Upstream Bio Phase 2 VALIANT Trial Conference Call Summary Company Overview - **Company**: Upstream Bio (NasdaqGS:UPB) - **Focus**: Clinical-stage immunology company targeting severe respiratory diseases, specifically developing Verekitug, a TSLP receptor antagonist [9][10] Industry Context - **Market Opportunity**: - Approximately 1.3 million patients in the U.S. are eligible for biologic therapies for severe asthma, with only 25% currently receiving treatment, indicating significant commercial potential for new biologics [10] - Global peak sales for biologics in severe asthma projected to exceed $12.5 billion by 2033 [11] Key Trial Results - **Trial Name**: VALIANT - **Type**: Phase 2, placebo-controlled, randomized trial - **Participants**: 478 adults with severe asthma [12] - **Dosing Regimens**: - 100 mg every 12 weeks (high dose) - 400 mg every 24 weeks (medium dose) - 100 mg every 24 weeks (low dose) - Placebo [12] Efficacy Findings - **Annualized Asthma Exacerbation Rate (AAER)**: - 100 mg every 12 weeks: 56% reduction in AAER [5] - 400 mg every 24 weeks: 39% reduction in AAER [6] - 100 mg every 24 weeks: 49% reduction in AAER [17] - **Lung Function Improvements**: - 100 mg every 12 weeks: 122 mL improvement in FEV1 and 20.4 ppb reduction in exhaled nitric oxide (FeNO) [5] - 400 mg every 24 weeks: 139 mL improvement in FEV1 and 26.3 ppb reduction in FeNO [6] - **Safety Profile**: Generally well-tolerated with no deaths reported; adverse events similar across treatment groups [16] Strategic Insights - **Differentiation**: Verekitug shows potential for a unique clinical profile compared to existing biologics, with less frequent dosing [7][8] - **Next Steps**: Plans to advance to Phase 3 studies in severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) pending regulatory discussions [23] - **Ongoing Trials**: Enrollment in the VENTURE trial for COPD is over 60% complete, with positive feedback from investigators [10] Market Dynamics - **Competitive Landscape**: The biologics market for asthma is characterized by multiple agents targeting different pathways, allowing for new entrants to capture market share without directly eroding existing products [50] - **Patient Convenience**: Dosing frequency and convenience are critical factors for adoption, with Verekitug's dosing schedule potentially offering a competitive advantage [40][51] Additional Considerations - **Regulatory Engagement**: Future Phase 3 trial designs will be informed by comprehensive data analysis and discussions with regulatory authorities [31][49] - **Antibody Development**: Anti-drug antibodies (ADAs) were observed in 50%-60% of subjects, but their impact on efficacy appears minimal [17][71] Conclusion - Upstream Bio is positioned to leverage the positive results from the VALIANT trial to advance Verekitug into Phase 3 studies, aiming to address significant unmet needs in severe asthma and capitalize on the substantial market opportunity in the biologics space [22][82]

Core Insights - Upstream Bio announced positive results from the Phase 2 VALIANT trial for verekitug, showing significant reductions in asthma exacerbation rates and improvements in lung function [2][3][4] Efficacy and Safety - Verekitug demonstrated a 56% reduction in annualized asthma exacerbation rate (AAER) at a dose of 100 mg every 12 weeks and a 39% reduction at 400 mg every 24 weeks compared to placebo [3] - Improvements in lung function were observed, with a placebo-adjusted increase in forced expiratory volume in one second (FEV1) of 122 mL for the 100 mg q12w group and 139 mL for the 400 mg q24w group [4] - The drug also significantly suppressed exhaled nitric oxide (FeNO), with reductions of 20.4 ppb and 26.3 ppb for the respective dosing regimens [4] Patient Enrollment and Future Trials - Over 90% of eligible patients from the VALIANT trial have transitioned to the Phase 2 VALOUR long-term extension study [8] - Upstream Bio plans to advance verekitug into Phase 3 trials for severe asthma and chronic rhinosinusitis with nasal polyps (CRSwNP) following regulatory interactions [6][9] Company Overview - Upstream Bio is focused on developing treatments for inflammatory diseases, particularly severe respiratory disorders, and is advancing verekitug as a unique antagonist targeting the TSLP receptor [19][12] - The company has conducted multiple Phase 2 trials for verekitug, including studies for chronic obstructive pulmonary disease (COPD) and CRSwNP, and is committed to addressing unmet needs in severe asthma treatment [18][19]

Summary of Conference Call on Upstream Bio and Verekitug Company and Industry Overview - **Company**: Upstream Bio - **Industry**: Biopharmaceuticals, specifically focusing on treatments for asthma and chronic rhinosinusitis with nasal polyps Key Points and Arguments 1. **Upcoming Data Readouts**: The company anticipates significant data readouts in Q1 2026 for Verekitug, particularly regarding asthma treatment efficacy, following the completion of enrollment on June 9, 2023, for a 24-week study [1][2][3] 2. **Efficacy Expectations**: The target for success in the asthma study is a 50% reduction in exacerbation rates on a placebo-adjusted basis, with hopes to achieve this through both quarterly and biannual dosing regimens [4][6] 3. **Potency of Verekitug**: The drug is characterized by its high potency, which has been demonstrated in previous studies, suggesting it could deliver best-in-class efficacy with extended dosing intervals [5][6][19] 4. **Comparison with Competitors**: The company aims to differentiate Verekitug from existing biologics like Tezspire and Dupixent by offering a unique dosing schedule and potentially superior efficacy [26][28] 5. **Clinical Trial Design**: The design of the trials is informed by previous data, with a focus on replicating successful outcomes seen in other biologics while adhering to regulatory standards [12][13][28] 6. **Market Penetration Challenges**: Despite the large market for asthma treatments, less than 10% of patients currently use biologics, attributed to factors such as patient eligibility based on eosinophil counts and market access issues [30][31] 7. **Regulatory Strategy**: The company plans to engage with regulatory agencies to potentially run concurrent studies for asthma and chronic rhinosinusitis, which is a unique approach compared to typical staggered study designs [29] Additional Important Insights 1. **Biomarker Relevance**: Exhaled nitric oxide (FeNO) levels are highlighted as a significant biomarker for predicting asthma exacerbations, with Verekitug expected to show superior results in this area compared to competitors [19][20] 2. **Patient Population**: The trials are designed to include patients with a history of exacerbations, ensuring that the study population is representative of those most likely to benefit from treatment [11][12] 3. **Future Development Plans**: The company is optimistic about the potential for Verekitug to address unmet needs in both asthma and chronic rhinosinusitis, with plans for robust data collection to inform future phase 3 trials [22][23] This summary encapsulates the critical discussions and insights from the conference call, focusing on the strategic positioning of Upstream Bio and its product Verekitug within the biopharmaceutical landscape.

Company Overview - Upstream Bio, Inc. (UPB) is developing Verekitug, a long-acting TSLP receptor-targeted biologic aimed at treating chronic respiratory diseases such as severe asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and COPD [2][3] - Verekitug is designed for dosing once every three to six months, which significantly improves patient compliance compared to competitors like Dupixent and Tezspire [2] Clinical Development - Phase 2 results for CRSwNP in September 2025 indicated that Verekitug was as effective, if not superior, to Tezspire and Dupixent, with the advantage of extended dosing [3] - An asthma trial involving 666 patients is underway to determine the optimal dosing interval of three or six months [3] Market Position and Valuation - UPB currently trades at a market cap of approximately $1 billion, which is significantly lower than peers with similar Phase 2 profiles, despite having nearly $400 million in cash to fund operations through 2027 [3] - Comparable companies like Viking and CellDex have market caps ranging from $1.5 billion to $3 billion, while GSK acquired Bellus for $2 billion based on less proven data [3] Commercial Potential - The patent protection for Verekitug extends into the 2040s, creating a potential multi-decade franchise [4] - Peak sales estimates for Verekitug exceed $10 billion in the U.S. alone, with additional upside potential outside the U.S., supporting a valuation of over $14 billion on risk-adjusted metrics [4] Investment Thesis - The combination of best-in-class potential, long-duration intellectual property, and an undervalued market cap presents a compelling investment opportunity with potential upside of 2 to 5 times on continued progress, and potentially 10 times on acquisition [4]

Core Points - Upstream Bio is hosting a conference call to discuss the Phase II VIBRANT top-line results of their lead asset, Verekitug [1][4] - The call includes forward-looking statements regarding the company's expectations and beliefs about future events [2] - Comparisons of Verekitug against existing treatments are based on third-party published data, with caution advised due to differences in trial designs and patient characteristics [3] Company Overview - Upstream Bio's CEO, Dr. Rand Sutherland, and Chief Medical Officer, Dr. Aaron Deykin, are present to discuss the results and future plans for Verekitug [4] - The agenda includes an overview of the results and a detailed review of the Phase II VIBRANT clinical study top-line results [4]

Core Insights - Upstream Bio, Inc. announced positive top-line results from the Phase 2 VIBRANT trial for verekitug, demonstrating significant efficacy in treating chronic rhinosinusitis with nasal polyps (CRSwNP) [1][6][12] Study Results - The VIBRANT trial met its primary endpoint with a statistically significant placebo-adjusted reduction in endoscopic nasal polyp score (NPS) of -1.8 (p<0.0001) at Week 24 [1][4] - Key secondary endpoints showed a reduction in nasal congestion score (NCS) by -0.8 (p=0.0003) and a 76% reduction (p=0.03) in the need for surgery or systemic corticosteroids [1][2][5] - The trial involved 81 adults and was designed as a global, randomized, double-blind, placebo-controlled study over 24 weeks [3][12] Safety Profile - Verekitug was generally well tolerated, with no serious adverse events (SAEs) reported, consistent with previous studies [1][5][6] Mechanism and Potential - Verekitug is a monoclonal antibody targeting the thymic stromal lymphopoietin (TSLP) receptor, which is unique in its mechanism of action compared to existing therapies [1][13][18] - The results suggest that verekitug could advance the standard of care for CRSwNP and may have potential applications in other respiratory diseases, including severe asthma [6][7][18] Future Plans - Upstream Bio plans to engage with global regulatory authorities for further development and potential product approval of verekitug [7][12] - The company will present additional details from the VIBRANT trial at an upcoming medical conference [8]