Assembly Biosciences surges 13% as Gilead deal drives 153% revenue jump
Biotech firm narrows loss 84% to $0.55 per share; $35M option fee from Gilead strengthens cash position to $248.1M
Assembly Biosciences shares surged in Thursday trading after the biotechnology company reported fourth-quarter results that blew past analyst expectations, driven by a $35 million licensing deal with Gilead Sciences that more than doubled revenue and extended its financial runway into 2028.
The South San Francisco-based company reported fiscal 2025 earnings per share of negative 55 cents, significantly better than the loss of $6.69 per share a year earlier and well ahead of analyst expectations for a loss of 65 cents. Revenue soared 153% to $72.3 million, according to regulatory filings.
The dramatic revenue increase was entirely attributable to Gilead's exercise of an option fee for Assembly's helicase-primase inhibitor program targeting recurrent genital herpes, which includes clinical candidates ABI-5366 and ABI-1179. The deal validates Assembly's platform approach to developing novel antivirals and provides critical funding as the company advances its pipeline.
Perhaps most importantly for investors, Assembly ended 2025 with $248.1 million in cash and equivalents, a substantial war chest that management said will fund operations into 2028. This extended runway eliminates immediate financing concerns that typically plague development-stage biotechnology companies.
"The successful licensing of our herpes program to Gilead represents a significant milestone for Assembly Biosciences and provides both financial resources and validation of our drug discovery capabilities," said company leadership in the earnings announcement.
The company's net loss narrowed dramatically from $40.2 million in 2024 to just $6.1 million in 2025, reflecting both the Gilead partnership proceeds and improved operational efficiency. This 84% reduction in losses demonstrates Assembly's progress toward profitability even as it continues investing in clinical development.
However, not all news was positive. Gilead declined to exercise its option on Assembly's hepatitis B virus candidate ABI-4334, leaving that program without a partner. The company will need to seek alternative collaborations or fund development independently for that asset.
Looking ahead, investors are focused on the anticipated launch of a Phase 2 trial for ABI-6250, Assembly's hepatitis delta virus candidate, by the end of 2026. With four analysts maintaining buy ratings on the stock and an average price target of $47.75—well above Thursday's trading levels—optimism remains high about the company's long-term prospects.
Assembly's shares have been highly volatile over the past year, trading in a range between $7.75 and $39.71, reflecting the binary nature of clinical-stage biotechnology investments. With 59.8% institutional ownership and 32.3% insider ownership, significant stakeholders remain deeply committed to the company's success.
The Gilead partnership marks a turning point for Assembly, which has transformed from a research-stage platform company into one with validated assets and substantial financial resources. The coming months will be critical as investors watch for updates on the ABI-6250 trial and any additional partnership announcements that could further de-risk the company's pipeline.