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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

 

 

FORM 8-K

 

 

 

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

 

Date of Report (Date of earliest event reported): June 14, 2021

 

 

 

PROTAGONIST THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

 

 

 

Delaware   001-37852   98-0505495
(State or other jurisdiction
of incorporation)
  (Commission
File Number)
  (IRS Employer
Identification No.)

 

Protagonist Therapeutics, Inc.

7707 Gateway Blvd., Suite 140

Newark, California 94560-1160

(Address of principal executive offices, including zip code)

 

(510) 474-0170

(Registrant’s telephone number, including area code)

 

Not Applicable

(Former name or former address, if changed since last report.)

 

 

 

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

 

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

 

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

 

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

 

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

 

Securities registered pursuant to Section 12(b) of the Act:

 

Title of each class   Trading Symbol(s)   Name of each exchange on which
registered
Common Stock, par value $0.00001   PTGX   The Nasdaq Stock Market LLC

 

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

 

Emerging growth company x

 

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. x

 

 

 

 

 

 

Item 8.01 Other Events.

 

On June 14, 2021, Protagonist Therapeutics, Inc. (the “Company”) made available an updated corporate presentation on the Company’s website. A copy of the corporate presentation is furnished herewith as Exhibit 99.1 and incorporated herein by reference.

 

In accordance with General Instruction B.2 of Form 8-K, the information in this Item 8.01, including Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities of that section, and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

 

Item 9.01 Financial Statements and Exhibits

 

(d) Exhibits.

   
Exhibit   Description
     
99.1   Corporate Presentation, dated June 14, 2021
104   Cover Page Interactive Data File (embedded within the Inline XBRL document).

 

 

 

SIGNATURES

 

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

 

  Protagonist Therapeutics, Inc.
     
Date: June 14, 2021 By: /s/ Don Kalkofen
    Don Kalkofen
    Chief Financial Officer

 

 

Exhibit 99.1

 

PN - 943 PTG - 200 PN - 232 PN - 235 rusfertide (PTG - 300) PTG - 100 Dinesh V. Patel, PhD President & CEO June 2021 COMPANY OVERVIEW 1

Forward - looking Statements 2 This presentation and the accompanying oral presentation contain forward - looking statements made pursuant to the safe harbor pro visions of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical facts contained in this presentation, including statements re gar ding our future results of operations and financial position, business strategy, product candidates, capital resources, potential markets for our product candidates, enrollment in our cli nic al trials, any potential impact on our business related to COVID - 19, our potential receipt of milestone payments and royalties under our Collaboration Agreement with Janssen Biotech, Inc ., are forward - looking statements. In some cases, you can identify forward - looking statements by terminology such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “ex pect,” “intend,” “may,” “plan,” “potentially” “predict,” “should,” “will” or the negative of these terms or other similar expressions. The forward - looking statements made in this presentation involve known and unknown risks, uncertainties and other important fact ors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the f orw ard - looking statements. These forward - looking statements are subject to risks and uncertainties, including those discussed in Protagonist’s filings with the Securities and Ex change Commission, including in the “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” sections of most recently filed perio dic reports on Form 10 - K and Form 10 - Q and subsequent filings and in the documents incorporated by reference therein. Because forward - looking statements are inherently sub ject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward - looking stateme nts as predictions of future events. The events and circumstances reflected in our forward - looking statements may not be achieved or occur and actual results could differ materiall y from those projected in the forward - looking statements. Except as required by applicable law, we do not plan to publicly update or revise any forward - looking statements con tained herein, whether as a result of any new information, future events, changed circumstances or otherwise. This presentation concerns products that are under clinical investigation and which have not yet been approved for marketing by the U.S. Food and Drug Administration. They are currently limited by Federal law to investigational use, and no representation is made as to their safety or effectiveness fo r t he purposes for which they are being investigated. The trademarks included herein are the property of the owners thereof and are used for reference purposes only. Such use should not be construed as an endorsement of such products. Nothing contained in this presentation is, or should be construed as, a recommendation, promise or representation by the pres ent er or Protagonist or any director, employee, agent or advisor of Protagonist. This presentation does not purport to be all inclusive or to contain all the information you may desi re.

Innovative Peptide Technology Platform 3 Multiple Assets from De Novo Discovery to Clinical Development Peptide Chemistry SAR, Leads Oral Stability Peptidomimetics GI Assays Phage Libraries Hits Computational Vectrix, Clusters Vectrix ® Clusters GI - Restricted Targeted GI absorption & delivery Systemic Availability Formulation SAR, Transport PROTEASES PEPTIDASES REDOX MICROBIOME 1 2 3 4 5 6 rusfertide PN - 943 PTG - 200 PN - 235 PN - 232 PTG - 100 ACIDIC

Product Portfolio 4 Multiple Development Candidates in Multiple Indications PROGRAMS CANDIDATE DISCOVERY PRE - CLINICAL PHASE 1 PHASE 2 KEY 2021 - 22 MILESTONES HEMATOLOGY & BLOOD DISORDERS Hepcidin Mimetics rusfertide (PTG - 300) s.c. 39 ‡ 3K  HQUROOPHQWFRPSOHWH  ྃ ‡ 8SGDWHG3K  GDWDRUDOSUHVHQWDWLRQ DW(+$  ྃ ‡ 5HJXODWRU\IHHGEDFNRQUHJLVWUDWLRQDO3K   +  ྃ ‡ ,QLWLDWHQHZ39VWXG\LQSWVZLWKHOHYDWHG +F7  ྃ  ‡ 8SGDWHDWPDMRUPHGLFDOFRQIHUHQFH  +  HH : Preliminary data disclosure anticipated (2H 2021) Oral NCE Plan to nominate an oral development candidate INFLAMMATORY & IMMUNOMODULATORY DISEASES Oral GI Restricted a4b7 - Integrin Antagonists PN - 943 150 Pt Ph2 PoC study continuation in 2021 with completion anticipated in 2Q 2022* Oral IL - 23R Antagonists PTG - 200 Study in progress* PN - 235 Study completion anticipated (2H 2021) PN - 232 ‡ 3K  LQLWLDWHG ྃ ‡ 6WXG\FRPSOHWLRQDQWLFLSDWHG  +  *Subject to COVID - 19 related delays Polycythemia Vera (PV) Ph2 PoC Crohn’s Disease (CD) Ph2 PoC study Ulcerative Colitis (UC) Ph2 PoC study Ph1 study Ph1 study Pre - Clinical 2 nd Indication: Hereditary Hemochromatosis (HH) Ph2 PoC PV: New Ph2 study in Patients with Elevated Hct

3RO\F\WKHPLD9HUD 5 Disease, Diagnosis, Prevalence, Treatment Goal Myeloproliferative neoplasm characterized by excessive production of red blood cells (RBCs) • Characterized by Janus Kinase 2 (JAK2) mutation Treatment goal is to control hematocrit level <45% • Elevated hematocrit is a hallmark of the disease • Maintaining hematocrit <45% is critical to minimizing thrombosis, CV events, and death Serious chronic condition • Rare disease: ~100,000 diagnosed patients in USA • Diagnosed commonly in individuals 50 - 70 years of age • Median survival ~20 years • Thrombotic and cardiovascular risks; may progress to myelofibrosis or leukemia

Polycythemia Vera 6 &XUUHQW7UHDWPHQW2SWLRQV 1. MPN Landmark Survey 2017, Trinity Primary Research 2019 • Treatment goal is to maintain HcT ≤ 45% • HcT control may be erratic with up and down excursions from 45% • Can lead to iron deficiency • Recommended when HcT cannot be controlled, or in high - risk patients • Potential long - term side effects • Some patients reluctant to use chemotherapeutic agents • Approved for HU resistant/intolerant patients • ~5,300 patients/yr treated • ~25% develop intolerance or resistance • Potential side effects include cytopenia CHRONIC TREATMENT OVER 20 YEARS Hydroxyurea +/ - Phlebotomy Jakafi 3KOHERWRP\

Understanding PV Patient Journey 7 Evaluating the Unmet Need of PV Patients in US 1 Symphony Patient Journey Data Large, representative, and longitudinal source of healthcare claims data that captures over 290MM patients with over 78% of a ll prescription claims and 60% of all medical claims. Medical, hospital, and prescription history is captured across treatment settings and payers with history bac k t o 2003 Treated PV Patients N = 28,306 Representative of treated PV population > 2 HcT Lab Tests N= 4,264 ‡ (YDOXDWLRQRI  39SDWLHQWVWUHDWHGLQ    ‡ +HPDWRFULWOHYHOVODEWHVWVRI  SDWLHQWV Key Findings in three categories Treatment patterns Hematocrit management to NCCN guidelines Thrombotic risks and events Real world PV patient treatment data (2018 - 2019) 1

Real World PV Patient Treatment Data 8 Treatment patterns • Predominant treatment is phlebotomy, regardless of risk • Hydroxyurea is the most commonly used cytoreductive agent • Combination of hydroxyurea and phlebotomy commonly used to control HcT Hematocrit management to NCCN guidelines • Only 22% patients had all HcT tests below 45% • In high - risk patients only 25% patients had all HcT test below 45% • 60% of these high - risk patients initiated treatment on phlebotomy vs 31% on HU and the majority of patients never switched therapies Thrombotic risks and events • For patients with a prior thrombotic event, ~40% had at least another TE while on treatment • For patients without prior thrombosis, ~10% had at least one TE while on treatment Symphony Patient Journey Data, August 2020; ASH Dec 2020

(OHYDWHG +F7  5HVXOWHGLQ*UHDWHU5LVNRI'HDWK 9 Death from CV or Major Thrombotic Events Endpoint 0 6 12 18 24 30 36 42 48 0.85 0.90 0.95 1.00 Months P r o b a b i l i t y o f R e m a i n i n g E v e n t - f r e e Low HCT (<45%) High HCT (45%-50%) Patients with hematocrit between 45 - 50% were ~4 times more likely to die from cardiovascular causes or major thrombotic events • Patients randomized to <45% (Low) or 45 – 50% (High) HcT group • At a median of 31 months, 9.8% of the High HcT group met the primary endpoint vs 2.7% in the Low HcT group Marchioli, R. et al., N Engl J Med. 2013

10 Rusfertide (PTG – 300) Market Opportunity for PV 7KHUHDUHDSSUR[LPDWHO\  SHRSOHLQWKH8QLWHG6WDWHV OLYLQJZLWK39  ‡ a  WUHDWHGSDWLHQWV ‡ *URZLQJPDUNHWZLWKa  QHZSDWLHQWVGLDJQRVHGDQQXDOO\ ‡ 0HGLDQVXUYLYDOLQ39DSSURDFKHVRUFDQH[FHHG  \HDUV 0DMRULW\RIGLDJQRVHGSDWLHQWVDUHWUHDWHG ‡ 39SDWLHQWVRQDYHUDJHVHHWKHLUSK\VLFLDQVL[WLPHVDQQXDOO\ /DUJHSRUWLRQRIWKHWUHDWHGSDWLHQWSRSXODWLRQDSSHDUVWRKDYH VXE  RSWLPDOFRQWURORI+F7 ‡ -DNDILLVWKHRQO\SURGXFWDSSURYHGE\WKH)'$LQ39IRUK\GUR[\XUHD +8 UHVLVWDQWLQWROHUDQWSDWLHQWV ~160K US patient prevalance 1 ~100K Treated patients ~70K HcT>45% 2 Not managed to NCCN guidelines Rusfertide, a natural hormone mimetic, is the only non - cytoreductive agent in clinical development for potential treatment of PV   0HKWDHWDO/HXN/\PSKRPD    %DVHGRQLQWHUQDOPHWULFVDQGWKLUG  SDUW\UHVHDUFK

PART 1 (28 wks) PART 2 (up to 12 wks) PART 3 (52 wks) Dose Finding * Efficacy Evaluation * Blinded Withdrawal Open Label Extension * Phase 2 Trial of Rusfertide in PV Patients 11 GOAL: Maintain Hematocrit <45% ELIGIBILITY REQUIREMENTS: • Phlebotomy dependent PV patients diagnosed as per 2016 WHO criteria • ≥3 phlebotomies in 6 months with or without concurrent cytoreductive therapy • Rusfertide (PTG - 300) doses of 10 - 80 mg administered subcutaneously weekly added to prior standard therapy Dose ± Titration Fixed Active/Placebo Dose (1:1) Dose ± Titration 7LWUDWHHYHU\  ZHHNVWRPDLQWDLQKHPDWRFULW   20 mg 40 mg 80 mg KEY ENDPOINTS: Safety Maintain Hematocrit <45% Reduction in Phlebotomies Symptom Scores: MPN - SAF TSS, PGI - C

Age/Sex Randomization - 20   - 12 - 8 - 4 0 4 8 12  20 24 28 32 36 48 - 24   52 56 60 64 68 72 76  40 44 84 Therapeutic Phlebotomies Prior to and on Rusfertide Weeks Subject  0.2 0.1 0.0 Pre - Dose Post - Dose Average Rate of phlebotomies 3  Screening Part 1 - Dose finding Part 2 - Blinded withdrawal Part 3 - Open label extension Dose decision Phlebotomy Last dose on study  Interim data as of May 11, 2021

Baseline Characteristics Characteristics Age (n=62) Range 27 - 76 years (Mean = 56.3 yrs ) Gender (n=62) Females 17 (27.4%) Males 45 (72.6%) Risk (n=62) Low 30 (48.4%) High 32 (51.6%) [Age based – 37.1%, Thrombotic event – 14.5%] Duration since PV Diagnosis ( n=60) <1 yr 11 (18.3%) 1 - <3 yrs 22 (36.7%) 3 - <5 yrs 9 (15%) ≥5 yrs 18 (30%) Characteristics Concurrent Therapies (n=62) PHL only 29 (46.8%) PHL + HU 18 (29%) PHL + IFN 9 (14.5%) PHL + RUX 3 (4.8%) PHL +Multiple 3 (4.8%) Phlebotomies in prior 6 months (n=62) 3 18 (29%) 4 - 5 29 (46.8%) ≥6 15 (24.2%) Allele Burden (n=47) <60% 18 (68%) ≥60% 29 (32%) 13 Interim data as of May 11, 2021

14 Rusfertide Controlled HCT for 1.5 year while Reducing RBC Count in PV patients 57  45 39 33 N Bas 4 8  16 20 24 28 32 36 40  48 52 56 60 64 68 72  31 27 22 17 17 12 12  7 7 8 5 5 4 3  40 62 HCT (%) Weeks Bas 4 8  16 20 24 28 32 36 40  48 52 56 60 64 68 72  31 25 22 17 16 12 12  7 7 8 5 5 4 3  38 62 8 7 6 4 3 1 5 Weeks RBC (10 6 / uL ) Hematocrit RBC Screening Part 2/3 – Blinded withdrawal/OLE 3DUW  ±  'RVHILQGLQJ Part 3 – Open label extension Interim data as of May 11, 2021

Rusfertide Normalized Iron Stores Screening Part 2/3 – Blinded withdrawal/OLE Part 1 – Dose finding Part 3 – Open label extension  Normalization observed in Ferritin levels Interim data as of May 11, 2021

2.3 1.8 0 0.5 1 1.5 2 2.5 Baseline Week 28 N=55 N=14 2.2 0.7 0 0.5 1 1.5 2 2.5 Baseline Week 28 N=55 1  3.3 2.4 0 1 2 3 4 Baseline Week 28 N=55 N=14 Improvement in MPN - TSS 1 Scores Observed Following Rusfertide Fatigue 3UREOHPVZLWK&RQFHQWUDWLRQ Itching Pruritis 16.9 16 12.8 10.8 0 5 10 15 20 Baseline Week 8 Week 16 Week 28 N=55 N=29 1  N=14 Total symptom score 16 1 Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (10 parameters) Interim data as of May 11, 2021

Grade 3 : Not related – Vomiting: 1; continuing drug – Intramural thrombus - lower left buttock 1; continuing drug • No Grade 4 Events • Injection site reaction (ISRs) were most common and associated with 28.1% of injections. All ISRs were transient, and no patient discontinued due to ISR • No drug related SAEs • One subject stopped treatment due to AE (Thrombocytosis) • No anti - drug antibody (ADA) response was noted in any patient System Organ Class Preferred term All AEs n (%) Total number of Subjects 62 No. of subjects with AE 31 (50) No. of subjects with treatment - related AE 30 (48.4) Gastrointestinal disorders 11 (17.7) Nausea 5 (8.1) Infections and infestations 7 (11.3) Metabolism and nutrition disorders 6 (9.7) Musculoskeletal and connective tissue disorders 13 (21.0) Nervous system disorders 11 (17.7) Psychiatric disorders 4 (6.5) Insomnia 2 (3.2) Renal and urinary disorders 2 (3.2) Respiratory 11 (17.7) Skin and subcutaneous tissue disorders 11 (17.7) Adverse Events in Ongoing Rusfertide Study (PTG - 300 - 04)  Interim data as of May 11, 2021

Rusfertide (PTG - 300) Phase 3 Study Design in PV 18 Based on End - of - Phase - 2 Meeting with FDA and Written Communication with EMA rusfertide Adult Patients with PV* N≈250 Enrollment Criteria: • High risk and low risk patients • Patients requiring frequent phlebotomy • With or without cytoreductive therapy 2EMHFWLYHV Primary endpoint: • Absence of phlebotomy eligibility based on HcT control between weeks 20 through 32 Key secondary endpoints: • Frequency of phlebotomies • Symptom improvement as measured by MPN - TSS criteria • Safety *Per 2016 WHO criteria Randomized [1:1] Placebo Expected to commence in early 2022 Additional assessments: • Durability of response weeks 32 - 52 • Open - label treatment to evaluate long - term effects and safety

5XVIHUWLGH0DUNHW3UHSDUDWLRQ Intend to Demonstrate Clinical & Economic Value Before Approval Confidential – Managed Markets Working Group Meeting 19 Value Proposition Market Access HEOR Competitive Landscape 3RVLWLRQLQJ 6WUDWHJ\ Prescriber Education Distribution Channels • Patients • Prescribers • Payers • Patient access • Pricing & Reimbursement Strategy • Demonstrating the economic burden and cost benefit of treatment • Raise awareness of PV, unmet need and NCCN Guidelines ‡ /HDGHUVLQ WUHDWPHQWRI 39 • Existing and future treatments

Hereditary Hemochromatosis (HH) 20 Disease Prevalence and Treatment If untreated, iron overload can cause hepatomegaly, diabetes mellitus, skin hyperpigmentation, cardiomyopathy, diastolic dysfunction, heart failure, cirrhosis, etc . Iron overload disease Excessive iron accumulation in heart, liver, pancreas, skin, joint tissues 3UHYDOHQFHRI a  PLOOLRQLQ WKH86DORQH Phlebotomy is the only therapeutic option; no approved drugs Source: Porter JL, Rawla P. Hemochromatosis. (Updated 2020 Jun 18], https:// www.ncbi.nlm.nih.gov /books/NBK430862 /

Hereditary Hemochromatosis (HH) 21 Rusfertide (PTG - 300) Rationale and Phase 2 Clinical PoC Study Design • 16 patient open - label study • Efficacy measures » Reduction in serum Iron, TSAT, ferritin » Phlebotomy reduction » Liver iron content (LIC) by MRI » Quality of Life (QOL) effects: SF - 36, PGI - C Clinical ‘Proof of Concept’ Study Design 3K  &OLQLFDO 3R&  6WXG\ Rusfertide (PTG - 300) rationale • HH is predominately due to a mutations leading to a deficiency of hepcidin in the body • Rusfertide, if approved, could serve as a hormone replacement therapy N=16 10 mg 20 mg 40 mg phlebotomy Adjust dose to maintain TSAT <40% Wk 0 Wk 24 Scrn - 1

IBD: Paradigm Shift Toward Targeted Oral and Combination Therapy 22 $*URZLQJ0XOWL  %LOOLRQ'ROODU0DUNHW • Injectable TNF mAbs – Blockbusters – Humira ® & Remicade ® • Significant room for improvement – Low response rates / loss of response – Safety concerns - black box warnings TNF mAbs dominated IBD Therapy 2019: ~ $14B sales 1 2029: projected ~ $24B sales 1 Historical IBD Treatment Paradigm Emerging IBD Treatment Paradigm • α 4 β 7 integrin: Entyvio ® (~ $4B sales 2020) • IL - 12/IL - 23: Stelara ® 3URWDJRQLVW P$E  9DOLGDWHG3DWKZD\V ‡ 31     Į  ȕ  LQWHJULQ ‡ 37*     ,/   5SDUWQHUHGZLWK-DQVVHQ  • S1P1: ozanimod, etrasimod • JAK*: Xeljanz ® , Rinvoq ® , filgotinib • * black box warnings Potential Future of IBD Oral Combo Therapy 1 GlobalData: Global Drug Forecast and Market Analysis to 2029; 7 Major Markets: US, EU5, JP 2 Investigational product candidate, not approved

Oral, IL - 23 Receptor Specific Peptide Antagonists: PTG - 200, PN - 235, PN - 232 23 Janssen Partnership IL - 23R ,/   5 ȕ  IL - 12R β 2 IL - 12R β 1 Stelara ® : Blocks both IL - 23 & IL - 12 pathways PTG - 200 : Designed to block IL - 23 receptor & IL - 23 pathway p19 antibody : Blocks IL - 23 pathway p40 p40 S  p35 CELL MEMBRANE IL - 23 IL - 12 Objective • Extend the Stelara ® franchise and transition from injectable to oral targeted therapy – Stelara approved for psoriasis, psoriatic arthritis, Crohn’s, UC Terms • May 2017: Partnership initiated; $50M upfront • Additional $30M in development milestones received to date • >$1B deal value, up to double digit royalties, US co - detailing rights Status • Multiple product candidate portfolio: IBD and non - IBD indications – Ph2A Crohn’s study in progress* – Ph1 in progress; completion anticipated in 2H 2021 – Ph1 in progress; completion anticipated in 1H 2022 • 3 rd generation research collaboration ongoing 9V  • ~$7.7B total global sales in 2020 Stelara ® is a key Janssen franchise *Subject to COVID - 19 related delays

Oral, Gut - Restricted, Investigational a 4 b 7 - Integrin Peptide Antagonist: PN - 943 24 Fully Owned Asset and Novel Approach against Validated Target Vs. %ULVNLQ0HWDO $P-3DWKRO      Clinically Validated, IBD Specific Target • T cell homing regulated by α4β7 integrin and MAdCAM - 1 interaction • MAdCAM - 1 expressed only in GI vasculature • Entyvio (Vedolizumab) approved for Crohn’s & UC – ~$4B fiscal 2020 sales • Superior efficacy for Entyvio vs. Humira in 52 wk Ph3B VARSITY study PN - 943: Gut - restricted Approach against Validated Target • First - in - class potential as an oral, GI - restricted α4β7 - specific antagonist • PN - 943 was ~3x more potent in numerous pre - clinical studies & Ph1 NHV study vs 1 st generation candidate PTG - 100 (DDW, 2019) 1 – PTG - 100 showed signals of potential activity in Ph2a UC trial ( UEGW, 2018 ) 2 • PN - 943 global Ph2 150 patient study in UC patients in progress • Study completion anticipated in 2Q 2022* *Subject to COVID - 19 related delays 1 Clinical Pharmacology in Drug Development, In Press 2 Manuscript submitted

PN - 943 vs. PTG - 100: Blood %RO based Clinical Proof - of - Concept* Ph1 NHV Single Ascending Dose Study Ph2A Study UC PTG - 100 900 mg Histologic Remission 44% (7/16) Clinical Remission* 16% (3/19) EDVHGRQEOLQGHGHQGRVFRSLFUH  UHDGV Ph1 SAD 100 mg 300 mg 1000 mg 0 20 40 60 80 100 M a x i m u m % R O 83% 74% 94% 74% Ph1 MAD, Day 14 PN - 943 vs. PTG - 100 Ph1 NHV study • Higher %RO suggests ~3x superiority of PN - 943 vs. PTG - 100 – PN - 943 300mg blood %RO > PTG - 100 1000 mg blood %RO activity • Saturable target engagement observed at 1000 mg QD dose Ph 1 Study NHVs PTG - 100 1000 mg % Blood RO 74% PTG - 100 Ph2 UC PoC PTG - 100 PN - 943 31   YV37*   3K  'DWD 25 Modi, N. B., Cheng, X., Mattheakis, L., Hwang, C. C., Nawabi , R., Liu, D., & Gupta, S. (2021). Single - and Multiple - Dose Pharmacokinetics and Pharmacodynamics of PN - 943, a Gastrointestinal - Restricted Oral Peptide Antagonist of α4β7, in Healthy Volunteers. Clinical pharmacology in drug development . * NOTE: For ILLUSTRATIVE PURPOSES ONLY – differences exist between study populations and trial designs and caution should be ex ercised when comparing data between unrelated studies.

PN - 943 26 Ph2 IDEAL Study in UC Study Patients • Global enrollment at multiple sites • Subject to COVID - related delays 5 weeks 12 weeks 40 Weeks Week 52 Randomize (n=150) Placebo BID (n=50) Active Drug 450 mg BID (n=50) $FWLYH'UXJ  PJ%,' Q  PN - 943 Eligibility: Moderate – Severe UC; 3 - Component Mayo Score 5 - 9 points Primary endpoint : Clinical Remission at Week 12 Inclusion : bio - naïve and bio - experienced patients Extended drug treatment: active drug for 40 weeks after 12 - week induction phase completion

Dinesh Patel, PhD | President & CEO David Liu, PhD | CSO, Head of Discovery & Pre - Clinical Dev 6DPXHO6DNV0'_ &OLQLFDO'HYHORSPHQW$GYLVRU Suneel Gupta, PhD | Chief Development Officer Donald Kalkofen | Chief Financial Officer Tracy Woody | EVP , Commercial Strategy Matthew Gosling | EVP, General Counsel Ashok Bhandari, PhD | S VP, Discovery Chem & Process Res Larry Mattheakis, PhD | S VP, Discovery Biology & Trans Res Mohammad Masjedizadeh, PhD | E VP, Chief Technical Officer Paula O’Connor, MD | S VP, Clinical Development Abha Bommireddi, MS | SVP, Program Management Carter King | SVP, Business Development Protagonist Team 27 Experience & Expertise in Drug Discovery, Clinical Development, and Commercialization

Financials 28 Cash and securities as of March 31, 2021 $279.7M $255M of capital raised during 2020 $20M available on debt facility; zero debt outstanding 43.9M shares of common stock outstanding

29 Anticipated Timeline Anticipated Key Event June 2021 • Updated data from rusfertide Ph2 PV trial 2021 • Rusfertide Ph2 PV trial update at medical conference • Preliminary rusfertide Ph2 result in HH • Third development program for rusfertide • Complete Ph1 trial of PN - 235 2022 • Initiate rusfertide Ph3 trial in PV • Complete Ph1 trial of PN - 232 • Ph2 completion and result for PN - 943 • New discovery targets & development candidates 2023 • Ph3 initiation in PN - 943 2024 • Rusfertide Ph3 result in PV Upcoming Catalysts Rusfertide and PN - 943 Two fully owned product candidates in Phase 2 $1B+ Janssen Collaboration Three Investigational oral IL - 23R Antagonists PTG - 200 PN - 232 PN - 235 Innovative Technology Platform New discovery programs with potential to generate new assets Growth Advantages: Three Major Pillars

PN - 943 PTG - 200 PN - 232 PN - 235 rusfertide (PTG - 300) PTG - 100 THANK YOU 30