Sometimes a research project starts with a molecular hypothesis.
This one started with patients.
While examining electronic health records from Leumit Health Services, we noticed something unexpected: people who had used simvastatin, one of the most widely prescribed cholesterol-lowering drugs in the world, appeared less likely to develop multiple myeloma.
At first, this was simply an epidemiological signal.
Medical databases are full of associations. Patients who take one medication may differ from those who do not in age, health status, medical follow-up, lifestyle, or many other ways. An association in electronic health records is not proof that a drug prevents a disease.
But this particular finding raised a question that could actually be tested:
Could simvastatin have a biological effect on multiple myeloma?
Together with our partners at Ariel University, we followed the clue from patient records into the laboratory.
First into myeloma cells.
Then into a living model of the disease.
And what we found became progressively more interesting.
A cancer that can often be seen coming
Multiple myeloma is a cancer of plasma cells, the immune cells in our bone marrow that normally produce antibodies.
In myeloma, one abnormal clone of plasma cells expands progressively. As the malignant cells accumulate in the bone marrow, they can interfere with normal blood formation, weaken bone, damage the kidneys, raise blood calcium levels and impair immunity.
Modern treatment has changed the disease profoundly.
Patients can now receive combinations of proteasome inhibitors, immunomodulatory drugs, corticosteroids and monoclonal antibodies such as daratumumab. Autologous stem-cell transplantation remains important for many patients, and newer approaches such as CAR-T cells and bispecific antibodies have produced remarkable responses even in advanced disease.
Yet multiple myeloma remains difficult to cure permanently.
What makes it especially interesting from a prevention perspective is that it usually does not appear suddenly.
Long before active myeloma develops, a small abnormal population of plasma cells is often already present.
The earliest recognizable stage is called MGUS (monoclonal gammopathy of undetermined significance).
MGUS is common, particularly with increasing age. People with MGUS have a small clone of abnormal plasma cells and a detectable monoclonal protein, but no damage to the bones, kidneys or other organs.
Most people with MGUS never develop multiple myeloma.
But some do.
In a subset of patients, the abnormal clone expands into an intermediate stage called smoldering multiple myeloma. The burden of abnormal plasma cells is higher and the risk of progression is greater, but the patient still does not have symptomatic myeloma.
Only later, in some patients, does active multiple myeloma emerge.
The sequence can therefore be thought of as:
MGUS → smoldering multiple myeloma → active multiple myeloma
That progression creates something unusual in cancer medicine:
a window of time in which the malignant process may be detectable before it becomes clinically destructive.
And that immediately raises another question:
Could we intervene during that window?
The first clue came from the medical records
For the epidemiological part of our study, we used longitudinal data from Leumit Health Services.
We identified 724 patients with multiple myeloma and compared them with 14,480 matched controls.
We then examined pharmacy purchases during the seven years preceding diagnosis.
One medication stood out.
Simvastatin had been purchased by 44.1% of patients who later developed multiple myeloma, compared with 49.7% of controls.
After adjustment, simvastatin exposure was associated with approximately 20% lower odds of multiple myeloma.
This was interesting.
But it was still only an observation.
There were many possible explanations other than a true protective effect.
If the project had stopped there, the finding would have remained an epidemiological curiosity.
Instead, we asked whether it had a biological counterpart.
What happens when myeloma cells meet simvastatin?
Our partners at Ariel University tested simvastatin directly on both human and mouse myeloma cell lines.
The drug inhibited their growth.
More importantly, the malignant cells began to undergo apoptosis: programmed cell death.
This was not indiscriminate toxicity. Normal human peripheral blood cells were considerably less sensitive under the experimental conditions.
There was also substantial variation between different myeloma cell lines.
Some were highly sensitive to simvastatin.
Others required considerably higher concentrations.
That heterogeneity is important because multiple myeloma is not one biologically uniform disease. If this pathway eventually proves useful therapeutically, it is quite possible that some myelomas will be much more susceptible than others.
There is also an important caveat.
The concentrations required to kill some human myeloma cells in vitro were higher than those usually achieved in the bloodstream with standard statin therapy.
So the experiment does not mean that taking an ordinary dose of simvastatin will kill myeloma cells in a patient.
But it changed the nature of the original finding.
The association we had seen in patients was now accompanied by a measurable biological effect on the malignant cells themselves.
Why would a cholesterol drug affect a cancer cell?
Simvastatin blocks an enzyme called HMG-CoA reductase, a central component of the mevalonate pathway.
Clinically, we usually think about this pathway because it is involved in cholesterol synthesis.
But cancer cells use it for much more than cholesterol.
Rapidly dividing cells need to manufacture new membranes. The mevalonate pathway also produces molecules required for important intracellular signaling proteins involved in growth, metabolism and survival.
A myeloma cell therefore depends on this pathway for reasons that have little to do with a patient’s LDL level.
Blocking it may place malignant plasma cells under metabolic stress severe enough, in some cases, to trigger cell death.
That provided a plausible biological explanation for the in-vitro findings.
But a cell culture still cannot reproduce what happens inside a living bone marrow.
So we moved to the next question.
Would the drug change the course of the disease?
Our collaborators at Ariel University used an immunocompetent mouse model in which multiple myeloma develops progressively within the bone marrow.
The animals were followed over an extended period.
At first, the difference between treated and untreated animals was modest.
Then the trajectories began to separate.
In untreated mice, the burden of myeloma cells in the bone marrow increased, together with the abnormal immunoglobulin produced by the tumor.
In mice receiving long-term simvastatin, progression was markedly reduced.
By day 190, using the combined criteria defined in the study, all of the untreated myeloma-bearing animals had progressed, while none of the simvastatin-treated animals had.
The numbers were small, as is common in mechanistic animal studies, and a mouse model is certainly not a human clinical trial.
But this was no longer simply a demonstration that simvastatin could affect cancer cells in a dish.
It suggested that long-term exposure could influence the trajectory of the disease itself.
And then the study produced another surprise.
The immune system was changing too
Multiple myeloma does not evolve in isolation.
It grows inside the bone marrow, surrounded by stromal cells, blood-forming cells, signaling molecules and immune cells.
As myeloma progresses, it gradually changes this environment in ways that favor its own survival.
One part of that process involves weakening the immune cells that might otherwise restrain the malignant clone.
When we examined the immune system in the mouse model, long-term simvastatin treatment was associated with changes in CD8+ T cells and with enhanced cell-mediated killing of myeloma cells.
This suggested that simvastatin might be acting at two different levels.
It could affect the malignant plasma cell directly.
But it might also alter the immune environment in which that malignant cell is trying to survive and expand.
In healthy animals, simvastatin also increased circulating IgA and IgG concentrations, another indication that its biological effects extended beyond cholesterol metabolism.
This possible dual action, direct anti-myeloma activity combined with immune modulation, may be particularly relevant to the slow evolution of the disease from precursor states.
Perhaps the most interesting target is not advanced myeloma
At the stage of symptomatic multiple myeloma, we already have powerful therapies.
A repurposed statin is unlikely to replace modern multi-drug regimens, transplantation, CAR-T therapy or bispecific antibodies.
But perhaps that is not where the main opportunity lies.
Imagine a patient with MGUS.
Or a patient with high-risk smoldering myeloma.
The abnormal clone is already detectable.
But the tumor burden is still much smaller than it will be once active myeloma develops.
There may still be a relatively favorable balance between the malignant clone and the immune system.
And irreversible organ damage has not yet occurred.
In that setting, an intervention might not need to eradicate every abnormal cell.
It might be enough to make the environment slightly less favorable to expansion.
Or to help the immune system maintain control for longer.
Could progression be delayed by several years?
Could some patients remain indefinitely in a precursor state and never develop symptomatic myeloma during their lifetime?
Those are very different goals from treating advanced cancer.
And they are becoming increasingly relevant.
For many years, precursor states were observed rather than treated.
MGUS is still monitored rather than treated.
But in selected patients with high-risk smoldering multiple myeloma, early treatment has now become a genuine clinical option.
The idea of preventing or delaying active myeloma is therefore no longer purely theoretical.
Does this mean people with MGUS should take simvastatin?
No.
Our study does not show that prescribing simvastatin to someone with MGUS or smoldering myeloma prevents multiple myeloma.
The human part of the study was observational and cannot prove causation.
The cell experiments demonstrate biological activity, but a culture dish does not reproduce human pharmacology.
The animal experiments demonstrate an effect on disease progression and immunity in a living organism, but mice are not humans.
So this study is not a treatment recommendation.
What it provides is something different:
a coherent hypothesis supported at three different levels.
We first observed a signal in patients.
Then we demonstrated a direct effect on myeloma cells.
Finally, we found delayed progression and altered anti-myeloma immunity in an animal model.
Each level of evidence has limitations.
Together, they make the question considerably harder to dismiss.
An old drug, a new question
Simvastatin is not an exotic cancer therapy.
It is a decades-old generic medication whose pharmacology and safety are already well understood.
This reasearch results raise important questions:
Could statin treatment influence progression from MGUS to smoldering myeloma?
Could it delay active disease in patients with high-risk smoldering myeloma?
Are some molecular forms of myeloma particularly dependent on the mevalonate pathway?
Can we identify patients whose malignant plasma cells are especially sensitive?
Is the most important effect direct inhibition of the tumor, modulation of the immune response, or both?
And could this pathway complement existing immune-based treatments?
Our newly published paper
Aharon Lion, Arieh Y. Israel, Eugene Merzon, Howard Oster, Abraham Weizman, Galia Luboshits, Bjarne Bogen, Moshe Mittelman and Michael A. Firer.
Simvastatin as an immunomodulator and anti-myeloma agent – epidemiological, in vitro and murine model studies.
Frontiers in Immunology. 2026;17:1882291.
DOI: 10.3389/fimmu.2026.1882291