Relapsed or refractory multiple myeloma: confirming progression and choosing the next treatment

A rising monoclonal protein can make a patient fear that every available treatment has stopped working. The next decision is usually more specific: is progression confirmed, how quickly is it developing, are organs threatened, and which treatments remain plausible? A single abnormal result, sustained biochemical progression and symptomatic relapse do not always require the same response. This guide, checked in September 2026, helps patients prepare a useful discussion with a hematology team in China or at home.

Key takeaways

These excerpts come from the original article. Read the full sections below for context.

The clinician compares serial measurements obtained with suitable methods and may repeat monoclonal protein, free light chains, blood counts, creatinine and calcium. Treatment-related analytical interference, a change of laboratory method or another illness can complicate interpretation. Whether progression criteria are met depends partly on how the patient's myeloma was measurable previously. The IMWG response criteria provide the framework; not every isolated increase in a light-chain result establishes relapse.
BCMA-directed bispecific antibodies, antibody–drug conjugates and CAR-T are not independent options that can always be arranged in any order. Changes in target expression, T-cell fitness, previous response and treatment intervals can affect later activity. The European Myeloma Network sequencing guidance recommends considering the subsequent pathway when choosing the current therapy.
First establish whether an urgent problem needs local treatment. Then assemble reproducible evidence of progression and a clear account of previous benefit, resistance and toxicity. A second opinion is most useful when it assesses the same facts. If recommendations differ, ask which evidence or assumption drives the difference and what would change the preferred option.

Quick answer

Full guide

Verify progression before acting on one laboratory result

The clinician compares serial measurements obtained with suitable methods and may repeat monoclonal protein, free light chains, blood counts, creatinine and calcium. Treatment-related analytical interference, a change of laboratory method or another illness can complicate interpretation. Whether progression criteria are met depends partly on how the patient's myeloma was measurable previously. The IMWG response criteria provide the framework; not every isolated increase in a light-chain result establishes relapse.

For disease that produces little measurable protein, blood tests may not fully describe what is happening. Report a new lump, persistent focal bone pain or neurological symptoms even if the monoclonal protein is unchanged. Repeat marrow studies, genetic assessment or imaging may be appropriate when they can explain the change and influence treatment. Keep earlier results in date order rather than bringing only the newest abnormal page.

Ask the doctor to state what evidence confirms progression and what remains uncertain. This helps another center understand the reason for referral and avoids restarting the discussion from an incomplete summary. If a repeat test is planned, clarify its timing and the symptoms that should prompt earlier contact.

Identify organ threats and other urgent problems

Marked deterioration in kidney function, symptoms of severe hypercalcemia, new limb weakness or bladder and bowel dysfunction, and a suspected pathological fracture can require urgent assessment. Fever with low blood counts may be an infectious emergency. These problems should not wait for a future overseas appointment. The IMWG renal recommendations emphasize prompt control of the relevant disease process and contributing factors.

In selected patients with slow biochemical change and no organ threat, closer monitoring may be used while the next treatment is arranged. High-risk features, rapidly rising markers or a history of light-chain kidney injury may make delay less acceptable. Observation needs a defined laboratory schedule and clear triggers for action, not an open-ended instruction to wait until symptoms become severe.

Confirm which doctor is responsible during the interval between referral and admission. A distant center reviewing records may not be providing day-to-day clinical care. The local team needs to know whether treatment should continue, change or be interrupted while the referral is being assessed.

Build a history of response and resistance

The most useful record is a timeline showing each regimen, start and stop dates, best response, duration of control and reason for discontinuation. Stopping because of infection or neuropathy is different from progression despite adequately delivered treatment. If progression occurred during maintenance, document the actual medicine, modifications and missed doses rather than only the name of the original induction regimen.

Terms such as triple-class exposed and triple-class refractory describe different situations. Ask which classes and products are involved. Previous exposure does not always establish resistance, while a short response years earlier does not guarantee that repeating the medicine will work now. The 2025 EHA–EMN guideline incorporates previous therapy and patient characteristics into relapse management.

This timeline is also useful for eligibility checks. A center may need to establish that a particular previous-treatment requirement has been met, or that a drug was stopped for a reason compatible with a trial. Original reports are more reliable than a family recollection of the number of “chemotherapies” received.

Choose a combination the patient can receive consistently

Relapse regimens can include active proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies or other mechanisms. In some circumstances, a previously effective treatment stopped after a durable response can be reconsidered, but the old prescription should not simply be restarted without review. Kidney function, cardiac health, neuropathy, blood counts and infection history influence the choice. The IMWG relapse recommendations provide general principles; newer products require the subsequent evidence and regulatory updates as well.

For a frail patient, a deliverable regimen may offer more practical benefit than a more intensive option repeatedly interrupted by toxicity. Explain which previous adverse effects were hardest to live with. For example, numb feet causing falls and recurrent admissions that overwhelm home support can be decisive considerations even when laboratory results remain acceptable.

Ask how response will be assessed and when the team would change course. A defined review point can prevent either abandoning a potentially useful treatment too early or continuing an ineffective one without reassessment. The decision should consider symptoms and organ function alongside protein measurements.

CAR-T eligibility is product-specific and has evolved

In the United States, the current cilta-cel indication includes adults with relapsed or refractory myeloma after at least one previous line containing a proteasome inhibitor and an immunomodulatory drug, who are refractory to lenalidomide. Relapse alone is insufficient to establish eligibility, and this indication does not describe every CAR-T product. The FDA CARVYKTI product page gives the current requirements.

CAR-T involves collection, manufacturing, disease management while waiting, lymphodepleting treatment and monitoring after infusion. A patient must be able to proceed through that pathway safely. Rapidly progressing disease may require a bridging strategy, and collection does not guarantee that the patient will ultimately reach infusion on the original timetable. Actual manufacturing arrangements and alternatives for clinical deterioration must be confirmed with the treating center.

Discuss referral early enough for the cell-therapy service to contribute to planning. This does not mean that every patient should proceed immediately, but it can prevent an avoidable loss of options through uncoordinated interim treatment. The team should explain which health changes would require postponement or cancellation.

Immunotherapy sequencing affects later choices

BCMA-directed bispecific antibodies, antibody–drug conjugates and CAR-T are not independent options that can always be arranged in any order. Changes in target expression, T-cell fitness, previous response and treatment intervals can affect later activity. The European Myeloma Network sequencing guidance recommends considering the subsequent pathway when choosing the current therapy.

If CAR-T is being considered, involve that service before starting another BCMA-directed treatment. Previous BCMA exposure does not make all subsequent immunotherapy ineffective, but expected benefit needs more specific assessment. A different target, another mechanism or a trial may be relevant in some cases. At the same time, immediate disease control should not be sacrificed solely to preserve a hypothetical future opportunity that has no feasible access route.

Bring the exact names and dates of previous immune therapies. A generic note saying “immunotherapy failed” cannot establish which target was used or whether discontinuation resulted from resistance, toxicity or access problems. Those distinctions can change both standard-treatment and trial options.

Check the indication for the exact bispecific combination

In March 2026, the FDA approved teclistamab with daratumumab/hyaluronidase for eligible relapsed or refractory patients after at least one previous line including a proteasome inhibitor and an immunomodulatory drug. The monotherapy indication has different previous-treatment requirements. The combination approval should not be read as proof that every patient previously treated with daratumumab is suitable; actual resistance and the supporting evidence still matter. The FDA approval notice is a starting point for verification.

Bispecific antibodies do not require personalized cell manufacturing, but they do require treatment preparation. Step-up dosing, observation, infection management and the effects of low immunoglobulins remain relevant. An available product cannot necessarily be started the day a visiting patient arrives; clinical assessment, supply and monitoring capacity must align.

Continuing treatment after returning home should be discussed before the first dose. The receiving clinician needs the exact product, schedule and any interruption history, because restart instructions may differ after a treatment gap. A general promise that injections can be provided locally is not enough.

A recent approval is not a universal answer to multidrug resistance

The iberdomide combination granted US accelerated approval in August 2026 was supported by a study that excluded anti-CD38-refractory and bortezomib-refractory patients. Its results cannot simply be substituted for evidence in those excluded groups. When reading “after at least one prior line,” also examine the exclusions, endpoint and country of approval. The FDA iberdomide announcement provides those qualifications.

Other possibilities may include an antibody–drug conjugate requiring eye monitoring or combinations selected for a particular treatment history. Being unsuitable for one medicine does not establish that no next step exists. Conversely, being able to list several medicines does not guarantee that any will work. A realistic discussion should address standard options, relevant research and symptom-directed support together.

Ask what evidence would make the clinician favor one option over another for this patient. The answer may involve resistance, organ function, expected time to treatment or monitoring requirements rather than simply the date of the latest approval.

Plan safety care beyond discharge

After multiple treatment lines, infection, low blood counts and nutritional problems can reduce tolerance of further therapy. Antiviral measures, other prophylaxis and immunoglobulin management should follow individual risk assessment. The IMWG infection-prevention consensus supports a comprehensive approach. Patients need an emergency route for fever or breathing difficulty, and the local service should know which immune therapies were recently given.

CAR-T follow-up extends beyond the initial fever-monitoring period. In October 2025, the FDA added a boxed warning for immune effector cell-associated enterocolitis after cilta-cel. Severe or prolonged diarrhea, abdominal pain and weight loss may occur weeks to months after infusion, with fatal cases reported. Such symptoms require assessment rather than automatic treatment as an ordinary stomach infection. The FDA safety communication also states that overall benefit continues to outweigh the risks for the approved use.

Keep a treatment summary available to emergency clinicians. A patient may be far from the infusion center when a delayed complication appears. The summary should identify the cellular product or antibody, treatment dates and the specialist contact, rather than only recording that cancer treatment was completed.

Verify the specific pathway in China

China's National Health Commission 2025 guidance lists equecabtagene autoleucel and zevorcabtagene autoleucel for adult relapsed or refractory myeloma progressing after at least three prior lines, including a proteasome inhibitor and an immunomodulatory drug. Current product information and hospital assessment must still be checked. A US earlier-line indication for a different product cannot automatically be transferred to these therapies. The National Health Commission document is a Chinese reference for that distinction.

Send the original diagnosis, treatment timeline, recent organ-function results, imaging, infection history and country of residence to the prospective service. Ask which exact product is under consideration, whether the pathway is routine treatment or a trial, and which conditions remain unconfirmed. A hospital's public description of a technology does not establish a manufacturing place, bed or trial slot for an individual.

The estimate should cover preparation, any bridging therapy, infusion or step-up treatment, monitoring and potential additional care. A product-only price is insufficient for planning a cross-border course. The schedule must also identify who will manage the patient after returning home and how longer-term information will be exchanged.

Turn the relapse finding into a sequence of decisions

First establish whether an urgent problem needs local treatment. Then assemble reproducible evidence of progression and a clear account of previous benefit, resistance and toxicity. A second opinion is most useful when it assesses the same facts. If recommendations differ, ask which evidence or assumption drives the difference and what would change the preferred option.

The emotional impact deserves attention too. Relapse does not erase the time and symptom relief gained from previous treatment. The next goal may be another deep response, or it may give greater priority to avoiding pain, fatigue and repeated admissions, depending on the disease and the patient's wishes. Recording the goal, review date and alternative plan can make the next phase more understandable and preserve the patient's role in decisions.