Slide 1: Prula-cel Clinical Data Update
September 28, 2026 Prula-cel Clinical Data Update
Slide 2: Forward-Looking Statements
Forward-Looking Statements This presentation contains “forward-looking statements” of Adicet within the meaning of the Private Securities Litigation Reform Act of 1995 relating to the business and operations of Adicet. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “in
Slide 3: Prula-cel Delivered High Rates of Immunosuppression-Free CRRs and DORIS Remissions
Prula-cel Delivered High Rates of Immunosuppression-Free CRRs and DORIS Remissions in Heavily Pre-Treated LN & SLE Patients 50% 12-Month CRR Rate 54% 12-Month DORIS Rate Favorable Safety Profile Generally well-tolerated — No IEC-HS, No ICANS and No > Grade 2 CRS observed Immunosuppressant-Free All p
Slide 4: Prula-cel Has Established Path to Potential Approval and Large Commercial Opportunity
Potential One-Time, Off-the-Shelf, Outpatient Therapy Aligned with FDA to make prula-cel available for enrollment in outpatient setting Scalable Manufacturing Significant Addressable Market 35,000 organ/life threatening LN1 (US) 35,000 organ/life threatening non-renal SLE2 (US) Strong Enrollment Exe
Slide 5: Anticipated Near-Term Value-Creating Milestones
Anticipated Near-Term Value-Creating Milestones Clinical, regulatory and platform catalysts expected across prula-cel, ADI-212 and in vivo CAR-T programs Prula-cel Autoimmune disease LN / SLE / SSc ADI-212 mCRPC In Vivo CAR-T MM Program In Vivo CAR-T NHL Program In Vivo CAR-T Solid Tumors Program 20
Slide 6: Prula-cel Phase 1 Autoimmune Study Design
Prula-cel Phase 1 Autoimmune Study Design Screening Lymphodepletion Treatment DLT Period (28 days) Follow Up LTFU Study Consent Day -28 Enrollment Single prula-cel Infusion Day 0 Response/Safety Assessments Day 28 Response/Safety Assessments Months 3-6-9-12-18-24 Cyclophosphamide / Fludarabine Lymph
Slide 7: Prula-cel SLE/LN Patient Characteristics
Prula-cel SLE/LN Patient Characteristics 24 Treated lupus patients (16 LN & 8 extra-renal SLE) Enrolled patients 24 safety evaluable patients (16 LN & 8 extra-renal SLE) Safety evaluable 22 efficacy evaluable patients (16 LN & 6 extra-renal SLE) Efficacy evaluable 13 efficacy evaluable with 12-month
Slide 8: High Rates of Both Complete Renal Response & DORIS Remissions Achieved By 12 Months
High Rates of Both Complete Renal Response & DORIS Remissions Achieved By 12 Months Post Treatment With Prula-cel CRR 3 5 6 5 N Subjects 15* 16 16 10 DORIS 2 7 7 7 N Subjects 21* 22 22 13 DORIS Response in LN & SLE Complete Renal Response in LN % of LN patients with CRR % of LN & SLE patients with D
Slide 9: Generally Well-Tolerated Safety Profile
Prulacabtagene leucel (prula-cel) LN/SLE, all dose levels Rapcabtagene autoleucel (rap-cel)1 Zolacabtagene autoleucel (zola-cel)2 Obecabtagene autoleucel (obe-cel)3 No. of Patients (n) 24 21 26 6 CRS (any / Gr 3+) (%) 25% / ─ 57% / -- 77% / 4% 50% / -- ICANS (any Gr) (%) -- 5% 4% -- Infections (any
Slide 10: Prula-cel's Favorable Safety Profile Rooted in Biology of γδ1 T Cells
Prula-cel’s Favorable Safety Profile in Autoimmune Compared to a Autologous ab CAR-T is Rooted in the Biology of γδ1 T Cells γδ1 T cells are defined by a clearly differentiated cytokine profile compared to ab T cells1-4 IEC-HS is primarily related to hyperproliferation of ab CAR-T and associated wit
Slide 11: SLEDAI Decline With Prula-cel In-Line With Autologous CD19 CAR-T Therapies
* Months SLEDAI Decline With Prula-cel In-Line With That Observed With Autologous αβ CD19 CAR-T Therapies Rapid and substantial decline in SLEDAI scores consistent with autologous CAR-T therapies Reductions in SLEDAI stable beyond 12 months SLEDAI-2K over time (mean) Leandro M. et al. EULAR 2026 Sch
Slide 12: 85% of Evaluable Patients with 12-Month Follow-Up Achieved PGA score of <0.5
* Months 85% of Evaluable Patients with 12-Month Follow-Up Achieved PGA score of <0.5 12 / 22 patients achieved PGA<0.5 at month 6 and month 9 11 / 13 patients achieved PGA<0.5 at month 12 Physician Global Assessment over time (mean) 12 DORIS remission threshold Cut-off date: August 28, 2026; Data c
Slide 13: Patients Discontinued Immunosuppressants and Tapered Steroids
Patients Discontinued Immunosuppressants and Tapered Steroids to ≤ 5 mg Prednisone Equivalent All patients discontinued immunosuppressants Immunosuppressants Background steroids tapered to ≤ 5mg prednisone in all patients but one Steroids 13 Cut-off date: August 28, 2026; Data cut included 22 effica
Slide 14: Recently Approved Therapies for SLE Have Not Shown High DORIS Remission Rates
Recently Approved Therapies for SLE Are Delivered On Top of Standard Therapy & Have Not Shown High DORIS Remission Rates DORIS Remission Rates for Recently Approved Therapies in SLE (%) Belimumab & std. therapy Placebo & std. therapy Anifrolumab & std. therapy Placebo & std. therapy Obinutuzumab & s
Slide 15: Anticipated Pivotal Design
Anticipated Pivotal Design Double-digit number of patients Key inclusion criteria Participants must meet EULAR/ACR 2019 criteria for SLE Biopsy-proven proliferative Class III or IV LN, with or without concomitant Class V involvement Inadequate clinical response to at least two immunosuppressants End
Slide 16: Major Unmet Needs in LN/SLE Remain
Major Unmet Needs in LN/SLE Remain Treatment-free remissions are rare Flares are common despite chronic therapy, reflecting ongoing disease activity Increased early mortality due to organ damage, cardiovascular disease, infections, renal disease and other causes Need for one-time therapy with favora
Slide 17: Prula-cel: Potential to Transform the SLE and LN Patient Journey
Prula-cel: Potential to Transform the SLE and LN Patient Journey One time treatment approach Off-the-shelf Favorable safety profile Potential for outpatient therapy and accessibility in non-academic medical centers Potential for durable immunosuppressant-free clinical benefit Reduced steroid burden
Slide 18: Multiple Independent Biomarkers Support Immune Reset
Multiple Independent Biomarkers Support Immune Reset IMMUNE RESET Memory B-cell clearance & naïve recovery Naïve repertoire emerges Deep B-cell depletion Undetectable B cells in 100% (22/22) of evaluable patients Tissue B-cell depletion Target engagement confirmed Complement normalization Reduced im
Slide 19: Deep B-cell Depletion with Naïve Recovery
Deep B-cell Depletion with Naïve Recovery CD19+ B-cell counts are presented as mean ± SEM. Naïve B-cell, switched memory B-cell, and plasmablast data are presented as median values at each study visit. B cells are considered undetectable when below the assay lower limit of detection (LLD; <2 cells/µ
Slide 20: Prula-cel Achieved Deep CD19+ B-cell Depletion in Tissues
Prula-cel Achieved Deep CD19+ B-cell Depletion in Tissues Baseline Day 10 Post Dose Blue : Nuclei Green: CD19+ cells Yellow: CAR Red: Granzyme B (T Cell Activation) MCL Patient Lymph Node Biopsies POC: Prula-cel rapidly depleted CD19+ B cells within secondary lymphoid tissue Robust tissue infiltrati
Slide 21: Reduction in Anti-dsDNA Titers and Immune Complex Burden Supports Immune Reset
Reduction in Anti-dsDNA Titers and Immune Complex Burden Supports an Emerging Immune Reset Of 22 efficacy evaluable patients, n=11 were baseline anti-dsDNA-positive and evaluable by ELISA. Data are presented as mean ± SD. For anti-dsDNA, the horizontal dotted line indicates the positivity cutoff. Fo
Slide 22: Prula-cel: Potentially First Off-the-Shelf, One-Time Therapy vs Autologous CAR-T
Prula-cel: Potentially First Off-the-Shelf, Easy to Administer, One-Time Therapy With Efficacy Comparable to Autologous CAR-T & Favorable Safety AUTOLOGOUS CAR-T Current paradigm Prula-cel Allogeneic / bank-ready γδ1 CAR-T Treatment Workflow Physician withdraws immunosuppression, schedules leukapher
Slide 23: Incomplete B-Cell Depletion With Protein-based Approaches
Incomplete B-Cell Depletion With Protein-based Approaches (mAbs & TCEs) Associated With Less Robust Clinical Responses in Patients With Autoimmune Diseases Incomplete B-cell depletion in lymph nodes with mAbs and TCE approaches in contrast to complete depletion in all CAR-T treated patient samples P
Slide 24: Prula-cel Potential Competitive Positioning in Lupus With and Without Nephritis
Prula-cel Potential Competitive Positioning in Lupus With and Without Nephritis Autologous CAR-T Proven immunosuppressant free DORIS/CRR Safety Challenges: IEC-HS, ICANS, CRS Require leukapheresis & personalized manufacturing Chen YH et al. NEJM (2026) Wang Q et al. NEJM (2025) Bi-Specifics Have not
Slide 25: Modality Comparison
Modality Comparison 25 Prula-cel target product profile Autologous αβ CAR-T T-cell engaging antibodies mRNA/LNP-based in vivo CAR-T Viral-based in vivo CAR-T Potency / durability Safety Logistics Scalability Potential for IS-free remissions Efficacy in-line with auto CAR-T Favorable safety profile N
Slide 26: Commercial Potential: ~70K-Patient Organ-Threatening SLE Opportunity in the US
Commercial Potential ~70K-Patient Organ-Threatening SLE Opportunity in the US US Prevalence of SLE & Non-Renal SLE (thousands of patients) Lupus Nephritis (LN) ~100K prevalent patients in the US Roughly 25–45% of LN patients fail to achieve remission after 24 months of SoC treatment → ~35K addressab
Slide 27: Developing Broad Pipeline of Allogeneic γδ1 CAR-T and In Vivo CAR-T Therapies
Program Indication Research IND-Enabling Clinical Potential Key Differentiation Prula-cel Target: CD20 LN/SLE Off-the-shelf, outpatient dosing — no leukapheresis or personalized manufacturing Quick, easy administration Favorable safety profile; reduced IEC-HS, ICANS, CRS risk Efficacy comparable to
Slide 28: Anticipated Near-Term Value-Creating Milestones
Anticipated Near-Term Value-Creating Milestones Clinical, regulatory and platform catalysts expected across prula-cel, ADI-212 and in vivo CAR-T programs Prula-cel Autoimmune disease LN / SLE / SSc ADI-212 mCRPC In Vivo CAR-T MM Program In Vivo CAR-T NHL Program In Vivo CAR-T Solid Tumors Program 20
Slide 29: Prula-cel Delivered High Rates of Immunosuppression-Free CRRs and DORIS Remissions
Prula-cel Delivered High Rates of Immunosuppression-Free CRRs and DORIS Remissions in Heavily Pre-Treated LN & SLE Patients 50% 12-Month CRR Rate 54% 12-Month DORIS Rate Favorable Safety Profile Generally well-tolerated — No IEC-HS, No ICANS and No > Grade 2 CRS observed Immunosuppressant-Free All p
Slide 30: Adicet Bio
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