Martina J. Porter, MD, is a dermatologist at Beth Israel Deaconess Medical Center.

Martina Porter, MD

Contextualizing JAK Safety With Povorcitinib in HS, With Martina Porter, MD

The 54-week STOP-HS data for povorcitinib showed deepening inflammatory response, broad and sustained improvements across patient-reported outcomes in people with moderate-to-severe 

Povorcitinib is an investigational oral JAK1-selective inhibitor - the JAK inhibitor class carries FDA black box warnings for major adverse cardiovascular events (MACE) and thromboembolic events, and these labels that loom over any new agent in the class.

Martina L. Porter, MD, of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, presented the 54-week STOP-HS data at the 2026 American Academy of Dermatology (AAD) Annual Meeting, and sat down with 

to discuss povorcitnib’s safety and efficacy data in the context of JAK safety signals.

The STOP-HS1 (NCT05620823) and STOP-HS2 (NCT05620836) phase 3 trials enrolled a combined 1,227 adults with moderate-to-severe HS, randomized 1:1:1 to povorcitinib 75 mg once daily, 45 mg once daily, or placebo for 12 weeks, followed by a 42-week blinded extension through week 54. The HS population enrolled in these trials shares several features with patients historically associated with elevated cardiovascular and thromboembolic risk in other JAK inhibitor programs: high rates of obesity, significant smoking history, and elevated systemic inflammatory burden. These are the same comorbidity factors implicated in the cardiovascular safety signals that emerged from JAK inhibitor trials in older rheumatoid arthritis populations and contributed to the class-wide black box labeling. Porter acknowledged this concern directly, noting it was among the most frequent questions she fielded at the meeting.

The STOP-HS safety data through 54 weeks did not reveal a pattern consistent with amplified risk in this higher-comorbidity population. Across both studies, thromboembolic events were infrequent, and MACE occurred in 1 patient (0.3%) in STOP-HS2. Porter noted that this MACE event — an ischemic cerebrovascular event — was also counted within the thromboembolic event category per the study's classification scheme, meaning that the total cardiovascular and thromboembolic event count is partially overlapping rather than additive. Serious treatment-emergent adverse events (AEs) occurred in 3.7% to 6.4% of patients across arms, and laboratory abnormalities were relatively uncommon — a finding Porter suggested may reflect the relative JAK1 selectivity of povorcitinib compared with less selective agents in the class, since hematologic abnormalities in particular tend to be mediated through JAK2 rather than JAK1 signaling.

She also noted that the absence of a dose-dependent safety signal across the 45 mg and 75 mg arms was specifically reassuring. JAK inhibitor AEs typically track with degree of JAK pathway inhibition, and a flat safety profile across doses is consistent with a compound that achieves meaningful JAK1 engagement without proportional off-target JAK2 or JAK3 effects. The most common treatment-emergent AE was acne, occurring in 16.4% to 21.1% of patients — a rate Porter contextualized as likely reflecting 2 overlapping factors: the known acne association with JAK inhibitor use as a class, and the demographic profile of the STOP-HS population, which skews toward younger women who may be on oral contraceptives as a trial requirement, some formulations of which have known acne-promoting effects independent of JAK inhibition. The acne observed was predominantly mild in severity and did not drive meaningful discontinuation.

At the primary efficacy endpoint of HiSCR50 at week 12, both doses achieved statistical significance versus placebo in both studies — 40.2% (45 mg) and 40.6% (75 mg) versus 29.7% for placebo in STOP-HS1 (

 <.025), and 42.3% for both doses versus 28.6% for placebo in STOP-HS2 (

 <.01) — with responses deepening through week 54 to HiSCR50 rates of 60.2% to 67.5% across studies and doses on continuous povorcitinib. Up to 29.0% of patients achieved HiSCR100 at week 54. Porter's overall assessment of the safety profile was that it is consistent with the established JAK class picture but without the amplification in cardiovascular or thromboembolic events that the comorbidity burden of the HS population might have been expected to produce — a finding she characterized as meaningful precisely because it was not the obvious outcome given the patient profile.

“[I thought the safety data] looked quite good for a HS clinical population. And I say this because HS clinical trials and Hs patients tend to have a lot more adverse events that occur. And we see this even in the beginning of the trial, when it's placebo controlled, that the patients on placebo have very high rates of adverse events, and it's probably related to their comorbidity burden,” Porter said.

Relevant disclosures for Porter include Abbvie, Bristol Myers Squibb, Janssen, Eli Lilly, Novartis, Pfizer, UCB, Trifecta Clinical, Incyte, and Anaptys Bio.

Porter ML, et al. Povorcitinib in moderate-to-severe hidradenitis suppurativa: 54-week results from the phase 3 STOP-HS1 and STOP-HS2 trials. Presented at: AAD Annual Meeting; Denver, Colorado; March 27-31, 2026.

Porter ML, et al. Povorcitinib efficacy in biologic-experienced patients with moderate-to-severe hidradenitis suppurativa: subgroup analysis from STOP-HS1 and STOP-HS2. Presented at: AAD Annual Meeting; Denver, Colorado; March 27-31, 2026.

Videos

54-week STOP-HS safety data for the JAK1-selective inhibitor povorcitinib showed no dose-dependent safety signal and few laboratory abnormalities.

Shifting Treatment Goals and Povorcitinib's Benefit in HS, With Martina Porter, MD

The 54-week STOP-HS data for povorcitinib in moderate-to-severe

 (HS) showed not only deepening inflammatory response but also broad and sustained improvements across patient-reported outcomes.

2026 American Academy of Dermatology (AAD) Annual Meeting

 held in Denver, Colorado, from March 27-31, by Martina L. Porter, MD, of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston. 

spoke with Porter about the STOP-HS1 (NCT05620823) and STOP-HS2 (NCT05620836) trials, identically designed global phase 3 trials with a combined enrollment of 1,227 adults with moderate-to-severe HS, randomized 1:1:1 to povorcitinib 75 mg once daily, 45 mg once daily, or placebo for 12 weeks, followed by a 42-week blinded extension through week 54. Mean disease duration was 10.3 years (SD, 9.4), mean AN count was 12.0 (SD, 8.8), and 75.5% had at least 1 draining tunnel at baseline.

At week 12, HiSCR50 was achieved by 40.2% (45 mg) and 40.6% (75 mg) of patients versus 29.7% for placebo in STOP-HS1 (

 <.025), and by 42.3% in both dose arms versus 28.6% for placebo in STOP-HS2 (

 <.01). Responses deepened substantially through week 54, with HiSCR50 rates of 60.2% to 61.9% in STOP-HS1 and 57.3% to 67.5% in STOP-HS2 in patients on continuous povorcitinib. Up to 29.0% of patients achieved HiSCR100 at week 54, and complete clearance of all inflammatory lesions was documented in 16.1% to 20.2% of patients across both studies.

The patient-reported outcome battery at week 54 included skin pain assessed by numerical rating scale, the Dermatology Life Quality Index (DLQI), the HS-specific quality-of-life instrument HiSQoL, and the FACIT-F fatigue scale — the last of which Porter noted is more commonly deployed in rheumatologic trials but is highly applicable to HS given the significant systemic burden of the disease. Rather than reporting aggregate total scores, the analysis focused on the proportion of patients achieving validated thresholds for clinically meaningful improvement on each measure. Across the 4 instruments, between approximately one-third and two-thirds of patients achieved these thresholds: ≥3-point decreases in skin pain NRS were reached by 40.5% to 58.0% of eligible patients, ≥4-point improvements in FACIT-F by 40.5% to 49.0%, ≥4-point decreases in DLQI by 59.4% to 64.7%, and ≥21-point decreases in HiSQoL total score by 33.7% to 40.2%. Porter emphasized that these measures continued to improve across the full 54-week observation period, consistent with the inflammatory response trajectory.

She offered important context for interpreting these gains relative to other dermatologic diseases. In psoriasis or atopic dermatitis, achieving PASI 100 or EASI 100 means skin can return to a visually normal state. In HS, the inflammatory targets — abscesses, nodules, and draining tunnels — can respond to therapy while patients remain left with significant residual scarring and hyperpigmentation, particularly in darker skin tones, which are disproportionately represented in the HS patient population. This means that even when inflammatory control is achieved, quality-of-life measures may not reach zero, and clinicians should counsel patients accordingly: the goal of anti-inflammatory therapy is halting progression and eliminating drainage, not reversing structural damage already present. Porter characterized this counseling as central to appropriate patient expectations — that freedom from drainage, the ability to wear clothing, travel, work, and exercise without fear of a flare represents meaningful therapeutic success even when discoloration and scarring persist.

On treatment positioning, Porter described povorcitinib's potential role as potentially first-line pending FDA approval, with efficacy in the biologic-experienced population — 37.2% of trial participants, a higher proportion than in prior phase 3 HS programs — providing reassurance for a treatment landscape where many patients will arrive having already failed a TNF-α or IL-17 inhibitor. She also described emerging clinical phenotype patterns from her practice that she presented independently of the STOP-HS data: patients with very severe disease predominantly affecting the groin and buttocks with extensive tunneling, as well as patients with high nodule burden but relatively few draining tunnels, both appear to achieve particularly high clearance rates on JAK inhibitors in her clinical experience. She framed these as observational signals that warrant prospective investigation and may ultimately guide which patients are directed toward JAK inhibition versus biologics as initial therapy — a precision-medicine framework the field has not yet been able to operationalize systematically

Safety through week 54 was consistent with the known JAK1 inhibitor class profile, with acne (16.4%–21.1%), nasopharyngitis (9.4%–13.6%), and upper respiratory tract infection (9.1%–12.2%) as the most common treatment-emergent adverse events. Serious treatment-emergent adverse events occurred in 3.7% to 6.4% of patients across arms; no malignancies excluding non-melanoma skin cancer were reported and MACE was observed in 1 patient (0.3%) in STOP-HS2.

“In the ideal dream world down the line is that what we really want to know for all these medications, because we're not looking at 90% of patients get 90% better. You know, we really need some markers, whether they're blood markers or clinical markers or demographic features, that help us really determine,” Porter said.

54-week STOP-HS data show clinically meaningful improvements in pain, fatigue, and quality of life in one-third to two-thirds of patients.


Povorcitinib Efficacy Holds in Biologic-Experienced HS, With Martina Porter, MD

Oral povorcitinib demonstrated sustained and deepening clinical response through 54 weeks in moderate-to-severe hidradenitis suppurativa (HS), with a biologic-experienced subgroup comprising nearly 40% of enrolled patients achieving efficacy rates comparable to those without prior biologic exposure.

Martina L. Porter, MD, of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, presented the 54-week STOP-HS extension data as a late-breaking abstract at the 

 held in Denver, Colorado, from March 27-31.

The STOP-HS extension follows up the STOP-HS1 (NCT05620823) and STOP-HS2 (NCT05620836), identically designed global phase 3 trials with a combined enrollment of 1,227 adults with moderate-to-severe HS (STOP-HS1, n = 608; STOP-HS2, n = 619), randomized 1:1:1 to povorcitinib 75 mg once daily, 45 mg once daily, or placebo for a 12-week placebo-controlled period, followed by a 42-week blinded extension through week 54. Enrollment required abscess and nodule (AN) count ≥5 in ≥2 anatomic areas, Hurley Stage II or III disease, duration ≥3 months, and prior systemic therapy. Mean disease duration was 10.3 years (SD, 9.4), mean AN count was 12.0 (SD, 8.8), and 75.5% had at least 1 draining tunnel at baseline. Biologic-experienced patients — those with prior exposure to a TNF-α or IL-17 inhibitor — comprised 37.2% of the trial population, a proportion Porter noted is substantially higher than in prior phase 3 HS programs.

At the primary endpoint of HiSCR50 at week 12, both doses achieved statistical significance versus placebo in both studies — 40.2% (45 mg) and 40.6% (75 mg) versus 29.7% for placebo in STOP-HS1 (

 <.01). Response continued to deepen through the blinded extension, with HiSCR50 reaching 60.2% to 61.9% in STOP-HS1 and 57.3% to 67.5% in STOP-HS2 by week 54 in patients on continuous povorcitinib, and placebo-crossover patients achieving comparable rates after switching at week 12. High-threshold responses accumulated substantially over time: up to 29.0% of patients achieved HiSCR100 at week 54, and complete clearance of all inflammatory lesions (ANdT = 0) was documented in 16.1% to 20.2% of patients across both studies. 

at the meeting, Porter characterized the new data as clinically important in a disease where mechanistic heterogeneity likely determines which patients succeed on which treatments. Porter framed the deepening responses as a recalibration of what clinicians should expect from HS therapy — response at the 12- to 16-week placebo-controlled primary endpoint represents an early signal, not a treatment ceiling, and 6 to 12 months of continued therapy may be required before patients reach their maximal benefit.

A separate subgroup analysis presented at the same meeting examined efficacy in the biologic-experienced cohort specifically. These patients carried greater baseline disease burden — higher AN counts and more draining tunnels — consistent with a more refractory disease phenotype. Despite this, their HiSCR response rates at both week 12 and week 54 were comparable to those seen in the overall trial population, a result Porter described as mechanistically explanatory: patients who failed TNF-α or IL-17 inhibitors may not have been signaling disease primarily through those pathways, and JAK1 inhibition via the JAK-STAT axis represents a genuinely distinct mechanism capable of capturing response in that population. She noted this pattern is consistent with her clinical experience. The depth-of-response data further support this picture: by week 54, up to approximately 20% of patients achieved near-complete or complete inflammatory clearance, a threshold more familiar from psoriasis and atopic dermatitis than historically from HS. Patient-reported outcomes at week 54 reflected the clinical gains, with ≥3-point decreases in skin pain NRS achieved in 40.5% to 58.0% of eligible patients and ≥4-point improvements in DLQI in 59.4% to 64.7%.

Safety through week 54 was consistent with the established class profile of JAK1 inhibitors. The most common treatment-emergent adverse events were acne (16.4%–21.1%), nasopharyngitis (9.4%–13.6%), and upper respiratory tract infection (9.1%–12.2%). Serious treatment-emergent adverse events occurred in 3.7% to 6.4% of patients across arms; no malignancies excluding non-melanoma skin cancer were reported and MACE was observed in 1 patient (0.3%) in STOP-HS2.

“I think our mentality or mindset about treating patients has really shifted to where we're not expecting them to respond to therapies like our psoriasis patients do, or even our atopic dermatitis patients, this is a very different disease, but the data is very reassuring in terms of the efficacy,” Porter said.

Extension data through week 54 reveal deepening responses with povorcitinib in moderate-to-severe HS.


Povorcitinib Delivers Deepening Responses Through 54 Weeks in Moderate-to-Severe HS, With Martina Porter, MD

An oral selective JAK1 inhibitor has demonstrated sustained and deepening clinical response through 54 weeks in moderate-to-severe 

, with up to 29% of patients achieving complete abscess and inflammatory nodule clearance — adding a mechanistically distinct option to a treatment landscape that has expanded rapidly but remained anchored to injectable biologics.

To discuss the findings, we spoke with Martina L. Porter, MD, of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, presenting author of the 54-week STOP-HS data at the 

 held in Denver, Colorado, from March 27-31. STOP-HS1 (NCT05620823) and STOP-HS2 (NCT05620836) are identically designed global phase 3 trials enrolling 1,227 adults total (STOP-HS1, n = 608; STOP-HS2, n = 619) with moderate-to-severe HS, randomized 1:1:1 to povorcitinib 75 mg once daily, 45 mg once daily, or placebo for a 12-week placebo-controlled period, followed by a 42-week blinded extension through week 54. Patients were required to have AN count ≥5 in ≥2 anatomic areas, Hurley stage II or III, disease duration ≥3 months, and prior systemic therapy — with 37.2% having previously received a biologic. Mean disease duration was 10.3 years (SD 9.4), mean AN count 12.0 (SD 8.8), and 75.5% had at least 1 draining tunnel at baseline.

At the primary endpoint of HiSCR50 at week 12, both doses were statistically significant versus placebo in both studies — 40.2% (45 mg) and 40.6% (75 mg) versus 29.7% placebo in STOP-HS1 (

 <.025), and 42.3% for both doses versus 28.6% placebo in STOP-HS2 (

 <.01) — with continuous improvement through week 54. By observed-cases analysis at week 54, HiSCR50 reached 60.2%–61.9% (STOP-HS1) and 57.3%–67.5% (STOP-HS2) in patients on continuous povorcitinib, with placebo crossover patients achieving comparable rates after switching at week 12. High-threshold responses deepened comparably, with up to 29.0% of patients achieving HiSCR100 at week 54. Full clearance of all inflammatory lesions (ANdT = 0) was achieved in 16.1%–20.2% of patients across both studies. Clinically meaningful improvements were observed across patient-reported outcome measures at week 54: ≥3-point decreases in skin pain NRS in 40.5%–58.0% of eligible patients, ≥4-point improvements in FATIGUE (FACIT-F) in 40.5%–49.0%, ≥4-point decreases in DLQI in 59.4%–64.7%, and ≥21-point decreases in HiSQoL total score in 33.7%–40.2%. 

Safety through week 54 was consistent with the class profile — the most common TEAEs were acne (16.4%–21.1%), nasopharyngitis (9.4%–13.6%), and upper respiratory tract infection (9.1%–12.2%). Serious TEAEs occurred in 3.7%–6.4% of patients across arms, with no malignancies excluding NMSC reported and MACE occurring in only 1 patient (0.3%) in STOP-HS2. Porter contextualized povorcitinib's JAK1 mechanism as genuinely complementary to existing options: while TNF-α and IL-17 inhibitors — including secukinumab, bimekizumab, and the phase 3-complete agents izokibep and imsidolimab — share overlapping proximity in the inflammatory signaling cascade, JAK-STAT pathway inhibition operates through a distinct mechanism that may benefit patients who have already failed biologic therapy, and Porter suggested it could potentially be considered first line pending the FDA approval pathway.

“For some patients who have already taken biologics and had very minimal response, this could be very promising for them especially. But I've also seen in clinical practice that it has a variety effects of on different types of HS patients, and so I also think it could be considered first line in the future as well, depending on how It's [potentially] approved through the FDA,” Porter said.

Porter ML, Martorell A, Sayed CJ, et al. Povorcitinib in patients with moderate to severe hidradenitis suppurativa: 54-week efficacy and safety results from the STOP-HS1 & STOP-HS2 phase 3 studies. Presented at: American Academy of Dermatology Annual Meeting; March 27–31, 2026; Denver, CO. Presentation 80034.

54-week data from the phase 3 STOP-HS1 and STOP-HS2 trials demonstrate JAK inhibitor povorcitinib's benefit in HS.

Martina Porter, MD

Articles