Monoclonal Antibodies for Multiple Myeloma: Benefits and Risks

If you’ve been told you have multiple myeloma, you’ve probably also been handed a brand-new vocabulary:
proteasome inhibitors, IMiDs, monoclonal antibodies and a whole alphabet of drug names. It’s a lot.
The good news? Monoclonal antibodies (often called “mAbs”) have become one of the biggest advances in
myeloma treatment over the last decade, helping many people live longer and feel better. The not-so-fun news?
Like every powerful therapy, they also come with side effects and trade-offs.

In this article, we’ll walk through what monoclonal antibodies are, how they’re used for multiple myeloma,
what their main benefits are, and what risks and side effects you should know about. We’ll keep the language
human, sprinkle in some gentle humor, and stay grounded in current medical evidence. This is for information
only and isn’t a substitute for personalized advice from your oncology team.

Multiple Myeloma 101: The Basics

Multiple myeloma is a type of blood cancer that starts in plasma cells, a kind of white blood cell that
normally helps you fight infections. In myeloma, these plasma cells become cancerous, multiply out of
control, and crowd out healthy blood-forming cells in the bone marrow. That can lead to:

• Bone pain or fractures
• Low blood counts (anemia, low platelets, low white cells)
• High calcium levels
• Kidney problems

Traditional treatment options include chemotherapy, steroids, immunomodulatory drugs (like lenalidomide),
proteasome inhibitors (like bortezomib), and stem cell transplant. Today, many treatment plans also include
monoclonal antibodies as a core piece of the puzzle, both for newly diagnosed and relapsed/refractory
multiple myeloma.

What Are Monoclonal Antibodies?

Think of monoclonal antibodies as highly specialized “guided missiles” built by scientists to latch onto
specific targets on cancer cells. Your own immune system makes antibodies to recognize viruses and bacteria.
Monoclonal antibodies are lab-made versions designed to recognize very particular proteins, often on the
surface of myeloma cells.

In multiple myeloma, the main monoclonal antibody classes used are:

• Anti-CD38 antibodies (like daratumumab and isatuximab)
• Anti-SLAMF7 antibodies (like elotuzumab)
• Newer antibody-based drugs, including bispecific antibodies and antibody–drug conjugates

These drugs don’t just float around looking pretty. Once they attach to their target, they can flag myeloma
cells for destruction by the immune system, directly damage the cancer cells, or deliver a toxic “payload”
to kill them. Different monoclonal antibodies use slightly different tricks, but the end goal is the same:
shrink the myeloma and keep it under control.

Main Monoclonal Antibodies Used in Multiple Myeloma

Anti-CD38 Antibodies: Daratumumab and Isatuximab

CD38 is a protein that’s highly expressed on myeloma cells, which makes it a handy “bullseye” for therapy.
Anti-CD38 monoclonal antibodies such as daratumumab and isatuximab bind to CD38,
helping the immune system recognize and kill myeloma cells. Large clinical trials have shown that combining
these drugs with standard regimens (like lenalidomide and dexamethasone or bortezomib-based combinations)
can deepen responses and extend the time before the disease comes back.

Daratumumab and isatuximab are now used in multiple settings: for people with newly diagnosed myeloma who
can’t have a stem cell transplant, for transplant-eligible patients alongside other drugs, and for those
whose myeloma has relapsed or become more resistant to prior therapies.

Anti-SLAMF7 Antibody: Elotuzumab

Elotuzumab targets SLAMF7, a protein found on myeloma cells and on natural killer (NK) cells,
a type of immune cell that can attack cancer. By binding to SLAMF7, elotuzumab acts like a matchmaker,
bringing NK cells and myeloma cells together so the immune system can do more damage to the cancer.

Elotuzumab is generally used in combination with other drugs such as lenalidomide or pomalidomide plus
dexamethasone. On its own, it doesn’t have much anti-myeloma activity, but in combination regimens it has
been shown to improve response rates and progression-free survival in relapsed/refractory multiple myeloma.

Newer Antibody-Based Approaches

In recent years, even more complex antibody-based strategies have shown promise, including:

• BCMA-directed bispecific antibodies (such as teclistamab), which engage T cells and bring them
  into direct contact with myeloma cells.
• Antibody–drug conjugates, which attach a chemotherapy-like toxin to an antibody so the drug
  is delivered straight to a cancer cell.

These treatments are usually used in heavily pretreated, relapsed/refractory myeloma and have their own,
sometimes more intense, risk profiles. But the core ideausing antibodies as precision-guided toolsremains
the same.

Key Benefits of Monoclonal Antibodies for Multiple Myeloma

1. Deeper Responses and Longer Control of the Disease

One of the biggest benefits of monoclonal antibody therapy is the ability to achieve
deeper remissions. When added to standard regimens, anti-CD38 monoclonal antibodies often:

• Increase the percentage of patients who respond to treatment
• Raise the number of patients reaching very good partial response (VGPR) or complete response
• Extend the time before the disease progresses again

For many people, that can translate into longer periods between treatment changes and more time feeling like
yourself instead of living from scan to scan.

2. Synergy with Other Myeloma Drugs

Monoclonal antibodies are rarely used alone. They’re usually combined with drugs like:

• Immunomodulatory drugs (IMiDs) such as lenalidomide or pomalidomide
• Proteasome inhibitors such as bortezomib or carfilzomib
• Dexamethasone, a steroid that also has anti-myeloma activity

These combinations attack myeloma from multiple anglesthink of it like a coordinated team effort rather
than a solo mission. The result is often more effective disease control than with older regimens alone.

3. Options for Relapsed or Refractory Myeloma

Many people with multiple myeloma will go through several lines of therapy over time. Some monoclonal
antibodies are specifically approved for relapsed or refractory multiple myeloma, offering renewed
hope even when prior treatments have stopped working.

For example, patients who have already been treated with proteasome inhibitors and IMiDs may still respond
to anti-CD38 antibodies or to newer bispecific antibodies. Having more tools available allows oncologists
to tailor the sequence of therapies to each person’s disease and overall health.

4. Potential Quality-of-Life Advantages

Monoclonal antibodies can still cause significant side effects, but for some patients they may be easier to
tolerate than traditional chemotherapy. Once you get past the first few infusions (which are often longer and
more closely monitored), treatments may become less frequent or faster, especially when subcutaneous (under
the skin) formulations are used.

Fewer days knocked out with severe nausea, hair loss, or classic “chemo fatigue” can mean more time being
present for work, family, and hobbieseven if you’re still juggling appointments and labs.

Main Risks and Side Effects of Monoclonal Antibody Therapy

Every powerful treatment comes with a price tag in the side-effects department. While your experience will
be unique, certain patterns show up often with monoclonal antibodies for multiple myeloma.

1. Infusion-Related Reactions

Infusion-related reactions are one of the most common side effects of monoclonal antibodies, especially
anti-CD38 drugs. These reactions typically happen during or shortly after the first doses and can include:

• Fever or chills
• Shortness of breath or cough
• Headache, nausea, or vomiting
• Flushing, rash, or itching
• Low blood pressure or chest discomfort

It sounds scary, but most reactions are mild to moderate and are managed with premedications (like steroids,
antihistamines, and acetaminophen) and by slowing or temporarily stopping the infusion. Subcutaneous forms of
some drugs may reduce the risk and intensity of these reactions, but monitoring is still essential.

2. Infections

Monoclonal antibodies can weaken parts of the immune system, especially when used with other myeloma drugs
that also affect white blood cells. This can increase your risk of infections, including:

• Upper respiratory infections and sinus infections
• Pneumonia
• Viral infections such as shingles

Some of the newer bispecific antibodies and heavily pretreated patients may have particularly high infection
rates, making infection prevention and early treatment a central part of care. Your team may recommend
vaccines, antiviral medications, or antibiotics in certain situations, along with careful monitoring.

3. Blood Count Changes (Cytopenias)

Because CD38 and other targets are not only on myeloma cells but also on some healthy blood cells, monoclonal
antibodies can cause:

• Neutropenia (low infection-fighting white cells)
• Anemia (low red blood cells, causing fatigue and shortness of breath)
• Thrombocytopenia (low platelets, raising bleeding or bruising risk)

These lab changes are monitored closely through regular blood tests. Management may include dose delays,
dose adjustments, growth factor injections, or transfusions, depending on the severity and your symptoms.

4. Fatigue, GI Symptoms, and Other “Everyday” Side Effects

Beyond the headline side effects, many people report more general issues such as:

• Tiredness or low energy
• Mild to moderate nausea or diarrhea
• Body aches or back pain
• Cough or shortness of breath

These can sound mundane, but over time, they add up. Good symptom managementlike staying on top of anti-nausea
medications, maintaining hydration, pacing activities, and reporting new symptoms earlycan make a meaningful
difference in how you feel day-to-day.

5. Lab Interference and Other Practical Issues

Anti-CD38 monoclonal antibodies can interfere with certain lab tests, particularly blood typing tests
before transfusions. This doesn’t mean you can’t get a transfusion; it just means the blood bank needs to know
you’re on these medications so they can use special techniques to accurately match your blood type.

There can also be:

• Potential concerns for pregnancy and fetal development (effective birth control is important)
• Financial and insurance hurdles, as these are high-cost therapies
• Time commitment for infusions, especially early in treatment

These are “real life” side effects that don’t show up on lab reports but can heavily influence your treatment
experience and decisions.

Who Might Receive Monoclonal Antibodies?

Whether monoclonal antibodies are right for you depends on several factors, including:

• Your stage of disease (newly diagnosed vs. relapsed/refractory)
• What treatments you’ve already had and how well they worked
• Other health conditions (heart, lung, kidney issues, infections, etc.)
• Your age, general fitness, and personal preferences
• Insurance coverage and access to infusion centers or specialty clinics

For many people, monoclonal antibodies are now part of “standard of care” regimens, but the specific drug,
dose, and schedule are individualized. Your hematologist/oncologist is the best person to help weigh benefits
and risks in your particular situation.

Questions to Ask Your Healthcare Team

When talking about monoclonal antibodies for multiple myeloma, consider asking:

• Why are you recommending this specific antibody (or combination) for me?
• What are the main benefits you hope I’ll get from this treatment?
• What side effects are most common, and how do you usually manage them?
• How often will I need infusions, and for how long?
• What signs of infection or reaction should make me call the clinic right away?
• How will this treatment affect my other medications or planned procedures?
• What are my alternatives if I can’t tolerate this regimen?

Bringing a written list of questions, and even a friend or family member to take notes, can make complex
conversations easier to navigateespecially when you’re absorbing a lot of new information.

Balancing Benefits and Risks

Monoclonal antibodies have reshaped the treatment landscape for multiple myeloma, turning what was once
considered an extremely limited field into one with multiple sophisticated options. Many patients experience
longer remissions, better disease control, and improved survival when these therapies are added to their
treatment plan.

At the same time, side effects like infusion reactions, infections, and blood count changes are not minor
detailsthey are central parts of the decision-making process and day-to-day life with myeloma. Smart
supportive care, honest communication with your medical team, and shared decision-making are key to getting
the most benefit while minimizing risk.

In short, monoclonal antibodies are powerful toolsnot magic wands. Used thoughtfully, they can offer many
people with multiple myeloma more time and better quality of life, which is a big win in a tough disease.

Real-World Experiences: What Living With Antibody Therapy Can Feel Like

Clinical trials provide the numbers, but real life is lived in infusion chairs, waiting rooms, and the quiet
moments at home when you’re deciding whether you have the energy to cook or if it’s going to be a cereal-for-dinner
kind of night. While everyone’s experience is personal, certain themes show up again and again in people who
receive monoclonal antibodies for multiple myeloma.

The First Infusion: “All Eyes on You”

Many people describe the first infusion of a monoclonal antibody as the longest and most nerve-wracking. The
infusion rate often starts very slow, and nurses are watching you like a hawk for any signs of reaction
not because they expect something terrible, but because they want to catch even mild symptoms early.

You’ll usually get premedications such as steroids, antihistamines, and acetaminophen. These help reduce the
chance of infusion-related reactions but may leave you feeling wired (from steroids) or sleepy (from
antihistamines). It’s not unusual to have some chills, flushing, or a scratchy throat during the first dose;
if that happens, the infusion is slowed or paused, more meds are given, and the team monitors you until
things settle down.

Finding a New Routine

Once you’ve made it past those early infusions, many people settle into a routine: certain days of the month
become “treatment days,” and life gets scheduled around them. Some bring a tablet, headphones, or a favorite
blanket to make the hours in the chair more comfortable. Others treat infusion days as a built-in time to
read, meditate, or simply nap.

Over time, infusion intervals may become less frequent or shorter, especially with subcutaneous formulations.
People often report that what once felt overwhelming gradually becomes another part of their calendarstill
serious, but not as all-consuming as it seemed at the beginning.

Managing Side Effects Day-to-Day

On the side-effect front, fatigue is often the star of the show. Some people describe it as
“battery-drain fatigue”you wake up with a half-charged battery, and by early afternoon you’re running on 5%.
Learning to pace activities, prioritize what truly matters that day, and accept help can make a big
difference. Short walks, light stretching, and staying hydrated can sometimes help, even when the couch is
calling your name.

Infections become something you think about more consciously. Many patients get used to carrying hand
sanitizer, avoiding sick contacts when possible, and calling their clinic sooner than they might have before
at the first sign of fever or cough. This hyper-vigilance can feel tiring, but it’s part of protecting yourself
while your immune system is under extra pressure.

Emotional Ups and Downs

Emotionally, monoclonal antibody therapy can bring mixed feelings. On one hand, there’s real hope: these
drugs exist because research has moved rapidly, and more options are on the way. On the other hand, ongoing
treatment is a reminder that myeloma is a chronic, serious illness that still requires constant attention.

Many people find it helpful to:

• Connect with myeloma support groups (in person or online)
• Talk with a counselor familiar with cancer-related stress
• Share honestly with close friends or family about how they’re really feeling

It’s completely normal to feel grateful, scared, frustrated, hopeful, and exhaustedsometimes all in the
same day. None of that means you’re “doing it wrong”; it just means you’re human.

Working with Your Care Team

One of the most powerful “side benefits” of long-term antibody therapy is the relationship many people build
with their care teams. Nurses and doctors get to know your patterns: how you react to premeds, what your
baseline energy is like, which lab values tend to dip. The more you communicate, the more they can fine-tune
your regimenadjusting infusion rates, supportive medications, or scheduling to fit your life better.

Keeping a simple symptom diaryjotting down fatigue levels, pain, mood, or any new issuescan help guide
these discussions. Showing up to visits with specific examples (“I’m wiped out for two full days after each
infusion” instead of just “I’m tired”) gives your team something concrete to work with.

Seeing the Bigger Picture

Ultimately, monoclonal antibodies for multiple myeloma are not just drugs on a chart; they’re part of a
longer story you’re living. For some, they offer the first real deep remission. For others, they’re a chance
to regain control after the disease has come back. For nearly everyone, they represent how far myeloma
treatment has comeand a hint of where it’s going next.

While statistics and trial results are important, your personal experience matters just as much. Partnering
closely with your healthcare team, listening to your body, and asking questions when something doesn’t feel
right are all part of making these powerful therapies work as well as possible for you.

Important: This article is for general informational purposes only and does not replace medical
advice. Always discuss diagnosis, treatment options, and medication changes with your hematologist/oncologist
or another qualified healthcare professional.