Executive Summary

Q4 delivered strong top-line growth, with total revenue of $122.5M, up from $83.4M in Q4 2023, driven entirely by ARCALYST net product revenue of $122.5M; however, the company posted a net loss of $8.9M as collaboration, R&D, and SG&A expenses rose with scale and portfolio activity .
Full-year 2024 ARCALYST net product revenue was $417.0M (+79% YoY), and total revenue was $423.2M; management guided 2025 ARCALYST net product revenue to $560–$580M and reiterated expectations to remain cash flow positive on an annual basis .
Strategic reprioritization: Kiniksa will discontinue abiprubart in Sjögren’s Disease and terminate the mavrilimumab license, with most related wind-down and termination costs recorded across Q4 2024 and H1 2025 (approx. $19M incurred; $14–$17M additional expected) .
Pipeline expansion: KPL-387 (monthly SC IL‑1R1 mAb) to start Phase 2/3 in recurrent pericarditis mid-2025; Phase 2 data expected in 2H 2026—supporting the strategy to extend leadership in recurrent pericarditis .

What Went Well and What Went Wrong

What Went Well
- ARCALYST momentum: Q4 net product revenue of $122.5M (+72% YoY) and FY 2024 of $417.0M (+79% YoY), with 2,850+ prescribers, ~27 months average duration, and ~13% penetration of the 14,000 multiple‑recurrence target population by year‑end .
- Collaboration profit scaled with growth: CFO highlighted ARCALYST collaboration profit of $76.3M in Q4 (+125% YoY) and $234.7M in FY 2024 (+108% YoY), reflecting strong commercial execution and leverage in the collaboration model .
- Clear 2025 growth set-up and pipeline: 2025 ARCALYST revenue guidance of $560–$580M and a mid‑2025 start for KPL‑387 Phase 2/3; CEO: “Strong commercial execution in 2024 resulted in 79% year-over-year ARCALYST sales growth to $417.0 million… expect 2025 sales of between $560 and $580 million” .
What Went Wrong
- Profitability pressure in Q4: Despite revenue growth, Q4 posted a net loss of $8.9M (vs. $25.2M profit in Q4 2023) as operating expenses rose to $141.8M (vs. $83.3M), including collaboration expenses tied to collaboration profitability and higher R&D and SG&A to support portfolio and commercial scale .
- Mix headwind vs prior year: Q4 2024 had no license/collaboration revenue (vs. $12.2M in Q4 2023), concentrating results in product revenue and collaboration expense share dynamics .
- Portfolio changes create near-term charges: Discontinuation of abiprubart in Sjögren’s and termination of the MedImmune mavrilimumab license trigger wind-down/termination costs; company expects ~$14–$17M additional expenses on top of ~$19M already incurred, with the vast majority recorded in Q4 2024 and H1 2025 .

Financial Results

Quarterly comparison (oldest → newest):

Metric	Q4 2023	Q3 2024	Q4 2024
Total Revenue ($M)	$83.395	$112.214	$122.536
ARCALYST Net Product Revenue ($M)	$71.220	$112.214	$122.536
License & Collaboration Revenue ($M)	$12.175	$0.000	$0.000
Income (Loss) from Operations ($M)	$0.081	$(9.658)	$(19.299)
Net Income (Loss) ($M)	$25.237	$(12.693)	$(8.888)
Diluted EPS ($)	$0.35	$(0.18)	$(0.12)
EBIT Margin %	~0.1% (0.081/83.395)	~−8.6% (−9.658/112.214)	~−15.8% (−19.299/122.536)
Net Income Margin %	~30.3% (25.237/83.395)	~−11.3% (−12.693/112.214)	~−7.3% (−8.888/122.536)

Full-year comparison (oldest → newest):

Metric	FY 2023	FY 2024
Total Revenue ($M)	$270.259	$423.239
ARCALYST Net Product Revenue ($M)	$233.176	$417.029
License & Collaboration Revenue ($M)	$37.083	$6.210
Income (Loss) from Operations ($M)	$(25.196)	$(45.616)
Net Income (Loss) ($M)	$14.084	$(43.193)
Diluted EPS ($)	$0.20	$(0.60)

Segment/revenue mix detail (quarterly):

Revenue Component	Q4 2023	Q3 2024	Q4 2024
ARCALYST Net Product Revenue ($M)	$71.220	$112.214	$122.536
License & Collaboration Revenue ($M)	$12.175	$0.000	$0.000
Total Revenue ($M)	$83.395	$112.214	$122.536

KPIs (focus on recurrent pericarditis commercial footprint and collaboration economics):

KPI	Q2 2024	Q3 2024	Q4 2024
Prescribers (cumulative)	>2,300	>2,550	>2,850
Multiple‑recurrence penetration	~11%	N/A	~13%
Avg. duration of therapy (months)	~26	~27	~27
ARCALYST Collaboration Profit ($M)	N/A	N/A	$76.3
Cash, Cash Equivalents & ST Investments ($M)	$218.8 (6/30/24)	$223.8 (9/30/24)	$243.6 (12/31/24)

Estimates vs actuals (Q4 2024):

Consensus (S&P Global) revenue and EPS were unavailable at time of analysis due to data access limits; thus, we cannot benchmark Q4 actuals vs estimates. We will update when available.

Guidance Changes

Metric	Period	Previous Guidance	Current Guidance	Change
ARCALYST Net Product Revenue	FY 2025	N/A	$560–$580M	New
Cash Flow (annual basis)	FY 2025	Maintain cash flow positive	Maintain cash flow positive	Maintained
ARCALYST Net Product Revenue	FY 2024	$405–$415M (Q2 guide)	$410–$420M (Q3 update)	Raised in Q3
KPL‑387 clinical timeline	Mid‑2025 start; Phase 2 data 2H 2026	N/A	Phase 2/3 start mid‑2025; Phase 2 data 2H 2026	New
Abiprubart in Sjögren’s	Program status	Enrolling Phase 2b (Q3)	Discontinuing; exploring alternatives	Lowered/Terminated
Mavrilimumab license	Program status	Active (historical)	Terminating for convenience, effective May 22, 2025	Terminated

Earnings Call Themes & Trends

Topic	Previous Mentions (Q‑2 and Q‑1)	Current Period (Q4 2024)	Trend
ARCALYST adoption/penetration	Q2: ~11% penetration; avg duration ~26 months; prescribers >2,300 . Q3: avg duration ~27 months; prescribers >2,550 .	~13% penetration; avg duration ~27 months; prescribers >2,850 .	Steady adoption, expanding breadth and depth.
Disease awareness & care pathways	Q2: AHA sponsorship; Lundqvist partnership . Q3: Life DisRPted campaign with Carly Pearce .	Continued promotion across all recurrences; building centers of excellence .	Scaling educational infrastructure.
Pipeline: KPL‑387	Not discussed previously as clinical program (pre‑announcement).	New IL‑1R1 mAb; monthly SC; Phase 2/3 mid‑2025; Phase 2 data 2H 2026 .	New growth vector in core IL‑1 franchise.
Abiprubart (Sjögren’s)	Q2/Q3: Fully funded; enrolling Phase 2b .	Discontinued; exploring strategic alternatives .	Portfolio reprioritization to CV focus.
Collaboration economics	Not quantified in Q2/Q3 PRs.	Q4 collab profit $76.3M; FY $234.7M; includes $10M Regeneron share of China milestone .	Scaling with ARCALYST growth; milestone flow-through.
Financial posture	Q2/Q3: Expect cash flow positive annually .	Reiterated; YE cash $243.6M, no debt .	Consistent discipline and liquidity.

Management Commentary

CEO (Sanj K. Patel): “Strong commercial execution in 2024 resulted in 79% year-over-year ARCALYST sales growth to $417.0 million… we expect 2025 sales of between $560 and $580 million.”
CMO (Dr. John Paolini) on KPL‑387: “Topline data from the single dose subcutaneous portion of the Phase 1 study support potential monthly SC dosing… we expect to initiate a Phase 2/3 trial in mid‑2025, with Phase 2 data expected in the second half of 2026.”
CCO (Ross Moat): Emphasized broadening prescriber base and earlier use across all recurrences; initiatives include disease education and centers of excellence to reduce barriers to care .
CFO (Mark Ragosa): “ARCALYST collaboration profit grew 125% to $76.3 million in the fourth quarter and 108% to $234.7 million for the full year of 2024… we ended 2024 with approximately $244 million cash and expect our current operating plan to remain cash flow positive on an annual basis.”

Q&A Highlights

KPL‑387 differentiation and dosing: Monthly SC dosing and liquid formulation seen as patient‑preferred vs weekly ARCALYST in some cases; mechanistically distinct by binding IL‑1R1 but still inhibiting IL‑1α/β signaling; KPL‑387 is wholly owned .
Development design and timelines: FDA interactions completed; details to come; targeted Phase 2/3 initiation mid‑2025 with Phase 2 readout 2H 2026; ClinicalTrials.gov updates forthcoming .
Regeneron arrangement: No non‑compete; Kiniksa remains committed to ARCALYST growth while advancing KPL‑387 to expand patient options .

Estimates Context

We attempted to retrieve S&P Global consensus for Q4 2024 and FY 2024 revenue and EPS, but data were unavailable due to access limits at request time. As a result, we cannot quantify beats/misses versus consensus for this quarter. We will update this section once S&P Global consensus data are accessible.

Key Takeaways for Investors

ARCALYST remains the growth engine: Q4 revenue accelerated to $122.5M with FY 2024 ARCALYST revenue of $417.0M; 13% penetration and growing prescriber base/therapy duration suggest runway for continued adoption .
2025 setup is robust: ARCALYST guidance of $560–$580M implies substantial YoY growth vs. 2024, providing a clear top‑line catalyst into the year while maintaining annual cash flow positivity .
Portfolio focus should improve capital efficiency: Discontinuation of abiprubart in Sjögren’s and termination of the mavrilimumab license concentrates resources on cardiovascular/IL‑1 opportunities (KPL‑387, KPL‑1161), though near‑term wind‑down costs weigh on reported profitability .
Collaboration leverage is material: ARCALYST collaboration profit scaled meaningfully in Q4/FY 2024 and included China milestone economics flow‑through—supportive to unit economics as revenue grows .
Near‑term modeling watch‑outs: Q4 operating expenses stepped up with collaboration, R&D, and SG&A; additional abiprubart wind‑down expenses ($14–$17M expected) will mainly appear across Q4 2024 and H1 2025 .
Medium‑term optionality: KPL‑387 monthly dosing could expand the recurrent pericarditis market and sustain Kiniksa’s IL‑1 leadership; Phase 2/3 start mid‑2025 and Phase 2 data in 2H 2026 create pipeline readout catalysts .
Estimate checks pending: Consensus comparisons were unavailable; as estimates update to reflect 2025 guidance and expense cadence, revisions are likely on both revenue (up) and operating expense lines (mixed, given scale and wind‑down costs).

References: Q4/FY 2024 8‑K and press release ; Q4 2024 earnings call transcript –; Q3 2024 press release –; Q2 2024 8‑K press release –.

Kiniksa Pharmaceuticals International, plc (KNSA)·Q4 2024 Earnings Summary