Indapta Therapeutics to Present Complete Phase 1 Data for IDP-023 Combination Therapy in Relapsed/Refractory Multiple Myeloma at SITC 2026
Indapta Therapeutics, Inc., a privately held clinical-stage biotechnology company focused on developing next-generation immunotherapies for cancer and autoimmune diseases, has announced that complete Phase 1 clinical data for its investigational allogeneic gamma-delta-negative natural killer (g-NK) cell therapy, IDP-023, will be presented at the Society for Immunotherapy of Cancer (SITC) 41st Annual Meeting. The presentation will highlight clinical findings from the combination of IDP-023 and isatuximab in patients with relapsed or refractory multiple myeloma (RRMM), a difficult-to-treat blood cancer.
The SITC 2026 Annual Meeting is scheduled to take place from November 4 to November 8, 2026, in Phoenix, Arizona. The presentation will provide comprehensive Phase 1 results covering the safety, clinical activity, and potential biological effects of IDP-023 when administered alongside isatuximab, an approved anti-CD38 monoclonal antibody used in multiple myeloma treatment.
The findings are particularly important because the clinical study enrolled patients with heavily pretreated and highly resistant disease. All participants had previously received daratumumab and had become refractory to this CD38-targeted therapy. Many had also undergone advanced treatment approaches, including B-cell maturation antigen (BCMA)-directed therapies, chimeric antigen receptor (CAR) T-cell therapy, and T-cell engagers. Despite these extensive treatment histories, the combination demonstrated encouraging antitumor activity, supporting further investigation of IDP-023 in patients with limited remaining treatment options.
Dr. Mark Frohlich, Chief Executive Officer of Indapta Therapeutics, expressed optimism about the clinical findings and described the results as an important step toward establishing clinical proof-of-concept for the company’s proprietary g-NK cell platform.
According to Dr. Frohlich, the patients enrolled in the study represented a particularly challenging population, having exhausted most currently available treatment options. All patients were refractory to daratumumab, while approximately two-thirds had previously received CAR-T therapy and a similar proportion had been treated with a T-cell engager.
He noted that the clinical findings support the company’s preclinical hypothesis that IDP-023 may help overcome resistance to CD38-directed treatment. Following recent discussions and feedback from the U.S. Food and Drug Administration (FDA), Indapta plans to expand the ongoing clinical study with an additional patient cohort. The company also intends to pursue a randomized, registration-enabling clinical trial in patients with highly refractory multiple myeloma.
Oral Presentation at the SITC 2026 Annual Meeting
Indapta will present the complete Phase 1 clinical findings during a clinical oral abstract session at the SITC 41st Annual Meeting. The presentation will focus on the safety and efficacy of IDP-023 combined with isatuximab, along with evidence of changes in the bone marrow tumor microenvironment following treatment.
The oral presentation is titled “IDP-023 Allogeneic g-NK Cells Combined with Isatuximab in Relapsed/Refractory Multiple Myeloma: Complete Safety, Efficacy, and Tumor Microenvironment Remodeling from a Phase 1/2 First-in-Human Study.”
Dr. Mark W. Frohlich, MD, Chief Executive Officer of Indapta Therapeutics, will serve as the presenter. The presentation is scheduled for Friday, November 6, 2026, from 12:00 PM to 12:15 PM Mountain Standard Time (MST), at the Phoenix Convention Center in Phoenix, Arizona, in Halls BC.
In addition to the oral presentation, the company will share supporting research findings through a poster presentation identified as Abstract Number 1185. The poster session will take place on Friday, November 6, 2026, during two scheduled periods: 12:15 PM to 1:45 PM and 5:30 PM to 7:00 PM MST. The presentation will be held in the Poster Hall at the Phoenix Convention Center.
These presentations will provide the scientific community with a detailed overview of the clinical performance of IDP-023 and its potential role in addressing treatment resistance among patients with advanced multiple myeloma.
Phase 1/2 Clinical Trial Evaluates IDP-023 and Isatuximab Combination
The clinical results being presented are derived from the Phase 1 portion of Indapta’s ongoing Phase 1/2 first-in-human clinical trial, registered under ClinicalTrials.gov identifier NCT06119685.
The study evaluated the combination of IDP-023 and isatuximab in 12 patients with relapsed or refractory multiple myeloma. The primary focus of the Phase 1 evaluation was to assess the safety and tolerability of the investigational cell therapy combination while examining preliminary evidence of clinical efficacy.
Isatuximab is an anti-CD38 monoclonal antibody approved for treating multiple myeloma. It works by targeting the CD38 protein expressed on multiple myeloma cells and supporting immune-mediated destruction of malignant cells. Combining this antibody with IDP-023 is intended to enhance antibody-dependent cellular cytotoxicity (ADCC), a mechanism through which immune cells recognize and eliminate antibody-coated cancer cells.
Under the clinical trial protocol, patients received three doses of IDP-023 during each treatment cycle. Each dose contained between 10 billion and 20 billion cells. The investigational cell therapy was administered alongside interleukin-2 (IL-2), an immune-signaling molecule used to support immune-cell activity. Selected patients received additional treatment cycles depending on their clinical circumstances.
The enrolled population had extensive prior treatment exposure, highlighting the significant unmet medical need addressed by the study. Patients had received a median of 6.5 previous lines of therapy, with the number ranging from two to 17.
All enrolled patients were refractory to daratumumab, demonstrating resistance to an established CD38-directed treatment. Furthermore, 92% of participants were triple-class refractory, meaning their disease was resistant to three major classes of multiple myeloma therapies. Approximately 58% were penta-refractory, indicating resistance across five major treatment categories.
Previous treatment histories also included advanced immune-based approaches. Approximately 83% of patients had received BCMA-directed therapy, while 67% had previously undergone CAR-T cell treatment. Another 67% had received a T-cell engager.
The disease characteristics were also particularly challenging. Among patients with available cytogenetic information, all had high-risk disease, with 80% classified as having ultra-high-risk cytogenetic features. Additionally, 25% of the patients had extramedullary disease, in which multiple myeloma develops outside the bone marrow.
These characteristics make the clinical findings noteworthy because the treatment was evaluated in a population with substantial disease resistance and limited therapeutic alternatives.
Encouraging Response Rates and Progression-Free Survival
One of the most important findings from the Phase 1 study was the clinical activity demonstrated by the combination of IDP-023 and isatuximab.
According to the 2026 International Myeloma Working Group (IMWG) response criteria, the combination achieved an overall response rate (ORR) of 45%, corresponding to five responses among 11 response-evaluable patients. The ORR included patients achieving a partial response or better.
The study also reported a median progression-free survival (mPFS) of 6.3 months, with a 95% confidence interval ranging from 2.0 months to not reached.
These results are particularly encouraging when considered against previously reported outcomes for isatuximab monotherapy in patients with daratumumab-refractory multiple myeloma. A 2021 study published by Mikhael and colleagues in the Blood Cancer Journal reported an ORR of 0% and a median progression-free survival of 1.6 months for isatuximab monotherapy in this patient population.
Although the results come from a small early-stage clinical study and should not be interpreted as a definitive comparative assessment, the findings suggest that adding IDP-023 may improve the antitumor activity of isatuximab in patients whose disease has become resistant to previous CD38-directed treatment.
The clinical response data provide an important foundation for further investigation of the combination in larger studies.
Durable Complete Response in a Highly Refractory Patient
Another notable finding involved a 72-year-old patient with particularly aggressive multiple myeloma.
The patient had ultra-high-risk cytogenetic features, bulky extramedullary disease, and a history of 10 previous lines of treatment. Previous therapies included BCMA-directed CAR-T cell therapy and two T-cell engagers, demonstrating the extent of prior treatment exposure and disease resistance.
Despite these challenging clinical characteristics, the patient achieved a stringent complete response following treatment with IDP-023 in combination with isatuximab.
The response was sustained for more than one year. Furthermore, positron emission tomography/computed tomography (PET/CT) imaging demonstrated complete resolution of the patient’s extramedullary disease.
This outcome represents an important observation because extramedullary multiple myeloma is generally associated with aggressive disease characteristics and can be difficult to manage with conventional treatment approaches.
While an individual patient response cannot establish the overall effectiveness of an investigational therapy, the durability of this response provides additional support for continued clinical evaluation of the IDP-023 combination.
Favorable Safety and Tolerability Profile
In addition to evaluating clinical activity, the Phase 1 study assessed the safety and tolerability of IDP-023 when administered with isatuximab.
The combination was generally well tolerated across the evaluated dose levels. Importantly, investigators reported no dose-limiting toxicities through dose level 3, which represented the maximum dose tested in the study at 20 billion cells per administration.
The study also reported no treatment-related deaths or treatment discontinuations. Furthermore, investigators did not observe clinically significant cases of cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), infections, or bleeding.
The most frequently reported adverse events were cytopenias associated with lymphodepleting chemotherapy administered as part of the treatment approach.
These blood-related adverse events had a predictable onset, and all affected patients recovered. The findings provide encouraging early evidence regarding the tolerability of the investigational treatment combination.
The absence of dose-limiting toxicities at the highest tested dose also provides useful information for determining appropriate dosing strategies in subsequent clinical development.
However, continued monitoring in larger patient populations will be important to establish the full safety profile of IDP-023 and identify any less common or longer-term treatment-related complications.
Tumor Microenvironment Analysis Indicates Potential Immune Remodeling
Beyond clinical response and safety outcomes, Indapta also conducted translational analyses to understand how IDP-023 may influence the tumor microenvironment.
The company evaluated paired bone marrow samples collected before and after treatment from 12 patients. These analyses focused on changes in immune-cell populations within the bone marrow, which plays an important role in multiple myeloma progression and treatment resistance.
The results demonstrated a trend toward increased CD8-positive T cells and gamma-delta T cells following treatment with IDP-023. At the same time, investigators observed a reduction in myeloid-derived suppressor cells (MDSCs).
These findings suggest that IDP-023 may influence the immune environment surrounding multiple myeloma cells.
CD8-positive T cells are important immune cells responsible for recognizing and destroying abnormal cells. Gamma-delta T cells represent another immune-cell population with potential antitumor activity. In contrast, MDSCs are immunosuppressive cells that can weaken the body’s immune response and support cancer progression.
A reduction in MDSCs, combined with an increase in potentially antitumor immune-cell populations, may create a more favorable environment for sustained immune-mediated cancer control.
Indapta believes these observations could help explain the clinical responses seen in the study and provide a rationale for investigating IDP-023 alongside additional immunotherapy approaches.
The company also highlighted the possibility that tumor microenvironment remodeling could complement subsequent T-cell-directed treatments, including T-cell engagers. This could become particularly relevant for patients with advanced multiple myeloma who have developed resistance to multiple existing treatment classes.
Nevertheless, the observed immune-cell changes represent preliminary translational findings and will require further investigation to establish their clinical significance.
Indapta Plans Clinical Trial Expansion Following FDA Discussions
Based on the Phase 1 findings and discussions with the FDA, Indapta is preparing to advance the clinical development of IDP-023.
The company held an End-of-Phase 1 Type B meeting with the FDA in July 2026. Following this interaction and consideration of the available clinical results, Indapta plans to extend its ongoing Phase 1 trial with an additional cohort of approximately 15 to 20 highly refractory multiple myeloma patients.
The proposed expansion cohort is intended to enroll patients who closely match the company’s targeted treatment indication. The expanded study will use a fixed dose and schedule, with patients receiving up to three treatment cycles.
This approach is expected to provide additional clinical information regarding the safety, tolerability, and antitumor activity of the IDP-023 and isatuximab combination in a more specifically defined patient population.
Following the expansion cohort, Indapta intends to initiate a randomized, registration-enabling clinical trial in patients with highly refractory multiple myeloma.
A randomized study could provide more comprehensive evidence regarding the clinical benefit of the investigational combination and help establish its potential role in future treatment strategies.
The company’s development plans reflect its intention to address a significant unmet need among patients whose disease has progressed despite multiple lines of standard and advanced immunotherapy treatments.
Indapta’s Proprietary Allogeneic g-NK Cell Therapy Platform
IDP-023 is based on Indapta’s proprietary universal allogeneic natural killer (NK) cell immunotherapy platform. The technology focuses on a naturally occurring subset of NK cells known as gamma-minus NK cells, or g-NK cells.
These specialized immune cells develop following epigenetic changes associated with exposure to cytomegalovirus (CMV). Unlike conventional NK cells, g-NK cells exhibit distinct immune functions that may provide advantages in cancer treatment.
To manufacture IDP-023, Indapta selectively expands g-NK cells obtained from healthy donors. The company’s manufacturing process is designed to produce a consistent cellular product while maintaining low donor-to-donor variability.
One of the distinguishing features of the platform is that IDP-023 does not require genetic engineering to achieve its intended immune-cell functions.
The therapy uses several naturally occurring mechanisms to recognize and eliminate target cells.
First, g-NK cells demonstrate strong antibody-dependent cellular cytotoxicity (ADCC). This mechanism allows immune cells to recognize cancer cells coated with therapeutic antibodies and subsequently destroy them. When combined with isatuximab, which targets CD38 on multiple myeloma cells, IDP-023 is intended to strengthen antibody-mediated immune-cell killing.
Second, g-NK cells can recognize HLA-E-expressing cells through the NKG2C receptor. This recognition pathway provides another mechanism through which the cells may identify and eliminate target cells.
Third, g-NK cells possess inherent antiviral activity, reflecting their distinctive immune characteristics following CMV-associated epigenetic changes.
According to Indapta, g-NK cells can release substantially higher levels of immune-activating cytokines and cell-killing compounds than conventional NK cells. These characteristics may contribute to their enhanced ability to recognize and destroy malignant cells.
Preclinical studies have also demonstrated that IDP-023 may produce more potent and durable antitumor activity when combined with cancer-targeting monoclonal antibodies compared with conventional NK cells.
Research supporting the company’s scientific approach was published by Bigley and colleagues in Blood Advances in 2021 (DOI: 10.1182/bloodadvances.2020002440).
Beyond oncology, Indapta’s g-NK cell platform may also have applications in autoimmune diseases. The company has reported that g-NK cells combined with a B-cell-targeting antibody can deplete normal B cells obtained from healthy donors or patients with autoimmune conditions.
This observation suggests that the platform could potentially support the development of immune-cell-based treatments across multiple disease areas.
Advancing Next-Generation Immunotherapy for Difficult-to-Treat Cancers
The complete Phase 1 findings for IDP-023 represent an important development milestone for Indapta Therapeutics as the company advances its proprietary g-NK cell technology.
The 45% overall response rate, median progression-free survival of 6.3 months, and durable complete response observed in a heavily pretreated patient provide encouraging early clinical evidence for the combination with isatuximab.
The generally favorable safety findings and preliminary evidence of tumor microenvironment remodeling further support continued investigation of the treatment approach.
Presentation of the complete data at the SITC 2026 Annual Meeting will provide researchers, clinicians, and the broader immunotherapy community with an opportunity to evaluate the clinical and biological findings.
With plans to expand the Phase 1 study and subsequently pursue a randomized registration-enabling trial, Indapta is working to determine whether IDP-023 can become a meaningful treatment option for patients with highly refractory multiple myeloma.
The company’s broader objective is to advance differentiated immune-cell therapies that address limitations in existing cancer treatments while exploring additional applications in autoimmune diseases.
About Indapta Therapeutics
Indapta is a privately held company focused on developing and bringing to market a diverse pipeline of cellular immunotherapies to treat the still unmet medical needs of patients with blood and solid-tumor cancers as well as autoimmune diseases. The company’s proprietary robust platform of naturally occurring g-NK cells is specifically designed to create best-in-class, highly potent, more accessible, and scalable cell therapies.