Biotech & Health Weekly: FDA Loses Its Commissioner

Marty Makary resigned on May 12. Three of the FDA’s top drug review positions are now held by acting officials. All three have a 210-day time limit under federal law before the White House has to make a decision on who fills them permanently.

That did not slow the calendar. ENHERTU got a landmark approval in early breast cancer on May 16. argenx expanded VYVGART’s label to cover every adult MG patient regardless of serotype on May 8. Regeneron posted one of the more expensive trial failures in recent memory. And new GLP-1 maintenance data started reshaping how doctors think about keeping weight off after the injections stop.

The agency is in transition. The pipeline is not waiting.

1. Marty Makary Is Out. Nobody Knows What Comes Next.

Makary’s resignation came on May 12, roughly 15 months into a tenure that had been anything but quiet. He came in with a mandate to tackle the “root causes” of chronic disease, take on the food industry, and move the agency faster on approvals. In practice that meant lowered pivotal trial requirements, more rare disease flexibility, additional special vouchers, and a string of early PDUFA decisions. His departure leaves all of it in limbo.

Kyle Diamantas stepped in as acting commissioner. The problem is he joins two other acting officials already running CDER and CDRH — the centers that do the actual drug and device reviewing. Federal law caps acting authority at 210 days. That clock is running on all three. BioPharma Dive noted that the situation “adds to a leadership void that’s left biotechnology industry watchers anxious about which direction the agency will take next.”

RFK Jr. and HHS are now the ones choosing who runs the FDA. That is not a reassuring sentence for a lot of biotech investors. The biotech-friendly initiatives Makary championed — faster timelines, rare disease flexibility, lower bar for pivotal data in some categories — may or may not survive whoever comes next. Nobody knows yet. That uncertainty is priced into small-cap biotech right now.

2. ENHERTU Just Got Approved for Early Breast Cancer. This Is a Big Deal.

On May 16, the FDA approved ENHERTU (fam-trastuzumab deruxtecan) for both the neoadjuvant and adjuvant treatment of HER2-positive early breast cancer. It is the first antibody-drug conjugate approved in the neoadjuvant setting for early-stage disease — meaning it can now be given before surgery to shrink tumors, not just after to prevent recurrence.

To appreciate why that matters: ENHERTU was originally approved for metastatic HER2-positive breast cancer in patients who had already tried other treatments. Then it moved into gastric cancer. Then lung cancer. Each expansion broadened the addressable patient population significantly. The early breast cancer approval is different in scale. HER2-positive early breast cancer is diagnosed in roughly 50,000 Americans per year. That is a much larger pool than metastatic patients.

AstraZeneca and Daiichi Sankyo, who co-develop ENHERTU, have been steadily building one of the more impressive label expansion records in oncology. The neoadjuvant data was strong enough that the FDA did not wait for the full adjuvant readout — a sign that the agency viewed the benefit-risk as clear. ENHERTU is now being used across four cancer types. That number will keep moving.

3. argenx Wins the Broadest MG Label in History

May 8. FDA expands VYVGART’s label to cover all adult patients with generalized myasthenia gravis, regardless of which antibody subtype they carry — or whether they carry any at all. That last part is the story.

About 10 to 15% of gMG patients are seronegative — no detectable antibody of any kind. They get a diagnosis based on clinical presentation, not a blood test. Before this approval, there was no FDA-cleared therapy specifically for them. They were typically managed off-label, often with less predictable outcomes.

The ADAPT SERON Phase 3 trial enrolled 119 of these patients across three seronegative subtypes. It met its primary endpoint: a statistically significant improvement in daily living scores at four weeks compared to placebo (-3.35 vs -1.90, p=0.007). The Muscular Dystrophy Association called it “a major advancement in reaching as many patients living with gMG as possible.” argenx now has the broadest MG label of any approved therapy. The commercial upside is significant — this is not a marginal label tweak.

4. Regeneron Lost Billions on a Single Trial Result

Monday May 18. Regeneron’s combination of fianlimab (anti-LAG-3) and Libtayo (cemiplimab) failed to significantly outperform Keytruda in a late-stage melanoma study. The result wiped out billions in market value and surprised Wall Street analysts who had expected the dual checkpoint approach to show a clear benefit over single-agent PD-1 blockade.

The thesis was straightforward: block two checkpoints instead of one and you get better responses. LAG-3 plus PD-1 had shown promise in earlier data. Bristol-Myers Squibb’s relatlimab plus nivolumab combination (Opdualag) already carries FDA approval in melanoma based on exactly that logic. Regeneron was following the same playbook.

It did not work. Or at least not well enough. That is the risk in late-stage oncology — even a mechanistically sound combination can fail to clear the bar against an already-effective standard of care. Keytruda sets a very high floor in melanoma. Clearing it requires data, not just logic.

5. GLP-1 Maintenance Is the Next Conversation

New data published in peer-reviewed journals this week addressed something the GLP-1 field has largely avoided discussing directly: what happens to patients who switch from high-dose weekly injectables to lower doses, or to pills. The findings suggest that strategic de-escalation can maintain most of the weight loss achieved at full dose — which changes the long-term treatment economics substantially.

This matters because GLP-1 drugs are expensive and most patients cannot stay on them indefinitely. Foundayo, Lilly’s oral GLP-1 pill, got its approval in April but is under an active FDA safety review — the agency requested additional post-marketing studies in the approval letter. Novo’s Wegovy pill is generating strong early prescription numbers but the real-world weight maintenance data is still accumulating.

The maintenance question is separate from the acute weight loss question. It asks: once someone hits their target weight on semaglutide or tirzepatide, can they step down to a lower dose or a cheaper format and hold it? If yes, the total cost of treatment drops. The addressable market expands. Lilly is already running trials on exactly this protocol. The results will shape prescribing patterns for years.

What to Watch: May 18 – May 28, 2026

May 24 is the Leqembi Iqlik PDUFA date. Biogen and Eisai are seeking approval for a subcutaneous autoinjector and a new once-weekly dosing formulation of their Alzheimer’s drug. If it clears, patients no longer need to come in for IV infusions every two weeks. That removes the single biggest barrier to adoption. The Alzheimer’s market is worth watching closely on this one.

FDA acting leadership: the 210-day clock on all three acting roles is running. Any signal from HHS or RFK Jr. on permanent nominees will move biotech broadly. A biotech-friendly pick stabilizes sentiment. A skeptical one reopens the regulatory risk premium.

Regeneron fallout: the fianlimab failure will trigger analyst reassessments of other LAG-3 combination programs across the industry. Several companies have similar assets in Phase 2 and 3. Watch for updated guidance or program prioritization announcements from those developers over the next two weeks.

United Therapeutics received FDA clearance this week to proceed with the UHeart xenotransplantation clinical trial — a pig-to-human heart transplant study. No commercial timeline yet. But it is a first-in-class human trial in one of the most technically challenging areas of medicine. Worth tracking as data starts accumulating.

Foundayo safety review: the FDA’s post-marketing study request from the April 1 approval letter will eventually produce data that either confirms the drug’s profile or complicates it. The first interim analysis is not imminent, but any FDA correspondence on the safety question will hit Lilly’s stock.

Sources

Editorial Disclosure

This roundup is based on press releases, regulatory filings, published clinical trial data, and independent market research sourced from publicly available information. It covers developments during the period of May 8 to May 18, 2026, in the biotechnology, pharmaceutical, and health sectors. Securities referenced in this article include argenx SE (Nasdaq: ARGX), AstraZeneca PLC (Nasdaq: AZN), Daiichi Sankyo (referenced as private co-developer), Regeneron Pharmaceuticals (Nasdaq: REGN), Eli Lilly and Company (NYSE: LLY), Novo Nordisk A/S (NYSE: NVO), Biogen Inc. (Nasdaq: BIIB), Eisai Co. Ltd. (referenced as co-developer), and United Therapeutics Corporation (Nasdaq: UTHR). None of these companies compensated aktiego.com for editorial coverage. All drug approval statuses are current as of May 18, 2026. Clinical trial efficacy data is sourced to named Phase 3 studies and company press releases and reflects results from specific study populations; real-world outcomes may vary. Foundayo’s active FDA post-marketing safety review is ongoing and no conclusions have been reached at the time of publication. Forward-looking statements attributed to named analysts and institutions represent opinions at the time of publication and are not guarantees of regulatory approval, commercial success, or future performance. Editorial forward-look commentary reflects the author’s own assessment. The information provided on this website is for informational and educational purposes only. Our content is derived strictly from verified online sources to ensure accuracy and objectivity. This analysis does not constitute financial, investment, or professional advice. Readers are encouraged to consult with qualified professionals before making decisions based on this information. For more information, please see our full DISCLAIMER.

Biotech & Health Weekly: FDA Loses Its Commissioner

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