oral or feeding-tube KCNT1 inhibitor for KCNT1-related epilepsy in children and young adults.
Key point: Actio Biosciences initiated the KYRON Phase 1b/2 trial and gained FDA RDEP process acceptance.
Implication: May influence prescriber choice and payer reviews pending full data.
🫀 Repair Biotechnologies gains RDEP eligibility [6] [US • 12 May 2026]
https://www.accessnewswire.com/newsroom/en/biotechnology/repair-biotechnologies-granted-rare-disease-evidence-principles-rdep-eligibility-by-t-1165799
Context: REP-0003 is an investigational mRNA therapy for homozygous familial hypercholesterolemia.
Key point: Repair Biotechnologies received FDA RDEP eligibility for REP-0003 and plans to open an IND application.
Implication: May influence prescriber choice and payer reviews pending full data.
🤝 Angelini to acquire Catalyst [7] [Italy–US • 07 May 2026]
https://www.angelinipharma.com/news-media/press-releases/angelini-pharma-to-acquire-catalyst-pharmaceuticals/
Context: Catalyst markets rare neuromuscular and neurological medicines, including FIRDAPSE, AGAMREE, and FYCOMPA US rights.
Key point: Angelini Pharma agreed to acquire Catalyst Pharmaceuticals for about $4.1B, with closing expected in Q3 2026.
Implication: Signals pipeline investment and modality expansion.
Why it matters
- FDA’s RDEP process appears in two rare-disease programs this week, ABS-1230 and REP-0003. [5], [6]
- Rare-disease M&A remains active, with Angelini entering the US market and BioMarin integrating Amicus. [4], [7]
- Manufacturing access is a recurring bottleneck for ultra-rare cell and gene therapies, which AGC Biologics and OTXL are targeting. [3]
- CRENESSITY guidance shifts attention from approval to real-world treatment optimization in classic CAH. [1]
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FAQ
What did Neurocrine publish for CRENESSITY?
Neurocrine published expert recommendations for reducing supraphysiologic glucocorticoid doses after starting CRENESSITY in classic CAH. The source describes separate pediatric and adult algorithms. [1]
Why did BioCryst stop avoralstat development?
BioCryst ended avoralstat development in diabetic macular edema to focus its pipeline on rare diseases. The Fierce Biotech article notes the company had not provided more detail at publication. [2]
What does AGC Biologics add to OTXL’s network?
AGC Biologics adds cell and gene therapy manufacturing capabilities to OTXL’s Orphan ClinDevNet. The collaboration is intended to support ultra-rare therapies from development toward access. [3]
What assets did BioMarin gain from Amicus?
BioMarin gained Amicus’ approved Fabry disease drug Galafold, Pompe disease combination Pombiliti-Opfolda, and Phase 3 FSGS asset DMX-200. [4]
What is ABS-1230 being tested for?
ABS-1230 is being tested in Actio’s KYRON Phase 1b/2 trial for KCNT1-related epilepsy. The study includes safety, tolerability, pharmacokinetics, seizure activity, and neurodevelopmental outcomes. [5]
What is Angelini buying in Catalyst?
Angelini is buying Catalyst’s rare neuromuscular and neurological disease portfolio and US commercial infrastructure. The portfolio includes FIRDAPSE, AGAMREE, and FYCOMPA US rights. [7]
Entities / Keywords
Neurocrine Biosciences, CRENESSITY, crinecerfont, classic congenital adrenal hyperplasia, classic CAH, glucocorticoid reduction
BioCryst Pharmaceuticals, avoralstat, diabetic macular edema, DME, hereditary angioedema, HAE, Orladeyo
AGC Biologics, Orphan Therapeutics Accelerator, OTXL, Orphan ClinDevNet, WASKYRA, CD34+ HSC, lentiviral vector
BioMarin Pharmaceutical, Amicus Therapeutics, Galafold, Pombiliti-Opfolda, DMX-200, Fabry disease, Pompe disease, FSGS
Actio Biosciences, ABS-1230, KYRON trial, KCNT1-related epilepsy, KCNT1 inhibitor, FDA RDEP
Repair Biotechnologies, REP-0003, homozygous familial hypercholesterolemia, HoFH, mRNA therapy, Cholesterol Degrading Platform
Angelini Pharma, Catalyst Pharmaceuticals, FIRDAPSE, amifampridine, AGAMREE, vamorolone, FYCOMPA, perampanel
References
- https://neurocrine.gcs-web.com/news-releases/news-release-details/neurocrine-biosciences-announces-publication-expert
- https://www.fiercebiotech.com/biotech/biocryst-culls-eye-disease-candidate-after-second-attempt-find-indication
- https://www.globenewswire.com/news-release/2026/05/11/3291817/0/en/agc-biologics-joins-orphan-therapeutics-accelerator-s-clinical-development-network-as-a-manufacturing-partner-to-advance-cell-and-gene-therapies-for-ultra-rare-diseases.html
- https://www.fiercepharma.com/pharma/biomarin-consolidates-staff-amicus-hq-after-closing-48b-deal-rare-disease-peer
- https://www.biospace.com/press-releases/actio-biosciences-announces-initiation-of-kyron-phase-1b-2-trial-of-abs-1230-for-the-treatment-of-kcnt1-related-epilepsy-and-acceptance-into-fdas-rare-disease-evidence-principles-process
- https://www.accessnewswire.com/newsroom/en/biotechnology/repair-biotechnologies-granted-rare-disease-evidence-principles-rdep-eligibility-by-t-1165799
- https://www.angelinipharma.com/news-media/press-releases/angelini-pharma-to-acquire-catalyst-pharmaceuticals/