Vyvgart Wins Broadest gMG Label; Merck Closes $6.7B Terns Deal

CSL posts its largest single-day drop on record — six hundred million in revenue cuts, five billion in impairments, and a Vifor Pharma acquisition that the company itself now says has not panned out.

Plus, an OX40 agonist doubles Keytruda's response rate in head and neck cancer, Rezdiffra clears three hundred million in quarterly sales, and European regulators greenlight the first clinical trial of a GLP-1 gene therapy.

Welcome to The Pharma Closeout for Monday, May eleventh, twenty twenty-six. I'm Alex Mercer.

And I'm Maya Patel. Let's get to work.

Our top story is a reckoning three years in the making. CSL cut its FY2026 revenue guidance to fifteen-point-two billion dollars and net profit after tax and amortization to three-point-one billion at constant currency. That's roughly a six hundred million dollar revenue haircut from previously guided two to three percent growth. But the number that matters most — approximately five billion dollars in additional non-cash pre-tax write-downs across FY2026 and FY2027, tied to underutilized manufacturing capacity and assets from the twenty twenty-two Vifor Pharma acquisition.

Business News Australia puts cumulative writedowns closer to six-point-nine billion when you include previously disclosed impairments. The interim CEO flagged R&D misses and market erosion, and extended the turnaround timeline beyond guidance that had already been reset once. Competition in iron-deficiency and nephrology has intensified materially since the deal closed, and the acquired assets haven't generated returns that justify an eleven-point-seven billion dollar price tag. CSL built a decades-long reputation on operational discipline. That reputation took a significant hit today.

Bloomberg calls this the largest single-day drop on record for CSL. Shares hit a nine-year low. Let's bring in Marcus Webb for the structural read on what five billion in write-downs means for the broader deal landscape.

The universal cautionary framing is tempting, but the specifics are more instructive. CSL didn't just overpay — they acquired into a space where the competitive moat was narrower than the diligence suggested, with pipeline assets that hadn't fully de-risked. The lesson isn't to avoid large deals. It's to be ruthlessly honest about what de-risked actually means at the time of signing versus what the target's management team presented.

What the market is pricing in goes beyond thesis risk, though. A nine-year-low stock price and a record single-day drop suggest investors are now questioning governance and capital allocation judgment — not just the nephrology competitive picture. That kind of overhang follows the next CEO into the seat.

And whoever inherits that seat permanently is taking on a credibility rebuild, not just an operational turnaround.

That CSL overhang won't resolve quickly. But shifting to the deal side — the clinical data today tells a completely different story, and the standout is Inhibrx Biosciences. Interim Phase 2 data from the HexAgon trial: INBRX-106, a hexavalent OX40 agonist, combined with Keytruda — forty-four percent confirmed objective response rate in first-line head and neck squamous cell carcinoma. High PD-L1 expressors, CPS twenty or above. Keytruda alone — twenty-one-point-four percent. That is a twenty-two-point-six percentage point absolute delta across fifty-three evaluable patients in a sixty-eight-patient randomized study.

Three complete responses in the combination arm. Zero with pembro alone. But it's the pharmacodynamic signal underneath the response data that really elevates this — up to a fifteen-fold increase in peripheral CD8-plus and CD4-plus T-cell proliferation in combination-treated patients, versus roughly two-and-a-half-fold with pembrolizumab monotherapy. That level of systemic T-cell expansion from an OX40 agonist in a randomized setting is what the co-stimulatory field has been trying to demonstrate for the better part of a decade. Phase 3 launches Q3. PFS data from Phase 2 expected Q4. The response rate opens the door — durability is what sets the valuation.

Any randomized combo that doubles Keytruda's hit rate in a tumor type Keytruda effectively owns puts Inhibrx on every large pharma shortlist. Especially with Merck having spent six-point-seven billion on Terns to shore up its post-cliff oncology pipeline. If the PFS data confirms what the response rates suggest, the acquisition math writes itself. Now — Rezdiffra. Madrigal reported Q1 net sales of three hundred eleven-point-three million dollars. Year-over-year growth of a hundred twenty-seven percent. More than forty-two thousand two hundred fifty patients on therapy — two-and-a-half times the patient count from Q1 twenty twenty-five.

Even after Wegovy picked up its MASH label expansion last August, Rezdiffra's commercial lane has only widened. A liver-targeted thyroid hormone receptor beta agonist carving out distinct territory from systemic metabolic agents — at forty-two thousand patients and growing, what we're seeing is physician conviction, not trial curiosity.

Lilly meanwhile announced an additional four-point-five billion in Indiana manufacturing investment to meet Mounjaro and Zepbound demand — on top of billions already committed. Supply remains the binding constraint even as the franchise scales. And Daiichi Sankyo unveiled a five-year strategic plan targeting global top-five oncology status by twenty thirty-five, with approximately fifteen billion dollars in oncology revenue targeted by twenty thirty. The ambition is anchored entirely on the ADC platform — Enhertu, Datroway, plus three additional DXd-platform candidates expected to reach market during the plan period.

GSK out-licensed bepirovirsen, its experimental hepatitis B therapy, to Sino Biopharmaceutical for the China market. That's the latest Western pharma opting for licensing over direct commercial operations in the region — a pattern accelerating as geopolitical dynamics reshape the calculus. And Braveheart Bio posted positive Phase 2 data for BHB-eighteen-ninety-three, a next-generation cardiac myosin inhibitor licensed from China's Hengrui, in non-obstructive hypertrophic cardiomyopathy — the same condition where Cytokinetics recently won in late-stage.

The HCM competitive map just added another serious contender. And the broader signal is that China-originated clinical assets are generating real Western data at an accelerating pace. Anyone running a business development pipeline who isn't sourcing from Chinese biotech is leaving options on the table.

That sourcing trend is real. And on the regulatory front, there's a precision oncology approval worth unpacking. The FDA approved Bizengri — zenocutuzumab — for NRG1 fusion-positive cholangiocarcinoma in patients who progressed after prior systemic therapy. What makes this notable isn't just the approval — it's the pathway. Bizengri came through the Commissioner's National Priority Voucher pilot, designed specifically to pull sponsors toward ultra-rare indications where traditional commercial economics would never justify the investment. NRG1 fusions appear in roughly zero-point-two percent of solid tumors. This is a live test case for whether the CNPV structure can actually attract capital to diseases the market would otherwise walk past.

And the FDA is hosting a public meeting June fourth to solicit feedback on the pilot's eligibility criteria and voucher selection process. If you work in rare-tumor development or regulatory strategy, that session could shape how the next wave of orphan oncology programs gets designed and funded.

The other regulatory milestone today carries a longer shadow. European regulators greenlit the first clinical trial of a GLP-1 gene therapy. Fractyl Health is now cleared to test a one-time treatment designed to program the body to produce GLP-1 endogenously. This is early-stage — years from any commercial relevance. But the moment a regulator says yes to human dosing, the conversation migrates from whiteboard to clinic. And the safety calculus here is fundamentally different from anything in the injectable or oral space. An irreversible gene therapy that can't be titrated or discontinued raises tolerability considerations that simply don't apply to a weekly injection you can stop taking. For Novo and Lilly, the long-term worry isn't whether gene therapy works. It's what happens to a recurring-revenue franchise model if a durable one-time treatment proves feasible over the next decade.

Looking ahead — Inhibrx targets Q3 for the Phase 3 launch of HexAgon and expects Phase 2 progression-free survival data in Q4. Those two milestones together will determine whether INBRX-106 stays on the acquisition shortlist or moves decisively to the top of it.

June fourth for the CNPV public meeting — critical if you're in rare-tumor regulatory strategy. And the first safety signal from Fractyl's trial, whenever it drops, will be the most closely watched early-stage readout in the metabolic space this year. One clean safety dataset rewrites the gene-therapy-for-obesity narrative entirely.

And Daiichi's five-year plan means a steady drumbeat of ADC clinical catalysts through the end of the decade. Three new DXd-platform candidates targeting market entry — each major readout will be a referendum on whether a single technology platform can sustain a top-five oncology ambition at that scale.

That is your Pharma Closeout for Monday, May eleventh. CSL's five-billion-dollar Vifor reckoning, Inhibrx doubling Keytruda's response rate in head and neck cancer, Rezdiffra at three hundred eleven million in Q1 sales, and the GLP-1 gene therapy era officially entering human trials. If this briefing saves you time, follow us on Spotify, Apple Podcasts, or wherever you listen and drop us a rating — it's the fastest way to help other pharma professionals find the show. We are back tomorrow.

Have a good Monday evening. See you tomorrow. ### Episode Metadata **Title:** CSL Flags $5B Vifor Impairment as Shares Hit Nine-Year Low; Inhibrx Doubles Keytruda Response Rate in HNSCC; GLP-1 Gene Therapy Enters Clinical Trials | May 11, 2026 **Description:** CSL's $5B write-down from the Vifor Pharma acquisition sends shares to a nine-year low — the largest single-day drop on record. Inhibrx's INBRX-106 posts 44% ORR vs Keytruda's 21% in head and neck cancer. Plus Rezdiffra clears $311M in Q1, Fractyl's GLP-1 gene therapy gets European clinical trial greenlight, and Daiichi Sankyo targets global top-5 oncology by 2035. **Tags:** CSL, Vifor Pharma, INBRX-106, Inhibrx Biosciences, Keytruda, pembrolizumab, Merck, HNSCC, head and neck cancer, Rezdiffra, resmetirom, Madrigal Pharmaceuticals, MASH, Fractyl Health, GLP-1 gene therapy, Eli Lilly, Mounjaro, Zepbound, Daiichi Sankyo, Enhertu, ADC, antibody-drug conjugate, Bizengri, zenocutuzumab, NRG1, CNPV, GSK, Sino Biopharmaceutical, bepirovirsen, hepatitis B, Braveheart Bio, Hengrui, hypertrophic cardiomyopathy, pharma, pharmaceutical, FDA, clinical trials, biotech, drug approvals #