Spero Therapeutics Secures $105 Million Non-Dilutive Royalty Financing to Advance Anti-CD40L Antibody SP001
Key Insights
Spero Therapeutics announced a $105 million non-recourse, non-dilutive royalty financing with Healthcare Royalty (search) (KKR (search)) backed by future Utebzi (search) milestone and royalty payments.
Proceeds will primarily fund Phase 2 development of SP001, a third-generation Fc-silent anti-CD40L (search) monoclonal antibody in-licensed from Innovent Biologics (search) for immune-mediated diseases.
The financing extends Spero's cash runway into the second half of 2029, with the company retaining 35% of GSK payments after loan repayment.
Spero Therapeutics, a clinical-stage biopharmaceutical company focused on immunology and inflammation, has secured a $105 million non-recourse, non-dilutive royalty financing transaction with affiliates of Healthcare Royalty (search) (HCRx), a business of KKR (search). The financing, backed by a portion of future milestone and royalty payments from sales of Utebzi (search) (tebipenem pivoxil), will primarily support the advancement of SP001, the company's lead immunology drug candidate.
The transaction was completed concurrently with an exclusive license agreement with Innovent Biologics (search) for SP001 and follows last month's U.S. approval of Utebzi (search) for complicated urinary tract infections (search) (cUTI). Spero has granted GSK an exclusive license to develop and commercialize Utebzi in all territories except certain territories in Asia, where Meiji (search) holds development and commercialization rights.
"Over the past year, in collaboration with GSK, we successfully advanced Utebzi (search) through FDA approval, while executing on our strategy to strengthen Spero and position the Company for its next phase of growth," said Esther Rajavelu, President and Chief Executive Officer of Spero Therapeutics. "This transaction further strengthens our balance sheet and provides non-dilutive capital as we embark on an immunology-focused strategy."
Financing Structure and Terms
Under the terms of the agreement, HCRx will provide Spero with a $105 million payment at closing, net of original issue discount and applicable fees, in exchange for rights to anticipated payments from Utebzi (search) sales owed by GSK. HCRx will receive quarterly principal and interest payments derived solely from those GSK payments until the loan balance is repaid. Following repayment, Spero will retain 35% of subsequent GSK payments related to Utebzi sales, preserving potential long-term upside from the asset.
J. Wood Capital Advisors served as Spero's exclusive financial adviser, with WilmerHale acting as legal advisor to Spero. Sidley Austin LLP acted as legal advisor to HCRx.
"We are pleased to partner with Spero on this acquisition of certain Utebzi (search) milestones and royalties," said Clarke Futch, Chairman and CEO of HealthCare Royalty (search). "As the first approved oral carbapenem therapy, Utebzi represents a meaningful innovation and value proposition for patients, physicians and payers."
SP001: A Next-Generation Anti-CD40L (search) Antibody
SP001 is a third-generation, fully humanized, Fc-silent IgG1 monoclonal antibody targeting CD40L (search), an upstream immune activation signal involved in T-cell, B-cell, antigen-presenting cell, and platelet biology. By blocking CD40L, SP001 has the potential to provide a targeted, non-B-cell-depleting treatment across multiple immune-mediated diseases where immune-cell interactions drive chronic inflammation, relapse, and tissue damage.
The antibody is specifically designed to address platelet activation concerns associated with earlier anti-CD40L (search) antibodies, while preserving key monoclonal antibody properties including FcRn interaction that supports IgG-like half-life. Spero plans to advance SP001 first in IgG4-related disease (search), with a broad potential for additional immune-related conditions.
Strategic Implications
Following the transaction, Spero has updated its cash runway guidance into the second half of 2029. The non-dilutive nature of the financing allows the company to fund SP001's clinical development without issuing equity, preserving shareholder value while unlocking immediate capital from the Utebzi (search) royalty stream.
The dual transactions — the HCRx financing and the Innovent Biologics (search) license for SP001 — mark a strategic pivot for Spero toward an immunology-focused pipeline, leveraging the commercial success of its infectious disease asset Utebzi (search) to fuel next-generation programs in immune-mediated diseases.