Research shows that Pepaxti is effective in high-risk myeloma
Oncopeptides recently announced new research demonstrating that Pepaxti (melflufen) maintains its anti-myeloma activity in patients with high-risk genetic features, including deletion 17p (del(17p)) and TP53 mutations. These abnormalities are known to be linked to more aggressive disease being less responsive to treatment. The data has been published in an article in Experimental Hematology & Oncology.
The findings come from a collaborative study conducted by researchers in Finland, Germany and Sweden, using patient samples, disease models and clinical data. The research supports earlier observations from the phase 3 OCEAN study.
Key highlights from the study
- Consistent activity in high-risk patients:
In laboratory testing of bone marrow samples from 24 myeloma patients, Pepaxti showed strong activity across all genetic subgroups, including those with del(17p) and TP53 mutations. This was in clear contrast to standard alkylating agents. - Mechanism of action maintained despite loss of functional TP53:
Pepaxti triggered rapid cell death and DNA damage in both normal and TP53-deficient myeloma models, indicating a mode of action that does not rely on functional TP53. - Clinical relevance confirmed in OCEAN:
A post-hoc analysis of the OCEAN study showed that patients with del(17p) treated with Pepaxti and dexamethasone achieved longer progression-free survival compared to pomalidomide-based treatment.
“These results help explain why Pepaxti performs well even in some of the most challenging forms of myeloma,” says Caroline Heckman, Senior Author and Research Director, Institute for Molecular Medicine Finland-FIMM, HiLIFE-Helsinki Institute of Life Science, University of Helsinki, Finland. “Understanding how Pepaxti works in these high-risk patients gives physicians additional confidence when evaluating treatment options.”
“The study adds to a growing body of evidence supporting Pepaxti and the PDC platform´s differentiation versus conventional alkylators and reflects what we have seen in both clinical trials and real-world patients,” says Stefan Norin, Chief Medical Officer at Oncopeptides. “We remain committed to expanding scientific knowledge and supporting the myeloma community with high-quality research. In addition we use our expanding scientific knowledge to further develop our PDC pipeline.”
The full research article, Efficacy of Melflufen in Multiple Myeloma with Mutated or Deleted TP53, is available through this link.
More information, including questions and answers for investors, will be posted on oncopeptides.com.
INVESTOR Q&A
What is being announced?
New independent and Oncopeptides-supported research showing that Pepaxti remains active in high-risk multiple myeloma, including patients with del(17p) and TP53 mutations.
Why is this important?
These patients often respond poorly to standard treatments. Demonstrating Pepaxti’s activity in this group strengthens its clinical positioning and relevance for later-line therapy.
What does the new research show?
- Pepaxti is active across all tested genetic backgrounds, including high-risk features.
- Its mechanism of action works independently of changes in TP53, a key genetic driver of poor prognosis.
- Findings are consistent with patient outcomes previously seen in the OCEAN study.
Is this clinical data?
It is a mix of laboratory research, patient-sample analysis and post-hoc evaluation of clinical outcomes from OCEAN.
Does this change the approved indication?
No. The results support Pepaxti’s existing clinical profile but do not affect the approved label.
How does this benefit Oncopeptides?
The data strengthen Pepaxti’s scientific foundation, particularly in high-risk disease, and help inform physicians and payers as awareness and usage continue to grow.
What is TP53?
TP53 is a gene that produces a protein called p53, often referred to as the “guardian of the genome.”
Its job is to help regulate cell growth, repair DNA damage, and prevent cells from becoming cancerous.
When TP53 is mutated, these protective functions are weakened, allowing cancer cells to grow more aggressively and become harder to treat.
What is del(17p)?
del(17p) means that a part of chromosome 17 is missing (“deleted”).
Importantly, this region includes the TP53 gene.
Patients with del(17p) therefore have reduced p53 function, which is associated with more aggressive disease and poorer response to many standard treatments.
Treating patients with del(17p) remains one of the biggest challenges in multiple myeloma.