Clinical data on romaciclib (RVU120) from REMARK study and dapolsertib(MEN1703) from JASPIS-01 study presented at the 2025 Annual Meeting ofthe American Society of Hematology (ASH)

The Management Board of Ryvu Therapeutics S.A., headquartered in Kraków(the "Company" or "Ryvu"), announces the latest data on romaciclib(RVU120) from REMARK study and dapolsertib (MEN1703) from JASPIS-01study were presented during the 2025 Annual Meeting of the AmericanSociety of Hematology (ASH), which is taking place on December 6-10,2025, in Orlando, USA.

Details on the posters presentations:

Poster Title:REMARK: A phase II, open-label, multicenter study oforally administered romaciclib (RVU120) for the treatment of anemia inpatients with lower-risk myelodysplastic neoplasms (LR-MDS)

Session name: 637. Myelodysplastic syndromes: Clinical andEpidemiological: Poster 3

Session date and time:December 8, 6:00-8:00 PM EST

Poster number: 5649

The Phase II REMARK study evaluates romaciclib (RVU120), an oralCDK8/CDK19 inhibitor, in patients with lower-risk myelodysplasticneoplasms (LR-MDS), a disease characterized by anemia and limitedtreatment options. As of the data cutoff, 42 patients had initiatedtreatment. The study follows a Simon's two-stage design, with 21patients included in the first stage who formed the basis for theinterim analysis. In stage 1, 11 patients completed C9D1 which is theprimary efficacy endpoint. Romaciclib was administered at 150 mg everyother day for 13 days in 21-day cycles, withan option to escalate to250 mg in non-responders or relapsing patients. Preliminary resultsdemonstrated early signs of clinical activity in some patients,including one patient with high transfusion burden (8RBCunits/16weeks) and another one with low transfusion burden, who achieved aprimary erythroid response (HI-E) per IWG 2018 criteria after 24 weeksof treatment. The first responder carried an SF3B1 mutation and hadpreviously failed three standard therapies (ESA, luspatercept,lenalidomide), while the second one harboured no relevant mutation anddid not receive any prior lines of therapy. No new safety signals wereidentified; the most frequent treatment-related adverse events werenausea, vomiting, asthenia, and decreased appetite. These AEs werepredominantly low grade; however, they led to discontinuation in somepatients. No sign of hematologic toxicity was observed in the studiedpatient population. Ongoing analyses aim to define further romaciclib'serythroid activity, optimal dosing, and molecular predictors of responsein LR-MDS.

Poster Title:An open-label, phase 2 study of dapolsertib (MEN1703,SEL24) as monotherapy andincombination with glofitamab in patientswith relapsed or refractory aggressive B-cell non-Hodgkin lymphoma

Session name: 627. Aggressive lymphomas: Targeted and pharmacologictherapies: Poster 3

Session date and time:December 8, 6:00-8:00 PM EST

Poster number: 5481

The Phase II JASPIS-01 study evaluates dapolsertib (MEN1703), a dualPIM/FLT3 kinase inhibitor, as monotherapy and in combination with theCD20xCD3 bispecific antibody glofitamab in patients with relapsed orrefractory (R/R) aggressive B-cell lymphomas who have received at least2 prior lines of therapy. Dapolsertib targets key oncogenic and survivalpathways, including MYC- and BCL6-associated signaling, and hasdemonstrated preclinical synergy with anti-CD20 antibodies. The studyaims to assess the safety, tolerability, and preliminary efficacy ofdapolsertib while exploring its potential to overcome resistanceassociated with CD20 downregulation. In Part 1, patients are enrolledinto two groups: (i) bispecific-nave patients receiving dapolsertib +glofitamab in dose-optimization cohorts, and (ii) heavily pretreatedpatients receiving dapolsertib monotherapy. Two dosing schedules arebeing explored - 125 mg (2 weeks on/1 week off) and 150 mg (1 week on/2weeks off) - to identify the optimal therapeutic window. Dose selectionfor Part 2 will be guided by the Data and Safety Monitoring Board(DSMB), following safety review after 2 treatment cycles. As of datacutoff, enrollment in Part 1 is ongoing across 32 sites in France,Poland, Spain, and the UK. 12 patients have been treated to date acrossthe combination and monotherapy cohorts. While enrollment isprogressing, the next program milestone, the Data and Safety MonitoringBoard (DSMB) review, is anticipated in upcoming weeks. This studyrepresents the first clinical evaluation of dapolsertib in B-celllymphoma and seeks to establish a foundation for novel combinationstrategies addressing resistance to CD20-targeted immunotherapies.

All posters are now available online and can be downloaded from the Ryvuwebsite: https://ryvu.com/publications as well as from the conferencewebsite: https://www.hematology.org/meetings/annual-meeting

Disclaimer: This English language translation has been prepared solelyfor the convenience of English-speaking readers. Despite all the effortsdevoted to this translation, certain discrepancies, omissions orapproximations may exist. In case of any differences between the Polishand the English versions, the Polish version shall prevail. RyvuTherapeutics S.A., its representatives and employees decline allresponsibility in this regard.