Mavenclad, whose active ingredient is cladribine, is a medication primarily used to treat relapsing forms of multiple sclerosis (MS). It works by selectively targeting certain immune cells, particularly lymphocytes, which play a role in the autoimmune process that damages nerve cells in MS. However, because it affects the immune system, concerns have been raised about whether Mavenclad increases the risk of cancer.
Mavenclad does carry a **potential increased risk of malignancy**. Clinical studies have shown that patients treated with Mavenclad experienced a higher incidence of cancers compared to those given a placebo. For example, in controlled trials, malignancies such as metastatic pancreatic carcinoma, malignant melanoma, and ovarian cancer were reported more frequently in patients receiving Mavenclad than in those on placebo. The overall rate of malignancies in Mavenclad-treated patients was roughly double that seen in placebo groups. However, the types of cancers and their severity varied, and some cancers in placebo groups were less severe and curable by surgery. The data also suggested that the risk might be higher in certain populations, such as patients in the United States, although this observation was based on limited data.
The risk appears to be linked to the **immune-suppressing effects** of Mavenclad. By reducing lymphocyte counts—sometimes dramatically—Mavenclad lowers the body’s immune surveillance, which normally helps detect and destroy cancerous cells early. This immune suppression can also increase vulnerability to infections, which is why patients on Mavenclad are closely monitored with blood tests to track lymphocyte levels. If lymphocyte counts drop too low, treatment is paused or delayed to reduce risks.
Importantly, Mavenclad is **not recommended for patients who currently have cancer**. For those with a history of malignancy or who are at increased risk for cancer, doctors must carefully weigh the benefits of treating MS with Mavenclad against the potential cancer risk on an individual basis. Standard cancer screening guidelines are advised for patients receiving Mavenclad to catch any malignancies early.
The treatment regimen itself is designed to minimize risk. Mavenclad is typically given in two annual courses, and additional treatment within two years after these courses is generally avoided because studies showed an increased incidence of malignancy when treatment was reinitiated too soon. The safety of restarting treatment after more than two years has not been well studied.
Besides cancer risk, Mavenclad’s side effects include common issues like headaches, upper respiratory infections, and blood cell count decreases. The drop in lymphocytes is dose-dependent and can be significant, affecting up to 87% of patients in trials. This immune suppression explains both the increased infection risk and the potential for malignancy, as the immune system’s ability to detect abnormal cells is compromised.
Patients on Mavenclad undergo regular blood monitoring before and after treatment courses to ensure lymphocyte counts remain within safe limits. If counts fall below critical thresholds, treatment is paused to allow recovery. This careful monitoring helps manage the balance between controlling MS and minimizing adverse effects, including cancer risk.
In summary, while Mavenclad is an effective treatment for certain forms of MS, it does increase the risk of developing malignancies due to its immunosuppressive action. This risk is managed through strict treatment protocols, patient selection, and ongoing monitoring. Patients with existing cancer or high cancer risk are generally advised against using Mavenclad, and those treated with it should follow recommended cancer screening practices. The decision to use Mavenclad involves weighing its benefits in controlling MS against the potential increased risk of cancer, with close medical supervision throughout treatment.
