Bridge Biotherapeutics Releases Updated Preclinical Data for BBT-207 at the AACR Annual Meeting

New preclinical data validate anti-tumor efficacy and intracranial activity of the drug candidate

Bridge submitted an IND application to the U.S. Food and Drug Administration in March,and expects to initiate the first-in-human study of BBT-207 this year

SEONGNAM,South Korea and CAMBRIDGE,Mass.,April 19,2023 --Bridge Biotherapeutics (KQ288330),a clinical-stage biotech company based in South Korea and Cambridge that is advancing novel drugs for cancer,fibrosis,and inflammation,presented a poster with preclinical data updates of its drug candidate BBT-207 at the American Association for Cancer Research (AACR) 2023 annual meeting,being held from April 14 to 19 in Orlando,Florida.

BBT-207,which has the potential to be a mutant selective and broad-spectrum fourth-generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR TKI),is the company's first internally discovered drug candidate with potent activity and efficacy against a broad range of EGFR mutations in non-small cell lung cancer (NSCLC),including C797S double mutations which arise after third-generation EGFR TKI treatment.

At last year's AACR annual meeting,the company disclosed initial preclinical data for BBT-207 and discussed the potency of the drug candidate against EGFR C797S double mutations inclusive of Del19/C797S (DC) and L858R/C797S (LC) as well as driver mutations including Del19 and L858R. In this year's poster presentation,the company highlighted BBT-207's intracranial anti-tumor activity,as well as additional data showing the experimental drug's anti-tumor efficacy.

In an in vivo study with an intracranial implantation model of luciferase-labeled PC-9 cells harboring EGFR Del19/T790M/C797S (DTC) mutations,BBT-207 exhibited significantly increased mouse survival rate compared to a control group. In three weeks from the baseline,both of groups treated with low-dose and high-dose of BBT-207 exhibited increased survival rate compared to the control group treated with Osimertinib. On Day 21 of the trial,the BBT-207 low-dose group,the high-dose group,and the control group exhibited 75%,100% and 25% of the survival rate each. Also,the bioluminescence imaging data collected from the same in vivo study demonstrated that the subjects with comparative treatment showed systemic metastases including brain metastases from Week 2,whereas BBT-207 treatment groups exhibited relatively lower level of metastases.

Following last year's data disclosure,both in vitro and in vivo efficacy data included in this year's poster have shown that BBT-207 boasts robust anti-tumor efficacy. BBT-207 demonstrated dose-dependent tumor regression efficacy against C797S double mutations from in vivo study with Osimertinib-resistant Ba/F3 CDX mouse models. The administration of 40mg/kg for 21 days resulted in significantly regressed tumor growth,with a tumor growth inhibition (TGI) rate of 107% in Del19/C797S (DC) model and 102% in L858R/C797S (LC) model. In DC model,tumor regression (TR) relative to the pre-treatment was observed in 8 out of 8 mice.

Jimmy Jin,M.D.,Ph.D.,Bridge's vice president and head of discovery biology,said,"We are pleased to present BBT-207's anti-tumor efficacy results and extended survival rates in intracranial disease models. Based on our extensive experience in drug development for lung cancer,we hope that we will soon initiate the first-in-human study for BBT-207 to treat patients with metastatic non-small cell lung cancer."

In March 2023,the company submitted an Investigational New Drug Application (IND) to the U.S. Food and Drug Administration (FDA) to enter a Phase 1/2 clinical trial of BBT-207.

The AACR Annual Meeting,one of the world's largest academic events in oncology,is held every April for cancer researchers,scientists,and biopharma companies to share the latest cancer-related basic and clinical research. Bridge Biotherapeutics first released preclinical research data on BBT-207 at AACR last year.

A copy of the poster presented at the AACR 2023 annual meeting is available at: http://bit.ly/3nVWprs

The details of the presentation are as follows:

Presentation Title: BBT-207,a Novel,C797X-active,4th Generation,Epidermal GrowthFactor Receptor (EGFR) Tyrosine Kinase Inhibitor (TKI) With Broad-Spectrum Activity against Treatment-Emergent as well as Drug-Naïve Mutants for the Treatment of NSCLC patients

Session Category: Experimental and Molecular Therapeutics

Session Title: Tyrosine Kinase and Phosphatase Inhibitors 1

Session Date & Time:Tuesday,April 18,2023,9:00 a.m. -- 12:30 p.m.

Abstract Number: 4018

About Bridge Biotherapeutics,Inc.

Bridge Biotherapeutics Inc.,based in the Republic of Korea,the U.S.,and China,is a publicly-traded,clinical-stage biotech company founded in 2015. Bridge Biotherapeutics is engaged in the discovery and development of novel therapeutics,focusing on therapeutic areas with high unmet needs including ulcerative colitis,fibrotic diseases,and cancers. The company is developing BBT-401,a first-in-class Pellino-1 inhibitor for the treatment of ulcerative colitis,BBT-877,a novel autotaxin inhibitor for the treatment of fibrotic diseases including idiopathic pulmonary fibrosis (IPF),and BBT-176,a potent targeted cancer therapy for non-small cell lung cancer (NSCLC) with C797S triple EGFR mutations. Learn more at https://www.bridgebiorx.com/en/.

About BBT-207

BBT-207,a novel fourth-generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor (EGFR TKI) currently under IND-enabling preclinical development,including C797S mutations which arise after third-generation EGFR TKI treatment. An investigational new drug application for the first-in-human study in patients with advanced NSCLC harboring EGFR mutation after treatment with EGFR TKI,was submitted in March,2023.