Cautionary Note Regarding Forward-Looking Statements This presentation contains "forward-looking statements" within the meaning of the federal securities laws, which statements are subject to substantial risks and uncert

Nasdaq: ETNB Powerful Science

Meaningful Medicines Changing Lives February 2023 Exhibit 99.1

Cautionary Note Regarding

Forward-Looking Statements This presentation contains "forward-looking statements" within the meaning of the federal securities laws, which statements are subject to substantial risks and uncertainties and are based on estimates and

assumptions. Other than statements of historical facts, all statements included in this presentation are forward-looking statements, including statements concerning our plans, objectives, goals, strategies, future events, plans or intentions

relating to product candidates, potential market opportunities, estimates of market size, estimates of market growth, the potential clinical benefit, effect on histology and safety and tolerability profile of pegozafermin (formerly BIO89-100), the

clinical potential of pegozafermin, potential indications for pegozafermin, the association of clinical data with potential clinical benefit in other indications, the anticipated timing, design, endpoints, and conduct of our ongoing clinical trials

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Highly competitive profile with Phase 2

results demonstrating robust efficacy across multiple histological and metabolic endpoints with favorable tolerability profile Well-powered study with three-panel consensus biopsy reading method to minimize variability Nonalcoholic Steatohepatitis

(NASH) - Phase 2b topline data expected 1Q23 ~$191.3 million pro forma1 cash as of Dec. 31, 2022 and up to $100 million credit facility with K2 HeathVentures2 Track record of developing and commercializing successful drugs Strong cash position

with experienced team Corporate Highlights Validated broad mechanism of action (FGF21) with potential differentiation on efficacy, tolerability and dosing Diversification across two large market opportunities with substantial development and

commercial synergies Pegozafermin - potential best-in-class cardio-metabolic drug in multiple indications Severe Hypertriglyceridemia (SHTG) - Phase 3 initiation planned in 1H23 De-risked program given positive Phase 2 data and defined

path to approval based on FDA feedback Large market opportunity with limited competition in the refractory population 1 Pro forma cash includes $25 million drawn under the K2 HealthVentures credit facility net of $20 million repaid under the SVB

term loan facility 2 $25 million of credit facility drawn at closing; remainder subject to achievement of milestones and/or lender approval

Pegozafermin is an FGF21 Analog

Optimally Engineered to Balance Efficacy and Long Dosing Interval glycoPEG(20kD) C-terminus X Strong and flexible linker (glycoPEGylation technology) Mutations in positions 173 and 176 (glycoPEG attached at position 173) X N-terminus Position 182

FGF21 Proprietary glycoPEGylation technology commercially validated with approved products Increases half-life of native FGF21 (<2 hours) to 55-100 hours based on single ascending dose study Low nanomolar potency against FGF receptors 1c, 2c, 3c,

similar to native FGF21 Composition of Matter patent expiring in 2038 C-terminus N-terminus FGFR FGFR C-terminus -Klotho -Klotho Signal transduction Functional response

Stojsavljevic-Shapeski S et al J Clin

Transl Hepatol 2021;9(1):51-59 Proposed Mechanisms of Action of Pegozafermin Adipose tissue Decrease lipogenesis and release of FFA Improve insulin resistance Increase TG uptake Increase adiponectin Liver Increase -oxidation Decrease de novo

lipogenesis Decrease FFA / TG Muscle Increase FFA oxidation Muscle Adipocytes Glucose FFA oxidation INSULIN RESISTANCE Adiponectin Leptin Lipolysis TG FFA Inflammation Apoptosis Fibrosis Mitochondrial

dysfunction ER stress FFA TG Steatosis -oxidation Lipogenesis Liver

NASH is a Serious Liver Condition With

Significant Co-Morbidities No treatments currently available U.S. Prevalence of ~17.5 million patients in 2022 Fastest growing reason for a liver transplant in the United States Co-morbidity Prevalence in NASH population Hypertriglyceridemia 83%

Obesity 82% Hyperlipidemia / Dyslipidemia 72% Metabolic syndrome 71% Type 2 diabetes 44% Metabolic Dysregulation Excess Liver Fat Accumulation Progressive Disease

Phase 1b/2a NASH Trial Design 7 weeks

SCREENING COHORT 1 COHORT 2 COHORT 3 COHORT 4 COHORT 5 COHORT 6 COHORT 7 SAFETY FOLLOW-UP Placebo (n=2) Placebo (n=3) Placebo (n=4) Placebo (n=3) Placebo (n=4) Placebo (n=3) 27mg QW (n=20) 3mg QW (n=6) 9mg QW (n=12) 18mg QW (n=11) 27mg QW (n10) 18mg

Q2W (n=14) 36mg Q2W (n=9) 27mg QW pegozafermin 12 weeks 20 weeks Cohorts 1-6 Cohort 7 B B KEY INCLUSION CRITERIA NASH* or phenotypic NASH (PNASH)# MRI-PDFF 10% KEY INCLUSION CRITERIA F2-F3 NASH; NAS 4 MRI-PDFF 8% *Patients with

biopsy-proven F1-3; #Central obesity plus T2DM or evidence of liver injury; Placebo (n=19) combined across cohorts for analysis ; Randomized, pharmacodynamic (PD) and safety analysis set n=81; Study completers n=71; MRI analysis set n=75 (patients

with post-baseline MRI) 19/20 (95%) patients completed treatment and had end-of-treatment biopsies; 1 patient discontinued treatment due to withdrawal of consent The three-reader pathologist panel scored 6/19 patients as having F4 fibrosis at

baseline (putative F4) COHORTS 1-6 COHORT 7 MRI-PDFF Liver Biopsy B **PGZ was delivered subcutaneously

Mean Relative Reduction in Liver Fat vs

Baseline Cohort 7 27mg QW Cohort 4 27mg QW Cohort 6 36mg Q2W Pegozafermin Demonstrated Robust Liver Fat Reduction With High Responder Rates 30% Relative Reduction in Liver Fat 50% Relative Reduction in Liver Fat Cohort 4 (27mg QW) 86%

71% Cohort 6 (36mg QW) 88% 50% Cohort 7 (27mg QW) 100% 78% *** Cohort 4 and Cohort 6: MRI Analysis Set; MMRM LS Mean; p value vs placebo; Data from week 13 Cohort 7: MRI Analysis Set; p value for change from baseline based on MMRM analysis; Data

from week 20 *** *** Placebo ***p <0.001

Pegozafermin Significantly Reduced ALT

With Greater Reduction Observed in Patients With Elevated Baseline ALT * * Cohort 4 and 6: Pre-planned sensitivity analysis; MMRM LS Mean at week 13; *** p<0.001 versus placebo Cohort 7: p value for change from baseline based on MMRM analysis;

Data from week 20; ***p<0.001 Absolute Change vs Baseline (U/L) Patients with elevated ALT at baseline 71% of pts on pegozafermin had 17 U/L reduction Mean Percent Change vs Baseline Cohort 7 27mg QW Cohort 4 27mg QW Cohort 6 36mg Q2W ***

*** *** Placebo Cohorts 1-6: PD Analysis Set in baseline ALT > 45 U/L; Pre planned sensitivity analysis; MMRM LS Mean at Week 13 Cohort 7: elevated ALT 30 U/L for women and 40 U/L for men; Week 20 Comparable changes were observed

Pegozafermin Demonstrated Clinically

Meaningful Improvements in Lipids *p<0.05 ***p<0.001 *** *** *** * p value for change from baseline based on MMRM analysis

Pegozafermin Demonstrated Clinically

Meaningful Improvement on HbA1c and Adiponectin With Notable Body Weight Reduction (Cohort 7) p value for change from baseline based on MMRM analysis; all data are from cohort 7 Patients with baseline HbA1c 6.5% were on an average of 2

anti-diabetic medications (40% were on a GLP-1) Absolute Change in HbA1c **p<0.01 HbA1c: Baseline: 7.3%; Week 20: 6.4% Mean absolute change Patients with baseline HbA1c 6.5% (n=10) Percent change Weight Change ***p<0.001 Total patient

population (n=19) Percent change Adiponectin Change ***p<0.001 Total patient population (n=18)

Proportion of patients 2pt

Improvement in NAS* Proportion of patients Pegozafermin Robustly Improved NAFLD Activity Score (NAS) and All Components of NAS (Cohort 7) 63% of patients had 2point improvement in NAS and no worsening of fibrosis* (primary endpoint) 100% of

patients had improvement or no change in ballooning and inflammation (15/19) (9/19) (14/19) (14/19) (95% CI: 49%-91%) Responder^ Rates by NAS Component -2.4 mean absolute change ^ 1 point change * with 1 point improvement in ballooning

Proportion of patients NASH

Resolution* 1 Stage Improvement in Fibrosis** (95% CI: 13%-57%) (95% CI: 9%-51%) Pegozafermin Demonstrated Clinically Meaningful Changes on Key Histological Efficacy Endpoints (Cohort 7) *and no worsening of fibrosis **and no worsening of

NASH *** In the post-hoc exploratory analyses, a panel of three additional expert NASH pathologists assessed the same baseline (BL) and end of treatment (EOT) slides that had been evaluated by the central pathologist. Slides from BL and EOT were

mixed and the three-reader pathologist panel were blinded to the timepoint; they scored 6/19 patients as having F4 fibrosis at baseline (putative F4) Single Central Reader NASH resolution: up to 47% (range: 26-47%) Fibrosis improvement: up to 42%

(range: 12-42%) 2-point NAS improvement: up to 79% (range: 68-79%) Three-PANEL READ All patients (n=19) Excluding putative F4 patients (n=13)*** Loomba et al AASLD 2022

Pegozafermin Showed Beneficial

Effects in Subset of Patients with F4 Stage Fibrosis *Patients assessed with F4 fibrosis by 2+ panel pathologists **N=5; one outlier with poor quality measurement was excluded. ***VCTE >20% reduction; FAST score 0.35. Loomba et al AASLD

2022 Fibrosis improvement 1 stage without worsening of NASH: 17-57% NASH resolution without worsening of fibrosis: 20-50% Parameter (Mean or %) Putative F4 fibrosis (n=6)* Liver Steatosis Relative liver fat reduction by MRI-PDFF (%) - 71%

MRI-PDFF 30%/50% responders 100%/100% Liver transaminases Percent change in ALT - 51% Percent change in AST - 49% Insulin sensitivity Percent change in adiponectin 99% Non-invasive markers of fibrosis Change in VCTE score (kPa)/VCTE responders***

-3.8** / 60%** Change in FAST score/ FAST responders*** -0.5** / 100%**

Pegozafermin Substantially Improved

Scores Across Non-Invasive Tests (NITs) Correlated with Advanced Fibrosis Mean Relative Change From Baseline -4.2 kPa -0.47 -0.29 -28%*** -76%*** -19%** -20%*** VCTE: Liver stiffness measure using FibroScan ; FAST score: Liver stiffness (VCTE)

and steatosis (CAP) using FibroScan plus AST; 0-1 scale; FIB-4 score: Composite serum marker/age measure; Pro-C3: Collagen deposition serum biomarker VCTE and FAST exclude one outlier with poor quality measurement p value for change from

baseline based on MMRM analysis Values in bars are absolute change versus baseline **p<0.01 ***p <0.001 -4.3 ng/ml VCTE FAST FIB-4 Pro-C3 VCTE >20% reduction; FAST 0.35; FIB-4 1.3; Pro-C3 15% reduction Responder

Rate by Clinically Relevant Threshold Cohorts 1-6 (n=81) VCTE 72% FAST 88% FIB-4 58% Pro-C3 63%

No treatment-related serious adverse

events; only 1 treatment-related discontinuation Pooled pegozafermin treatment related AEs observed in 10% of patients were: Increased appetite (13%) vs placebo (0%) Diarrhea (13%) vs placebo (11%) Nausea (12%) vs placebo (11%) Most GI AEs

were mild and of short duration Few mild injection site reactions No tremor or hypersensitivity AEs reported No adverse effects on blood pressure or heart rate Pegozafermin - Favorable Safety and Tolerability in NASH Study

Comparative Profile of FGF21 Analogs

in NASH Note: All data regarding third-party molecules on this slide are based on third-party studies and not our own. Conclusions on this slide are not based on head-to-head results * based on range including histology assessment from 3-panel read

and post-hoc exploratory analyses ** not based on head-to-head comparison; calculation based on assumptions derived from molecular weights and PK properties *** Akero Therapeutics AASLD 2022 poster, Tillman et al - Efruxifermin, a bivalent Fc-FGF21

analog, demonstrates improved biophysical and pharmacological engagement with live cells compared to monovalent FGF21 analogs Pegozafermin (PGZ) Efruxifermin (EFX) Structure (molecular weight) GlycoPEGylated FGF21 (40 kDa) Structurally different

from other monovalent analogs Fc-fusion FGF21 (92 kDa) Potency against FGF receptors 1c, 2c, 3c Low nanomolar potency Similar moles of FGF21 delivered with PGZ 30mg and EFX 50mg** Low nanomolar potency (equivalent to monovalent FGF21 without Fc

fusion)*** Efficacy* Similar effects on NAS>2, non-invasive liver markers, metabolic and lipid changes 1-point fibrosis improvement in F2/F3 population was similar Tolerability Lower incidence of GI events No tremors Higher frequency of GI events

Tremors observed in multiple studies Dosing frequency Weekly and Every Two-Weeks Weekly Phase 2b drug product Liquid Frozen

Pegozafermin Shows Similar/Superior

Effects On Non-Invasive Markers To Other NASH Drugs in Development * EFX data are reported from the 16-week phase 2a BALANCED trial Note: All data regarding third-party molecules on this slide are based on third-party studies and not our own.

Conclusions on this slide are not based on head-to-head results Parameter PGZ (Week 20) EFX (Week 24) Resmetirom (Week 36) 27mg QW 28mg QW 50mg QW 60 - 100mg QD LIVER MRI-PDFF (% change) -64% -52% -64% -40% MRI-PDFF (50% responder) 78% 63% 77% N/A

ALT (%) -46% -38% -47% -31% Liver stiffness by VCTE - (kPa) -4.2 -2.6 -4.3 N/A Pro-C3 ( g/L) -4.3 -5.1 -5.2 -2.2 Adiponectin (%) 88% 69%* 88%* 28% METABOLIC Weight (kg) -3.7 -0.2 -2.6 -0.6 HbA1c 6.5% or T2DM (%) -0.9% -0.5% -0.5% 0.0%

LIPIDS Triglycerides (%) -26% -25% -29% -15.4% LDL-C (%) -13% -8% -8% -11.2% Non-HDL-C (%) -18% -13% -13% N/A

Phase 2b (ENLIVEN) NASH Trial Design

F2-F3 NASH; NAS 4 KEY INCLUSION CRITERIA MRI-PDFF Liver Biopsy B SCREENING RANDOMIZATION B B PLACEBO (QW or Q2W) Pegozafermin 30mg QW Pegozafermin 44mg Q2W Pegozafermin 15mg QW PLACEBO Q2W Pegozafermin 30mg QW Pegozafermin 44mg Q2W

Pegozafermin 15mg QW MAIN STUDY (24 weeks) EXTENSION PHASE (24 weeks) PLACEBO* (QW or Q2W) Wk 24 Wk 48 Wk 12 Primary endpoint - Regulatory meeting * Some placebo patients will be re-randomized in the extension phase to receive pegozafermin

BIOPSY READING Three-panel consensus read for baseline and end of treatment biopsies SELECTED KEY ENDPOINTS Fibrosis Improvement NASH Resolution Key metabolic endpoints 4 4 2.5 1 The primary analysis will include patients who met histologic entry

criteria [F2/F3 patients and NAS 4] based on the three-panel consensus read of biopsies at baseline. This three-panel consensus read was instituted after receipt of cohort 7 data prior to which biopsy entry criteria was based on a single

Trial design helps reduce/minimize

variability Large sample size provides robust powering on key dosing arms Three-panel consensus reading methodology for baseline and end of treatment biopsies to minimize reader variability Positive histology results from competitive trials de-risk

ENLIVEN study Similar geography (N. America), biopsy timepoint and expected patient population to FGF21 HARMONY trial Comparable or superior non-invasive data relative to the resmetirom phase 2 trial that translated into positive results in the

MAESTRO NASH phase 3 trial Dose selection optimizes probability of success Doses selected based on concentration response analyses High dose PGZ (27mg QW) performed similar to high dose EFX (50mg QW) on all key non-invasive markers Key Readthroughs