ASCO 2026: New Data for Relapsed/Refractory and Smoldering Multiple Myeloma Patients

The 2026 American Society of Clinical Oncology’s (ASCO) Annual Meeting kicked off this weekend, bringing together experts from around the globe for one of the most important events in cancer research. Over 200 abstracts, posters, and presentations related to myeloma will be presented over the course of the meeting, including groundbreaking research and clinical updates.

During the first two days of ASCO 2026, several studies have provided new insights into questions that many patients and caregivers are asking across their myeloma journeys:

• What treatment should come next if my current therapy stops working?
• Should high-risk smoldering multiple myeloma be treated before symptoms develop?
• What new therapies are being developed that could expand treatment options in the future?

Below, read the MMRF’s takeaways.

New therapies for patients whose myeloma has returned

As new treatments are being developed, researchers are trying to figure out how they can better help patients whose disease returns, also known as “relapse,” after one or several therapies. Two studies showed promise for patients who have relapsed once or multiple times.

Mezigdomide: new option for patients who relapse after taking a CD38 monoclonal (like Darzalex^®/daratumumab) and Revlimid^® (lenalidomide)

One study showed that combining a new oral drug (called mezigdomide) with Kyprolis^® (carfilzomib) and dexamethasone improved how long patients survive without their disease getting worse, compared to just taking Kyprolis and dexamethasone alone.  The most significant side effect was neutropenia (loss of white blood cells), which could be recovered through medication or adjusting the dose of mezigomide. Mezigdomide is part of a new class of drugs called CELMoDs which are similar to IMiDs like Revlimid and Pomalyst.

While bispecific therapies (like Tecvayli^®/teclistamab-cqyv) are also being investigated for patients who have relapsed, mezigdomide offers a new, convenient oral option that extends disease control after first relapse without the need for step-up dosing or the potential for cytokine release syndrome. It is easier to take, and more widely available for patients.

Etentamig: a new option for relapse after CAR T-cell therapy

Researchers evaluated etentamig, an investigational bispecific antibody, in 41 patients with relapsed/refractory multiple myeloma (RRMM) who had previously received BCMA-targeted therapies, including CAR T-cell therapy or antibody-drug conjugates (ADCs) like Blenrep^® (belantamab mafodotin-blmf). Nearly half of patients responded to treatment with etentamig, with an overall response rate (ORR) of 47 percent. Progression-free survival (PFS)—the length of time patients lived without their disease worsening—was 3.4 months among all responders but extended to 9.4 months in patients who had most recently received CAR T.

Importantly, these findings address a growing unmet need in myeloma care: what to do when the disease progresses after BCMA-targeted therapy. As more patients receive CAR T-cell therapy and other BCMA-directed treatments earlier in their treatment journey, new therapies like etentamig could help fill an important gap and provide another line of effective treatment.

Elrexfio may delay progression of high-risk smoldering myeloma

Smoldering multiple myeloma (SMM) was another research area with promising findings at ASCO 2026. In a phase 2 clinical trial, 50 patients with high-risk SMM who had not previously received treatment received Elrexfio^® (elranatamab), a bispecific antibody therapy currently approved for RRMM, for up to two years. Nine months after, 95 percent of patients had not progressed to active multiple myeloma. While cytokine release syndrome (CRS), a common side effect of bispecific antibodies, occurred in 68 percent of patients, most cases were mild. About half of patients experienced infections, some of which were serious.

These findings suggest that bispecific antibodies may have a role much earlier in the myeloma journey, potentially delaying or preventing progression to active disease in patients with high-risk SMM. However, longer follow-up is needed to understand how durable these benefits are and whether they outweigh the risks of treatment.

KLN-1010: a new treatment to keep an eye on

Lastly, updates from one ongoing study highlighted the potential of next-generation therapies in treating RRMM.

In the first, a small phase 1 study, six patients with RRMM were treated with KLN-1010, an investigational BCMA-targeted CAR T therapy designed to create CAR T cells directly inside the body, an approach known as in vivo CAR T, without the need for high-dose chemotherapy. All six patients (100 percent) responded to KLN-1010, becoming minimal residual disease (MRD)-negative within one month of treatment, meaning no myeloma could be detected in these patients with highly sensitive tests. The patients remained MRD-negative at six months of follow-up. In addition, one patient with extramedullary disease (EMD), a difficult-to-treat form of myeloma that spreads outside the bone marrow, had no EMD within one month.

While this study is still in its early stages, in vivo CAR T is an exciting therapy to watch because it has the potential to address several limitations of traditional CAR T treatment. Potential advantages include:

• No need for lymphodepletion chemotherapy prior to treatment.
• Simplified logistics, which could expand access beyond major academic centers and make CAR T therapy available to more patients regardless of where they live.
• Preservation of T-cell health and fitness, since T cells do not need to be collected, engineered outside the body, and reinfused.

Although additional research is needed to confirm its safety and effectiveness, in vivo CAR T could represent a significant step forward in making cellular therapies more accessible, convenient, and widely available.

The bottom line

We’re encouraged by the continued momentum in RRMM research that we saw in the first two days of ASCO 2026. We’ll have more highlights and key highlights from the meeting in the days ahead.