Iaso Bio Announces Updated Long-Term Follow-Up Data of Fucaso® (Equecabtagene Autoleucel) at 2023 IMS, Demonstrating 82.4% Stringent Complete Response Rate in CAR-T Naïve RRMM Patients

Nanjing, Shanghai, and San Jose, CaliforniaSeptember 28, 2023PR Newswire -- IASO Bio, a biopharmaceutical company dedicated to the research, development, manufacturing, and commercialization of innovative cell therapies, and Innovent Biologics (HKEX stock code: 01801), a biopharmaceutical company committed to developing, manufacturing, and commercializing innovative drugs for oncology, autoimmune diseases, metabolic disorders, ophthalmology, and other major disease areas, presented two research findings in poster presentations at the 2023 International Myeloma Society (IMS) Annual Meeting:（1）Whole Person Source AutologousLatest Long-term Follow-up Results of Phase 1b/2 Study (FUMANBA-1) of Ixcellen Injection, a B-Cell Maturation Antigen (BCMA) Chimeric Antigen Receptor Autologous T-Cell (CAR-T) Therapy for Relapsed/Refractory Multiple Myeloma (RRMM) (Abstract No. P-290); (2) Risk Model Analysis for Predicting Prolonged Recovery Time of Thrombocytopenia in Patients with Relapsed/Refractory Multiple Myeloma after Anti-BCMA CAR-T Therapy (Abstract No. P-288)。

（1) Abstract Title:Latest Long-term Follow-up Results of the Phase 1b/2 Study (FUMANBA-1) of Ixcellen Injection in the Treatment of Relapsed/Refractory Multiple Myeloma (RRMM)

Meeting Theme: Treatment of Relapsed/Refractory Multiple Myeloma

Abstract Number:P-290

Report Time:12:30 PM - 1:30 PM, September 28, 2023 (Local time in Athens, Greece)

This report updates the safety and efficacy data of the phase 1/2 registrational clinical study (FUMANBA-1) on the treatment of relapsed/refractory multiple myeloma (hereinafter referred to as "RRMM") with Ixcellen injection at 14 clinical research centers in China.

This study (CTR20192510, NCT05066646) requires the enrollment of RRMM patients who have previously undergone at least three lines of treatment or more (including chemotherapy regimens based on proteasome inhibitors and immunomodulatory agents) and have experienced disease progression in the last line of therapy. As of December 31, 2022, a total of 105 subjects receiving IASO Bio's CT103A infusion were enrolled, with an infusion dose of 1.0×10.⁶CAR-T cells/kg, with a median follow-up time of 18.07 (IQR 12.6-21.8) months, and a median number of prior treatment lines of 4 (3-23).

Among the 105 subjects who received the infusion of Idecabtagene Vicleucel Injection, 69.5% (73/105) had high-risk cytogenetic abnormalities according to the mSMART3.0 criteria, 13.3% (14/105) had extramedullary plasmacytoma, and 11.4% (12/105) had previously received non-fully human BCMA CAR-T therapy.

In terms of effectiveness:Among 103 evaluable subjects, the overall response rate (ORR) was 96.1% (99/103), with 91.3% (94/103) achieving very good partial response or better (≥VGPR). The stringent complete response/complete response (sCR/CR) rate was 77.7% (80/103). Among 91 subjects without prior CAR-T treatment history,ORR reached 98.9% (90/91), with sCR/CR rate reaching 82.4% (75/91), and the 12-month progression-free survival (PFS) rate was 85.5% (95% CI: 75.75, 91.51).。

Among the 103 evaluable subjects, the median time to response was 16 (11, 179) days, and the 12-month PFS rate was 80.0% (95% CI: 70.33, 86.76). 94.2% (97/103) of the subjects achieved minimal residual disease (MRD) negativity, with all sCR/CR subjects achieving MRD negativity. 80.8% (95% CI: 69.59, 88.24) of the subjects maintained MRD negativity for over 12 months.

Idecabtagene vicleucel injection also demonstrated good efficacy in multiple myeloma (hereinafter referred to as "MM") subjects who had previously received CAR-T therapy. Among 12 MM subjects who had previously received CAR-T therapy, 9 achieved remission and 5 achieved stringent complete remission.

In terms of safety:Among 105 subjects, 93.3% (98/105) experienced cytokine release syndrome (CRS), the majority being grade 1-2 CRS, with only one subject experiencing grade 3 or higher CRS. The median onset time of CRS was day 6.0 (range: 1-13) post-infusion, and the median duration of CRS was 5.0 (range: 2-30) days. Only 1.9% (2/105) of subjects developed immune effector cell-associated neurotoxicity syndrome (ICANS), including one case each of grade 1 and grade 2, with no ≥grade 3 ICANS. All subjects’ CRS and ICANS were resolved.

In terms of expansion and sustainability:The median peak time for CAR copy numbers in peripheral blood was 12 days post-infusion, with a median peak level of 88,001.13 copies/microgram DNA. Among subjects followed up to 12 months and 24 months post-infusion, 50% (32/64) and 40% (4/10), respectively, still showed detectable CAR-T cell persistence. Only 19.2% (20/104) of the subjects tested positive for anti-drug antibodies (ADA) after infusion.

（2) Abstract Title:Risk Model Analysis for Prolonged Thrombocytopenia Recovery Time in Patients with Relapsed/Refractory Multiple Myeloma After Anti-BCMA CAR-T Therapy

Conference ThemeTreatment of Relapsed/Refractory Multiple Myeloma

Abstract Number:P-288

Report Time:September 28, 2023, 12:30 PM - 1:30 PM (Local time in Athens, Greece)

The most common adverse reaction in RRMM patients after BCMA CAR-T cell therapy is hematological toxicity, particularly persistent thrombocytopenia. This report also presents a model for distinguishing the clinical risk levels of long-term thrombocytopenia. After analyzing baseline characteristics of the participants, the final platelet count, hemoglobin, C-reactive protein, ferritin, and the proportion of plasma cells in the bone marrow were identified as being associated with the recovery from thrombocytopenia and were used to establish the model. Patients with a model score of 5 or higher have an increased risk of persistent thrombocytopenia following infusion.

The principal investigator of this clinical study,Professor Luogui Qiu from the Blood Disease Hospital of the Chinese Academy of Medical Sciences and Professor Chunrong Li from Tongji Hospital, Tongji Medical College, Huazhong University of Science and TechnologyMultiple myeloma is a common and highly prevalent malignant tumor in the blood system, and recurrence and drug resistance are almost inevitable during treatment. There is an urgent clinical need for treatments with good tolerability and deep, lasting responses. Idecabtagene vicleucel injection is a fully human BCMA-targeted CAR-T product that can more precisely kill tumor cells and has longer persistence in the body. Compared to the follow-up data presented at the 2023 ASCO Annual Meeting, the updated data presented at this year's IMS meeting shows that the ORR for subjects who had not previously received CAR-T therapy remained consistently high at 98.9%, with significant improvements in sCR/CR rates and 12-month PFS rates. This indicates that after including more subjects and longer follow-up periods, idecabtagene vicleucel injection continues to demonstrate encouraging efficacy and safety, with the potential to change the treatment landscape for RRMM and offer hope of a cure to patients.