1. Molecular Partners presented data on MP0533 at ASH Annual Meeting. 2. Phase 1/2a trial shows MP0533 has acceptable safety and efficacy. 3. Promising results in low disease burden patients with AML. 4. Ongoing interest from consortia for further studies of MP0533. 5. MP0533 targets multiple antigens, enhancing T-cell activation.
FAQ
Why Bullish?
Strong preliminary results from Phase 1/2a trial can drive investor interest, resembling past successes like KITE Pharma's Yescarta.
How important is it?
Positive trial data from MP0533 could significantly influence MOLN’s market perception and engagement.
Why Short Term?
Immediate investor reactions are expected post-presentation, similar to historic biotech conference impacts.
Molecular Partners Presents Updated Data on MP0533 at ASH Annual Meeting
On December 7, 2025, Molecular Partners AG (SIX: MOLN; NASDAQ: MOLN), a pioneering clinical-stage biotech company, revealed promising new data from their ongoing Phase 1/2a trial of the multispecific T-cell engager MP0533. This research focuses on patients suffering from acute myeloid leukemia (AML) and was presented at the 67th American Society of Hematology (ASH) Annual Meeting and Exposition held in Orlando, Florida, from December 6 to 9, 2025.
Trial Overview and Key Findings
The trial, which is documented on ClinicalTrials.gov under the identifier NCT05673057, is an open-label, multicenter study assessing the efficacy of MP0533 in treating relapsed/refractory (R/R) AML and myelodysplastic syndrome (MDS) combined with AML. The latest data from cohorts 8 and 9 indicate that the densified dosing regimen is acceptable and leads to significantly improved serum exposure during treatment cycle 1, showing preliminary antitumor activity.
- 54 patients have been treated with MP0533 as of the data cut-off on September 1, 2025.
- Eight out of 48 evaluable patients achieved a response:
- 5 achieved composite complete responses (3 complete responses and 2 with partial hematologic recovery).
- 3 reached a morphologic leukemia-free state (MLFS).
- Six of the eight responders and 11 of 14 patients who showed more than a 50% reduction in bone marrow blasts had less than 20% bone marrow blast counts at baseline.
Expert Commentary on MP0533 Findings
Prof. Courtney DiNardo, M.D., from The University of Texas MD Anderson Cancer Center, highlighted the significance of the results: "The results in patients with higher frequency dosing regimens of MP0533 are very encouraging. This data suggests that MP0533 could greatly enhance treatment options for AML patients, particularly those with a lower disease burden."
As per the study data, one patient from cohort 8 has maintained complete remission for over a year, while another in cohort 9 continues treatment after four months. The ongoing cohort 10 aims to reach the same target dose as cohort 8 but with a prolonged exposure to the drug, with results expected in 2026.
Safety and Future Development Plans
Philippe Legenne, M.D., the Chief Medical Officer of Molecular Partners, stated: "The Phase 1/2a trial with MP0533 is progressing well, showcasing a feasible densified dosing regimen and an acceptable safety profile, yielding clinical benefit. These results support the need for further exploration of MP0533 across both R/R and front-line AML settings."
Molecular Partners is engaging with potential partners and regulators to advance the development of MP0533 in combination with existing treatments.
The Mechanism of Action of MP0533
MP0533 is a novel tetra-specific T cell-engaging DARPin, designed to target AML cells selectively while preserving healthy tissue. It binds to three tumor-associated antigens (CD33, CD123, and CD70) and the immune activator CD3 on T cells, making it more effective against AML cells that often co-express these antigens.
About Molecular Partners
Molecular Partners AG (SIX: MOLN; NASDAQ: MOLN) focuses on developing innovative DARPin therapeutics for a range of medical challenges that are not adequately addressed by current drug modalities. Established in 2004, the company has made significant advancements in oncology drug design and development.
For more information, visit www.molecularpartners.com or follow them on social media via LinkedIn and Twitter/X @MolecularPrtnrs.