Taxol (paclitaxel) is the brand name for a chemotherapy drug that is experimental for mesothelioma treatment. It has been in use for other purposes since its U.S. Food and Drug Administration (FDA) approval in 1998. Researchers hope it will be useful in treating mesothelioma as part of a multi-modal approach, but initial studies have had mixed and limited results.
What Is Taxol?
Taxol is a brand-name drug used to treat several types of cancer. Other names for this drug include the generic name paclitaxel, as well as Praxel, Bristaxol, Onxol, Asotax, and the albumin-bound version called Abraxane. The FDA first approved the drug in 1992.[1]
What Type of Cancer is Taxol Used For?
Paclitaxel is currently approved to treat breast cancer, ovarian cancer, lung cancer, and AIDS-related Kaposi sarcoma.
Common off-label uses include the treatment of esophageal, endometrial, head and neck, bladder, and cervical cancers.[2]
Is Taxol Used for Mesothelioma?
Taxol is not commonly used to treat mesothelioma, but researchers continue to test it in combination with other treatments or medications.
The History of Taxol
Today, Taxol is an important drug, particularly for treating advanced ovarian cancer in patients who have not responded to other treatments. The discovery of this natural compound came from National Cancer Institute (NCI)-funded research.
The story began in the 1950s when the NCI began a research project to screen synthetic and already-known compounds for chemotherapeutic properties.
In the 1960s, the NCI partnered with the U.S. Department of Agriculture to screen natural compounds from plants. Over a couple of decades, more than 30,000 compounds were screened, and the compound that would become Taxol was discovered.
Researchers isolated it from the bark of the Pacific yew tree and studied it for decades. Finally, in 1977, it was noted to be effective at stopping tumor growth in mice. It was then employed in clinical trials and eventually approved by the FDA in 1992.
The big breakthrough was a study showing that 30% of women with advanced ovarian cancer responded to the medication. Taxol quickly became the first blockbuster chemotherapy, and research continues to determine how it can help patients.
How Does Taxol Work?
Paclitaxel is a type of drug called an antimicrotubule agent. Like other chemotherapy drugs, it targets cells in the body that grow and divide rapidly and slows or stops their growth.
Antimicrotubule agents do this by interfering with microtubules and how they arrange during cell division. These proteins have to line up in a certain way inside a cell for that cell to reproduce and divide successfully. When paclitaxel interferes with this process, the cancer cells can no longer thrive.
What Are the Side Effects of Paclitaxel?
As with any type of chemotherapy, there are possible side effects when using Taxol. It is a cytotoxic drug and harms healthy cells along with cancer cells.
The most common side effects seen with paclitaxel include:[2]
- Pain and swelling at the injection site
- Nausea
- Vomiting
- Diarrhea
- Weakness
- Muscle and joint pain
- Stomach pains
- Mouth sores
- Hair loss
These are usually not serious, but they can be painful or uncomfortable. Nausea and mouth sores can make healthy eating more challenging, so patients could also experience unintended weight loss due to this medication.[2]
Serious Potential Complications of Taxol
In addition to the more common and less serious side effects that many patients experience with Taxol, there is a potential for more severe adverse events. The FDA has labeled Taxol with a black box, which it reserves for the most serious and potentially life-threatening side effects of drugs.
One is the risk that Taxol will significantly reduce white blood cell count through bone marrow suppression. This can make a patient susceptible to dangerous infections. Patients with already compromised immune systems are cautioned not to use this drug or to be carefully monitored while on it.[2]
Another risk is the potential for infusion-related reactions, similar to anaphylaxis. Taxol contains polyoxyethylated castor oil to help the chemical stay as a liquid, and some people may have a life-threatening allergic reaction to it.
Notably, Abraxane does not have this same issue, as the drug is bound to small proteins in a more expensive manufacturing process.[2]
Early Studies Treating Mesothelioma with Paclitaxel
Researchers have been eager to find out what else this drug can do because Taxol proved so successful in advanced ovarian cancer. Despite the drug’s success in other challenging cancers, results in trials with mesothelioma have been disappointing.
Early trials using Taxol for mesothelioma showed little or no improvement when it was used by itself. Patient survival in these studies was only five to nine months, not a great improvement over other treatments.
More recently, researchers have combined paclitaxel with other treatments and are hoping for better results. A published case study of a woman with peritoneal mesothelioma showed there could be hope for this drug.
She was given intraperitoneal carboplatin with paclitaxel and achieved complete remission after six cycles. The doctors treating her concluded that combinations with paclitaxel, given aggressively, could possibly help other patients with mesothelioma.[3]
There is another case in which Abraxane (nanoparticle albumin-bound paclitaxel) was administered with carboplatin to a patient who didn’t respond well to first-line treatment. He responded so well to the initial treatment that he was given a break. Then, when the mesothelioma came back, they treated him with the same regimen, and he saw benefits again.[4]
Recent Paclitaxel/Mesothelioma Studies
More recent studies using paclitaxel show more promise for treating patients with mesothelioma:
- Researchers gave patients with peritoneal mesothelioma either paclitaxel or pemetrexed before or after surgical interventions. The results indicate that paclitaxel could be part of a useful combination of chemotherapy drugs for this therapy.[5]
- The 2017 results of a study using paclitaxel and a novel therapy show promise. Researchers loaded bone marrow stromal cells with paclitaxel and pemetrexed. The cells released the drugs and inhibited the growth and spread of pleural mesothelioma cells.[6]
- In 2020, researchers published the results of a study using nanoparticles to deliver paclitaxel to pleural tissue. The study involved animals rather than humans, but the results showed promise for future human trials.[7]
Mesothelioma Clinical Trials Using Paclitaxel
Because Taxol is not a standard treatment for mesothelioma, it can be difficult for patients to access. Talk to your doctors about the possibility of joining a clinical trial. Currently, a few trials involving paclitaxel or Taxol are actively recruiting qualified mesothelioma patients, including these:
- Intraperitoneal Paclitaxel for Patients With Primary Malignant Peritoneal Mesothelioma (INTERACT MESO). Patients with peritoneal mesothelioma might qualify for this study using paclitaxel for intraperitoneal chemotherapy. Researchers are looking for patients intelligible for or are unwilling to undergo surgery. [8]
- Study of IDE397 in Participants With Solid Tumors Harboring MTAP Deletion. This is a broader study, recruiting patients with many types of advanced cancer, including mesothelioma. Participants will receive an experimental drug as well as paclitaxel and other chemotherapy drugs.[9]
While early studies of Taxol in mesothelioma patients were disappointing, more recent studies combining this drug with other medications and as part of a multimodal treatment approach are showing great promise. In the future, Taxol may be used more commonly for treating patients with all types of mesothelioma, but for now, the medication is not often utilized.
