Everest Medicines Announces that Licensing Partner Pfizer Reports Positive Topline Results from Yearlong Phase 3 Trial of Etrasimod in Ulcerative Colitis Patients, Underscoring Best-in-Class Potential

SHANGHAI,March 30,2022 --Everest Medicines (HKEX 1952.HK) announced today that its licensing partner,Pfizer Inc. (NYSE: PFE) reported positive topline results from a second Phase 3 study of etrasimod,an investigational,oral,once-a-day,selective sphingosine 1-phosphate (S1P) receptor modulator in development for the treatment of moderately to severely active ulcerative colitis (UC).

In this 52-week study,also known as ELEVATE UC 52,etrasimod patients achieved statistically significant improvements in the co-primary endpoints of clinical remission at weeks 12 and 52 when compared to placebo. Statistically significant improvements were attained in all key secondary endpoints at both 12 and 52 weeks. Etrasimod demonstrated a safety profile consistent with previous studies,including the Phase 2 OASIS trial.

The global Phase 3 multi-center,randomized,double-blind,placebo-controlled study enrolled 433 UC patients who had previously failed or were intolerant to at least one conventional,biologic,or Janus kinase (JAK) inhibitor therapy. Participants received etrasimod 2 mg or placebo once-daily. ELEVATE UC 52 utilized a treat-through design in which patients were eligible to continue with their randomized treatment independent of whether they reached the objective criteria of clinical response at week 12.

Full results from the studies will be submitted for future scientific publication and presentation. The positive 12- and 52-week results from ELEVATE UC 52 follow the recent announcement of positive 12-week findings from the ELEVATE UC 12 trial earlier this month. These data,along with results from ELEVATE UC 12 and the long-term extension from these two trials (ELEVATE UC OLE),are expected to form the basis for planned future regulatory filings. Pfizer expects to initiate regulatory filings later this year.

Etrasimod was developed by Arena Pharmaceuticals,which was recently acquired by Pfizer,and Everest Medicines secured exclusive rights from Arena to develop,manufacture and commercialize etrasimod in Greater China and South Korea in 2017. Everest Medicines is conducting a phase 3 study for etrasimod in Asia for the treatment of moderate-severe ulcerative colitis,which is expected to complete enrollment in 2023.

"We are excited to see continuing positive topline results on Etrasimod,underlying its potential as a best-in-class therapy," said Kerry Blanchard,MD,PhD,CEO of Everest Medicines. "We'll actively move forward our phase 3 study in Asia in order to bring the product to moderate-severe ulcerative colitis patients in this region as early as possible."

About Etrasimod

Etrasimod is an oral,selective sphingosine 1-phosphate (S1P) receptor modulator being investigated for a range of immuno-inflammatory diseases including ulcerative colitis,Crohn's Disease,atopic dermatitis,eosinophilic esophagitis,and alopecia areata.

In a Phase 2,placebo-controlled,dose-ranging study (OASIS) in moderate to severe UC patients,most patients who achieved clinical response,clinical remission,or endoscopic improvement at week 12 experienced sustained or improved effects up to week 46,with etrasimod 2 mg in the open-label extension. Etrasimod also demonstrated a favorable benefit/risk profile,consistent with safety findings reported in the double-blind portion of OASIS.

About ELEVATE UC 52

ELEVATE UC 52 is one of two pivotal trials that are part of the ELEVATE UC global Phase 3 registrational program. ELEVATE UC 52 is a 2:1 randomized,placebo-controlled trial to assess the efficacy and safety of etrasimod 2 mg once-daily in participants with moderately-to-severely active UC. This is a one-year trial evaluating clinical remission at 12 weeks,or induction,and at 52 weeks. ELEVATE UC 52 utilized a treat-through design in which patients were eligible to continue with etrasimod independent of whether they reached clinical response at week 12.

The primary objective of this trial is to assess the safety and efficacy of etrasimod on clinical remission after both 12 and 52 weeks. The primary endpoint is based on the 3-domain,modified Mayo score. Key secondary measures include the efficacy of etrasimod,symptomatic remission,endoscopic improvement,corticosteroid-free remission,and mucosal healing in these participants at time points up to 52 weeks of treatment.

About Ulcerative Colitis

UC is a chronic and often debilitating inflammatory bowel disease[i] that affects many people worldwide,including an estimated 3.8 million people in North America and Europe.[ii] Symptoms of UC can include chronic diarrhea with blood and mucus,abdominal pain and cramping,and weight loss. [iii] UC can have a significant effect on work,family and social activities.[iv]

About Everest Medicines

Everest Medicines is a biopharmaceutical company focused on developing and commercializing transformative pharmaceutical products that address critical unmet medical needs for patients in Asian markets. The management team of Everest Medicines has deep expertise and an extensive track record of high-quality clinical development,regulatory affairs,CMC,business development and operations both in China and with leading global pharmaceutical companies. Everest Medicines has built a portfolio of eleven potentially global first-in-class or best-in-class molecules,many of which are in late-stage clinical development. The Company's therapeutic areas of interest include oncology,autoimmune disorders,cardio-renal diseases and infectious diseases. For more information,please visit its website atwww.everestmedicines.com.

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[i] Crohn's and Colitis Foundation. What is Ulcerative Colitis. Available at: What is Ulcerative Colitis? | Crohn's & Colitis Foundation (crohnscolitisfoundation.org) Accessed March 18,2022.

[ii] Seyedian,SS. A review of the diagnosis,prevention,and treatment methods of inflammatory bowel disease. J Med Life 2019 Apr-Jun; 12 (2): 113-122. Available at: A review of the diagnosis,and treatment methods of inflammatory bowel disease - PMC (nih.gov). Accessed March 22,2022.

[iii] Hanauer SB. Inflammatory bowel disease. N Engl J Med. 1996;334(13):841-8. Available at: Inflammatory Bowel Disease | NEJM. Accessed March 18,2022.

[iv] Irvine EJ. Quality of Life of Patients with Ulcerative Colitis: Past,Present,and Future. Inflammatory Bowel Diseases. 2008;14(4):554-563. Available at: Quality of life of patients with ulcerative colitis: Past,present,and future | Inflammatory Bowel Diseases | Oxford Academic (openathens.net). Accessed March 18,2022.