10-K: AnaptysBio Reports Strong Jemperli Sales, Plans Two-Company Split

AnaptysBio, a clinical-stage biotechnology company, announced plans to separate into two independent public entities, reporting significant Jemperli sales growth and positive Phase 2b rheumatoid arthritis trial data for rosnilimab.

Summary

• The company plans to separate its business into two independent, publicly traded companies: 'Royalty Management Co' (focused on Jemperli and imsidolimab royalties) and 'Biopharma Co' (focused on rosnilimab, ANB033, ANB101 development), with completion expected in Q2 2026.
• Rosnilimab's Phase 2b trial for moderate-to-severe rheumatoid arthritis (RA) met its primary endpoint (reduction of DAS-28 CRP score) and secondary endpoints (ACR20, ACR50, CDAI LDA) at Week 12 across all three doses.
• Rosnilimab demonstrated deepening of responses through six months on CDAI LDA, CDAI remission, and ACR70, particularly in b/tsDMARD-experienced patients for 400mg Q4W and 600mg Q2W doses.
• Week 28 clinical responses for rosnilimab were durable off-drug for at least three months, suggesting the potential for extended dosing (e.g., Q8W/Q12W) after initial monthly dosing.
• Rosnilimab showed rapid, deep, and sustained reductions of approximately 90% in pathogenic T cells in blood and synovial biopsies, and was generally well-tolerated with no treatment-related serious adverse events (SAEs).
• ANB033's Phase 1a trial in healthy volunteers showed no safety concerns, a rapid and sustained pharmacokinetic (PK) profile, and effective reduction of CD122-expressing CD8 T cells and NK cells while maintaining immune competency.
• ANB033 is currently in randomized, placebo-controlled Phase 1b trials for Celiac Disease (CeD) (60 patients) and Eosinophilic Esophagitis (EoE) (50 patients).
• ANB101's Phase 1 clinical trial in healthy volunteers is ongoing, with preclinical data suggesting it is a more potent antibody with a longer half-life compared to litifilimab.
• GSK reported $1.1 billion in sales for Jemperli for the year ended December 31, 2025, representing over 80% sales growth compared to $598.0 million in 2024.
• GSK terminated the TIM-3 antagonist antibody development program in October 2025, with all rights reverting to AnaptysBio.
• Vanda Pharmaceuticals submitted a Biologics License Application (BLA) to the U.S. FDA for imsidolimab in Generalized Pustular Psoriasis (GPP) in December 2025, which was accepted in February 2026 with a target action date of December 12, 2026.
• AnaptysBio received an upfront payment of $10.0 million and a $5.0 million payment for existing drug supply from Vanda, and is eligible for $35.0 million in future milestones and a 10% royalty on net sales.
• The net loss for the year ended December 31, 2025, was $13.2 million, a significant improvement from a net loss of $145.2 million in 2024.
• Collaboration revenue increased to $234.6 million in 2025 from $91.3 million in 2024.
• Research and development expenses decreased to $136.0 million in 2025 from $163.8 million in 2024.
• General and administrative expenses increased to $50.7 million in 2025 from $42.4 million in 2024, primarily due to legal expenses related to the GSK lawsuit and business separation.
• Non-cash interest expense for the sale of future royalties increased to $79.9 million in 2025 from $50.1 million in 2024, primarily due to increased Jemperli sales.
• Cash, cash equivalents, and investments totaled $311.6 million as of December 31, 2025, and the company believes this will fund operations for at least the next 12 months.
• A $100.0 million common stock repurchase program was approved in November 2025, supplementing a previous $75.0 million authorization, with $106.4 million remaining available as of December 31, 2025.
• Litigation is ongoing with GSK/Tesaro regarding the Collaboration Agreement, with AnaptysBio alleging material breach and tortious interference, and Tesaro alleging anticipatory breach by AnaptysBio.

Sentiment

Score: 8

Explanation: StockSavvy.ai views this as a strong positive report, driven by excellent clinical data for rosnilimab, robust Jemperli sales, and strategic clarity through the planned company separation, despite ongoing litigation and the termination of one partnered program.

Positives

• Rosnilimab's Phase 2b trial for rheumatoid arthritis met its primary and secondary endpoints, demonstrating statistical significance and numerical superiority across all doses.
• Rosnilimab showed deepening of responses and durable off-drug effects, suggesting potential for extended dosing intervals (e.g., Q8W/Q12W).
• The safety profile of rosnilimab was favorable, with no treatment-related serious adverse events (SAEs), malignancies, anaphylaxis, or systemic hypersensitivity.
• ANB033's Phase 1a trial demonstrated no safety concerns and effective reduction of pathogenic T cells and NK cells while maintaining immune competency.
• ANB101 preclinical data suggests it is a more potent antibody with a longer half-life compared to a competitor (litifilimab).
• Jemperli sales by GSK grew over 80% to $1.1 billion in 2025, indicating strong commercial performance of a partnered asset.
• Vanda Pharmaceuticals submitted a Biologics License Application (BLA) for imsidolimab in GPP, with FDA acceptance and a target action date, signaling progress towards commercialization.
• Collaboration revenue significantly increased to $234.6 million in 2025 from $91.3 million in 2024.
• Net loss was substantially reduced to $13.2 million in 2025 from $145.2 million in 2024.
• The company maintains a strong cash position with $311.6 million in cash, cash equivalents, and investments as of December 31, 2025.
• Management believes existing capital will fund operations for at least the next 12 months.
• The Board approved a $100.0 million stock repurchase program, with $106.4 million remaining available, indicating confidence in the company's value.

Negatives

• GSK terminated the TIM-3 antagonist antibody development program in October 2025, resulting in no future milestones or royalties from this program.
• Ongoing litigation with GSK/Tesaro regarding the Collaboration Agreement introduces significant uncertainty and potential adverse impacts on rights and financial position.
• General and administrative expenses increased by $8.3 million, primarily due to legal expenses related to the GSK lawsuit and the proposed business separation.
• Non-cash interest expense for the sale of future royalties increased by $29.8 million, indicating a faster amortization of the liability due to higher Jemperli sales, which means the company is repaying the monetized royalty stream more quickly.
• The company has a history of operational losses and an accumulated deficit of $772.6 million as of December 31, 2025.
• Interest income decreased by $6.3 million, primarily due to a decrease in investment balances and the timing of sales, maturities, and purchases of investments.

Risks

• Product candidates in development may fail or suffer delays, adversely affecting commercial viability.
• Results from initial clinical trials may not be representative of results in later clinical trials.
• Ongoing and planned clinical trials may reveal significant adverse events, toxicities, or other side effects.
• Inability to obtain, or delays in obtaining, required regulatory approvals in the United States or foreign jurisdictions.
• Even if product candidates receive regulatory approval, they will be subject to significant post-marketing regulatory requirements.
• Inability to successfully expand the pipeline of product candidates and develop marketable products.
• Lack of history in commercializing biotechnology products may make it difficult to evaluate future viability.
• Significant competition from major pharmaceutical and biotechnology companies.
• Product candidates may not achieve adequate market acceptance among physicians, patients, and health care payors.
• Absence of an internal marketing and sales force, requiring reliance on third parties.
• Complexity of biologics manufacturing and reliance on third-party manufacturers, which may encounter production difficulties.
• Political, economic, or public health events may have a material adverse impact on business.
• Limited operating revenue and a history of operational losses, with no guarantee of achieving or sustaining profitability.
• Requirement for additional capital to finance operations, which may not be available on acceptable terms or at all.
• The proposed separation of the business into two independent companies is subject to various risks and uncertainties and may not be completed as contemplated.
• Existing collaborations (e.g., with GSK) are important, and their termination or lack of success could adversely affect the business.
• Inability to obtain or protect intellectual property rights in the U.S. and globally.
• Difficulty attracting and retaining highly skilled employees.
• The market price of common stock has been and may continue to be volatile.
• Broad discretion in the use of net proceeds from public offerings, which may not be used effectively.
• Potential for securities litigation, which is expensive and could divert management attention.
• Requirements of being a public company may strain resources and divert management attention.
• Future sales and issuances of common stock or rights to purchase common stock could result in additional dilution.
• Disclosure controls and procedures may not prevent or detect all errors or acts of fraud.
• No intention to pay dividends on common stock, limiting returns to stock value appreciation.
• Cash and investments could be adversely affected if financial institutions fail.
• Provisions in organizational documents might discourage, delay, or prevent a change in control or management.
• Exclusive forum provisions in organizational documents may limit stockholders' ability to bring claims in certain judicial forums.
• Dependence on a small number of suppliers for raw materials, with potential for supply disruptions.
• Operations are vulnerable to interruption by fire, earthquake, power loss, terrorist activity, health epidemics, or other events beyond control.
• Changes in patent law could diminish the value of patents.
• Failure to comply with privacy and data security laws, regulations, and standards.
• Employees may engage in misconduct or other improper activities.
• Any drugs developed may become subject to unfavorable third-party reimbursement practices and pricing regulations.
• Healthcare legislative reform measures may increase the difficulty and cost of obtaining marketing approval and affect product pricing.

Future Outlook

The company expects to complete the proposed separation of its business into two independent, publicly traded companies (Royalty Management Co and Biopharma Co) in the second quarter of 2026. The clinical-stage biotechnology company (Biopharma Co) is expected to launch with adequate capital to fund operations for at least twelve months post-separation. An update on rosnilimab Phase 3 advancement is expected in the first half of 2026. The FDA has accepted Vanda's BLA for imsidolimab in GPP with a target action date of December 12, 2026.

Management Comments

• "We intend to launch the clinical-stage biotechnology company with adequate capital to fund operations for at least twelve months after the date the proposed separation is completed."
• "While the proposed separation is anticipated to be a taxable event, we are focused on minimizing overall corporate and shareholder-level taxes across the entire transaction."
• "We believe these molecules [rosnilimab, ANB033, ANB101] have potential applicability across a broad range of autoimmune and inflammatory diseases."
• "Rosnilimab results demonstrated deepening of responses through six months... results which we believe suggest the potential for extended dosing (e.g., Q8W/Q12W) after initial monthly dosing."
• "ANB101 preclinical data suggests it is a more potent antibody compared to litifilimab with a longer half-life that results in a deeper and more durable PD effect on pDC depletion."
• "We believe that our existing cash, cash equivalents and investments will fund our current operating plan for at least the next 12 months."

Industry Context

StockSavvy.ai notes that AnaptysBio's strategic move to separate its royalty-generating assets from its clinical-stage pipeline aligns with a trend in the biotechnology sector to unlock shareholder value by creating focused entities. The strong sales growth of Jemperli (PD-1 antagonist) by GSK highlights the continued commercial success of established immuno-oncology therapies, while the advancement of imsidolimab (IL-36R antagonist) by Vanda Pharmaceuticals into BLA submission positions it to potentially compete in the GPP market, which currently has limited approved biologics. The development of novel immunology therapeutics like rosnilimab (T-cell depleter), ANB033 (CD122 antagonist), and ANB101 (BDCA2 modulator) reflects the industry's ongoing pursuit of differentiated mechanisms of action for autoimmune and inflammatory diseases, an area with significant unmet medical needs and competitive intensity.

Comparison to Industry Standards

• Rosnilimab's Phase 2b results in RA, including statistical significance in ACR20, ACR50, and CDAI LDA, suggest a competitive profile against existing RA treatments like anti-TNF (Humira; Abbvie), IL-6 (Actemra; Roche and Kevzara; Regeneron), CD-80/86 (Orencia; BMS), CD-20 (Rituxan; Roche), and JAK inhibitors (Rinvoq; AbbVie, Olumiant; Eli Lilly, and Xeljanz; Pfizer). The durability and potential for extended dosing could offer differentiation.
• ANB033's development for Celiac Disease and Eosinophilic Esophagitis targets areas with limited approved therapies. Currently, there are no FDA-approved therapies for celiac disease and only one FDA-approved biologic (Dupixent) for EoE, suggesting a high unmet need and potential for significant market entry if successful. Competitors like FB-102 (Forte Bioscience), GIA632 (Novartis), and TEV-53408 (Teva) are in earlier phases (Phase 1b/2a), indicating ANB033 is progressing in a relatively open field.
• ANB101's preclinical data suggesting higher potency and longer half-life compared to litifilimab (Biogen), which is in Phase 3 for SLE and CLE, positions it as a potentially best-in-class BDCA2 modulator. This could be a significant advantage in a competitive landscape that also includes DNTH212 (Dianthus Therapeutics) in Phase 1 and daxdilimab (Amgen) in Phase 2.
• Jemperli's over 80% sales growth to $1.1 billion in 2025 demonstrates strong commercial performance, indicating successful market penetration and competitive standing within the immuno-oncology space, particularly for endometrial cancer.

Corporate Governance

Legal Proceedings

• On November 20, 2025, AnaptysBio filed a Verified Complaint in Delaware Chancery Court, requesting a court declaration that TESARO, Inc. (Tesaro) has materially breached the Collaboration and Exclusive License Agreement and that GSK, Tesaro's corporate parent, has tortiously interfered with the Collaboration Agreement.
• AnaptysBio has requested that the court declare it is entitled to all rights and remedies under the Collaboration Agreement.
• On the same day, Tesaro, without notice, initiated a lawsuit against AnaptysBio, requesting a declaration that it has not breached the Collaboration Agreement and for an injunction prohibiting AnaptysBio from terminating the Collaboration Agreement.
• Tesaro alleges that AnaptysBio has materially breached the agreement by improperly alleging Tesaro's breach, which allegedly caused an anticipatory breach of contract.
• AnaptysBio believes Tesaro's claims are entirely without merit and has moved to dismiss the anticipatory breach claim.
• The litigation creates uncertainty as to the ownership of related intellectual property rights and is diverting significant management time and resources.

Stakeholder Impact

• Shareholders: Potential for increased value through the proposed separation into two focused companies; benefit from the stock repurchase program; risk of dilution from future capital raises; impact from stock price volatility; potential adverse impact from ongoing litigation with GSK/Tesaro.
• Employees: Need to attract and retain highly skilled personnel, especially for later-stage product development; potential operational disruptions and allocation of management time due to the proposed separation.
• Customers (collaborators like GSK, Vanda): Continued collaboration for Jemperli and imsidolimab; termination of the TIM-3 program by GSK affects future collaboration scope.
• Patients: Potential for new innovative immunology therapeutics for autoimmune and inflammatory diseases (rosnilimab, ANB033, ANB101) if clinical trials are successful and products gain approval.
• Creditors: Impact from the liability related to the sale of future royalties, which is being repaid faster due to Jemperli sales.

Next Steps

• Complete the proposed separation of the business into two independent, publicly traded companies in Q2 2026.
• Launch the clinical-stage biotechnology company (Biopharma Co) with adequate capital to fund operations for at least twelve months post-separation.
• Provide an update on rosnilimab Phase 3 advancement in the first half of 2026.
• Vanda Pharmaceuticals awaits FDA target action date of December 12, 2026, for imsidolimab BLA in GPP.
• Continue to prosecute pending patent applications and pursue patent issuance and protection for rosnilimab, ANB033, ANB101, dostarlimab, and imsidolimab.
• Manage ongoing litigation with GSK/Tesaro.
• Continue stock repurchases under the program expiring March 31, 2026.

Key Dates

Recommendation

AnaptysBio presents a mixed but generally positive outlook. The strong Phase 2b data for rosnilimab in RA and the significant sales growth of Jemperli are clear positives, indicating progress in both its wholly-owned pipeline and partnered assets. The planned separation into two companies could unlock value by creating focused entities. However, the ongoing litigation with GSK/Tesaro introduces significant uncertainty and potential financial and operational risks. While the company has a solid cash position and a clear strategy for its pipeline, the legal dispute and the inherent risks of clinical-stage drug development warrant a 'hold' recommendation until there is more clarity on the litigation outcome and further advancement of its wholly-owned assets towards commercialization.

Keywords

Biotechnology, Immunology, Autoimmune Diseases, Inflammatory Diseases, Rheumatoid Arthritis, Rosnilimab, ANB033, ANB101, Jemperli, Dostarlimab, Imsidolimab, GSK, Vanda Pharmaceuticals, Drug Development, Clinical Trials, Corporate Separation, Royalty Monetization, Biologics, Antibody Therapeutics, Endometrial Cancer, Generalized Pustular Psoriasis, BDCA2, CD122, T-cell depleter, Financial Results, Stock Repurchase, SEC Filing, 10-K