Mesothelioma SS1P Therapy

According to a recent research study, published in the journal, Clinical Cancer Research. Providing a continuous dose of a new immunotoxin therapy, that is SS1P, is appropriately safe and indicates some efficiency and effectiveness against mesothelioma. Moreover, the new drug doesn’t appear to be any more efficient and effective when provided by continuous infusion than in many intermittent doses.

In some types of cancer, including ovarian, squamous cell cancers and mesothelioma display a kind of protein called mesothelin usually in larger-than-normal amounts. One major potential new treatment option, known as SS1P, is an immunotoxin—it is an antibody attached to a toxic substance which binds to and kills mesothelin-positive cancer cells such as mesothelioma.

What is SS1P?

“SS1P contains an antibody fragment which binds to mesothelin specifically, so it will selectively kill mesothelin-expressing tumors,” explains lead author Robert J. Kreitman, MD, Chief of the Clinical Immunotherapy Section in the Laboratory of Molecular Biology at the National Cancer Institute.

In a previous study of SS1P, researchers gave the cancer patients the therapy in many intermittent doses that is bolus infusion. In this case study, Dr. Kreitman and his team wanted to determine whether providing the drug by continuous infusion might give mesothelioma patients with more constant levels of SS1P, thereby improving its efficiency and effectiveness.

An in-depth Research study

Among the twenty-four patients with mesothelioma, pancreatic cancer and ovarian cancer were provided a continuous infusion of SS1P for more than 10 to 15 days.

In the final phase of the study, only

• One patient had a partial response to treatment.
• Twelve patients had stable disease
• 11 patients the cancer worsened.

The total therapy with SS1P was usually safe. The rarest side effects were, fatigue, weight gain, swelling caused by fluid build-up (edema), nausea, low blood pressure, fever and allergic rash.

Results of the research study

Even though the mesothelioma, pancreatic cancer and ovarian cancer patients bear the treatment well and one person had a very partial response, the results were not up to the mark to indicate that continuous infusion of SS1P has any advantage over one large bolus dose. This may be because after bolus dosing SS1P stays in the blood for more than a day, permitting it to function for a long period of time, says Dr. Kreitman.

Dr. Kreitman’s colleagues, Ira Pastan and Raffit Hassan have began a phase II study looking at the efficiencies and effects of adding two chemotherapy drugs that is plus cisplatinum plus pemetrexed before SS1P treatment. It is hoped chemotherapy will provide a good distribution of SS1P to tumor cells, and really improve the response against mesothelioma.

Please contact mesothelioma doctors for more information!