In a landmark shift for the treatment of blood cancers, the Phase II ImmunoPRISM trial has unveiled clinical data that could fundamentally alter how physicians approach high-risk smoldering multiple myeloma (SMM). Presented at the 2026 European Hematology Association (EHA) Congress in Stockholm, the results demonstrate that teclistamab—a B-cell maturation antigen (BCMA)-targeted bispecific antibody—is significantly more effective than current standard-of-care combinations.
By intervening before the onset of symptomatic disease, researchers at the Dana-Farber Cancer Institute believe they have identified a pathway to "intercept" cancer progression, moving beyond simple management to potentially achieving deep, durable remissions in patients previously left in a state of clinical observation.
Main Facts: A Paradigm Shift in Treatment
High-risk smoldering multiple myeloma is a precursor condition characterized by an abnormal buildup of plasma cells in the bone marrow. While it does not yet exhibit the classic "CRAB" symptoms (calcium elevation, renal failure, anemia, and bone lesions) associated with active multiple myeloma, its prognosis is sobering: approximately 50% of patients progress to active, symptomatic disease within two years.
Historically, the clinical management of high-risk SMM has been defined by a "watch and wait" philosophy, or at most, the use of lenalidomide plus dexamethasone to delay the inevitable progression. The ImmunoPRISM trial challenged this standard by introducing teclistamab, a bispecific antibody designed to bind to both BCMA on the surface of myeloma cells and CD3 on the surface of T-cells. This "bridge" forces the immune system to recognize and eliminate malignant cells.
The study, led by Omar Nadeem, MD, Medical Director of the Center of Early Detection and Interception of Blood Cancers at Dana-Farber, is the first randomized trial to pit this potent immunotherapy against the conventional lenalidomide-dexamethasone regimen. The results suggest that by deploying T-cell redirection technology early—before the immune system is exhausted by later-stage treatments—clinicians can achieve unprecedented depths of response.
Chronology of the ImmunoPRISM Trial
The journey toward these findings began with a recognition that the "waiting game" in oncology often results in missed opportunities for curative-intent intervention.
- Trial Initiation: The ImmunoPRISM study was designed to enroll 59 patients diagnosed with high-risk SMM, based on strict, validated risk-stratification criteria.
- Patient Randomization: The cohort was divided into two arms: 45 patients received the investigative treatment of teclistamab, while 14 patients received the established standard-of-care combination of lenalidomide and dexamethasone.
- Data Collection (2024–2026): Over a median follow-up of 23.4 months, researchers meticulously monitored patient response rates, progression-free survival (PFS), and toxicity profiles.
- The EHA Congress (June 2026): Dr. Nadeem presented the late-breaking results in Stockholm, confirming that the early intervention strategy was not only feasible but clinically superior to the standard approach.
Supporting Data: By the Numbers
The clinical metrics reported from the ImmunoPRISM trial are stark, highlighting a clear divergence between the two treatment arms.
Unprecedented Response Rates
The most striking finding was the depth of remission. In the teclistamab group, an impressive 75.6% of patients achieved a complete response (CR). In contrast, the control group receiving the standard combination therapy saw a 0% complete response rate. When looking at "very good partial response" or better, the disparity remained vast: 87% for the teclistamab arm compared to just 14% for the control group.
Minimal Residual Disease (MRD) Negativity
Minimal Residual Disease (MRD) is a critical metric for determining the depth of remission. It measures the presence of cancer cells at a molecular level. Among the evaluable patients in the ImmunoPRISM trial, 82% of those treated with teclistamab achieved MRD-negativity. The control group saw zero patients reach this milestone. Notably, all MRD-negative responses in the teclistamab group remained ongoing at the time of data cutoff, suggesting a high level of durability.
Progression-Free Survival (PFS)
The impact on disease progression was equally significant. With a median follow-up of over 23 months, only 7% of patients in the teclistamab group experienced disease progression, compared to 36% in the combination therapy group. Statistical modeling projects that 92% of patients receiving teclistamab will remain alive and disease-free after two years, compared to an estimated 51% in the control arm.
Safety and Tolerability
Immunotherapy often carries the risk of unique side effects, specifically cytokine release syndrome (CRS). While 71% of the teclistamab cohort experienced CRS, it was universally categorized as low-grade. Importantly, there were no reported neurological toxicities, and the incidence of high-grade infections—a common concern with T-cell redirection therapies—was notably lower than what has been documented in trials for relapsed/refractory myeloma.
Official Responses and Clinical Perspectives
The medical community has received these findings with a mix of optimism and scientific rigor. Dr. Omar Nadeem, in his presentation at the EHA Congress, emphasized the strategic timing of the intervention. "We saw rapid, deep responses, including a high rate of complete responses and MRD negativity, and those responses have remained durable so far," Nadeem stated. "These findings suggest that treating patients earlier—before they develop symptomatic multiple myeloma—may meaningfully change the trajectory of the disease."
Dr. Irene Ghobrial, Director of the Center for Early Detection and Interception of Blood Cancers at Dana-Farber, underscored the broader implications for the field of hematology. "Taken together, these findings provide compelling evidence that early immunologic intervention may be a highly effective strategy for myeloma interception," she noted.
The rationale is clear: by using immunotherapy while the patient’s immune system is still "fit" and before the cancer has developed complex mechanisms of drug resistance, clinicians can maximize the chances of long-term disease control. This represents a fundamental shift from treating symptoms to managing risk.
Implications: The Future of Myeloma Interception
The ImmunoPRISM results have far-reaching implications for the standard of care in oncology.
1. Re-evaluating the "Watch and Wait" Approach
For decades, clinicians have been hesitant to treat smoldering myeloma because the toxicities of standard chemotherapies often outweighed the benefits of delaying the active disease. The ImmunoPRISM trial provides a compelling counter-argument. If a treatment can achieve high-level, durable remission with a manageable side-effect profile, the justification for "watching and waiting" diminishes.
2. The Power of Early Intervention
The "immune fitness" argument is gaining significant traction. Patients with smoldering myeloma have not yet been exposed to multiple lines of therapy, which can deplete T-cell populations and weaken the immune system. Utilizing bispecific antibodies at this stage preserves the immune system’s ability to respond to the treatment, potentially leading to more effective surveillance of the cancer long after the treatment phase ends.
3. Moving Toward Personalized Medicine
As the field moves forward, the success of the ImmunoPRISM trial will likely lead to further studies aimed at identifying which patients are the best candidates for early intervention. While not every patient with SMM progresses at the same rate, the ability to achieve such deep remissions in a high-risk group opens the door for potentially curative-intent strategies in the future.
4. Setting a New Benchmark
The data generated by the ImmunoPRISM trial sets a new, higher benchmark for future trials. Any new therapy proposed for high-risk smoldering myeloma will now be measured against the high complete response and MRD-negativity rates established by teclistamab.
In conclusion, the results of the ImmunoPRISM trial represent a transformative moment for hematology. By successfully deploying advanced immunotherapy to intercept multiple myeloma in its precursor stage, researchers have provided a roadmap for what could eventually become a standard practice of prevention rather than just treatment. As the medical community continues to digest these results, the shift toward early, aggressive, and highly targeted immunologic intervention appears not only inevitable but essential for improving the lives of patients facing a diagnosis of smoldering multiple myeloma.
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