SNAPSHOT

Regeneron pays up to $2.3 billion for Parabilis’ new class of ADC-like cancer therapies

Regeneron will pay $125 million upfront, split between cash and an equity investment, to partner with Parabilis on developing “antibody-Helicon conjugates” (AHCs), a next-generation therapeutic platform designed to target hard-to-drug intracellular proteins.

Why it matters: Many disease-driving proteins remain “undruggable” because traditional small molecules struggle to bind to flat or inaccessible protein surfaces. Parabilis’ Helicon peptides could open up a much larger universe of targets in cancer and other diseases, potentially expanding beyond what today’s antibody-drug conjugates (ADCs) can treat.

Backstory: Parabilis, formerly known as FogPharma, has been developing stabilized alpha-helical peptides called Helicons that can penetrate cells and bind difficult intracellular targets. The biotech recently raised $305 million to advance its lead oncology asset, zolucatetide, into late-stage development for desmoid tumors. Meanwhile, Regeneron has been looking to diversify its pipeline and reinforce its oncology portfolio after setbacks, including the recent phase 3 failure of its LAG-3 inhibitor fianlimab against Keytruda in melanoma (more details in Snippets).

Big picture: The partnership reflects a broader biotech race to move beyond conventional ADCs and unlock intracellular targets previously considered unreachable. Companies across oncology are increasingly combining delivery technologies with novel payloads to improve precision and expand the range of treatable diseases.

Zoom in: The collaboration initially covers five targets. Parabilis receives a $50 million upfront cash payment, a $75 million equity investment and up to $2.2 billion in milestone payments tied to development and commercialization success. The companies will also explore Helicons as standalone therapies, though the primary focus is on AHCs that pair Regeneron antibodies with Helicon payloads for targeted intracellular delivery.

What’s next: The partners will begin discovery work on the first five targets, with Regeneron retaining options to expand the collaboration to additional targets through further payments. Regeneron will lead the development and commercialization of any therapies emerging from the collaboration.

SNIPPETS

What’s happening in biotech today?

📉 Pipeline pressure: As we mentioned above, Regeneron reported a major setback for its oncology pipeline after a Phase 3 melanoma trial showed that its immunotherapy combination of fianlimab and Libtayo failed to significantly outperform Merck’s Keytruda in delaying cancer progression, despite showing a median progression-free survival of 11.5 months versus 6.4 months for Keytruda. The disappointing result surprised analysts, who had expected the treatment to succeed based on similar therapies targeting the LAG-3 protein, and wiped out a potential multibillion-dollar market opportunity.

💸 Acquisition ache: BioMarin’s enzyme replacement therapy, BMN 401, failed to fully meet expectations in a Phase 3 trial for ENPP1 deficiency, a rare genetic disorder that causes severe bone and mineralization problems. While the drug achieved one co-primary endpoint by significantly increasing plasma inorganic pyrophosphate levels, it failed to demonstrate meaningful skeletal healing on X-rays and showed no positive trends across secondary measures such as rickets severity, growth, and weight gain. Although the therapy appeared generally safe, the mixed results cast doubt on its clinical effectiveness, prompting the company to reevaluate the program’s future.

🏃 Obesity arms race: Harbour BioMed has released preclinical data for LET003, an experimental obesity treatment designed to compete with Eli Lilly’s bimagrumab, a drug Lilly acquired through its $1.9 billion purchase of Versanis. LET003 targets the same ACVR2A/2B receptors involved in muscle and fat regulation and was developed using Harbour’s AI-enabled Hu-mAtrIx antibody platform. In animal studies, LET003 demonstrated slower blood clearance and appeared to promote greater lean muscle gains than a competing molecule while also enhancing fat loss when combined with semaglutide, the active ingredient in Ozempic and Wegovy. Harbour said the results support advancing LET003 into clinical development.

💊 Pill slimdown: Vincentage Pharma reported that its oral GLP-1 obesity drug VCT220 achieved up to 12.4% average weight loss over 52 weeks in a Phase 3 trial involving 840 Chinese adults with obesity or overweight-related conditions, positioning the company to compete with Eli Lilly’s oral candidate orforglipron in China. Patients receiving the once-daily 120 mg and 160 mg doses lost 12.2% and 12.4% of body weight, respectively, compared with 1.3% for placebo, with results appearing comparable to Lilly’s orforglipron but below Novo Nordisk’s oral Wegovy data. Vincentage said the drug showed favorable tolerability, with mostly mild gastrointestinal side effects and low discontinuation rates, and plans to seek regulatory approval in China soon while continuing development for diabetes and other cardiometabolic diseases.

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