Key Takeaways
- Immunotoxins are immune cells that have been chemically bound to toxic compounds and programmed to target and kill specific cancer cells — in this case, mesothelioma cells — without affecting healthy cells the way chemotherapy does.
- Immunotoxins target mesothelioma through mesothelin, a surface protein that is highly elevated on mesothelioma cells but present only in trace amounts on normal cells. This makes mesothelin an effective “address label” for directing immunotoxins to the right target.
- LMB-100 is a mesothelin-targeting immunotoxin that has successfully completed clinical trials. It represents a non-systemic treatment approach — meaning it attacks cancer cells directly rather than disrupting all cells in the body.
- A key challenge: the patient’s own immune system often destroys immunotoxins before they reach the tumor. Researchers addressed this by administering chemotherapy before LMB-100 to temporarily reduce the patient’s natural immunity, allowing the immunotoxins to reach their target.
- Immunotoxin therapy also appears to prevent mesothelioma recurrence — a significant finding, since recurrent mesothelioma is considerably harder to treat than the initial disease.
- Immunotoxin-based treatment is not yet widely available because the cells must be engineered in labs and are highly patient-specific. However, the clinical trial success is promising for future treatment development.
What is an Immunotoxin?
Scientists have the capability to artificially “program” immune cells. In the case of
immunotoxins, immune cells are engineered with toxic elements—hence, immuno“toxin”—so
that when they bind to their target cells, the target cells are killed. In the context of mesothelioma
treatment, immunotoxins target only mesothelioma cells—so, the treatment isn’t systemic, or
disruptive to all cells, like chemotherapy or radiation.
How do Immunotoxins Help Treat Mesothelioma?
A thorough understanding of mesothelioma’s growth (oncogenesis and carcinogenesis),
maintenance, biological tendencies and products, and physiological proclivities presupposes
successful immunotoxin treatment. This means that scientists need to understand how
mesothelioma grows, what it produces, and what systems keep it alive in order to target it;
currently, we don’t yet know all of the answers. Plus, because immunotoxins rely on the injection
of toxins into the body, the patient’s existing immune cells usually attempt to destroy them
before they can reach their target.
Despite these obstacles, scientists have identified mesothelin as a viable biomarker (and target)
for mesothelioma therapies. Mesothelin is a highly-upregulated surface protein on mesothelioma
cells; in normal cells, there are trace amounts of mesothelin, but not nearly enough to be targeted
by immunotoxic cells. By programming immune cells—like cytokines, T cells, and B cells—to
seek out mesothelin-marked cells, scientists are able to “train” them to kill mesothelioma cells.
Are There Clinical Trials for Immunotoxins?
Because of the aforementioned issues, scientists have taken to a multimodal approach for
implementing immunotoxin therapy. The immunotoxin LMB-100 has successfully completed
clinical trials, and works by targeting mesothelin. Adjustments accounting for the immune
system’s tendency to destroy LMB-100 include Hassan et al.’s work, in which researchers gave
patients chemotherapeutic drugs prior to LMB-100 introduction. This way, the patient’s natural
immunity was somewhat decreased, so the immunotoxic immune cells weren’t destroyed en
route to the mesothelioma tumors.
As a plus, immunotoxic therapies also seem to prevent the recurrence of mesothelioma once it
has been destroyed, so LMB-100’s administration helps scientists uncover the pathways of
mesothelioma’s growth. Recurrent mesothelioma is significantly harder to treat, so this finding is
exciting.
Because immunotoxins need to be engineered in labs and are highly patient-specific,
immunotoxin-based therapy isn’t yet widespread. However, its discovery is exciting, and the
treatment will likely evolve as scientists uncover more about the insertion, growth, and spread of
mesothelioma.
If you or a loved one has been diagnosed with mesothelioma, please call 1 (800)-505-6000 or fill
out our form. We are here to help you navigate the legal process of filing a claim to receive
compensation for your mesothelioma diagnosis. We help mesothelioma victims and their
families in Pennsylvania.
Frequently Asked Questions
What is an immunotoxin?
An immunotoxin is an immune cell that has been artificially engineered with a toxic compound so that when it binds to a specific target cell, that cell is killed. Scientists can “program” these immune cells — including cytokines, T cells, and B cells — to seek out and destroy only cancer cells, leaving healthy cells unharmed. This makes immunotoxins a targeted, non-systemic treatment — unlike chemotherapy, which affects all rapidly dividing cells throughout the body.
How do immunotoxins target mesothelioma cells specifically?
Immunotoxins target mesothelioma through a surface protein called mesothelin. Mesothelioma cells produce significantly elevated levels of mesothelin compared to normal cells — making it a reliable “address label” that immunotoxins can lock onto. By programming immune cells to seek out mesothelin-marked cells, scientists can direct the immunotoxins to attack mesothelioma tumors while leaving healthy tissue — which has only trace amounts of mesothelin — largely unaffected.
What is LMB-100?
LMB-100 is a recombinant immunotoxin that targets mesothelin and has successfully completed clinical trials for mesothelioma treatment. It works by binding to the mesothelin on the surface of mesothelioma cells and delivering a toxic payload that kills the cancer cell. LMB-100 represents a significant step forward because it demonstrated that mesothelin-targeted immunotoxin therapy is a viable treatment approach for mesothelioma.
Why does the body’s immune system sometimes destroy immunotoxins before they work?
Because immunotoxins are engineered and introduced externally, the patient’s existing immune system can recognize them as foreign objects and attempt to neutralize them before they reach the mesothelioma tumor. This is one of the primary challenges of immunotoxin therapy. Researchers led by Hassan et al. addressed this by administering chemotherapeutic drugs before introducing LMB-100 — temporarily reducing the patient’s natural immune response so the immunotoxins could survive long enough to reach their target.
How is immunotoxin therapy different from immunotherapy?
Both involve the immune system, but they work in opposite ways:
- Immunotherapy (e.g., Keytruda, Opdivo) works by strengthening the patient’s existing immune system — removing the brakes that mesothelioma uses to suppress immune function, so the body’s own T cells can attack the cancer.
- Immunotoxin therapy (e.g., LMB-100) works by introducing externally engineered immune cells that have been loaded with toxic compounds and programmed to target mesothelioma cells directly.
Immunotherapy boosts what’s already there; immunotoxin therapy introduces new weaponry. The two approaches may eventually be used in combination.
Can immunotoxins prevent mesothelioma from coming back?
Early research suggests yes. Clinical trial results with LMB-100 indicate that immunotoxin therapy may help prevent the recurrence of mesothelioma after the initial tumors are destroyed. This is a significant finding because recurrent mesothelioma is considerably harder to treat than the original disease. Immunotoxin therapy also helps researchers better understand the growth pathways of mesothelioma, which could lead to even more effective recurrence prevention in the future.
Is immunotoxin therapy available to patients now?
Immunotoxin-based therapy is not yet widely available as a standard treatment. Because immunotoxins must be engineered in laboratories and are often highly patient-specific, scaling the treatment for widespread clinical use remains a challenge. However, the successful completion of LMB-100 clinical trials is a promising step, and the technology is expected to evolve as researchers learn more about mesothelioma’s biology and growth patterns.
What should I do if I’ve been diagnosed with mesothelioma and want to learn about emerging treatments?
If you or a loved one has been diagnosed with mesothelioma, understanding the full range of treatment options — including emerging therapies like immunotoxins, immunotherapy, vaccines, and other clinical trials — is an important step. Your oncologist can help determine whether you may be eligible for current trials. For information about your legal options, call (800) 505-6000 or fill out our contact form for a free consultation.
