Mesothelioma Immunotherapy: FDA Options

FDA-Approved Immunotherapies for Mesothelioma

As of 2026, three immune checkpoint inhibitors have received FDA approval as first-line treatments for mesothelioma:

Drug	Brand Name	Approval	Target
Nivolumab	Opdivo	October 2020	PD-1
Ipilimumab	Yervoy	October 2020	CTLA-4
Pembrolizumab	Keytruda	2023 (combo)	PD-1

These checkpoint inhibitors work by “releasing the brakes” on your immune system, allowing T cells to recognize and attack cancer cells.

CheckMate 743: The Landmark Trial

The combination of nivolumab plus ipilimumab was approved based on the CheckMate 743 trial results:

Measure	Nivolumab + Ipilimumab	Chemotherapy
Median overall survival	18.1 months	14.1 months
2-year survival	41%	27%
3-year survival	23%	15%

This represents a 4-month improvement in median survival and a 14% absolute improvement in 2-year survival compared to standard chemotherapy.

How Immunotherapy Works

Checkpoint Inhibitors

Cancer cells can hide from the immune system by activating “checkpoints” that tell T cells to stand down. Immunotherapy drugs block these checkpoints:

PD-1 Inhibitors (Nivolumab, Pembrolizumab)

• Block the PD-1 protein on T cells
• Prevent cancer cells from activating the “off switch”
• Allow T cells to attack cancer

CTLA-4 Inhibitors (Ipilimumab)

• Block CTLA-4, another immune checkpoint
• Boost overall immune activation
• Work synergistically with PD-1 inhibitors

Ongoing Clinical Trials (2025-2026)

DREAM3R Trial

A Phase III study comparing treatment approaches:

• Arm 1: Durvalumab + chemotherapy
• Arm 2: Chemotherapy alone
• Arm 3: Nivolumab + ipilimumab

Preliminary result: The durvalumab + chemotherapy arm showed 20.4 months median overall survival.

TEADES Trial (December 2025)

Orion Pharma initiated this Phase 2 trial evaluating ODM-212, an oral pan-TEAD inhibitor:

• Targets Hippo pathway dysfunction
• Enrolling approximately 300 patients globally
• Represents a shift toward targeted mechanisms beyond traditional checkpoint inhibition
• Endpoints: Response rate, progression-free survival, overall survival

Alliance A092001 Trial

Sponsored by the National Cancer Institute:

• Evaluates atezolizumab (Tecentriq) + bevacizumab (Avastin) + chemotherapy
• Compares against chemotherapy + Avastin alone
• Targets anti-angiogenesis combined with immunotherapy

SMARTEST Trial

A multimodal approach combining:

• Radiation therapy
• Cyclophosphamide
• Surgery
• Tremelimumab + Durvalumab

IMPRINT Trial

Phase I study evaluating:

• Pembrolizumab combined with intensity-modulated pleural radiation therapy
• Investigates radiation as immune system booster

Emerging Immunotherapy Approaches

CAR-T Cell Therapy

Clinical trials are testing CAR-T therapies that target mesothelin, a protein highly expressed in mesothelioma:

• Mesothelin-targeting autologous CAR T products
• Tumor-infiltrating lymphocyte (TIL) therapy combined with chemotherapy
• Genetic modification of patient’s own immune cells

Therapeutic Cancer Vaccines in Trials

Therapeutic vaccines under investigation:

• Dendritic cell vaccines
• Tumor antigen vaccines
• Personalized neoantigen vaccines

Using Biomarkers to Guide Treatment

Research in 2025 demonstrated that circulating tumor DNA (ctDNA) levels in blood samples can predict treatment response:

• Declining ctDNA correlates with positive treatment outcomes
• May enable more personalized treatment decisions
• Allows earlier identification of non-responders

ADI-PEG20: Breakthrough Results

The Phase III ATOMIC-Meso trial (2024 data) showed remarkable results for ADI-PEG20 (pegarginimase) when added to chemotherapy:

Measure	ADI-PEG20 + Chemo	Chemotherapy Alone
3-year survival	4x higher	Baseline
Median OS improvement	+2 months	:
Progression-free survival	6 months	:

This arginine-depleting therapy exploits mesothelioma cells’ inability to produce their own arginine.

Who Responds Best to Immunotherapy?

Who Tends to Respond Well

Non-epithelioid cell types, particularly sarcomatoid mesothelioma, respond better to immunotherapy than to chemotherapy alone. Higher PD-L1 expression gives the checkpoint inhibitors more targets to bind to. Good performance status (ECOG 0 or 1) helps patients tolerate treatment, and lower tumor burden at the start of therapy gives the immune system a better chance to catch up with the disease.

Less Favorable Factors

• Very low PD-L1 expression
• Poor overall health
• Heavily pre-treated disease
• Significant immunosuppression

Side Effects

Immunotherapy side effects differ from chemotherapy:

Common:

• Fatigue (30-40%)
• Skin rash (20-30%)
• Diarrhea (15-25%)
• Nausea (15-20%)

Management:

• Most side effects are manageable with steroids
• Early reporting is crucial
• Dose adjustments or treatment pauses may be needed

Immunotherapy vs. Chemotherapy

Factor	Immunotherapy	Chemotherapy
Median survival	18+ months	12-14 months
3-year survival	23%	15%
Side effect profile	Immune-related	Blood counts, nausea
Long-term survivors	More common	Less common
Works for all patients	No	Generally yes

Immunotherapy may produce durable responses in some patients, meaning the cancer stays controlled for years. This is less common with chemotherapy.

Combination Approaches

The most promising results come from combining immunotherapy with other treatments:

Immunotherapy + Chemotherapy

• Durvalumab + chemo: 20.4 months median survival
• Pembrolizumab + chemo: 17 months median survival

Multimodal Therapy

Eligible patients may move through a sequence of surgery to remove visible tumor, chemotherapy to reach microscopic disease, immunotherapy to sustain the immune response, and radiation to target any remaining cells. This multimodal approach produces the best outcomes for surgical candidates.

Finding Clinical Trials

Resources for locating immunotherapy trials include ClinicalTrials.gov (search “mesothelioma immunotherapy”), NCI-designated cancer centers (many of which lead ongoing trials), mesothelioma specialty centers at institutions like MD Anderson, Memorial Sloan Kettering, and Dana-Farber (which often have access to investigational therapies), and your own oncologist, who can identify trials you may qualify for.