Clapper, Patti, Schweizer and Mason

Cisplatin

Cisplatin has been the “go-to” chemotherapy drug for mesothelioma patients for years.  The drug has a relatively low risk profile and, in most cases, is the most effective option.  While other drugs have come on the market specifically targeting mesothelioma, such as pemetrexed, cisplatin-based treatments are still the norm.  However, that doesn’t mean that mesothelioma doctors are complacent and just using the ‘same-old, same-old’ to treat their patients.  Indeed, many scientists are experimenting with different chemotherapy formulations which include combining cisplatin and various other drugs.  One recent study looked at the effectiveness of cisplatin when combined with prolonged low-dose administration of a nucleoside analog called gemcitabine.

Gemcitabine (Gemzar)

Gemcitabine, under the U.S. brand name of Gemzar, is manufactured by Ely Lilly and is marketed as an effective form of treatment for a variety of cancers, including non-small-cell lung cancers, such as mesothelioma.  Building on that success, researchers suspected that it might provide better or similar results to “traditional” chemotherapy drugs used in mesothelioma treatments.

During the Phase II clinical trial for mesothelioma patients, researchers gathered 78 eligible patients who had all been diagnosed with malignant pleural mesothelioma through biopsy and histological staining.  None of the patients had received chemotherapy before yet all were deemed to have normal liver and kidney functions – important when undergoing toxic chemotherapy. 

This group of patients was then given an infusion of gemcitabine in combination with cisplatin.  In total, the group was given four 3-week cycles of both drugs and then two additional cycles without cisplatin. 

The side effect profiles experienced by the patients closely match what would be expected for “traditional” chemotherapy regimens including:

• Anemia (in two patients)
• Neutropenia – low amounts of key immune system agents in the bloodstream (in 18 patients)
• Nausea/vomiting (in one patient)
• Reversible thrombocytosis (high platelet count – clotting agents) was recorded in 10 patients
• Alopecia –hair loss – in 60 patients

The results of the treatment regimen were encouraging.  Four of the patients in the trial experienced a complete response and an additional 35 experienced a partial improvement of their disease.  Additionally, 35 of the patients enjoyed a prolonged progression-free state or minimal response to the combined chemotherapy treatment.  Only four patients failed to respond at all.

The patients were then asked to self-report their experiences while on these treatment cycles.  A vast majority (over 89%) of the patients reported improvements of their mesothelioma symptoms and stated that the quality of life they were enjoying after the treatment was at least as good if not better than that they had before the treatment. 

Realistically, the median progression-free survival (time before the diseased recurred) was 8.0 months while the overall survival rate was 17.0 months.  Over 67% of the patients survived for longer than a year with roughly 19% of them living to the three-year mark. 

As expected, the only histological type which responded to the chemotherapy treatment was epithelioid mesothelioma.  This type of mesothelioma is the most common, representing up to 70% of all diagnosed cases, but it is also the most treatable.

In retrospect, this Phase II clinical trial was deemed a success by the scientists behind it.  They concluded that because this form of combined cisplatin/gemcitabine chemotherapy is not only cost effective and reasonably effective but also carries with it an acceptable side effect profile, that it should not only be further investigated but should perhaps move beyond clinical trials into real world treatment situations.