SLN

Silence Therapeutics Plc: Q2 2025 10-Q Summary

Business Context and Reporting Period

Silence Therapeutics Plc is a biotechnology company focused on discovering and developing RNA therapeutics, specifically short interfering RNA (siRNA) molecules. The company operates as a single reportable segment. This report covers the quarterly period ended June 30, 2025. Effective January 1, 2025, the company transitioned its reporting currency from British Pounds Sterling (GBP) to U.S. Dollars (USD) and adopted U.S. GAAP retrospectively.

Key Financial Metrics

Liquidity: As of June 30, 2025, the company held $41.7 million in cash and cash equivalents and $72.4 million in short-term investments. Management believes these resources are sufficient to fund operations into 2028, contingent on anticipated milestone payments.

Material Changes vs. Prior Period

• Revenue Decline: Revenue for the six months ended June 30, 2025, dropped to $0.4 million from $16.5 million in the prior year. This decrease is primarily due to the absence of a $10.0 million milestone payment from the AstraZeneca collaboration recognized in the prior year and the conclusion of development activities under the Hansoh and Mallinckrodt collaborations.
• Increased R&D Spend: R&D expenses increased by $12.8 million year-over-year (YTD) to $38.5 million. This reflects the advancement of proprietary programs, specifically the Phase 2 clinical trial for divesiran (SLN124) and increased contract manufacturing for zerlasiran (SLN360) Phase 3 readiness.
• Restructuring Charges: The company incurred $1.3 million in non-recurring restructuring charges in Q2 2025 related to a reduction in workforce. No such charges were recorded in the prior year.
• Foreign Currency Impact: A significant foreign currency loss of $10.4 million was recorded for the six months ended June 30, 2025, compared to a gain of $0.1 million in the prior year. This was driven by the remeasurement of U.S. treasury bills held in USD against the functional currency.

Outlook, Guidance, and Risks

Management Commentary & Outlook:

• Divesiran (SLN124): The SANRECO Phase 2 trial for polycythemia vera (PV) exceeded 50% enrollment in June 2025 and is on track to complete enrollment by year-end 2025. Data presented at the EHA 2025 Annual Meeting showed durable control of hematocrit levels.
• Zerlasiran (SLN360): Core Phase 3 readiness activities, including manufacturing scale-up, are complete. The company is in discussions with potential third-party partners for Phase 3 development and commercialization.
• Strategic Shift: The company has paused the initiation of a Phase 1 study for SLN548 (complement-mediated diseases) to prioritize extra-hepatic cell targeting activities showing promising preclinical activity.
• Capital Needs: While current cash is projected to last into 2028, the company expects to incur operating losses for the foreseeable future and may seek additional funding through equity, debt, or collaborations.

Risks and Contingencies:

• Regulatory & Legislative: Risks include potential changes in U.S. healthcare legislation (e.g., the "One Big Beautiful Bill Act" signed July 4, 2025) affecting Medicaid spending and drug pricing, as well as evolving EU regulations on clinical trials and health technology assessments.
• Data Privacy: Significant exposure to data privacy laws (GDPR, CCPA) and cross-border data transfer restrictions, particularly regarding transfers from Europe to the U.S.
• Collaboration Dependency: Future revenue is heavily dependent on achieving milestones under the AstraZeneca collaboration, which are not guaranteed.

Key Facts for Investor Verification

• Cash Runway: Verify the assumption that existing cash ($114.2M) plus anticipated milestones ($20M) will fund operations into 2028, given the high burn rate ($34.1M operating cash outflow in H1 2025).
• Revenue Recognition: Confirm the timing of future revenue recognition from the AstraZeneca collaboration, as the $10M milestone recognized in H1 2024 did not recur in H1 2025.
• Currency Exposure: Assess the impact of the $10.4M foreign exchange loss on future earnings, given the company's significant USD-denominated investments and GBP/EUR operational costs.
• Restructuring Impact: Monitor whether the $1.3M restructuring charge and workforce reduction will result in sustained G&A expense reductions in future quarters.
• Partnership Progress: Track the status of partnership discussions for zerlasiran (SLN360), as a deal could significantly alter the capital structure and development timeline.