Cellectar Biosciences raises up to $140M in oversubscribed financing
What's the deal? Cellectar Biosciences, a late-stage clinical biopharmaceutical company, has secured up to $140M in financing to advance its cancer therapy iopofosine I 131 toward accelerated approval for Waldenström macroglobulinemia (WM), a rare blood cancer.
The deal breaks down into roughly $35M upfront and $105M in milestone-based securities, structured as a registered direct offering of common stock and a concurrent private placement of common stock, pre-funded warrants, and milestone-based warrants.
Nantahala Capital Management led the oversubscribed round, with participation from Balyasny Asset ManagementDealroom has a profile for this one. Try Dealroom →, Caligan PartnersDealroom has a profile for this one. Try Dealroom →, Janus Henderson Investors, SilverArc Capital Management, Stonepine Capital Management, Stempoint Capital, and Empery Asset Management, among others. Members of the executive management team also participated.
As part of the deal, Andrew Gu of Nantahala Capital will join Cellectar's board of directors upon closing.
Why now? Cellectar plans to initiate a global confirmatory study for iopofosine I 131 in the fourth quarter of 2026 and pursue accelerated approval with the FDA in the US and conditional marketing approval in Europe. The financing provides the runway to support both an NDA filing and continued development of its pipeline, including CLR 125 for triple-negative breast cancer.
"This oversubscribed financing provides important validation of our strategy to pursue accelerated approval," said James Caruso, president and chief executive officer.
What could go wrong? The bulk of the financing — $105M of the $140M total — is tied to milestones, meaning Cellectar only receives the full amount if it hits specific development targets. Accelerated approval pathways, while faster, still carry regulatory risk. And rare disease programmes, despite lower patient recruitment thresholds, can face challenges in running confirmatory trials.
The signal: The investor syndicate here skews heavily toward dedicated healthcare funds rather than generalist venture capital, underscoring that specialist conviction — not broad market exuberance — is driving late-stage biotech financing right now. Nantahala Capital's lead role, paired with institutional names like Janus Henderson Investors and Balyasny Asset Management, suggests that sophisticated public-market crossover investors see a viable regulatory path for iopofosine I 131. The milestone-heavy structure, with 75% of the capital contingent on progress, has become a hallmark of post-2023 biotech deals where investors want asymmetric upside without fronting full dilution risk.
Read more: globenewswire.com
