Is there a specific patient profile for new ARCALYST enrollments, and what was the gross-to-net for the quarter?

No significant change in patient profile was observed; growth is broad across demographics and institutions due to better understanding of recurrent pericarditis. Gross-to-net was 7.2% year-to-date, down from 8.6% in Q1, primarily due to lower co-pay support program changes. Gross-to-net is expected to be favorable annually, with a typical sequential pattern of lower in Q2/Q3 and higher in Q4. “Year-to-date. gross to net is 7.2%, down from 8.6% in the first quarter with the main driver being lower co-pay due to the changes that we made to our support program at the beginning of the year.”

How will KPL-387 differentiate in Phase III, and what are the demand trends for ARCALYST in the first recurrence population?

KPL-387's target profile of monthly dosing and liquid formulation, combined with rapid onset and durable efficacy seen in Phase II, is exciting. For ARCALYST, 80% of new prescriptions are for patients with 2+ recurrences, while 20% are for first recurrence patients, a segment that is growing over time, reflecting increasing confidence in using ARCALYST across its broad label. “There's around 40,000 patients in any given year that fit within the recurrent pericarditis label. When you break that down, we have about 80% or new patient prescribing happening in the 2-plus recurrence.”

Is KPL-387's time to response consistent with ARCALYST's RHAPSODY data, and what does market research suggest about a monthly regimen?

KPL-387's Phase II time to response, pain response, and CRP normalization data are robust and consistent with previous trials supporting rilonacept (ARCALYST) approval. Market research indicates high excitement for KPL-387's monthly target product profile, with 75% of patients preferring it over current therapies and 92% of HCPs highly likely to prescribe it for new patients. “And really, that showed both to a high degree for both the patients and the health care professionals, they were pretty excited about the KPL-387 target product profile with around 75% of patients saying that they would prefer the KPL-387 target product profile over current commercial or available -- or investigational therapies.”

KNSA

Kiniksa Pharmaceuticals (KNSA) Q2 FY26 earnings call: guidance and Q&A

Earnings call· Jun 2026 (Q2 FY26)· Health Care· Jul 28, 2026

Source: earnings call transcript

Executive summary

Kiniksa Pharmaceuticals Q2 FY26 — Strong ARCALYST Growth and KPL-387 Phase III Initiation

Kiniksa Pharmaceuticals delivered a strong second quarter, driven by robust commercial execution for ARCALYST, which saw significant revenue growth and increased patient enrollment. The company also advanced its pipeline with the initiation of the KPL-387 Phase III trial for recurrent pericarditis, following positive Phase II data. With a solid financial position and continued pipeline progress, Kiniksa is well-positioned for future value creation.

Highlights

ARCALYST net revenue grew 55% year-over-year to $243.6 million in Q2 FY26.
Full-year 2026 revenue guidance was raised from $930M-$945M to $980M-$995M.
KPL-387 Phase II data affirmed a 300mg monthly dose, leading to the initiation of the pivotal Phase III PASTORALE trial.
The company ended Q2 FY26 with a robust cash balance of $525.9 million, reflecting $58 million of net cash generation.
ARCALYST penetration into the multiple recurrence population increased to 21% from 18% at the end of 2025.

Guidance & targets

Category	Target	Timeline	Confidence
Full-year 2026 ARCALYST Revenue	$980 million to $995 million high materiality	FY26	High
KPL-387 Commercial Launch	2028 and 2029 time frame high materiality	CY28-CY29	Medium

Segment performance

Segment	Revenue	YoY	QoQ	Margin
ARCALYST Strong commercial execution drove significant revenue growth and increased market penetration. The company is leveraging AI, DTC campaigns, and ACC guidance dissemination to expand adoption. Penetration into multiple recurrence population: 21% (vs 18% end of 2025)New patient enrollment: significantly higher than any quarter since launchNew prescribers: ~450 additional HCPs in Q2 FY26Total prescriber base: >5,000 launch to dateHCPs with multiple prescriptions: ~150 additional in Q2 FY26HCPs with multiple prescriptions (% of base): ~29%New prescriptions for 2+ recurrence: 80%New prescriptions for first recurrence: 20%	$243.6 million	55%	more than $29 million	—

KNSA operating KPIs by quarter

KNSA operating KPIs stated on its earnings calls, by fiscal quarter
KPI	Dec 2025 Q4 FY25	Mar 2026 Q1 FY26	This call Jun 2026 Q2 FY26	Change vs prior quarter
Prescribers	4,150+ At the end of 2025, more than 4,150 prescribers had written a prescription for ARCALYST. Source: earnings call transcript	—	5,000+ Approximately 450 additional health care professionals wrote their first ARCALYST prescription in the second quarter, bringing the total prescriber base to more than 5,000 launch to date. Source: earnings call transcript	—
Repeat prescribers	1,200+ Of those, around 29% or more than 1,200 prescribers have written ARCALYST for 2 or more recurrent pericarditis patients. Source: earnings call transcript	~1,320 We also saw growth in the number of health care professionals who became repeat prescribers during Q1, resulting in approximately 1,320 prescribers in total who have now prescribed ARCALYST multiple times. Source: earnings call transcript	—	—

Operating figures the company stated on at least two of the calls shown, checked against each call's transcript. Click a figure to read the sentence. A dash means it was not stated that quarter.

What to watch in Q3 FY26

ARCALYST Sales Growth

Next quarter

Current $243.6 million (up 55% YoY)

Target Continued strong growth

Why it matters

To assess the sustainability of the strong commercial momentum and impact of new strategies.

So just wanted to drive into what drove this growth specifically in Q2? And could this level of growth continue throughout the rest of the year and into next year?

Find out whether KNSA delivers this. Inve re-checks your case every morning.

Q&A highlights

What drove the strong ARCALYST growth in Q2, and can this level of growth continue?

Management attributed growth to continued execution across the commercial strategy, including increased new and repeat prescribers, leveraging AI/machine learning for sales, the 'Heart's Home' DTC campaign, and dissemination of ACC clinical guidance. They believe significant opportunity remains for continued growth.

“Ultimately, we've seen a substantial uplift in the number of both new prescribers and new repeat prescribers, as Sanj said, we have more than 450 new prescribers come into the total prescriber base more than 150 new repeat prescribers, meaning they've prescribed for 2 or more patients in the quarter.”

asked by Nicholas Lorusso · answered by Ross Moat

2 min read 5 chapters

Detailed narrative

ARCALYST Commercial Momentum

ARCALYST achieved $243.6 million in net revenue for Q2 FY26, marking a 55% year-over-year growth and the largest quarterly net revenue increase since its launch. This growth was driven by a substantial uplift in new and repeat prescribers, with approximately 450 additional healthcare professionals writing their first ARCALYST prescription and 150 more writing multiple prescriptions.

The company leveraged AI and machine learning for sales team insights, launched a targeted DTC campaign ('Heart's Home'), and disseminated the 2025 ACC concise clinical guidance, encouraging earlier ARCALYST use.

KPL-387 Phase II Data and Phase III Initiation

Kiniksa announced positive data from the dose-focusing portion of the KPL-387 Phase II/III study in recurrent pericarditis. The 300mg monthly dose demonstrated rapid and sustained onset of action, with a median time to treatment response of 4 days, pain response of 4 days, and CRP normalization of 8 days.

Based on these results, the pivotal Phase III PASTORALE study has been initiated and is actively enrolling and dosing patients, targeting a 2028-2029 commercial launch timeframe.

Pipeline Advancement with KPL-1161

The company's Fc modified IL-1 alpha and beta inhibitor, KPL-1161, is progressing well. This program, designed for quarterly dosing, remains on track to initiate a Phase I study by the end of 2026. This early-stage asset represents another potential value-creating driver within Kiniksa's development portfolio.

Robust Financial Position

Kiniksa maintains a strong financial position, ending Q2 FY26 with a cash balance of $525.9 million. This reflects $58 million of net cash generation for the period. Operating income and net income also saw year-over-year increases, driven by ARCALYST revenue growth, disciplined commercial investment, and increased R&D for pipeline advancement.

Market Penetration and Opportunity

ARCALYST's penetration into the multiple recurrence patient population reached approximately 21% by the end of Q2 FY26, up from 18% at the end of 2025. With over 25,000 healthcare professionals managing recurrent pericarditis patients and a broad label, significant opportunity for continued growth remains.

Approximately 80% of new ARCALYST prescriptions are for patients with two or more recurrences, while 20% are for first recurrence patients, a segment that is growing over time.

Summary of the company's earnings call; see how call summaries are prepared. Not investment advice.