Executive Summary

Q1 2025 delivered first collaboration revenue ($2.55M) from Novo Nordisk, while R&D investment stepped up as KRRO-110 advanced; net loss widened to $23.39M and diluted EPS was $(2.49) .
Management streamlined operations with a ~20% workforce reduction and expects one-time restructuring charges of ~$1.2M in Q2 to extend the cash runway into 2027 .
Clinical execution remains on track: interim readout from the Phase 1/2a REWRITE study for KRRO-110 in AATD expected in H2 2025; trial expansion underway to New Zealand and targeted for the U.S. .
Street consensus for Q1 2025 EPS and revenue was unavailable via S&P Global, limiting beat/miss analysis; near-term stock catalysts center on H2 2025 KRRO-110 data and clarity on regulatory path .

What Went Well and What Went Wrong

What Went Well

Initiated revenue generation via collaboration; $2.55M recognized in Q1 tied to Novo Nordisk agreement .
Cash runway extended into 2027 through cost reductions and workforce realignment; CEO emphasized staying “on track to achieve our clinical and pipeline milestones” .
Clinical momentum: regulatory approval to expand REWRITE in New Zealand, with continued progress on enrollment and site activation; interim data H2 2025 and completion in 2026 remain on track .

Specific quotes:

“We remain on track to achieve our clinical and pipeline milestones, most notably reporting interim data from our Phase 1/2a REWRITE clinical trial of KRRO-110 in the second half of 2025.” — Ram Aiyar, Ph.D., CEO and President .
“Streamlining the organization is essential to enable Korro’s long-term success.” — Todd Chappell, COO .

What Went Wrong

Net loss widened YoY to $(23.39)M (from $(19.56)M), driven by higher KRRO-110 and personnel-related R&D spend; R&D rose to $19.74M vs $13.57M YoY .
Operating expenses increased to $27.57M vs $21.45M YoY, reflecting scale-up into clinical execution; cash decreased to $138.99M from $163.05M at year-end .
Organizational restructuring (~20% workforce reduction) introduces near-term execution risk and ~$1.2M of one-time charges expected in Q2 2025 .

Financial Results

Income Statement Comparison

Metric	Q1 2024	Q3 2024	Q1 2025
Collaboration Revenue ($USD Millions)	$0.00	N/A (not disclosed)	$2.55
Research & Development Expense ($USD Millions)	$13.57	$15.96	$19.74
General & Administrative Expense ($USD Millions)	$7.88	$7.33	$7.83
Total Operating Expenses ($USD Millions)	$21.45	$23.29	$27.57
Other Income, net ($USD Millions)	$1.91	$2.28	$1.63
Net Loss ($USD Millions)	$(19.56)	$(21.00)	$(23.39)
Diluted EPS ($USD)	$(2.44)	$(2.26)	$(2.49)

Note: Prior quarter Q4 2024 was reported on a full-year basis without separate quarterly detail in 8-K materials .

Cash Position

Metric	Sep 30, 2024	Dec 31, 2024	Mar 31, 2025
Cash, Cash Equivalents & Marketable Securities ($USD Millions)	$169.11	$163.05	$138.99
Working Capital ($USD Millions)	$139.17	$116.57	$108.35
Total Stockholders’ Equity ($USD Millions)	$179.63	$160.42	$138.96

Results vs Estimates

Metric	Actual Q1 2025	Consensus Q1 2025	Beat/Miss
Revenue ($USD Millions)	$2.55	N/A	N/A
EPS ($USD)	$(2.49)	N/A	N/A

Consensus was unavailable in S&P Global for Q1 2025.

Segment Breakdown

Not applicable; Korro reports as a single operating entity focused on RNA-editing programs .

KPIs (Program and Collaboration)

KPI	Q-2 (Q3 2024)	Q-1 (Q4 2024)	Current (Q1 2025)
REWRITE Participants (planned)	Up to 64 participants	Up to 64 participants	Up to 64 participants
REWRITE Status	Regulatory filing submitted (Australia)	Dosed first two SAD cohorts; no SAEs observed	NZ approval; progressing enrollment; expansion planned incl. U.S.
Interim Readout Timing	H2 2025	H2 2025	H2 2025
Novo Nordisk Collaboration	Announced; up to two targets	Progressing; focus on cardiometabolic	Progressing; up to two programs through preclinical
Second Development Candidate	Expected 2025	Expected 2025	Expected 2025

Guidance Changes

Metric	Period	Previous Guidance	Current Guidance	Change
Cash Runway	Through H2 2026	“Cash runway into the second half of 2026” (Q3 2024; FY 2024)	“Cash runway into 2027” (post-streamlining)	Raised (extended)
Restructuring Charges	Q2 2025	None disclosed previously	~$1.2M one-time charges; majority recognized in Q2 2025	New
REWRITE Interim Data	H2 2025	H2 2025	H2 2025 (unchanged)	Maintained
Trial Geographies	2025	Australia (filed; Q3 2024)	Expansion approved in New Zealand; planning expansion incl. U.S.	Expanded
Second Dev. Candidate	2025	Expected in 2025	Expected in 2025	Maintained

Earnings Call Themes & Trends

(Company did not furnish an earnings call transcript for Q1 2025; management commentary derived from Q1 press release and May 2025 RBC conference transcript.)

Topic	Previous Mentions (Q-2: Q3 2024)	Previous Mentions (Q-1: Q4 2024)	Current Period (Q1 2025)	Trend
Clinical execution (REWRITE)	Filing submitted in Australia; first dosing expected Q1 2025	First two SAD cohorts dosed; no SAEs; interim H2 2025	NZ expansion approved; enrollment progressing; interim H2 2025	Consistent progress
Regulatory/Orphan status	CAB formed; preparing for clinic	FDA Orphan Drug Designation granted for KRRO-110	Ongoing regulatory interactions; planning U.S. expansion	Strengthening pathway
Collaboration (Novo Nordisk)	Announced; up to two cardiometabolic targets	Collaboration progressing	Working to advance up to two preclinical programs	Steady execution
Financing/Runway	Strong balance sheet; runway into H2 2026	Runway into H2 2026	Streamlining extends runway into 2027	Improved runway duration
LNP safety/approach	N/A	N/A	CEO addressed LNP safety and dosing frequency expectations (q3–q6 weeks) at RBC	De-risking narrative
Technology differentiation	OTS preclinical data showcased OPERA efficacy	Emphasized best-in-class potential	Reinforced editing potency and translation in animals (80% editing; protein translation)	Confidence building

Management Commentary

“We believe that KRRO-110 represents a groundbreaking therapy with best-in-class potential for patients with AATD… executing our 3-2-1 strategy through 2027” — Ram Aiyar, CEO .
“Streamlining… reducing [the] workforce by approximately 20%… to advance its programs to key value inflection points” — Press release detail and COO statement .
On editing potency and dosing: “We are the only ones that have shown… 80% editing in vivo… expectation… dosing frequency is somewhere between once in three weeks to once in six weeks” — CEO at RBC .
On regulatory landscape: “Data… is going to drive everything… [we] have open communication channels [with FDA]; approvals may become more challenging” — CEO at RBC .

Q&A Highlights

Regulatory path and accelerated approval: Management believes protein-level data (M variant at near-normal levels) plus functional comparability could support accelerated approval, with additional liver benefit if editing exceeds 50% at any point .
LNP safety in AATD and fibrosis: CEO cited historical LNP experiences and competitor dosing to argue transaminase elevations are unlikely dose-limiting; infusion reactions are more typical; focus is to find the lowest dose that achieves target protein levels .
Upcoming interim data scope: Plan to show all eight SAD cohorts (six healthy, two PiZZ) together with safety/tolerability, dose-response, M/Z ratios, and ex vivo neutrophil elastase activity over 2–4 weeks .
Z vs M protein dynamics: Expect Z proportion to decline with higher editing; anticipate M predominance at ≥50% editing with potential “bolus” of Z clearance post-dose, potentially beneficial for liver outcomes .
Runway/financing: ~$139M cash and runway into 2027; Novo milestones not included; aim to nominate second asset and hit milestones through early 2027 .

Estimates Context

S&P Global consensus for Q1 2025 EPS and revenue was unavailable; therefore, beat/miss analysis vs Street cannot be determined. Actuals: Revenue $2.55M, EPS $(2.49) .
Implication: Post-collaboration revenue initiation and higher R&D spend may prompt analysts to refine cash burn trajectories and timing expectations around H2 2025 KRRO-110 interim data; broader coverage may remain limited until clinical readouts .

Key Takeaways for Investors

Near-term catalyst: H2 2025 interim REWRITE data that will inform editing levels, M/Z ratios, protein levels, and safety — key for establishing an accelerated approval case and valuation inflection .
Strategic runway: Streamlining extends cash runway to 2027, reducing financing overhang while focusing spend on KRRO-110 and OPERA platform investments .
Collaboration monetization: Initial collaboration revenue recognized; Novo programs progressing — provides non-dilutive validation and optionality ahead of clinical data .
Execution watchpoints: Monitor Q2 restructuring charge (~$1.2M) and operational impact; track site activations and U.S./EU regulatory interactions .
Safety and dosing profile: Management’s confidence in LNP safety and achievable dosing frequency (q3–q6 weeks) supports chronic-use feasibility if efficacy is confirmed .
Competitive differentiation: Preclinical data and translational claims (high editing, protein output) position KRRO-110 as potentially best-in-class; human data will be decisive .
Trading setup: Stock is likely to be event-driven into H2 2025; upside tied to robust interim efficacy/safety; downside risk if editing/protein levels fall short or regulatory tone tightens .

Sources: Q1 2025 Form 8-K with Exhibit 99.1 (press release and financials) ; FY 2024 8-K (for runway and dosing updates) ; Q3 2024 8-K (for prior trends and collaboration announcement) ; RBC Capital Markets Global Healthcare Conference 2025 transcript (management Q&A) .

Korro Bio, Inc. (KRRO)·Q1 2025 Earnings Summary