How real is the breast cancer risk with Ocrevus?

Here is My Question:
My sister has relapsing/remitting form of MS and is currently under treatment with Ocrevus. She is doing quite well and other than fatigue and depression ( under treatment with antidepressants) she is a highly functional individual. Our concern is the increased risk of breast cancer that comes as a warning with Ocrevus - especially since our mum died from breast cancer at the age of 53. Would that be meaningful for my sister to switch over to the newly approved Briumvi when it becomes available? How real is the breast cancer risk with Ocrevus? Thank you a lot in advance.

Answer:
There are continuing reasons to be cautious about the risk of Breast cancer and other malignancies in people with MS treated with immunosuppressive therapies, including the B cell depleting therapies. Current B cell depleting therapies include Rituximab, Ocrevus, Briumvi and Kesimpta.

Remember the risk of malignancy increases with age. Therefore, the most relevant clinical data sets will be those that include older people with MS. Ocrelizumab was studied in 2 separate trials involving younger relapsing patients and older primary progressive patients.

The median age of patients participating in the Ocrevus primary progressive trial was 46, whereas patients participating in the relapsing trial were approximately 10 years younger on average.

In the primary progressive MS clinical trial called Oratorio there were 11 cases of malignancy (4 cases of breast cancer) among 488 patients (2.25 %) treated with Ocrevus versus 2 cases of malignancy (no cases of breast cancer) among 244 patients (0.82 %) treated with placebo.

As expected, rates of cancer in the younger patients participating in the Opera clinical trials for relapsing remitting MS were lower; there were 4 cases of cancer (2 breast cancer) among 827 people (0.48 %) treated with Ocrevus and 2 cases of cancer (no case of breast cancer) among 829 patients (0.24 %) treated with Interferon Beta-1a (Rebif).

While these rates of cancer are still relatively low, it is also important to realize that they occurred within 3 years of onset of treatment- a relatively short period of time- and there was no formal screening of participants for cancer or cancer risk prior to onset of treatment. It is certainly possible that cancer was already developing in some of these patients prior to starting therapy and the expression of the cancer was accelerated by treatment.

How do we use this information to help minimize risk of cancer on treatment? The most important step is to perform cancer screening prior to initiation of immunosuppressive MS therapy. The screening should be individualized for age, past medical history and family history but should, at a minimum, include baseline followed by annual mammograms in woman.

Remember, these therapies are wonderfully effective, particularly in younger individuals with relapsing MS. Their effectiveness diminishes with age (> 50) and with progressive disease, while risk of cancer increases with age. Because of the differential risks of cancer and infections by age group and disease type, the decision on when to initiate or stop therapy must be made individually. 

Revere P (Rip) Kinkel, MDProfessor of Neurosciences
Director of the Multiple Sclerosis Program
University of California San Diego
#MS #multiplesclerosis #Ocrevus #cancer #Briumvi