Upstream Bio Reports $143.4 Million Net Loss for 2025 Amid Increased R&D Expenses

Upstream Bio, Inc., a clinical-stage biotechnology firm focused on inflammatory disease treatments, reported a net loss of $143.4 million for the year ended December 31, 2025, a significant increase from the $62.8 million loss reported in the previous fiscal year. The company, which has no products approved for commercial sale, attributed the increased losses to escalating research and development expenses as it advances its lead drug candidate, verekitug, through clinical trials. Verekitug is currently undergoing Phase 2 trials for severe asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and chronic obstructive pulmonary disease (COPD). Collaboration revenue, primarily from its licensing agreement with Maruho Co., Ltd., increased to $2.9 million in 2025 from $2.4 million in 2024.

Research and development expenses for Upstream Bio surged to $136.8 million in 2025, compared to $63.0 million in 2024. This increase was largely driven by the initiation of a Phase 2 clinical trial for COPD, as well as continued progress in Phase 2 trials and a long-term safety extension study for severe asthma. The company also incurred significant unallocated manufacturing costs related to the development of Phase 3 clinical material. General and administrative expenses also rose, reaching $26.4 million in 2025, up from $17.2 million in 2024, due to increased headcount and professional fees associated with operating as a public company.

Upstream Bio's financial position remains relatively strong, with cash, cash equivalents, and short-term investments totaling $341.5 million as of December 31, 2025. The company believes these resources will be sufficient to fund operations through 2027. The company's cash flow from operating activities was negative $133.3 million, while investing activities used $93.5 million, primarily for short-term investments. Financing activities provided $2.4 million, mainly from the exercise of stock options.

Looking ahead, Upstream Bio plans to initiate dosing in Phase 3 trials for both severe asthma and CRSwNP in the first quarter of 2027. The company is prioritizing a Phase 3 development strategy focused on maximizing efficacy without biomarker restriction, with quarterly at-home administration of verekitug. The company anticipates that operating expenses will continue to increase as it progresses verekitug through clinical development and seeks regulatory approvals. The company's future success hinges on its ability to successfully develop, obtain regulatory approval for, and commercialize verekitug.