Regenxbio FDA Hold, Sanofi Vaccine Demand Softness, and CMS Negotiation Expansion – This Week in Biotech #87
FDA pauses two AAV programs, Sanofi reports US vaccine uptake slipping, and CMS widens negotiations to more blockbuster drugs (Jan 23-29, 2026).
Welcome back to This Week in Biotech by Biotech Blueprint, edition 87, covering biotech and pharma news from January 23rd to 29th, 2026.
🎙️ Biotech Blueprint brings you weekly video updates on the latest biotech and pharma news, plus in-depth podcast interviews with industry leaders. You can find us on YouTube, Spotify, and Apple Podcasts.
If you want to be featured, get in touch.
IN COLLABORATION WITH CYTIVA
Succeeding in an industry under pressure
60% of biopharma firms are missing market share goals. Find out why, and learn what leaders are doing to deliver.
VIDEO SUMMARY
THIS WEEK’S KEY TAKEAWAYS 🔑
This week showed how quickly “defensive” biopharma revenue stops looking defensive when policy and patient behavior shift at the same time. Sanofi basically said US vaccine demand is soft because patients are confused and uptake is falling. Flu and Covid held up, but Beyfortus (pediatric RSV antibody) and pediatric combos didn’t, and management is guiding to slightly negative vaccine growth in 2026. The sector’s most reliable cash flows are now exposed to the same forces as everything else: trust, messaging, and who sets the default in the clinic. This week made it uncomfortably clear that even the safest looking franchises depend on fragile inputs like federal guidance and public trust.
That trust theme showed up again in gene therapy, but with even sharper edges. The FDA froze two Regenxbio AAV programs after a brain tumor was found on routine MRI in one child treated 4 years ago, with causality still undetermined. The scientific signal regulators can’t ignore is the reported vector integration event tied to PLAG1 overexpression, even if it ends up being coincidence. The human reality families can’t ignore is the other math: 41 treated patients with years of clean follow-up versus one uncertain case, and a pause that reportedly hit one program just days from a potential FDA decision. The correct move may still be “hold,” but the standard should be speed and specificity - what data would actually distinguish causality from background risk, and what’s the fastest path to generate it without turning rare disease into collateral damage.
This week, CMS named 15 new drugs for Medicare price negotiation for 2028, and for the first time the list includes Part B drugs, not just pharmacy (Part D). That’s not a symbolic change, but a widening funnel for pricing pressure onto large, durable franchises (think Botox, Xolair, Cosentyx, Biktarvy, Trulicity). If you hold mature winners, you now have to underwrite not just competition and patent cycles, but government’s growing willingness to set prices and live with the consequences.
Innovation delivered both relief and reality. Intellia got the FDA to lift the hold on its ATTR polyneuropathy study after proposing tighter liver monitoring, but the cardiomyopathy program remains on hold, and that is where the upside lives. Roche’s CT-388 looks legitimately competitive, with weight loss still trending at 48 weeks, which is enough to justify Phase 3. Investors barely blinked because the bar in obesity has moved. Now the fight is tolerability, durability, body composition, and who can actually get reimbursed.
AstraZeneca’s $15B China push is a clear bet on speed: faster trials, deeper manufacturing, and a dense partnering ecosystem. The uneasy part is that scale cuts both ways. It can accelerate the pipeline, but it also increases exposure to policy shifts that can show up suddenly and matter a lot.
BIOTECH/PHARMA NEWS 🧬
🔹 Sanofi’s vaccine franchise is hitting a real demand headwind in the US: management said “confusion” around vaccination and falling uptake is showing up in results, with Q4 vaccine sales down 2.5% and the company guiding to slightly negative vaccine growth in 2026, even as influenza vaccines beat expectations during a heavy flu season. The mix matters: flu and COVID vaccines were up (Q4 +31.5%), but Beyfortus (RSV antibody) fell (Q4 -14.9%) and core pediatric combos (polio, pertussis, Hib) also declined (Q4 -9.5%), leaving total vaccine sales weaker despite broader company momentum (FY 2025 sales +9.9% at constant exchange rates; Dupixent +25.2% to €15.7B). Sanofi is still leaning into vaccines strategically, pointing to the Vicebio acquisition and the pending Dynavax deal as a bet that today’s demand wobble is cyclical not structural, but the near-term setup is straightforward: if US uptake stays soft, “defensive” vaccine revenues look less defensive, and you should expect more emphasis on adult immunization, international rollout, and pipeline optionality to offset policy-driven noise.
🔹 AstraZeneca said it will invest $15B in China through 2030 to expand R&D and manufacturing, leaning into China as both its second largest market and a faster innovation engine. The plan spans drug discovery, clinical development and new and expanded sites across Wuxi, Taizhou, Qingdao and Beijing, with an explicit push into higher value modalities like cell therapy and radioconjugates and more partnering with local biotechs, all announced alongside Keir Starmer’s Beijing visit. Read it as a bet that China speed plus AZ execution can keep the pipeline fed, but it also raises the obvious geopolitical and policy headline risk of building deeper dependence on a strategic hub.
🔹 Regenxbio reported a delayed safety signal that regulators have to treat as potentially platform-wide until proven otherwise. The FDA put RGX-111 on clinical hold after a routine brain MRI found an intraventricular central nervous system tumor in a 5 year old who had been dosed about four years earlier, and early analysis flagged an AAV vector genome integration event linked to overexpression of a proto-oncogene (PLAG1), even though causality is not established and the child is asymptomatic. The agency then extended the hold to RGX-121 as a precaution because of product and population similarities, despite RGX-121 having a long follow-up story in more than 30 patients, including some treated nearly seven years ago.
🔹 CMS just named the next 15 drugs headed into Medicare price negotiations for 2028, and this round matters because it pulls in Part B drugs for the first time, not just pharmacy (Part D) products. The list spans some of the biggest “known knowns” in biopharma spend, including Trulicity, Biktarvy, Cosentyx, Botox, Xolair, and Xeljanz (plus others like Entyvio, Kisqali, Verzenio, Lenvima, and Orencia). Collectively, these drugs accounted for about $27.0B in Medicare Part B and Part D spending over Nov 2024 to Oct 2025, across roughly 1.78M Medicare users, so the intent is clearly to keep widening the aperture of where pricing pressure can land.
🔹 Intellia got a partial green light on its in vivo CRISPR program nexiguran ziclumeran (“nex-z”) in transthyretin amyloidosis: the FDA lifted the clinical hold on MAGNITUDE-2 (the polyneuropathy study) after Intellia proposed new risk mitigation steps, including enhanced liver lab monitoring, and bumped planned enrollment to about 60 patients. The bigger overhang remains MAGNITUDE (the cardiomyopathy study), which is still on hold, and that is the real value driver. The pause traces back to October 29, 2025, after a patient dosed in MAGNITUDE developed severe liver toxicity meeting the protocol’s stopping criteria and subsequently died, so the market is essentially waiting to see what the FDA will require for the older, higher-risk cardiomyopathy population.
🔹 On January 26, The American Academy of Pediatrics (AAP) published its 2026 schedule and, for the first time in decades, it is no longer fully harmonized with the federal schedule. The headline divergence is simple: AAP continues to recommend routine COVID-19 and influenza vaccination starting at six months, while the updated CDC schedule shifts COVID-19 and flu into “shared clinical decision making” rather than a routine recommendation. For biopharma, it is less about new science and more about a messy implementation year. Pediatricians and states are already signaling they will lean on AAP guidance (for example, California has explicitly told providers to follow AAP’s schedule). Vaccine demand becomes more geography- and provider-driven, which raises U.S. policy risk for Covid and flu franchises (Moderna, Pfizer/BioNTech, Novavax; and the flu complex) even if AAP keeps the medical “default” intact in much of clinical practice.
CLINICAL TRIAL UPDATES 📊
🔹 Roche posted encouraging phase 2 obesity data for CT-388, a once-weekly dual GLP-1/GIP agonist acquired via the Carmot deal. In patients who stayed on the regimen for 48 weeks, placebo-adjusted weight loss reached 22.5% at the highest dose. Using a more real world analysis that counts people who missed doses or fell off schedule, the placebo-adjusted effect was 18.3%. Roche highlighted that weight loss did not appear to plateau by week 48 and said the readout validates two phase 3 trials slated to start this quarter, though investor reaction was muted given how crowded the category is and how far a launch still is.
🔹 Sarepta reported positive topline three year functional results from Part 1–treated patients in the phase 3 EMBARK study of Elevidys in ambulatory Duchenne muscular dystrophy. Elevidys-treated patients had mean North Star Ambulatory Assessment (NSAA) scores above baseline at year 3 while the external controls declined. On timed function, Sarepta said Elevidys showed a 73% slowing of decline on time-to-rise (TTR) and about 70% slowing on the 10 meter walk/run (10MWR), with the functional gap versus external controls widening between year 2 and year 3. The company said no new treatment-related safety signals were observed in this ambulatory dataset.
PUBLIC HEALTH SPOTLIGHT 🔍
🔹 Two confirmed Nipah infections in India’s West Bengal, reportedly in healthcare workers, triggered tighter border health measures across parts of Asia. Officials traced 196 contacts and said all were asymptomatic and tested negative, so near term public risk is still considered low. Nipah is a bat linked zoonotic virus that can cause encephalitis and has had high fatality rates in past outbreaks (often cited around 40% to 75%), but it typically requires prolonged close contact and does not spread easily. With no approved vaccine or specific treatment, the real takeaway is platform readiness: surveillance and sequencing, rapid diagnostics, infection control capacity, and vaccine R&D that can move quickly from sequence to clinic.
Have a great rest of your week and thanks for reading Biotech Blueprint!
