Gossamer Bio, Inc. · NASDAQ:GOSS
Gossamer Bio — Corporate Update (July 2023)
33 slides from Gossamer Bio's corporate update, Jul 20, 2023
Slide 1: Interim TORREY OLE Update and PROSERA Phase 3 Design
Interim TORREY OLE Update and PROSERA Phase 3 Design July 2023
Slide 2: Forward Looking Statements
Forward Looking Statements This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products,
Slide 3: I. TORREY 24 Week Data
I. TORREY 24 Week Data 3
Slide 4: Selected Baseline Disease Characteristics (ITT Population)
Selected Baseline Disease Characteristics (ITT Population) 4 Characteristic Placebo (N=42) Seralutinib (N=44) Total (N=86) Number of PAH background therapies – n (%) 1 2 (4.8) 1 (2.3) 3 (3.5) 2 16 (38.1) 18 (40.9) 34 (39.5) 3 24 (57.1) 25 (56.8) 49 (57.0) WHO FC – n (%) Class II 20 (47.6) 30 (68.2)
Slide 5: TORREY Study Phase 2 Topline Results
• Met Primary Endpoint: Statistically significant reduction in PVR in heavily-treated study population • Consistent, favorable PVR benefit seen in all pre-specified sub-groups in favor of seralutinib with enhanced effects in patients with more severe disease at baseline§ • Consistently favorable res
Slide 6: II. New Developments
II. New Developments 6
Slide 7: New Developments in the Seralutinib Program
New Developments in the Seralutinib Program • Summary of OLE findings to date: Differentiated efficacy and safety profile emerging • Continued improvement in reduction of PVR • 30 patients with Week 72 PVR data • Early enrollers; milder disease baseline than overall population • Continual improvemen
Slide 8: III. Interim TORREY OLE Extension Results
III. Interim TORREY OLE Extension Results Data available to date – Subject to change – Study is ongoing Data as of June 23, 2023. 8
Slide 9: TORREY Open-Label Extension Interim Update
TORREY Open-Label Extension Interim Update • Of 80 TORREY completers (38 seralutinib arm, 42 placebo arm), 73 (91.3%) elected to rollover into the open-label extension • PVR measured via right heart catheterization at Baseline, Week 24, and Week 72 (approximately 1 year into OLE) • As of interim dat
Slide 10: Seralutinib Profile Emerging From OLE
Seralutinib Profile Emerging From OLE ✓Seralutinib treatment leads to hemodynamic improvement in ~60-70% of patients ✓ Almost all patients who have short-term benefit (at 6 months) continue to improve with long-term treatment ✓The continued improvement in PVR, along with the ECHO and FRI data gather
Slide 11: Interim Analysis Shows Deepening PVR Improvement in Continued-Seralutinib Group
Interim Analysis Shows Deepening PVR Improvement in Continued-Seralutinib Group * Interim update for first 16 continued-seralutinib patients to reach Week 72 PVR = pulmonary vascular resistance; WHO = World Health Organization; OLE = open-label extension 11 Baseline Week 24 Week 72 Median Baseline P
Slide 12: Further Improvements Seen in 6MWD and NT-proBNP for Phase 3 Target Population
6MWD N = 32 20 18 12 Baseline (m) 409 389 377 368 Further Improvements Seen in 6MWD and NT-proBNP for Phase 3 Target Population in Continued-Seralutinib Group 12 16 4247 71 0 50 100 Week 24 Week 64 Overall Population Phase 3 Target Patient Population* NT-pro BNP N = 32 13 17 9 Baseline (ng/L) 595 87
Slide 13: Encouraging Early Trends Observed in Placebo-Crossover Group
Encouraging Early Trends Observed in Placebo-Crossover Group 13 • 7 / 14 patients had improvement in PVR after beginning seralutinib treatment in OLE • 11 / 14 patients had improved PVR vs. baseline PVR at Week 72 6MWD N = 40 17 17 7 Baseline (m) 408 415 337 336 0 4 15 25 0 20 40 Week 24 Week 64 Ove
Slide 14: TORREY OLE Safety To Date
14 TORREY OLE Safety To Date • Safety results consistent with controlled period – seralutinib generally well tolerated with no new safety concerns • Results support chronic treatment in PAH patients • Reports of cough diminish as patients get used to DPI • Vast majority of patients have reached and
Slide 15: IV. PROSERA Phase 3 Overview
IV. PROSERA Phase 3 Overview 15
Slide 16: Regulatory Feedback
Regulatory Feedback • FDA & EMA - Alignment on the following key design elements of Phase 3 protocol: • One Dose: Single dose of seralutinib (90 mg BID); 2-arm study, with ~175 patients per arm • Enriched Population: Eligibility criteria for a target PAH population based on prespecified subgroup in
Slide 17: PROSERA Phase 3 Study Design Schema
17 PROSERA Phase 3 Study Design Schema Double Blind Placebo-Controlled Treatment Period (24 weeks) Placebo BID + Background PAH Therapy N = 175 Seralutinib 90mg BID + Background PAH Therapy N = 175 Extended Double Blind Treatment Period (up to an additional 24 weeks)* Primary Endpoint (6MWD) Evaluat
Slide 18: PROSERA Study Overview
PROSERA Study Overview Design • Randomized, double-blind, placebo-controlled, parallel group • Up to 48-week double-blinded treatment period; primary endpoint assessed at Week 24 • Open-label extension option under separate protocol Primary Endpoint • Change in 6MWD at Week 24 from Baseline Key Seco
Slide 19: PROSERA Phase 3 Study Population
PROSERA Phase 3 Study Population Key Inclusion Criteria • Adults ≥ 18 and ≤ 75 years old • WHO Group 1 PAH • WHO Functional Class II or III • PVR ≥ 400 dyne•s/cm5 • Baseline 6MWD 150 - 450m* • Either REVEAL Lite 2 Risk Score ≥ 5 or NT-proBNP ≥ 300 ng/L* • Stable treatment with at least one SOC backg
Slide 20: Broad Global Footprint with Trusted Sites and Clinical Partners
Broad Global Footprint with Trusted Sites and Clinical Partners • Broad global footprint planned: > 160 sites across ~30 countries • Experienced global Gossamer team to support sites, educate, and drive enrollment • Strong CRO partner (PPD) with deep experience in PAH • Enrollment target: 18 months
Slide 21: Further Validation of REVEAL Lite Enrichment for Phase 3
21 Further Validation of REVEAL Lite 2 Enrichment for Phase 3 TORREY Week 24 Δ6MWD with REVEAL Lite 2 Score Incorporated • Right side consists of patients who are • Class II (n=15) • Class III (n=35) • Treatment effect in this population used as a basis for powering phase 3 with a conservative adjus
Slide 22: Appendix I – OLE Safety
Appendix | — OLE Safety gossamerbio
Slide 23: Incidence of TEAEs by preferred term: ≥ 5% in total column
Incidence of TEAEs by preferred term: ≥ 5% in total column (Safety Population) 23 Preferred terma Placebo Switch (N=40) Seralutinib Cont. (N=34*) Total (N=74) Number of subjects with a TEAE 38 ( 95.0) 32 ( 94.1) 70 ( 94.6) Headache 9 ( 22.5) 8 ( 23.5) 17 ( 23.0) Cough 9 ( 22.5) 7 ( 20.6) 16 ( 21.6)
Slide 24: Incidence of TEAEs by preferred term - Continued
Incidence of TEAEs by preferred term: ≥ 5% in total column (Safety Population) - Continued 24 Preferred terma Placebo Switch (N=40) Seralutinib Cont. (N=34*) Total (N=74) Number of subjects with a TEAE 38 ( 95.0) 32 ( 94.1) 70 ( 94.6) Pneumonia 3 ( 7.5) 2 ( 5.9) 5 ( 6.8) Pulmonary arterial hypertens
Slide 25: Incidence of Related TEAEs in 2 or More Patients
Incidence of Related TEAEs in 2 or More Patients (Safety Population) 25 Preferred terma Placebo Switch (N=40) Seralutinib Cont. (N=34*) Total (N=74) Number of subjects with a related adverse event 16 ( 40.0) 11 ( 32.4) 27 ( 36.5) Cough 7 ( 17.5) 3 ( 8.8) 10 ( 13.5) Headache 2 ( 5.0) 3 ( 8.8) 5 ( 6.8
Slide 26: Incidence of TEAEs Leading to Study Drug Discontinuation
Incidence of TEAEs Leading to Study Drug Discontinuation (Safety Population) 26 *One patient from the Phase 1b clinical trial, who remains on drug, is included in this group. Abbreviations: d/c, discontinuation; MedDRA, Medical Dictionary for Regulatory Activities; TEAE, treatment-emergent adverse e
Slide 27: Appendix II – FLUIDDA CT Sub-Study
Appendix II – FLUIDDA CT Sub-Study 27
Slide 28: FLUIDDA CT Sub-Study: Assessing Pulmonary Vascular Remodeling
FLUIDDA CT Sub-Study: Assessing Pulmonary Vascular Remodeling in Patients Treated on Seralutinib • Purpose: Provide evidence consistent with a reverse remodeling effect of seralutinib • Hypothesis: volume of distal pulmonary arteries relative to volume of proximal pulmonary arteries will be increase
Slide 29: Pulmonary Vascular Volume of Small Distal Arterial Vessels is Decreased in PAH
29 Pulmonary Vascular Volume of Small Distal Arterial Vessels is Decreased in PAH, Leading to Dilation of Larger Proximal Vessels BV5A= blood vessel volume of pulmonary arteries with a Cross-sectional area (CSA)<5mm2 BV5-10A= blood vessel volume of pulmonary arteries with a CSA Between 5-10 mm2 BV10
Slide 30: Seralutinib Treatment Increases BV510ARatio, Supporting Reverse Remodeling
30 Seralutinib Treatment Increases BV510ARatio, Supporting Reverse Remodeling Hypothesis Parameter LSMD Estimate (95% CI) P-value BV510ARATIO 0.845 (0.105,1.585) 0.028 PAC=pulmonary artery compliance SV=stroke volume Linear regression models adjusted for baseline values and treatment arm; Abbreviati
Slide 31: FRI Imaging Case Study (Placebo Patient)
FRI Imaging Case Study (Placebo Patient) WHO FC2 IPAH Patient on PDE/PRA, treated with Placebo • 6% Decrease in BV5APRA (red areas) • 5% Increase in BV10APRA (blue areas) • Decrease in BV5A/BV10A ratio • 283 dyne•s/cm5 increase in PVR coincident with arterial volume shifts BVA5PRA = Proportion of pu
Slide 32: FRI Imaging Case Study (Seralutinib Patient)
32 FRI Imaging Case Study (Seralutinib Patient) WHO FC2 IPAH and Severe RA Patient on Triple Therapy, treated with Seralutinib • 6% Increase in BV5APRA (red areas) • 8% Decrease in BV10APRA (blue areas) • Increase in BV5A/BV10A ratio • 159 dyne•s/cm5 improvement in PVR coincident with arterial volum
Slide 33: Summary of FRI Sub-study and Plans for Phase 3
33 Summary of FRI Sub-study and Plans for Phase 3 • The BV510ARatio correlates with important measures of RV-PA coupling as measured by pulmonary artery compliance and cardiopulmonary hemodynamics (i.e., Stroke Volume) • There was a significant improvement in the ratio of blood vessel volume in dist