MLTX, AVTX, ZURA vs. ABBV: The Hidradenitis Suppurativa Race Hinges on One Readout

AbbVie's lutikizumab readout is the next big test for MLTX, AVTX and ZURA. A side-by-side look at HS efficacy, safety and dosing, Merck's new data, and how I'm playing it.

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MLTX, AVTX, ZURA vs. ABBV: The Hidradenitis Suppurativa Race Hinges on One Readout

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Approved drugs, the late-stage pipeline, and efficacy and safety side by side — plus why AbbVie's lutikizumab Phase 3 is the print that will reprice the whole group.


Psoriasis is crowded: more than a dozen biologics and orals compete for the same patients, and a new drug needs PASI 100 data to get noticed. Hidradenitis suppurativa (HS) looks like psoriasis did a decade ago. It has three approved biologics, one clear leader still growing fast, and response rates that leave most patients with active disease.

That's why so many companies have piled in. The field's first real stress test is AbbVie's lutikizumab Phase 3 topline, guided for later this year. In my view it is the most important print of the year for MoonLake (MLTX), Avalo (AVTX) and Zura Bio (ZURA), and it will move UCB too.

The tape seems to agree. Since early September the three small caps have fallen 27–37% while XBI is down about 8%. I can't find company-specific news that explains the gap, so my read is that investors are stepping aside before luti. Merck's Sept 30 Phase 2b data for its own HS antibody came after most of that selling, but it adds another competitor to the overhang.

Disclosure first: I'm long MLTX and AVTX. Read those sections with that in mind; I've tried to be harder on both, not softer.


TL;DR

  • HS is already a blockbuster market. Bimzelx did €1.5B in H1 2026, a third of it from HS, less than two years after its US approval in HS [UCB H1'26].
  • The bar is HiSCR75 at week 16. Large trials keep landing around 35% absolute. Placebo responses vary widely, and Phase 2 deltas tend to shrink in Phase 3.
  • Lutikizumab is the near-term swing factor. Its Phase 2 deltas came from about 40 patients per arm. With ~1,300 patients in Phase 3, the debate will mostly be whether it beats Bimzelx, not whether it hits.
  • MLTX has a submitted BLA, the closest new biologic to market, and the most shots on goal outside HS (PsA, PPP, axSpA). A strong luti result is its biggest HS threat.
  • AVTX has strong Phase 2 data with monthly dosing, but its Phase 3 hasn't started and it shares luti's biology. In the short term it likely trades with luti.
  • ZURA reads out in the same window. Its IL-17 arm blocks IL-17A only, so the BAFF arm has to add something.
  • Merck is the longer-term threat. Tulisokibart (anti-TL1A) posted a strong Phase 2b on Sept 30, including a monthly arm. But each main arm had 42 patients and the placebo rate was low. MoonLake's own Phase 2 had a gap at least as big before it shrank by roughly half in Phase 3. AVTX feels Merck most.

Why HS, Why Now

What HS is: hair follicles in the armpits, groin and buttocks get blocked and rupture, and the immune system overreacts. Painful nodules and abscesses keep coming back in the same places and, over time, form tunnels under the skin that drain and scar. It usually starts in the late teens or twenties, affects women more often, and is underdiagnosed. US claims data put diagnosed prevalence at about 0.1% [PubMed 28492923].

Why it's an attractive market:

  • Few approved options: three biologics (table below), compared with more than a dozen in psoriasis.
  • A low ceiling: even the best approved drug leaves about two-thirds of patients short of HiSCR75 at week 16.
  • Payers already pay: UCB reports more than 45% dynamic share in HS (new and switching patients) and guides to at least €7B peak sales for Bimzelx across indications [UCB H1'26].
  • Chronic therapy in a young population, the kind of revenue tail pharma pays for.

The catch: payers usually make patients fail a cheap adalimumab biosimilar first, which pushes most new entrants to second line unless they are clearly better. That is exactly AbbVie's pitch for lutikizumab: "earlier lines."

Approved HS Biologics (US)
DrugTargetUS HS approval1HS dosing
HumiraAbbVie + biosimilars
TNF-α
Sep 2015
40 mg weekly or 80 mg Q2Wafter a loading phase
CosentyxNovartis
IL-17A
Oct 2023
300 mg Q4Wafter weekly loading; Q2W option
Bimzelx2UCB
IL-17A + IL-17F
Nov 2024
320 mg Q2W to Wk 16, then Q4W
  1. Approval months per FDA/company announcements. Biosimilar adalimumab is typically the payer-mandated first step.
  2. Bimzelx HS: 33% of H1 2026 Bimzelx sales; >45% dynamic (new + switching patient) share in HS [UCB H1’26 call].

The Biology: Four Ways to Fight the Same Fire

My analogy: HS is a fire that keeps relighting in the same spots. IL-1 is the spark, IL-17 is the fuel line, and B cells are the embers that stay hot inside the tunnels. Each drug cuts in at a different point.

  • IL-17A/F (Bimzelx, sonelokimab). Th17 cells release IL-17A and IL-17F, which tell skin cells to recruit neutrophils, the main ingredient of pus. Across trials, blocking both A and F has done better than blocking A alone (Cosentyx). Sonelokimab is a ~40 kDa nanobody with an albumin-binding arm that MoonLake says concentrates it in inflamed tissue. That's plausible, but it hasn't been tested head-to-head.
  • IL-1 (lutikizumab, abdakibart). IL-1 sits upstream of IL-17. IL-1α is stored in skin cells and released when they rupture (the alarm). IL-1β is made by immune cells once the inflammasome switches on (the amplifier). Lutikizumab blocks both; abdakibart blocks only β. Avalo's bet is that β does most of the damage and that sparing α preserves some host defence. The biology is plausible, but no human data yet show a safety benefit.
  • IL-17A + BAFF (tibulizumab). BAFF keeps B cells and plasma cells alive, and both accumulate in chronic lesions and tunnels. Tibulizumab is a bispecific that hits IL-17A and BAFF. Its IL-17 arm blocks A only, which puts it closer to Cosentyx than Bimzelx, so the BAFF arm has to make up the difference.
  • TL1A (tulisokibart, Merck). TL1A is a master volume knob for T cells, turning up the Th1, Th2 and Th17 channels at once. Merck is already in Phase 3 with it in ulcerative colitis and Crohn's; HS is its first dermatology readout.
  • Orals (povorcitinib and upadacitinib, both JAK1; remibrutinib, BTK). They're convenient, but JAK inhibitors carry class boxed warnings, and HS efficacy so far sits below the best biologics.
The Late-Stage HS Pipeline
Drug (company)Target / formatStatusDosing
SonelokimabMoonLake (MLTX)
IL-17A + IL-17F~40 kDa nanobody
BLA submitted Sep 30, 2026
Wks 0–8 Q2W, then Q4W1
LutikizumabAbbVie (ABBV)
IL-1α + IL-1β
Ph3 16-wk data guided late 2026
Weekly ×16 wks, then weekly or Q2W
AbdakibartAvalo (AVTX)
IL-1β
Ph3 start 1H 2027
Q4W or Q2W in Ph22
TibulizumabZura Bio (ZURA)
IL-17A + BAFFbispecific
Ph2 topline Q4 2026
Q4W
TulisokibartMerck (MRK)
TL1A
Ph2b positive Sep 30, 2026; Ph3 planned
Q4W or Q2W in Ph2b4
PovorcitinibIncyte
JAK1 (oral)
US launch guided Q1 20273
Daily pill
UpadacitinibAbbVie (Rinvoq)
JAK1 (oral)
Ph3 post-TNF; data late 2026
Daily pill
RemibrutinibNovartis
BTK (oral)
Ph3 fully enrolled
Pill
  1. Sonelokimab 120 mg in VELA: induction at weeks 0, 2, 4, 6 and 8, then every 4 weeks.
  2. LOTUS: 600 mg load then 300 mg Q4W, or 300 mg load then 150 mg Q2W. Phase 3 regimen not yet disclosed.
  3. Incyte guides EU approval late 2026 and US launch Q1 2027 (NDA accepted Q1 2026).
  4. MK-7240-012: 480 mg Q2W or 480 mg Q4W (main arms); 240 mg Q4W was exploratory. No HS Phase 3 timing given yet; tulisokibart is already in Phase 3 for UC and Crohn’s.
  5. Statuses per company disclosures as of early Oct 2026. Highlighted rows = the small caps this article focuses on, plus lutikizumab.

Efficacy: HiSCR75 Is the New Bar

HiSCR50 means at least 50% fewer abscesses and inflammatory nodules, with no increase from baseline in abscesses or draining tunnels. It got Humira approved in 2015. The field has moved to HiSCR75, the primary endpoint for VELA, LOTUS and luti's Phase 3:

HiSCR75 at Week 16The endpoint that now matters
Trial (drug, regimen)DrugPlaceboΔ (pts)
BE HEARD IBimzelx Q2W · Ph3
33%
18%
+15
BE HEARD IIBimzelx Q2W · Ph3
36%
16%
+20
VELA-11sonelokimab · Ph3
34.4%
17.5%
+16.9
VELA-21sonelokimab · Ph3 · missed
34.1%
24.9%
+9.2
MIRA, 120 mg (Wk 12)4sonelokimab · Ph2
43.3%
14.7%
+28.6
Luti Ph2, 300 mg weekly2lutikizumab · TNF-failed
38.5%
17.5%
+21.0
Luti Ph2, 300 mg Q2W2lutikizumab · TNF-failed
45.9%
17.5%
+28.4
LOTUS, 150 mg Q2W3abdakibart · Ph2
42.2%
25.6%
+16.6
LOTUS, 300 mg Q4W3abdakibart · Ph2
42.9%
25.6%
+17.3
MK-7240-012, 480 mg Q2W6tulisokibart · Ph2b
41%
15%
+26
MK-7240-012, 480 mg Q4W6tulisokibart · Ph2b
40%
15%
+25
  1. Prespecified primary analysis (composite estimand). VELA-1 p<0.001; VELA-2 missed significance (p=0.053). The alternative treatment-policy analysis gave 34.8% vs 17.5% (VELA-1) and 35.9% vs 25.6% (VELA-2, p=0.033).
  2. Lutikizumab Phase 2: TNF-failed patients only, 37–40 per arm, Bayesian design [JAMA Dermatol 2026].
  3. Raw differences shown; Avalo reports adjusted deltas of ~17 pts for both arms.
  4. MIRA (sonelokimab Phase 2): Week 12 primary endpoint; 234 patients across four arms (two sonelokimab doses, adalimumab reference, placebo). The same drug delivered +9 to +17 in Phase 3.
  5. Cross-trial comparison, not head-to-head; populations, imputation and sample sizes differ. Shaded rows = Phase 2.
  6. Tulisokibart: 42 patients in each main dose arm vs 44 on placebo (plus an exploratory 21-patient low dose). HiSCR75 was a non-ranked secondary with no p-values disclosed; the HiSCR50 primary analysis borrowed historical placebo data; prior-biologic mix not disclosed [Merck, Sep 30, 2026].

What I take from it:

  • The large IL-17A/F trials land in the same place. Bimzelx and sonelokimab reached similar absolute HiSCR75, and most of the difference in deltas is placebo. Across these separate trials, sonelokimab looks numerically similar to Bimzelx, not better.
  • Abdakibart posted the highest absolute HiSCR75 of any trial here with ~250 or more patients, but also the highest placebo. After subtracting placebo, it sits in the IL-17A/F band and below the 20-point "clear win" bar Avalo's CEO set before the readout [Fierce Biotech].
  • Monthly dosing held up. Abdakibart's Q4W arm matched its Q2W arm, and tulisokibart's Q4W arm nearly matched its Q2W arm on HiSCR75 (less so on HiSCR50). Avalo no longer owns the monthly argument alone.
  • The biggest deltas come from the smallest trials. Lutikizumab, tulisokibart and sonelokimab's MIRA each had roughly 40–60 patients per arm and a 25–29 point gap. MIRA's gap was the largest by a hair, and in Phase 3 it shrank to 9–17 points; MoonLake stock fell about 90% on that result in September 2025. Lutikizumab's Phase 2 enrolled only TNF-failed patients and used a Bayesian analysis. Its best arm was Q2W, not the weekly regimen the Phase 3 uses for induction.

The second table covers HiSCR50 across a decade of HS trials. Look at the placebo column:

HiSCR50 Over a DecadeWatch the placebo column
Trial (year)DrugPlaceboΔ (pts)
PIONEER I (2016)1Humira
41.8%
26.0%
+15.8
PIONEER II (2016)1Humira
58.9%
27.6%
+31.3
SUNSHINE (2023)Cosentyx Q2W
45.0%
33.7%
+11.3
SUNRISE (2023)Cosentyx Q2W
42.3%
31.2%
+11.1
BE HEARD I (2024)Bimzelx Q2W
47.8%
28.7%
+19.1
BE HEARD II (2024)Bimzelx Q2W
52.0%
32.2%
+19.8
VELA-1 (2025)6sonelokimab
51.0%
30.3%
+20.7
VELA-2 (2025)6sonelokimab
55.6%
42.2%
+13.4
Luti Ph2 (2026)2lutikizumab 300 mg Q2W
59.5%
35.0%
+24.5
LOTUS (2026)abdakibart Q4W · Ph2
64.3%
40.7%
+23.6
MK-7240-012 (2026)5tulisokibart 480 mg Q4W · Ph2b
64%
35%
+29
  1. Humira PIONEER results at Week 12; all others Week 16.
  2. TNF-failed patients only; 37 on drug vs 40 on placebo. The 300 mg weekly arm (Phase 3 induction regimen) reached 48.7%.
  3. Oral reference: povorcitinib Phase 3 (Week 12) 40–42% vs 29–30% placebo.
  4. Year = publication or topline year. Cross-trial, not head-to-head. Shaded rows = Phase 2.
  5. Primary endpoint (Bayesian analysis borrowing historical placebo data). The 480 mg Q2W arm reached 72% (+37); 42 patients per main dose arm.
  6. VELA: prespecified primary analysis (composite estimand). Treatment-policy analysis: 51.6% vs 30.3% and 58.7% vs 43.0%.
  • Placebo is the wild card. Placebo HiSCR50 ranges from the mid-20s in Humira's trials to the low 40s in VELA-2 and LOTUS. It varies a lot and has run high in some recent large trials, which compresses deltas.
  • Responses deepen after week 16 with IL-17A/F. MoonLake reported 67% HiSCR75 at week 52 (pooled VELA), and UCB reported more than 55% at week 48 (observed cases). The methods differ, but both point the same way.

None of these trials are head-to-head. Populations, imputation rules and timepoints differ.


Safety: No Advantage Established Yet

Safety SnapshotWhat 16-week data show — no comparative advantage established
DrugClass watch-items16-week signalCaveat
Bimzelx
Candidiasis, IBD
Oral candidiasis 7.8% (Q2W) vs 0% placebo1
IBD 0.39 per 100 pt-yrs2
Sonelokimab
Candidiasis, IBD
Oral candidiasis 7.3% vs 0.4% placebo; 0 IBD
~560 patients on drug
Lutikizumab
Infection, neutropenia
SAEs 2–5% vs 2.5% placebo; no neutropenia
~110 patients, Ph23
Abdakibart
Infection, neutropenia
TEAEs ≈ placebo; 0 serious infections, 0 neutropenia
~170 patients, Ph2
Tibulizumab
Candidiasis, infection
No HS data yet
Topline Q4 2026
Tulisokibart
Infection (new class)
SAEs 2.4% per main arm (4.8% low dose) vs 2.3% placebo; 0 serious or opportunistic infections
~105 patients, Ph2b
Povorcitinib / Rinvoq
JAK class boxed warnings
Class labelling expected
Limits first-line use
  1. US label, 16-week placebo-controlled HS period: oral candidiasis 7.8% (Q2W) and 3.9% (Q4W); other Candida infections 3.6% and 6.7%. Earlier trial-level reports gave 4.4–6.7%.
  2. US label: 5 new-onset IBD cases across 1,272 patient-years of HS treatment.
  3. Lutikizumab Phase 2 also reported no opportunistic infections, MACE or serious hypersensitivity [JAMA Dermatol 2026].
  4. Sonelokimab Week 16 data from VELA-1/2 pooled [MLTX 8-K, Sep 2025]; abdakibart from LOTUS topline deck; tulisokibart from Merck release (Sep 30, 2026). Separate trials with different definitions; not directly comparable.
  • Candidiasis is the IL-17 class cost. It is usually mild to moderate and rarely leads patients to stop, but it's real. Rates aren't comparable across trials and definitions: the Bimzelx label reports 7.8% oral candidiasis on Q2W over 16 weeks, and VELA reported 7.3%. A safety advantage for sonelokimab hasn't been established; its differentiators are dosing and format.
  • The IL-1 and TL1A trials look clean so far. Abdakibart's adverse-event rates tracked placebo, with no serious infections or neutropenia. Lutikizumab's Phase 2 showed no neutropenia or opportunistic infections. Tulisokibart's main arms had serious-AE rates in line with placebo and no serious or opportunistic infections.
  • But the databases are small. Fewer than 200 patients have had either IL-1 drug for 16 weeks in HS, and approved IL-1 blockers carry serious-infection warnings. Luti's ~1,300-patient Phase 3 will be the first large IL-1 safety dataset in HS, and that can help or hurt Avalo.
  • JAK boxed warnings (serious infections, MACE, malignancy, thrombosis) limit how far up the treatment line oral JAKs can go in a young population.

The Readout That Sets the Tape: Lutikizumab Phase 3

What we know [NCT06468228; ABBV Q2'26 call; Wells Fargo conf., Sept 9]:

  • Design: ~1,280 patients planned, adults and adolescents, biologic-naive and biologic-experienced. The primary endpoint is HiSCR75 at week 16. Patients get weekly dosing to week 16, then are re-randomized to stay weekly or step down (every other week or a lower dose).
  • Timing: On the July 31 call AbbVie guided to "16-week data later this year" for lutikizumab and Rinvoq in HS, and repeated it on September 9. The registry lists primary completion as December 2026, so a slip into AbbVie's Q4 call (late January or early February) is plausible.
  • AbbVie's framing: CSO Roopal Thakkar called the Phase 2 deltas "very high," said they "would position it very favorably against anti-TNFs and anti-IL-17s," and pointed to "earlier lines." Rinvoq would sit alongside it for patients who have failed a biologic.

Why I expect some fade:

  1. Sample size. With ~40 patients per arm, a handful of responders shifts HiSCR75 by 5–10 points.
  2. Placebo. Placebo HiSCR75 in recent large trials has run anywhere from the mid-teens to the mid-20s.
  3. Population. Phase 2 enrolled only TNF-failed patients. Phase 3 adds biologic-naive patients, who respond better to drug but can also lift placebo (VELA-2).
  4. Regimen. The best Phase 2 arm was Q2W, while Phase 3 induction is weekly. Weekly means more exposure, but it isn't the arm behind the headline numbers.

A statistical miss isn't the main risk. With roughly 640 patients per arm, even a 6-point gap would likely be significant. A miss is still possible if placebo runs high or the effect shrinks a lot. The bigger question is whether it beats Bimzelx. The IL-17A/F reference range is a 9–20 point delta at about 35% absolute.

Dosing is a tiebreaker, not a moat. Weekly dosing for 16 weeks, then weekly or every other week, is less convenient than the monthly maintenance of Bimzelx, sonelokimab, tibulizumab and the monthly arms of abdakibart and tulisokibart. But Humira's HS label has been 40 mg weekly for a decade. If luti is clearly more effective, dermatologists will accept weekly dosing. If it's only equal, the monthly drugs have the better story.

Time to market. Even with a clean result, AbbVie still needs maintenance data and a filing. I'd pencil in a US launch around 2028.


Name by Name

MLTX — The Only New Biologic Close to Market

  • BLA submitted Sept 30, 2026, seeking a label for adults and adolescents 12 and up. In January FDA agreed that VELA-1, VELA-2 and MIRA can support a filing without another trial. At the pre-BLA meeting it agreed to include the VELA-TEEN adolescent data. MoonLake will propose label efficacy based on MIRA, but FDA decides what goes on the label.
  • FDA calendar: The filing decision is due around late November, about 60 days after submission, along with any decision on the Priority Review MoonLake has said it will seek. The review timeline follows around mid-December (day 74). MoonLake guides to a Q3/Q4 2027 launch under standard review, about three months earlier with Priority Review.
  • Dosing: five induction doses (weeks 0–8), then monthly. Bimzelx stays every two weeks until week 16.
  • More shots on goal than anyone else here:
  • PsA: IZAR-1 (biologic-naive) hit its ACR50 primary endpoint in August, and the full 52-week readout is due in 1H 2027. IZAR-2 (TNF-refractory, with a risankizumab reference arm) was due to finish enrollment in Q3 2026.
  • PPP (palmoplantar pustulosis): Fast Track in February, and a ~370-patient Phase 3 starts enrolling in 2H 2026. Few approved options exist in the US.
  • axSpA: S-OLARIS was a small imaging study (26 treated patients, 81% ASAS40 at week 12, no placebo comparison reported). It's an early signal, and next steps aren't set.
  • Why breadth matters: Bimzelx has already validated IL-17A/F in psoriasis, PsA, axSpA and HS, so each extra indication carries less biology risk. It also spreads a solo commercial build over more revenue. Only MLTX among the three has positive Phase 3 data outside HS.
  • What bothers me: Sonelokimab is a late IL-17A/F entrant against an incumbent with more than 45% dynamic share. It has the same mechanism, no head-to-head data and no established safety advantage. With no commercial partner, the launch will be expensive. The June raise was priced at $20, far above today's price.
  • Luti read-through: A beat adds an earlier-line competitor with AbbVie's sales force behind it. A disappointment keeps IL-17A/F as the efficacy standard, with sonelokimab the only new biologic launching in 2027.

AVTX — Strong Phase 2 Data, With Phase 3 Still Ahead

  • LOTUS (May 2026): Both doses hit HiSCR75 and the key secondaries (HiSCR50, IHS4, draining tunnels). The monthly arm matched the every-other-week arm, and biologic-experienced patients responded at least as well as biologic-naive ones [AVTX LOTUS deck].
  • Weak spots: Placebo was high. HiSCR90 and the skin-pain responder endpoint didn't separate from placebo. The delta came in below management's own "clear win" bar.
  • Timeline: Phase 3 starts in 1H 2027. The design and any end-of-Phase 2 feedback haven't been disclosed. My estimate is topline around 2028 and launch no earlier than about 2029, which puts AVTX one to two years behind lutikizumab in the same pathway.
  • Funding: Management guides runway into 2029, which covers the Phase 3 start; whether it funds the whole program depends on its size. AVTX-010, a longer-acting IL-1β antibody with an IND planned for 1H 2027, extends the dosing story.
  • Overhang: The May raise was priced at $17.75, above today's price, and short interest is about a quarter of the float.
  • Merck: Tulisokibart targets the same slot: a non-IL-17 mechanism, monthly dosing, and a Phase 3 starting around the same time. It brings a bigger Phase 2 delta (from a smaller trial with lower placebo) and Merck's balance sheet. Luti is AVTX's near-term catalyst; Merck may be the bigger long-term problem.

Luti read-through, and where I've changed my mind. My first instinct was that a luti win simply validates IL-1 and helps AVTX. It's more two-sided than that:

  • If luti beats, AVTX gets validation and probably a short-term rally. It also gets a stronger competitor in the same pathway that reaches market first. Long term, it has to win on monthly dosing and IL-1β selectivity.
  • If luti disappoints, AVTX is probably the most exposed name on day one, if the market reads it as an IL-1 problem. But a miss also removes its most advanced IL-1 rival, and AVTX has its own 253-patient randomized dataset. If the miss traces to placebo or the regimen, a selloff looks more like an entry point than a broken thesis.

ZURA — The Wildcard in the Same Window

  • TibuSHIELD: 247 patients randomized (target ~180), testing two monthly doses against placebo, with topline in Q4 2026. The primary endpoint is percent change in AN count at week 16. HiSCR50 and HiSCR75 are secondaries, and those are the numbers the market will compare.
  • What I want to see: a HiSCR75 delta of 15 points or more, in the IL-17A/F band. A Cosentyx-like result wouldn't show the differentiation I'm looking for. The trial has no IL-17A-only arm, so it can't isolate what BAFF adds.
  • Valuation: an EV of about $0.3B (table below), with runway through 2028.
  • Luti read-through: second-order. A beat raises ZURA's bar, and a miss gives it room. Its own data matters more, and the two results may land weeks apart.

Merck (Tulisokibart) — A New Big-Pharma Entrant

  • What happened: On Sept 30 Merck reported Phase 2b data (MK-7240-012). 149 patients were randomized, 105 of them to tulisokibart. The high (Q2W) and medium (Q4W) doses, 42 patients each versus 44 on placebo, met the HiSCR50 primary endpoint; the 21-patient low dose was exploratory. The primary analysis used a Bayesian design that borrowed historical placebo data. On the non-ranked HiSCR75 secondary, both main doses landed in the same range as the best Phase 2 results in the tables above. The data were presented at EADV.
  • Why it matters: It's a third mechanism class with strong Phase 2 numbers. Its monthly arm nearly matched every-other-week on HiSCR75, and Merck can easily fund a global Phase 3. There's no HS Phase 3 timing yet.
  • What I'd discount: only 42 patients per main arm, a 15% placebo HiSCR75 (versus ~25% in LOTUS and VELA-2), the historical placebo borrowing, no disclosed HiSCR75 p-values and no prior-biologic breakdown. MIRA had a similar setup and a gap at least as big before it shrank in Phase 3.
  • Who it hurts: AVTX most, because it targets the same slot on a similar timeline. MLTX less, since sonelokimab should launch in 2027 and I don't see a TL1A launch before about 2029–30.
  • Market reaction: From Sept 30 to Oct 6, AVTX fell about 11% (7% on Oct 6 alone), MLTX about 6% and XBI about 4%. That fits Merck weighing most on AVTX, but a week of trading can't prove it or show how much is already priced in.

UCB and the Rest

  • UCB is the incumbent to beat. On the H1 call, management said nothing in the pipeline (naming lutikizumab and remibrutinib) "suggests stronger efficacy" than Bimzelx. A luti beat would test that claim, and a miss would remove the main long-term threat to Bimzelx's HS share.
  • Incyte's povorcitinib is set to be the first oral HS drug, with a US launch guided for Q1 2027. It's convenient, but weaker numbers and JAK labelling likely place it after biologics.
  • AbbVie's Rinvoq has a post-TNF Phase 3 reading out alongside luti.
  • Novartis' remibrutinib (oral BTK) is in a fully enrolled Phase 3 after a strong but small Phase 2.

For investors: HS could have six or seven advanced options by 2028 and closer to ten by 2030. The window is real but closing, so speed to market matters more than most models assume.


Scenario Map: How I Think Each Name Trades on the Luti Print

Lutikizumab Phase 3: How I Think Each Name Trades
Luti result1MLTXAVTXZURA
BeatΔ ≥20 pts, clean safety · ~30%2
Negativestrong earlier-line rival
MixedIL-1 validated, but a stronger rival reaches market first
Negativehigher bar for its Q4 data
In lineΔ 12–19 pts · ~45%2
ReliefBimzelx-like rival with weekly dosing
Mildly positiveIL-1 works; Q4W edge vs luti intact
Neutralits own data decides
DisappointΔ <12 pts or safety issue · ~25%2
PositiveIL-17A/F stays the standard
Likely down firstif read as an IL-1 problem; entry if placebo-driven
Positivemore room to differentiate
  1. HiSCR75 placebo-adjusted delta at Week 16. Bands are mine, anchored to Bimzelx BE HEARD (+15 to +20) and sonelokimab VELA (+9 to +17, primary analysis).
  2. My rough probabilities, not a model output.
  3. My expectation for UCB: the opposite of luti — a beat would pressure its long-term HS share, a disappointment would remove the main threat.

My base case is "in line": a large Phase 3 lands luti near the IL-17A/F band with clean safety. I'd expect the market to shrug, with a relief bounce in the three small caps after a month of selling. From there, the race comes down to dosing, safety and commercial muscle. Not all of the recent weakness is about luti, though. Broader biotech weakness and two raises priced well above today's prices (MLTX at $20, AVTX at $17.75) weigh on these stocks too.


Balance Sheets: Who Can Afford to Wait

Balance SheetsEarly October 2026
TickerMarket cap1Cash2Approx. EV3
MLTX$100M debt drawn4
~$0.94B
~$567M
~$0.48B
AVTXrunway into 2029
~$0.85B
$472M
~$0.38B
ZURArunway through 2028
~$0.49B
$205M
~$0.29B
  1. Common-equivalent basis at Oct 6, 2026 closes (MLTX $10.95, AVTX $13.59, ZURA $3.95): common shares + pre-funded warrants + as-converted preferred; excludes options and RSUs. MLTX 85.1M + 1.0M; AVTX 53.6M + 1.4M + ~7.7M (~62.7M); ZURA 95.8M + 29.3M (~125.1M). Update at publication.
  2. June 30, 2026. MLTX adds ~$30M gross from the July over-allotment exercise. Q3 burn not deducted, so true EVs are somewhat higher.
  3. Market cap + debt − cash.
  4. Hercules facility. Further tranches depend on IZAR-1/IZAR-2 results, a market cap above $1.5B, or lender discretion. MLTX guides runway to mid-2028.
  • None needs to raise money before the luti print. MLTX guides runway to mid-2028, AVTX into 2029 and ZURA through 2028. MLTX has $100M of debt drawn. The remaining tranches depend on IZAR results, a market cap above $1.5B or lender discretion, so I don't count on them.
  • MLTX looks the most asymmetric on paper. For an EV of about half a billion dollars you get a submitted BLA, a positive PsA Phase 3 and a Fast Track Phase 3 in PPP. The offsets are the debt and the cost of a solo launch.
  • ZURA is the cheapest option on its own data.
  • AVTX is the most expensive for its stage, which reflects its strong Phase 2 data and monthly dosing.

Catalyst Calendar

HS Catalyst Calendar
When / movesEventWhat I’m watching
~Late Nov 2026MLTX
Sonelokimab BLA filing decision (~day 60), incl. Priority Review if granted
Priority = launch ~3 months earlier
~Mid-Dec 2026MLTX
Sonelokimab review timeline (~day 74)
PDUFA date
Q4 2026ZURA
TibuSHIELD topline (tibulizumab)
HiSCR75 Δ vs the IL-17A/F band
Late 20261MLTX, AVTX, ZURA, UCB
Lutikizumab Phase 3 16-week topline
Magnitude vs Bimzelx; safety
Late 2026ABBV, UCB
Rinvoq HS Phase 3 (post-TNF)
Oral option in refractory HS
Q4 2026INCY
TRuE-HS topline (ruxolitinib cream, mild–moderate)
Topical in earlier disease
Late 2026 EU / Q1 2027 USINCY
Povorcitinib approval and launch
First oral in HS
1H 2027AVTX
Abdakibart Ph3 start; AVTX-010 IND
Ph3 regimen (Q4W?)
Not yet guidedMRK, AVTX
Tulisokibart HS Phase 3 start
Q4W regimen; start date vs AVTX
Q3–Q4 2027MLTX, UCB
Sonelokimab US launch (company guidance)
Label content
  1. AbbVie guides “later this year”; registry primary completion is December 2026, so a slip into early 2027 (e.g., the Q4 call) is possible.
  2. Dates per company guidance as of early Oct 2026.

Risk Matrix (Prioritized)

  1. A luti beat (biggest impact on MLTX and ZURA). A clean delta of 20+ points, plus AbbVie's "earlier lines" push, would reset the bar.
  2. Phase 3 fade (the main clinical risk for AVTX). LOTUS already had a high placebo arm, and a 2027–28 Phase 3 could come in below the Phase 2 delta.
  3. Crowding (the main commercial risk for MLTX, and now AVTX). Biosimilar adalimumab is the gatekeeper and payers require step therapy. UCB holds the IL-17A/F slot, and two big pharmas are coming with non-IL-17 mechanisms.
  4. Financing and execution. MLTX faces a solo launch, AVTX an offering overhang and high short interest, and ZURA a binary readout.

Bottom Line

The part of the HS story I'm most confident in is the market itself. Bimzelx has proven that payers will fund a better HS drug at scale, and the ceiling is still low. The part I'm least confident in is how many winners that market can hold once six or seven options compete by 2028.

So timing and breadth matter as much as the next readout: - MLTX reaches market first among the new biologics, with PsA and PPP behind HS. - AVTX has strong Phase 2 data and monthly dosing, but now shares the new-mechanism lane with Merck. - ZURA has to prove the BAFF idea in Q4.

Lutikizumab is where the sorting starts. Here's how I'm approaching it:

  • Into the print: I'm holding MLTX and AVTX and not adding to either. The group has already sold off, which prices in part of the "beat" risk.
  • If luti lands in line or disappoints: MLTX is my first add, as the only one of the three with a 2027 launch and positive Phase 3 data outside HS.
  • If luti beats clearly (20+ point delta, clean safety): I'd reassess my MLTX sizing, and I wouldn't add to AVTX into a read-through rally.
  • AVTX after Merck: I'm eager to see Avalo's Phase 3 design and hear how management positions abdakibart against tulisokibart, not just against luti.
  • Merck's data: I'm not repricing anything on a Phase 2 with about 40 patients per arm. MIRA already taught that lesson.
  • ZURA in Q4: A HiSCR75 delta of 15 points or more makes it interesting. A Cosentyx-like result means I pass.
  • The dates that matter: MLTX's FDA filing decision (late November) and review timeline (mid-December), ZURA topline (Q4), and luti and Rinvoq HS topline (guided for late 2026, possibly early 2027).

This is not advice.


Disclosure: The author holds long positions in MLTX and AVTX at the time of publication. This is not financial advice. Clinical-stage biotech investing carries substantial risk, including total loss of capital. Do your own due diligence. Cross-trial comparisons in this article are not head-to-head and should be read as directional only.


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