Introduction

Guselkumab (GUS), a dual-acting interleukin-23p19 subunit inhibitor, demonstrated efficacy in participants (pts) with ulcerative colitis (UC) treated with intravenous (IV) or subcutaneous (SC) induction. Here, we report the efficacy and safety of SC induction followed by SC maintenance through Week (W) 48 in ASTRO, a phase 3, randomized, double-blind, placebo (PBO)-controlled, treat-through study in pts with moderately to severely active UC.

Aims & Methods

Eligible pts had modified Mayo scores of 5 to 9, rectal bleeding subscore of ≥1, and Mayo endoscopic subscore (MES) ≥2. Pts also had documented inadequate response/intolerance to biologics, Janus kinase (JAK) inhibitors, and/or sphingosine-1-phosphate (S1P) inhibitors (BIO/JAKi/S1Pi-IR) or to corticosteroids, 6-mercaptopurine, or azathioprine. Randomization was stratified by baseline BIO/JAKi/S1Pi-IR status and MES with 418 pts allocated 1:1:1 to GUS 400 mg SC every 4 weeks (q4w) (×3)→GUS 200 mg SC q4w (N=140), GUS 400 mg SC q4w (×3)→GUS 100 mg SC every 8 weeks (q8w) (N=139), or PBO SC (N=139). PBO pts who met rescue criteria were switched to GUS at W16; GUS pts who met rescue criteria stayed on their assigned GUS dose regimen (sham rescue).

Results

At W48, greater proportions of pts in the GUS groups achieved clinical remission compared with PBO (36.7% for GUS 100 mg q8w [Δ 29.5%], 42.9% for GUS 200 mg q4w [Δ 35.6%], 7.2% for PBO) (Table). Endoscopic remission proportions were 25.9% for GUS 100 mg q8w (Δ 20.9%), 26.4% for GUS 200 mg q4w (Δ 21.4%), and 5.0% for PBO. Clinical response, symptomatic remission, endoscopic improvement, histologic improvement, and histologic remission proportions were also greater for GUS vs PBO. Consistent with the results of the overall population, efficacy was also observed for subpopulations of BIO/JAKi/S1Pi-naïve and BIO/JAKi/S1Pi-IR pts. Safety events per 100 pts-years were not greater in the GUS groups compared with the PBO group: adverse events (AE) (GUS 100 mg q8w and 200 mg q4w vs PBO: 308.3 and 310.7 vs 357.1), serious AEs (6.5 and 8.2 vs 38.4), serious infections (0.8 and 2.5 vs 3.7), and AEs leading to treatment discontinuation (4.9 and 4.1 vs 19.8).
Table. Efficacy endpoints at Week 48 in the overall population and by biologic, JAK inhibitor, and/or S1P inhibitor history

Conclusion

GUS SC induction followed by SC maintenance was efficacious through 1 year in pts with moderately to severely active UC, and the safety profile is consistent with GUS in its approved indications including UC.

Disclosure

ML reports research support from Lilly, Pfizer, and Takeda; consulting for AbbVie, Bristol Myers Squibb, Intercept, Janssen (Johnson & Johnson), Lilly, Pfizer, Prometheus, Roivant, Takeda, and Target RWE.
JRA reports grant support from Janssen, Merck, and Pfizer; consultancy fees from AbbVie, Adiso, Bristol Myers Squibb, Ferring, Genentech, GlaxoSmithKline, Janssen, Merck, Pfizer, Roivant, Celltrion, TrexBio, Shattuck Labs and Seres Therapeutics; payments for speaking from AbbVie, Bristol Myers Squibb, and Janssen; and is a steering committee member and investigator for Janssen.
SD reports consultancy fees from AbbVie, Alimentiv, Allergan, Amgen, AstraZeneca, Athos, Biogen, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Enthera, Ferring, Gilead, Hospira, Inotrem, Janssen, Johnson & Johnson, MSD, Mundipharma, Mylan, Pfizer, Roche, Sandoz, Sublimity, Takeda, TiGenix, UCB, and Vifor; and reports lecture fees from AbbVie, Amgen, Ferring, Gilead, Janssen, Mylan, Pfizer, and Takeda.
MG, TB, YA, KH, SJ, LJ, and HZ are employees of and may own stock in Johnson & Johnson.
TH reports research grants from AbbVie GK, Boston Scientific Corporation, EA Pharma Co. Ltd., JIMRO Co. Ltd., Kissei Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corporation, Mochida Pharmaceutical Co. Ltd., Nippon Kayaku Co. Ltd., Pfizer Inc., Takeda Pharmaceutical Co. Ltd., and Zeria Pharmaceutical Co. Ltd.; consulting fees from AbbVie GK, Abivax, Bristol Myers Squibb, EA Pharma Co. Ltd., Gilead Sciences, Janssen Pharmaceutical K.K., Lilly, Mitsubishi Tanabe Pharma Corporation, and Pfizer Inc.; and lecture fees from AbbVie GK, EA Pharma Co. Ltd., Janssen Pharmaceutical K.K., JIMRO Co., Kissei Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Mitsubishi Tanabe Pharma Corporation, Mochida Pharmaceutical Co., Ltd., Pfizer Inc., and Takeda Pharmaceutical Co. Ltd.
DTR reports consulting and/or speaker fees and/or advisory board participation for AbbVie, Altrubio, Apex, Avalo, Bristol Myers Squibb, Buhlmann Diagnostics, Celgene, Connect BioPharma, Intouch Group, Iterative Health, Janssen (Johnson & Johnson), Lilly, Pfizer, Samsung Neurologica, and Takeda; Altrubio, Datos Health, and Iterative Health stock options; grants from Takeda; and membership on the Board of Directors of Cornerstones Health, Inc. and on the Crohn’s & Colitis Foundation’s Board of Trustees.
LPB reports grants or contracts from Celltrion, Fresenius Kabi, Medac, MSD, and Takeda; consulting and/or payment or honoraria and/or data safety monitoring board or advisory board participation for AbbVie, Abivax, Adacyte, Alfasigma, Alimentiv, Amgen, Applied Molecular Transport, Arena, Banook, Biogen, Bristol Myers Squibb, Celltrion, Connect Biopharm, Cytoki Pharma, Enthera, Ferring, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GlaxoSmithKline, IAC Image Analysis, Index Pharmaceuticals, Inotrem, Janssen, Kern Pharma, Lilly, Medac, Mopac, Morphic, MSD, Nordic Pharma, Novartis, Oncodesign Precision Medicine, ONO Pharma, OSE Immunotherapeutics, Pandion Therapeutics, Par' Immune, Pfizer, Prometheus, Protagonist, Roche, Samsung, Sandoz, Sanofi, Satisfay, Takeda, Telavant, Theravance, Thermo Fischer, Tigenix, Tillots, Viatris, Vectivbio, Ventyx, and Ysopia; and meeting attendance/travel support from AbbVie, Alfasigma, Amgen, Celltrion, Connect Biopharm, Ferring, Galapagos, Genentech, Gilead, Gossamer Bio, Janssen, Lilly, Medac, Morphic, MSD, Pfizer, Sandoz, Takeda, Thermo Fischer, and Tillots.

Introduction

Fistulizing perianal Crohn’s disease (CD) remains a significant therapeutic challenge, with limited randomized controlled trials to date, restricted so far to infliximab and, more recently, filgotinib. The USTAP (NCT04496063) trial aimed to evaluate the efficacy and safety of UST in patients with actively draining perianal fistulas through a multicenter randomized controlled design.

Aims & Methods

This double-blind, placebo-controlled, multicenter trial enrolled adult patients with active draining fistulizing perianal CD. Between April 2020 and June 2024, eligible patients with persistent fistula drainage were randomized 1:1, after seton placement when necessary, to receive either UST (6 mg/kg IV at baseline followed by 90 mg SC at week 8, then every 8 weeks) or placebo. Steroids were allowed at baseline with a standardized steroid taper. Seton removal was planned at week 6. The primary endpoint was combined clinical remission (absence of drainage from all external fistula openings) and radiological remission (defined as the absence of abscesses >2 cm confirmed by blinded central pelvic MRI) at week 12. Secondary endpoints included clinical remission, radiological remission, changes in disease activity (CDAI, PDAI), IBD-DI, and safety. Endpoints were independently reviewed by a blinded adjudication committee. Randomization was stratified by prior anti-TNF exposure and study center. The intended sample size was 73 patients per group to detect a 20% difference in remission rates (power 80%, alpha 5%). Due to slow recruitment, the study was discontinued in June 2024 after randomizing 32 patients, without unblinding the study data. Patients were subsequently followed until week 48.

Results

Thirty-three patients consented to participate with 32 patients (women: 41%; median age: 42) ultimately randomized (UST: 16; placebo: 16) across 10 French centers. Seventy percent had prior anti-TNF exposure (50% in UST arm, 50% in placebo arm), and 23% had previously failed two or more anti-TNF therapies. At baseline, 84% had one draining fistula, 16% had two, and 25% had associated abscesses. At week 12, combined remission was achieved in 62% in the UST group versus 25% in the placebo group (Table). Clinical remission was observed in 69% in the UST group vs. 31% in the placebo group, while radiological remission rates were 87.5% in the UST group and 75% in the placebo group. In the UST arm, mean change in CDAI, PDAI and IBD-DI from baseline to week 12 was -56.3, -2.2 and -4.9, (vs. -9.8, -1.6 and +4.9, in the placebo arm, respectively). Adverse events (AE) and serious adverse events (SAE) were similar in both treatment groups: 23 AE (62%) occurred in the placebo group, and 14 AE (38%) in the UST group. Six SAEs were reported overall, including two gastrointestinal events, one renal disorder, and one anal abscess. Two patients in the placebo group discontinued study by week 6 due to SAEs (an anal abscess and a peri-ileal abscess).

Conclusion

In this trial, where the majority of patients had prior anti-TNF exposure, the observed short-term clinical benefit of UST supports its use in fistulizing perianal CD.

Disclosure

This work was supported by a grant from Johnson & Johnson
Pauline Wils : Johnson & johnson, Takeda, Amgen, Abbvie, Celltrion, Ferring
S Nancey: Abbvie, Johnson and Johnson, Fresenius Kabi, Biogen, Takeda, Medac, Celltrion, MSD, Pfizer, Sandoz, Lilly,Ferring, Amgen
E. Messmer: No conflict of interest for this study
A Bourreille: Johnson and Johnson
A Buisson: Consulting fees from: Abbvie, Amgen, Arena, Biocon, Biogen, Celltrion Healthcare, CTMA, Ferring, Galapagos/AlfaSigma, GutyCare/Resilience Janssen, Lilly, MSD, Nexbiome, Pileje, Pfizer, Roche, Sandoz, Takeda et Tillotts. Lecture fees from: Abbvie, Amgen, Biogen, Celltrion Healthcare Galapagos/AlfaSigma, Ferring, Janssen, Lilly, Mayoli-Spindler, MSD, Nordic Pharma, Norgine, Pfizer, Roche, Takeda, Tillotts and Vifor Pharma. Research grants/fundings from: Abbvie, Celltrion Healthcare, Janssen, Lessaffre, Lilly, Pfizer, Sandoz and Takeda
L Caillo: No conflict of interest for this study
L Vuitton: abbvie amgen J&J Pfizer Takeda Lilly MSD Mayoli Ferring Dr Falk Alpha Sigma
R Altwegg: Abbvie, Johnson ans Johnson, Takeda, Pfizer, Lilly, Alphasigma, Celltrion, Amgen, Biogen, Sandoz, Ferring
X Hébuterne reports clinical research funding from Abbvie, Abivax, Amgen, Celltrion, Lilly, Fresenius-Kabi, J&J, InDex Pharmaceuticals, Pfizer, Prometheus, MSD, Roche, Takeda, serving on advisory boards for Abbvie, Biogen, Celltrion, Lilly, J&J, and participating in lectures and educational activities for Abbvie, Amgen, Celltrion, Lilly, Fresenius-Kabi, Galapagos, J&J, MSD, Nestlé Health Sciences, Nutricia, Pfizer, Tillots, Takeda.
O Ernst: No conflict of interest for this study
P Meunier: No conflict of interest for this study
V Laurent: No conflict of interest for this study
D Laharie: received board and lecture fees from: Abbvie, Alfasigma, Amgen, Biogen, Celltrion, Ferring, Fresenius-Kabi, Janssen, Lilly, MSD, Pfizer, Roche, Sandoz, Takeda
E Vicaut: No conflict of interest for this study
L Peyrin-Biroulet: Consulting : Abbvie, Abivax, Adacyte, Alimentiv, Amgen, Applied Molecular Transport, Arena, Banook, Biogen, BMS, Celltrion, Connect Biopharm, Cytoki Pharma, Enthera, Ferring, Fresenius Kabi, Galapagos, Genentech, Gilead, Gossamer Bio, GSK, IAC Image Analysis, Index Pharmaceuticals, Inotrem, Janssen, Lilly, Medac, Mopac, Morphic, MSD, Nordic Pharma, Novartis, Oncodesign Precision Medicine, ONO Pharma, OSE Immunotherapeuthics, Pandion Therapeuthics, Par' Immune, Pfizer, Prometheus, Protagonist, Roche, Samsung, Sandoz, Sanofi, Satisfay, Takeda, Telavant, Theravance, Thermo Fischer, Tigenix, Tillots, Viatris, Vectivbio, Ventyx, Ysopia ; lecture : Abbvie, Amgen, Arena, Biogen, Celltrion, Ferring, Galapagos, Genentech, Gilead, Janssen, Lilly, Medac, MSD, Nordic Pharma, Pfizer, Sandoz, Takeda, Tillots, Viatris

Introduction

Complex perianal fistulas represent one of the most challenging manifestations of Crohn’s disease. Combined surgical and medical therapy with biologic drugs represents today the first-line treatment option, but its efficacy does not exceed 60% in terms of healing. Recently, new therapeutic approaches, such as autologous microfragmented adipose tissue (M-Fat) injection, have shown promising results. Indeed, a recent non-profit prospective pilot study on 15 patients has demonstrated that the local injection of M-Fat is a safe and promising “rescue therapy” for patients with multiresistant complex fistulizing Crohn’s disease (PCD), with a 66.7% rate of combined remission in such difficult patients. It has to be highlighted that the M-Fat injection is minimally invasive, with less risk of sphincteric damage and can be carried out in day-surgery setting.

Aims & Methods

The primary aim of this multicentre double-blind randomized controlled trial (ATTIC) is to evaluate the efficacy of the infiltration of M-Fat in the healing of perianal complex fistulas not-responding to treatment with biologics. Consecutive patients referring to the 6 investigation Centers for surgical treatment of persistent complex fistulizing PCD refractory to biosurgical approach were assessed for eligibility. After baseline pelvic magnetic resonance imaging, those included were submitted to surgical drainage with “cone-like” fistulectomy, and then randomized to receive a 15 to 20 cc local injection, at the internal orifice level and along fistula tracts, of M-Fat obtained by a lipoaspiration and processed with an enzyme-free technology (treatment group), or a suture placement and injection of 15 cc of saline solution at the internal orifice (control group). Clinical follow-up were conducted at 2, 4, 8, 12, and 24 weeks; at 24 weeks after surgery, pelvic magnetic resonance was obtained. Success was defined as “combined remission”, combination of clinical (absence of drainage upon gentle finger compression) and radiological healing (absence of residual collections > 3 mm). Clinical remission was defined as clinical healing of all external openings not confirmed at radiological assessment.

Results

An overall 92 patients were screened, and 66 (33 per group) completed the 24-week follow-up. A statistically significant difference in favour of the treatment group in terms of combined remission emerged at the primary endpoint at 24-week follow-up (control group, 18.18%; treatment group: 57.58%; p = 0.0020). No significant differences in clinical outcome measures were encountered at any of the other follow-up points. No significant differences emerged between the groups in terms of recurrence rate, complication rate, and number of adverse events. Clinical remission was 63.64% in the treatment group compared to 51.52% in the control group with no statistically significant difference (p > 0.05).

Conclusion

This multicentre double-blind randomized controlled trial demonstrates that the intraoperative injection of M-Fat, associated with surgical complete drainage of perianal sepsis, is safe, effective, and reproducible in healing complex multirefractory perianal Crohn's disease, while improving the quality of life and significantly reducing the risk of definitive oostomy.

Introduction

The phase 2b GALAXI 1 and phase 3 GALAXI 2&3 studies evaluated guselkumab (GUS), a dual-acting IL-23p19 subunit inhibitor, in participants (pts) with moderately to severely active CD.¹ Pts treated with ustekinumab (UST) who met inadequate response criteria during the long-term extension (LTE) could cross over to GUS 200 mg SC q4w. Here, we present efficacy and safety results in pts who received GUS after experiencing an inadequate response to UST in the pooled GALAXI LTE.

Aims & Methods

Individuals with prior inadequate response or intolerance to UST were excluded from GALAXI; however, during the LTE, pts treated with UST 90 mg SC q8w who met inadequate treatment response criteria (not in clinical response [≥100-point reduction in CDAI score from baseline or CDAI<150] and CDAI ≥220) between Wks 52-80 of LTE were eligible for a treatment switch to GUS 200 mg SC q4w, without IV induction. Clinical response and clinical remission (CDAI<150) were both assessed 16 weeks after treatment switch. Endoscopic response (≥50% improvement from baseline SES-CD or SES-CD≤2) and endoscopic remission (SES-CD≤4 and ≥2-point reduction from baseline and no subscore >1 in any individual component) were assessed at Wk 96. Safety was assessed through Wk 96.

Results

In total, 80 pts treated with UST underwent treatment switch to GUS 200 mg SC q4w maintenance therapy due to meeting inadequate treatment response criteria between Wks 52-80 of the LTE. Of these 80 pts, 75 were included in the efficacy analyses (baseline mean age, 35.2yrs; male, 64.0%; mean CD disease duration, 8.21yrs; mean CDAI, 291.5; mean SES-CD, 12.8; history of inadequate response/intolerance to biologics [BIO-IR], 60.0%).
The proportions of pts achieving clinical response and clinical remission 16 weeks after treatment switch from UST to GUS 200 mg SC q4w were 61.3% and 52.0%, respectively. These results were comparable to the proportions of pts treated with GUS 200 mg IV q4w induction in the BIO-IR subgroup of the total LTE population who achieved clinical response and clinical remission at Wk 12 (61.7% and 46.7%, respectively).
The proportions of pts achieving endoscopic response and endoscopic remission at Wk 96 (ie, ~1 year after treatment switch from UST to GUS 200 mg SC q4w) were 49.3% and 30.7%, respectively. These results were similar to the proportions of pts in the BIO-IR subgroup receiving GUS 200 mg SC q4w maintenance who achieved endoscopic response and endoscopic remission at Wk 48 (57.2% and 35.5%, respectively).
Safety results are summarized in the Table.

Table. Safety Summary From Treatment Switch Through Week 96

Conclusion

Among pts who experienced inadequate response to UST in the LTE, more than half achieved clinical remission 16 weeks after treatment switch to GUS 200 mg SC q4w, and approximately 50% were in endoscopic response ~1 year after treatment switch. These data suggest pts with an inadequate treatment response to UST may benefit from GUS treatment. Results should be interpreted considering that pts received GUS SC maintenance therapy directly without IV induction. Key safety event rates were consistent with the known safety profile of GUS in approved indications.

References

1) Sachen K, Hammaker D, Sarabia I, et al. Frontiers in Immunology. 2025; doi:10.3389/fimmu.2025.1532852.

Disclosure

AA reports potential conflicts of interest with AbbVie, Bristol Myers Squibb/Celgene, DiaSorin, Eli Lilly, Gilead, IBD Horizons, Janssen, Pfizer, Takeda, and TLL Pharmaceuticals
DW reports consulting fees from AbbVie, Bristol Myers Squibb, Janssen, Lilly, Pfizer, Takeda
RL reports having received advisory board fees from AbbVie, Aspen, BMS, Celgene, Celltrion, Chiesi, Ferring, Glutagen, Hospira, Janssen, Lilly, MSD, Novartis, Pfizer, Prometheus Biosciences, and Takeda; received research grants from Celltrion, Shire, Janssen, Takeda, Joanna Tiddy grant from University of Sydney, McCusker Charitable Trust, Gastroenterological Society of Australia, NHMRC, Gutsy Group, and Pfizer
RVR, WvD, and CB are employees of Johnson & Johnson and own company stock/stock options.
TH received grant support from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, JIMRO Co. Ltd., Zeria Pharmaceutical Co. Ltd., Kyorin Pharmaceutical Co. Ltd., Nippon Kayaku Co. Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc., Mochida Pharmaceutical Co. Ltd., Boston Scientific Corporation, Kissei Pharmaceutical Co. Ltd., consulting fees from Mitsubishi Tanabe Pharma Corporation, EA pharma Co. Ltd., AbbVie GK, Janssen Pharmaceutical K.K., Pfizer Inc., Nichi-Iko Pharmaceutical Co. Ltd., Eli Lilly, Gilead Sciences, Bristol Myers Squibb, and lecture fee from Mitsubishi Tanabe Pharma Corporation, AbbVie GK, EA pharma Co. Ltd., Kyorin Pharmaceutical Co. Ltd., JIMRO Co., Janssen Pharmaceutical K.K., Mochida Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co. Ltd., Pfizer Inc. Kissei Pharmaceutical Co. Ltd.
JP reports consultancy fees/honorarium from AbbVie, Alimentiv, Athos, Atomwise, Boehringer Ingelheim, Celsius, Ferring, Galapagos, Genentech/Roche, GlaxoSmithKline, Janssen, Mirum, Nimbus, Pfizer, Progenity, Prometheus, Protagonist, Revolo, Sanofi, Sorriso, Surrozen, Takeda, and Wasserman, and has served on a data safety monitoring board for Alimentiv, Mirum, Sorriso, Sanofi, and Surrozen.

Introduction

Endoscopic resection techniques, particularly endoscopic submucosal dissection (ESD), are increasingly adapted for lesions located beyond the gastrointestinal tract, including the hypopharynx. Atypical lesions in the pyriform sinus are uncommon and pose significant diagnostic and therapeutic challenges due to their anatomical complexity and limited endoscopic experience. We present a rare case of a flat mucosal lesion in the left pyriform sinus, initially suggestive of low-grade dysplasia (LGD) managed by ESD for excisional biopsy. Our optical diagnosis and resection strategy were based on a previously published case by Di et al., who demonstrated the feasibility of modified ESD in the hypopharyngeal region. (BMC Cancer 17, 712 (2017).

Aims & Methods

A 28-year-old female presented with upper abdominal pain and was referred for diagnostic esophagogastroduodenoscopy (EGD). She was a non-smoker with no relevant oncological family history. Routine examination of the esophagus, stomach, and duodenum was unremarkable. However, careful inspection of the hypopharynx revealed a flat elevated lesion (Paris 0-IIa), approximately 10×10 mm in size, with a demarcated border, located in the left pyriform sinus. Under narrow-band imaging (NBI) with dual focus, intrapapillary capillary loop (IPCL) pattern type IV was observed, raising suspicion for low-grade neoplasia or high-grade neoplasia. The lesion was photo-documented, and the patient was referred for therapeutic resection.
ESD was performed under general anesthesia. En bloc excision was achieved without adverse events; the resection time was 12 minutes.

Results

Histopathologic analysis revealed stratified non-keratinizing squamous epithelium overlying subepithelial lymphoid tissue, consistent with mucosa-associated lymphoid tissue (MALT). Areas of lymphoid follicular hyperplasia with fused follicles were present. The epithelium was non-dysplastic, with regenerative changes and mild intraepithelial lymphocytosis. Immunohistochemistry revealed non-block-type p16 staining, and Ki-67 expression was limited to the basal layer. No morphological or immunohistochemical evidence of high-grade squamous intraepithelial lesion (HSIL) was found.
The patient experienced mild local discomfort for two weeks post-procedure, controlled with ibuprofen. Follow-up endoscopy at one month confirmed complete healing with no recurrence.

Conclusion

This case highlights the growing applicability of advanced endoscopic techniques beyond the gastrointestinal tract and emphasizes the diagnostic limitations of optical assessment in small hypopharyngeal lesions. Despite features suggestive of squamous dysplasia, accurate diagnosis relied on excisional biopsy. ESD proved to be a safe and effective therapeutic option in this anatomically challenging location.

References

Di, L., Fu, KI., Xie, R. et al. A modified endoscopic submucosal dissection for a superficial hypopharyngeal cancer: a case report and technical discussion. BMC Cancer 17, 712 (2017). https://doi.org/10.1186/s12885-017-3685-7