Silence Therapeutics' Q1 Loss Spotlights High-Stakes R&D Push and 2028 Cash Runway Claims

Silence Therapeutics plc (SLNCE) reported a GAAP net loss of $28.5 million for Q1 2025, or $0.20 per share, marking a stark contrast to its $2.3 million loss in the same period last year. The widening deficit reflects the biotech’s aggressive pivot toward advancing its mRNAi GOLD™ platform, with clinical trials and manufacturing costs driving a sharp rise in expenses. But as the company claims its cash runway now extends “into 2028,” investors must weigh whether its strategic bets will pay off—or if the burn rate is unsustainable.

The EPS Dive: R&D Spending in Overdrive

The Q1 loss was no surprise given the company’s deliberate focus on scaling clinical programs. Research and development expenses jumped to $20.8 million in Q1 2025, a $9 million increase from the prior-year period, as Silence prioritized enrollment in its Phase 2 SANRECO study for divesiran (a treatment for polycythemia vera) and manufacturing readiness for its cardiovascular candidate, zerlasiran. General and administrative costs also rose, climbing to $7.7 million, reflecting compliance costs as the company transitioned to a U.S. domestic issuer.

The question is: Is this spending a necessary investment in high-potential programs, or a reckless gamble? Silence’s management insists the former, arguing that $136.5 million in cash as of March 31, 2025—down from $147.3 million at year-end 2024—provides ample runway to execute its priorities.

The 2028 Runway: Math That Hangs on Cost Discipline

To sustain operations until 2028, Silence must manage its cash burn rate meticulously. In Q1 alone, its cash decreased by $10.8 million, implying an annualized burn of roughly $43 million. With $136.5 million remaining, that math suggests about 3.1 years of cash, aligning with its 2028 timeline. But this assumes no acceleration in spending or delays in partnerships.

The company has already begun deprioritizing less critical programs, funneling resources into its two crown jewels:
1. Divesiran: Phase 2 SANRECO data is slated for presentation at the EHA 2025 Congress, a potential catalyst for investor confidence.
2. Zerlasiran: Silence is pursuing Phase 3 readiness for its cardiovascular candidate, with discussions ongoing about potential partnerships to share development costs.

Risks on the Horizon

The strategy hinges on execution:
- Clinical Milestones: Delays in SANRECO or zerlasiran trials could force further cash draws.
- Partnership Uncertainty: Without a deal for zerlasiran, Silence may need to fund late-stage trials alone.
- Market Volatility: Biotech stocks often face funding headwinds if broader markets sour, and Silence’s stock has underperformed peers in 2025.

Conclusion: A High-Reward, High-Risk Gamble

Silence’s financials paint a clear picture: the company is all-in on its mRNAi platform, willing to accept short-term losses for long-term gains. While the math just supports the 2028 runway under current assumptions, any misstep—whether operational or financial—could force a pivot.

Investors should focus on two key metrics:
1. Cash Burn Rate: If the Q1 $10.8 million quarterly burn accelerates, the runway narrows sharply.
2. Clinical Catalysts: Positive data from SANRECO or a zerlasiran partnership could revalue the stock significantly.

At present, Silence’s valuation trades at a $350 million market cap, a fraction of peers in mRNA therapies. If its candidates deliver on their promise, the stock could surge. But if trials stumble or partnerships falter, the 2028 timeline may prove overly optimistic. For now, the company’s bet is clear: spend boldly now, or risk missing the window for commercialization. The next 18 months will decide if that gamble pays off.