FDA Grants Bexmarilimab Orphan Drug Designation for MDS
The investigational immunotherapy bexmarilimab has been granted orphan drug designation from the FDA for patients with myelodysplastic syndromes.
US FDA
- The FDA has granted bexmarilimab orphan drug designation (ODD) for the potential treatment of patients with myelodysplastic syndromes (MDS).
- Bexmarilimab is an investigational immunotherapy bexmarilimab that binds to Clever-1.
- An ongoing phase 1/2 BEXMAB trial (NCT05428969) is assessing bexmarilimab in patients with MDS, chronic myelomonocytic leukemia (CMML), or acute myeloid leukemia (AML).
The FDA has granted orphan drug designation to the investigational immunotherapy bexmarilimab as a potential therapeutic option for patients with myelodysplastic syndromes (MDS).1
Bexmarilimab is an investigational immunotherapy that aims to overcome resistance to existing treatments and optimize clinical outcomes. This is done by targeting myeloid cell function and igniting the immune system.
The agent works by binding to Clever-1, an immunosuppressive receptor that is seen on macrophages, leading to tumor growth and metastases. When the Clever-1 receptor is targeted, bexmarilimab changes the tumor microenvironment, reprogramming macrophages from an immunosuppressive to an immunostimulatory state.1
“Receiving FDA’s orphan drug designation for bexmarilimab for the treatment of MDS marks a significant milestone for Faron Pharmaceuticals as we continue to develop bexmarilimab for MDS and other cancers,” said Petri Bono, MD, PhD, chief medical officer of Faron Pharmaceuticals, in a press release. “This FDA orphan drug designation, along with the previously granted FDA fast track designation, highlights our continued progress and reinforces our belief in the potential of bexmarilimab to address this significant unmet need for treatment of MDS. These designations allow us to receive important regulatory guidance for the development of bexmarilimab and potential additional market exclusivity upon approval.”
The ongoing phase 1/2 BEXMAB trial (NCT05428969) is currently evaluating bexmarilimab for the treatment of patients with MDS, CMML, or AML.2
In phase 1 of the study, bexmarilimab was given to patients at 4 different dose levels plus standard-of-care azacitidine. Patients received bexmarilimab was once a week, then once every 2 weeks during 28-day cycles. Patients with newly diagnosed AML unfit for induction therapy were treated with bexmarilimab at 1 of 4 dose levels plus azacitidine and venetoclax (Venclexta). In phase 2 of the study, patients are being treated with bexmarilimab at a dose determined in phase 1 in combination with venetoclax and/or azacitidine.
The study is open to patients aged 18 years or older with morphologically confirmed intermediate-, high-, or very high–risk MDS, as defined by the revised International Prognostic Scoring System, or CMML-2 with an indication for azacitidine. Eligible patients must have demonstrated a lack of response to a hypomethylating agent (HMA)-containing regimen.
Additionally, the study includes patients with morphologically confirmed relapsed/refractory AML following at least 1 prior line of therapy and who are indicated for azacitidine, as well as patients with AML who are unfit for induction therapy and are indicated for azacitidine plus venetoclax. All participants must have adequate renal and liver function.
Dose-limiting toxicities, safety, complete response (CR) rate for patients with MDS or CMML-2, overall response rate for patients with MDS or CMML who progressed on a prior HMA, CR with incomplete blood count recovery rate in patients with relapsed/refractory AML, and minimal residual disease status for those with newly diagnosed AML serve as the primary end points of the trial.
The study's secondary end points included the frequency and severity of treatment-emergent adverse events and serious adverse events, assessed by NCI-CTCAE grading from study start to 30 days after end of treatment. Clinical efficacy was measured by progression-free survival and overall survival over 2 years. Additionally, anti-bexmarilimab antibody positivity was tracked pre-dose and at key timepoints, and serum concentrations of bexmarilimab were measured at defined intervals through cycle 2.
The estimated study completion date is December 31, 2025.
For patients with newly diagnosed MDS or relapsed/refractory MDS following progression on an HMA, topline data are anticipated to be released in April 2025.1
REFERENCES
Inside information: FDA grants orphan drug designation for bexmarilimab in MDS. News release. Faron Pharmaceuticals. March 3, 2025. Accessed March 4, 2025. https://tinyurl.com/4356vnnc
A study to assess safety, tolerability and preliminary efficacy of bexmarilimab in combination with standard of care in patients with hematological malignancies (BEXMAB). ClinicalTrials.gov. Updated January 16, 2025. Accessed March 4, 2025. https://clinicaltrials.gov/study/NCT05428969
