Kyntra Bio roxadustat shows TI benefit in LR-MDS regardless of RS status
Kyntra Bio has presented new data from the Phase 3 MATTERHORN trial showing that roxadustat improved transfusion independence (TI) in patients with anaemia associated with lower-risk myelodysplastic syndromes (LR-MDS), with consistent benefit observed irrespective of ring sideroblast (RS) status. The data were shown as a poster at the European Hematology Association Congress in Stockholm on 12 June 2026.
The post-hoc analysis is clinically notable because RS-negative disease has historically responded poorly to the existing standard-of-care options, making the drug's mechanism of action, which stabilises HIF-1 alpha to promote red blood cell production, potentially meaningful for a broader patient population. Among the 84 RS-negative patients enrolled in the trial, roxadustat achieved TI for eight or more weeks over a 28-week period in 48% of patients, compared with 28% for placebo.
Trial results and regulatory status
In the broader trial population, the initial analysis had already shown that more patients on roxadustat achieved transfusion independence versus placebo, at 48% versus 33% (p=0.22). The p-value indicates the primary result did not reach conventional statistical significance, though the company notes the figures are from a trial not powered for that subgroup comparison. In the high transfusion burden (HTB) subgroup of 37 patients, roxadustat achieved higher rates of durable TI at 8, 12, and 16 weeks versus placebo, with treatment-emergent adverse events reported as generally low-grade and medically manageable, with no new safety signals identified.
Kyntra Bio said it is finalising the protocol for a pivotal Phase 3 trial in LR-MDS patients with HTB, incorporating feedback from the US Food and Drug Administration. The company expects to initiate that study in the second half of 2026.
Amer Zeidan, Professor of Medicine at Yale School of Medicine and global principal investigator for the planned Phase 3 trial, said the results showed "clinically meaningful RBC transfusion independence among high transfusion burden patients, as well as clear evidence of hemoglobin increase among patients who received roxadustat compared to placebo."
Market context and competitive landscape
LR-MDS anaemia represents a segment with significant unmet need and limited approved oral options. Current treatments including erythropoiesis-stimulating agents, luspatercept, and imetelstat are administered by subcutaneous injection or intravenous infusion, and only 35 to 40% of patients respond durably. Roxadustat, as an oral HIF-PH inhibitor, offers a differentiated delivery profile if efficacy is confirmed in a properly powered pivotal study.
The drug is already approved in Europe, Japan, China, and several other markets for anaemia in chronic kidney disease, giving Kyntra Bio a substantial body of safety data to draw on in regulatory discussions. The MDS indication, however, requires de novo evidence, and the FDA has not yet received a submission in this setting. Kyntra Bio holds rights to roxadustat in the US, Canada, and Mexico, while AstraZeneca and Astellas hold territories elsewhere, creating a complex commercial structure that investors will want to understand before ascribing full market value to a successful approval.
Bristol Myers Squibb's luspatercept, marketed as Reblozyl, currently holds an FDA approval for LR-MDS anaemia in transfusion-dependent patients with RS-positive disease, which makes the RS-agnostic signal from MATTERHORN a point of competitive differentiation worth watching as the field matures. The planned Phase 3 readout will be a key catalyst for Kyntra Bio's valuation over the next two to three years.