Taste Loss From a Breakthrough Myeloma Drug May Push Patients to Quit Therapy

A cancer therapy that reprograms the immune system to hunt down myeloma cells is delivering striking remissions in heavily treated patients, but it is also stripping away something most people never think about until it is gone: the ability to taste. A new study from University Hospital Würzburg in Germany has now documented, in unusual detail, just how heavy that sensory burden can be. In a cohort of 32 patients with relapsed or refractory multiple myeloma treated with the bispecific antibody talquetamab, every single participant reported taste disturbances at some point during therapy. For a quarter of them, standardized taste-strip testing found no correct identification of any taste stimulus at all, a result that underscores how profound the gustatory shutdown can become even while the drug keeps the underlying cancer in check.

Talquetamab belongs to an emerging class of T-cell-redirecting bispecific antibodies. It works by binding GPRC5D, a target abundantly expressed on malignant plasma cells, on one arm, and CD3 on T cells on the other, physically bridging the immune cell to the tumor and triggering a lethal synapse. The drug has shown impressive antimyeloma activity in patients whose disease had exhausted other options, and it was approved on the strength of those responses. But GPRC5D is also expressed in certain normal tissues, and the collateral consequences have become a defining feature of the treatment profile: dry mouth, nail changes, peeling skin, weight loss, and, most distinctively, dysgeusia, the distortion or loss of taste.

The Würzburg team, led by Anna Fleischer and colleagues, set out to move beyond the blunt binary of an adverse-event checklist. They combined objective taste-strip testing, in which filter-paper strips soaked with sweet, sour, salty, bitter, and umami solutions at four concentrations each are placed on the tongue, with a study-specific questionnaire, the EORTC QLQ-C30 quality-of-life instrument, and the PHQ-4 screening tool for anxiety and depression. Participants were asked to recall when their taste problems began, how their appetite and weight had changed, whether their food preferences had shifted, and whether they had ever considered abandoning the drug. The assessments took place during routine visits between 2024 and 2025, and patients were instructed to abstain from food, drink, smoking, and chewing gum for at least an hour beforehand.

The objective results were sobering. The median number of correctly identified taste stimuli was just 2.5 out of the administered panel, with an interquartile range of 0.75 to 7.25 and an observed range spanning zero to 14. Eight patients, 25 percent of the cohort, could not correctly identify a single taste. On the patient-reported side, the picture was equally stark: 15 of the 27 participants whose impairment could be graded described it as severe or very severe. Dry mouth, a frequent companion of taste loss, affected more than four in five patients. The symptom also arrived fast, with nearly 72 percent of participants recalling onset within 14 days of their first dose, a timing pattern that suggests the gustatory system is hit early in the course of treatment.

The most consequential finding, however, was the link between measured taste performance and appetite. Twenty patients, 62.5 percent of the cohort, reported currently reduced appetite, and their mean taste-identification count was 2.45, compared with 7.83 among those without current appetite reduction. That difference of 5.38 correct identifications, with a 95 percent confidence interval of minus 8.20 to minus 2.57 and a p-value of 0.0006, held up under rank-based sensitivity analysis and when a single participant with resolved appetite loss was excluded. In plain terms, patients whose tongues performed worse on the test were the same patients who had lost the desire to eat, a convergence of objective measurement and lived experience that strengthens the case that the sensory deficit carries real nutritional consequences.

The downstream effects on the body were visible in the numbers. Half of the participants reported directional weight loss since starting talquetamab, with a median loss of 4.5 kilograms and individual losses reaching 15 kilograms. Those reporting weight loss also scored substantially higher on the EORTC appetite-loss scale, 66.7 versus 33.3 points, although the binary appetite question and weight history did not align neatly, a discrepancy the authors attribute to the different time windows each measure captures. Food preferences had shifted in more than half of patients: savory and salty foods were favored by about 40 percent, while sweet foods and fruit appealed to a similar share, and a notable minority developed outright aversions to sweetness or alcohol. The heterogeneity, the authors note, argues against any one-size-fits-all dietary prescription.

Perhaps the most clinically alarming statistic concerns treatment persistence. Ten patients, nearly a third of the cohort, had seriously considered stopping talquetamab, and seven of them explicitly cited taste disturbance as a reason. That means roughly one in five patients in the study linked this sensory side effect to thoughts of abandoning an otherwise effective therapy. The authors are careful to distinguish these contemplations from actual nonadherence, since no missed doses or discontinuations were documented, but the signal is hard to ignore. In an era when bispecific antibodies are extending survival in myeloma, a side effect potent enough to make patients weigh quitting is a problem that supportive care can no longer treat as an afterthought.

Quality-of-life data reinforced the connection between taste and well-being. Mean global health status on the EORTC scale was 50.5 out of 100, and it correlated positively with taste-identification counts, with a Pearson correlation coefficient of 0.406 and a p-value of 0.021. Among patients whose current impairment could be graded, greater impairment tracked with both lower taste scores and lower global health. Role functioning and social functioning posted the lowest mean scores among the functional scales, while fatigue and appetite loss dominated the symptom scales. Psychological distress, measured by the PHQ-4, was heterogeneous rather than uniformly severe: just over half of participants showed minimal distress, about a third mild, and none severe, a reminder that taste loss can erode the pleasure of eating without necessarily registering as depression.

The authors are refreshingly candid about the limits of what a single-center, cross-sectional survey of 32 patients can establish. There was no pretreatment taste assessment, no contemporaneous comparator group, and no way to verify a norm-referenced hypogeusia classification from the aggregate counts retained in the records. Recalled onset dates and weight changes are vulnerable to memory distortions, the study-specific questionnaire was not a validated dysgeusia instrument, and the many exploratory associations were examined without correction for multiple comparisons. Crucially, a cross-sectional correlation cannot prove that talquetamab causes the taste loss, that taste loss causes the appetite reduction, or that the two share some third cause such as disease burden, oral infection, or other medications. The universal symptom reporting in this selected sample should also not be read as the true incidence of dysgeusia among all patients receiving the drug.

Even with those caveats, the study lands at a moment of genuine clinical need. Earlier work by the same group and others had described taste and oral symptoms under talquetamab, but this analysis is among the first to tie measured gustatory performance to appetite and quality of life within a single cohort, and to quantify how often the burden reaches the point of treatment doubt. The early onset narratives argue for proactive conversations about taste soon after the first dose, and the authors suggest that individualized exploration of tolerated flavors, textures, and hydration, alongside nutritional assessment when taste complaints, reduced intake, or weight change appear, is a reasonable supportive-care stance. What remains to be proven, they emphasize, is whether any of these strategies actually work: neither dietary adjustments nor dose modification has been tested prospectively. Future studies, they write, should track taste and patient-reported outcomes serially before, during, and after treatment, distinguish temporary improvement from sustained recovery, and preserve item-level taste responses so that the full sensory profile of this remarkable but demanding therapy can finally be mapped.

Subject of Research: Taste dysfunction, appetite loss, and quality of life in multiple myeloma patients treated with the bispecific antibody talquetamab

Article Title: Gustatory dysfunction under talquetamab therapy in multiple myeloma: a cross-sectional study of patient-reported course, nutritional changes, and quality of life

Article References: Fleischer, A., Burger, C., Roll, M., Panther, F., Strunz, P.-P., Peter, J., Kadel, S.-K., Gesierich, A., Mersi, J., Waldschmidt, J., Kortüm, M., Einsele, H., Maatouk, I., & Rasche, L. (2026). Gustatory dysfunction under talquetamab therapy in multiple myeloma: a cross-sectional study of patient-reported course, nutritional changes, and quality of life. Supportive Care in Cancer, 34(10), Article 1059. https://doi.org/10.1007/s00520-026-11288-4

Image Credits: AI Generated

DOI: 10.1007/s00520-026-11288-4

Keywords: talquetamab, multiple myeloma, dysgeusia, bispecific antibody, GPRC5D, taste strips, appetite loss, weight loss, quality of life, supportive care, EORTC QLQ-C30, immunotherapy side effects