Editor’s Briefing: September 18, 2026

In Short. Ultragenyx’s Fayuvi (ex-UX111) won FDA approval as the first disease-modifying gene therapy for Sanfilippo A a day ahead of its listed PDUFA; Xenon paused new enrollment in phase 3 depression trials of Kv7 opener azetukalner after rare psychosis-coded events while still treating dosed patients and filing epilepsy; Bristol Myers Squibb walked away from the $100 million Orum CD33 degrader-antibody conjugate after phase 1; Bayer’s Kerendia became the first U.S. drug in three decades cleared for type 1 diabetes–associated CKD (UACR reduction); Roche’s Lunsumio plus lenalidomide beat R2 on PFS in confirmatory Celestimo; Electra banked an upsized $350 million IPO for SIRP-targeted ipsoprubart in secondary HLH as reverse-merger and PIPE activity stayed hot; and Novo put up to $1.4 billion behind Orbis’s oral macrocycle platform for cardiometabolic targets.

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Fayuvi: Sanfilippo gene therapy clears

The FDA approved Ultragenyx’s Fayuvi for children with mucopolysaccharidosis type IIIA (Sanfilippo syndrome type A), the first therapy designed to treat the underlying SGSH deficiency rather than manage symptoms alone. Fayuvi, previously UX111, is an AAV gene therapy delivering a working SGSH copy; Ultragenyx cites roughly 3,000 to 5,000 patients in the developed world. Acting Commissioner Kyle Diamantas called the Sept. 17 decision a landmark for a disease that had no approved disease-modifying option. The path was not clean: a prior complete response cited manufacturing issues at Ultragenyx’s own plant and a third-party site; resubmission was accepted in April under priority review, with commercial supply framed at Bedford, Massachusetts, and Andelyn in Columbus. Efficacy rested on a small single-arm package versus natural history: CSF heparan sulfate as biomarker plus neurodevelopment. Among 17 younger or earlier-stage children, a one-time IV infusion showed a 23.2-point Bayley-III cognitive treatment effect versus natural history, and eight reached a 36-month cognitive developmental age that no natural-history peer hit; among ten older or later-stage children, functional retention in at least one of three domains exceeded typical untreated decline. The win is Ultragenyx’s second FDA gene-therapy approval in under a month (after Genglycos in GSDIa) and lands against the company’s recent phase 3 Angelman antisense miss and talk of “significant expense reductions.” (Fierce Pharma)

Xenon: Kv7 depression pause, epilepsy still filing

Xenon Pharmaceuticals voluntarily stopped new enrollment in X-Nova2 (major depressive disorder) and X-Ceed (bipolar depression) after mostly mild-to-moderate neuropsychiatric adverse events, including a small number coded under the broad preferred term psychosis, while continuing to treat already enrolled participants. CMO Christopher Kenney said confusion, aphasia, and ataxia appear in a small percentage of psychiatry patients, consistent with epilepsy experience; across more than 1,500 patient-years of azetukalner (a Kv7 potassium-channel opener) exposure, those events were short and reversible without long-term sequelae. CEO Ian Mortimer said dosing will be adjusted over coming months with FDA notified. X-Nova2 was about 360 patients in (~80% of target) when paused; Xenon argues the MDD study already has power for a clinically meaningful effect, will stop early, and still expects topline in 1Q next year. Premarket shares fell about 26%. The company this week used its phase 3 epilepsy program to file for focal seizures; William Blair cut MDD probability of success from 60% to 50% but did not treat the pause as a class Kv7 signal versus Biohaven’s separate BHV-7000 epilepsy enrollment pause. (Fierce Biotech)

BMS exits Orum DAC; Kerendia’s T1D kidney door

Bristol Myers Squibb terminated ORM-6151 / BMS-986497, the CD33-directed degrader-antibody conjugate it bought from Orum Therapeutics for $100 million in 2023, after reviewing phase 1 data. The asset delivered a GSPT1 degrader to CD33-expressing cells and was in monotherapy and azacitidine/venetoclax combinations with a prior February 2027 completion estimate; Orum loses up to $80 million in remaining clinical milestones. AbbVie had already killed its own CD33 DAC (ABBV-787) last year. Separately, Bayer won Kerendia’s (finerenone) third U.S. indication: reducing UACR in adults with CKD associated with type 1 diabetes, framed as the first FDA nod in that setting in about thirty years. Fine-one (n=242) cut UACR more than 25% by six months, with benefit from three months; Bayer estimates about 30% of roughly 2 million U.S. type 1 patients develop CKD in their lifetime. Kerendia is now the only non-steroidal mineralocorticoid-receptor antagonist labeled for type 1 or type 2 diabetes–associated CKD, on top of prior T2D CKD and HFpEF/HFmrEF heart-failure labels. (Fierce Biotech; Fierce Pharma)

Lunsumio confirmatory: Celestimo PFS win

Roche/Genentech said Lunsumio plus lenalidomide beat rituximab plus lenalidomide (R2) with a statistically and clinically meaningful PFS improvement in phase 3 Celestimo in follicular lymphoma after at least one prior line. No detailed numbers yet; overall survival immature; no new safety signals beyond known profiles. The trial is the confirmatory study to convert Lunsumio’s third-line monotherapy accelerated approval to traditional approval and potentially support second-line use. It sets up a three-way commercial fight with AbbVie/Genmab’s Epkinly (CD20×CD3) and Incyte’s Monjuvi (CD19) on top of R2, which last year posted 79% and 57% PFS risk reductions versus R2 alone in their own phase 3s. Roche pitched a two-drug outpatient Lunsumio regimen as an earlier-line option; CD19 CAR-T (Yescarta Zuma-22) and BTK combinations remain in the same earlier-line scrum. (Fierce Pharma)

IPO window, reverse mergers, oral macrocycles

Electra Therapeutics priced an upsized Nasdaq IPO at $350 million gross (23.3 million shares; underwriters’ option could add $52.5 million), ticker ETRA, after sitting on $97.7 million cash at June end and a $183 million series C in 2025. Proceeds prioritize ipsoprubart, a SIRP-targeted antibody in a global phase 2/3 for secondary hemophagocytic lymphohistiocytosis (about $220 million earmarked toward that path and filing), plus earlier work in NK/T-cell malignancies and ELA822. BioPharma Dive counted Electra as the 21st biotech IPO of 2026 and the eleventh to raise $300 million-plus this year, matching 2021’s big-deal tally. On the reverse-merger side, North Immunology (ADAR1-founded; IL-13/IL-18 dual antibody NOR-101 aimed at Dupixent’s eczema limits) agreed to combine with Aethlon, with a $180 million PIPE and expected NRTX ticker after close in 1Q 2027; Lisata, after a collapsed Kuva deal and deep cuts, is merging with cardioendocrine Marea plus a $225 million placement, leaving Lisata holders ~2.4% while MAR001 (severe hypertriglyceridemia) and MAR002 (acromegaly) phase 2 readouts loom in 4Q. Novo deepened its oral-biologics bet with Orbis Medicines on orally bioavailable macrocycles for unnamed cardiometabolic targets: up to $1.4 billion in upfront and milestones plus royalties and a strategic equity stake. Orbis’s nGen/nCycle platform sits beside Novo’s Wegovy pill push and a crowded macrocycle lane (Merck’s Lipfendra; Novartis–Unnatural Products; PeptiDream work). Novo Holdings backed Orbis early; Lilly’s VC arm was in the series A. (Fierce Biotech; BioPharma Dive; BioPharma Dive; Fierce Biotech; BioPharma Dive; BioSpace; Fierce Biotech)

Policy sidebar

STAT reported that Health secretary Robert F. Kennedy Jr. used a Children’s Health Defense keynote to revive vaccine-risk framing (hepatitis B insert example; claims linking shots to chronic illness without causal evidence) even while calling serious vaccine harm “very rare,” and separately named eight new USPSTF members after more than a year without meetings. Five appointees are specialists rather than the panel’s traditional generalist base; AMA warned that primary-care voice must stay central. AHRQ, which staffs the evidence reviews, fell from nearly 300 employees in 2024 to 84 in 2026 under DOGE-driven cuts. (STAT News; STAT News)

What to watch

pdufa.bio (as of September 18) and today’s regulatory packet still list Ultragenyx UX111 on September 19 as Upcoming even though Fierce Pharma (and STAT+ headlines) report Fayuvi approved September 17: treat the packet/API row as stale until the calendar flips. Merck Winrevair HYPERION label work remains September 21; Mirum/Incyte zilurgisertib (FOP) September 26. Ameluz BCC and Scholar Rock Isembyld (apitegromab) show Decided/Approved on the anonymous API against original late-September goal dates, while regulatory.json still carries them as Upcoming (stale). Nuvalent’s zidesamtinib (NVL-520) is marked Decided for September 18 on the calendar. Mim8 (denecimig) remains Upcoming without a clean date in the API slice. October: Roche Tecentriq adjuvant MSI-H/stage III colon (October 9), Merck/Daiichi I-DXd in extensive-stage SCLC (October 10), Roche Enspryng in thyroid eye disease (October 15), Viatris/Opus MR-141 phentolamine ophthalmic (October 17). Telix Pixclara is still Awaiting on packet/API (days-to-decision negative) despite earlier Fierce approval reporting. BioProcess International’s Boston conference runs September 22–25; overnight BPI hard-news was thin beyond features (AI data-quality/oversight; prior antibody-image scandal already briefed). Bavarian Nordic’s new CEO Tarja Stenvall starts October 15. (pdufa.bio; Fierce Pharma; BioProcess International)

Open mechanism and franchise questions from this tape: whether CSF heparan-sulfate biomarker packages plus small natural-history contrasts will keep clearing AAV rare-disease doors after Fayuvi; whether Kv7 openers can be dose-tuned for psychiatry without bleeding into the epilepsy franchise Xenon is filing now; whether CD33-directed degrader payloads are a dead alley after BMS and AbbVie exits or merely the wrong first pairings; whether UACR-only T1D CKD labels (Kerendia) translate into hard kidney outcomes the way T2D programs did; whether Lunsumio’s still-undisclosed Celestimo effect size can compete with Epkinly/Monjuvi triplets on PFS and outpatient practicality; and whether oral macrocycle platforms (Orbis/nCycle and peers) can fix peptide gut loss enough to matter beside Wegovy pill pharmacokinetics.