The Cancer Years

What is mogamulizumab?

Mogamulizumab, sold under the brand name Poteligeo, is an immunotherapy used specifically to treat two forms of cutaneous T-cell lymphoma: mycosis fungoides and Sézary syndrome.

It is what is known as a monoclonal antibody. That sounds complicated, but in basic terms it means the drug is a laboratory-made antibody designed to recognize a particular target on certain cells.

That target is called CCR4.

That feels like an important change in my treatment. Until now, much of what I have been doing has been aimed at controlling what the disease was doing to my skin. With mogamulizumab, we are much more directly targeting the cancer itself.

How is the treatment given?

Mogamulizumab is given through an IV infusion. The medication is diluted into an IV bag and administered slowly rather than being injected all at once.

The infusion itself generally takes at least an hour, although the entire appointment can obviously take longer because of preparation, monitoring, bloodwork, medications given beforehand, and whatever else needs to happen that day.

Because some people experience reactions while the medication is being infused, particularly during the first treatment, I will be monitored while I receive it. Medications such as acetaminophen and an antihistamine may also be given beforehand to reduce the chance or severity of an infusion reaction.

I will be able to describe this much better after September 23. Right now, anything I said about what sitting through the infusion feels like would simply be a guess, and I would rather tell you what actually happens.

What side effects can it cause?

This is the part of every cancer drug description that can become intimidating very quickly. There is a long list of things that can happen, but that does not mean all of them will happen to me, or to anyone else who receives the treatment.

The more commonly reported side effects of mogamulizumab include skin rash, infusion reactions, fatigue, diarrhea, muscle or joint pain, respiratory infections, nausea, fever, headaches, constipation, mouth irritation, and changes in blood counts.

Fatigue

Fatigue is one of the more commonly reported effects. Cancer-related fatigue can be different from simply being tired after a long day. It can be a much deeper feeling of having very little physical energy.

This is something I will be watching closely because fatigue is already a major part of my life. I have been sick for a long time, so it may initially be difficult to know what comes from the cancer, what remains from previous treatment, and what is actually being caused by mogamulizumab.

Skin reactions and rashes

Skin reactions are particularly interesting with this treatment because the cancer itself already affects my skin.

Rashes are fairly common with mogamulizumab. Most are mild or moderate, but more serious skin reactions can occur. One complication is that a drug-related rash can sometimes resemble the lymphoma itself, so doctors may occasionally need to investigate a skin change rather than assuming they know what is causing it.

Very rare but potentially serious skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, have also been reported. Those are very different from an ordinary rash and require immediate medical attention.

Infusion reactions

An infusion reaction means the body reacts while the medication is being given or shortly afterward.

Symptoms can include chills, fever, nausea, vomiting, headache, shaking, or a rapid heartbeat. These reactions are particularly associated with the first infusion, which is one of the reasons the medical team monitors patients closely while the drug is being administered.

If a reaction happens, the infusion can be slowed or stopped while the symptoms are treated. Having an infusion reaction does not automatically mean the treatment has to be abandoned.

Diarrhea and nausea

Both diarrhea and nausea can occur with mogamulizumab. Constipation can occur as well, which is a good example of how differently the same medication can affect different people.

I am particularly interested in what happens with this side of the treatment because eating has already been difficult for me for a long time. I currently rely heavily on meal replacement drinks because solid food can be difficult to keep down.

Whether mogamulizumab makes that better, worse, or has very little effect on it is something I simply do not know yet.

Infections

Because mogamulizumab affects part of the immune system, infections are something the medical team has to watch for.

Respiratory infections and skin infections have occurred in people receiving the drug, and more serious infections can sometimes happen as well. That means things such as fevers, unusual symptoms, or signs of infection may need to be reported rather than simply ignored.

Muscle and joint pain

Some people experience muscle, joint, back, bone, neck, or limb pain while receiving the treatment.

Again, I have no idea whether this will happen to me. It is simply one of the things I will be paying attention to once treatment begins.

Blood counts

Mogamulizumab can affect blood counts, including red blood cells and platelets. This is one of the reasons bloodwork is such a routine part of cancer treatment.

The doctors are not only checking whether the treatment appears to be working. They are also watching what it is doing to the rest of the body.

The rarer but more serious risks

I include these things because I want this page to be accurate, not because I expect every frightening possibility listed in the drug information to happen to me.

There is a very big difference between “this can happen” and “this will happen.”

What do I actually expect?

Right now, I honestly do not know.

I know the list of possible side effects. I know what I have been told. I know what the research and drug information say. What I do not know is which version of this treatment I am personally going to experience.

Two people can receive exactly the same cancer medication and have very different experiences with it. I could tolerate it relatively well. I could feel terrible. The first treatment could be difficult and later ones could become easier. Some side effects could appear immediately, while others might not appear until weeks or months into treatment.

Until I actually start, all of that is hypothetical.

I do not want The Cancer Years to become a place where I pretend that reading the drug information is the same thing as actually living through the treatment.

Why I am hopeful

Despite the list of possible side effects, I am approaching this treatment with hope.

For much of the last couple of years, I have felt as though we were treating what the cancer was doing rather than really attacking the cancer itself. There is an important difference for me now.

Mogamulizumab has a specific target. It recognizes CCR4 on certain T cells and helps the immune system destroy them. For a cancer that is fundamentally a disease of T cells, that feels much more concrete to me than simply trying to keep the skin inflammation under control.

I know that does not guarantee it will work, and it certainly does not guarantee that the treatment will be easy.

But after spending so much time feeling sick while trying to keep the disease contained, I am ready to start treating the thing itself.