Wednesday, May 17, 2006
Inoperable Mesothelioma Survival Improves With ONCONASE® (ranpirnase)
ONCONASE® Improves Survival in Inoperable Mesothelioma
According to a press release from Alfacell Corporation, the addition of ONCONASE® (ranpirnase) to Adriamycin® (doxorubicin) improves survival over doxorubicin alone in patients with inoperable mesothelioma.
Malignant pleural mesothelioma is a rare cancer that develops in the tissue that covers the lungs and lines the interior of the chest. It is often caused by chronic exposure to asbestos. The majority of patients are not diagnosed until the disease has progressed to an advanced stage and treatment with surgery or radiation is not an option. Patients with this disease often have a decreased quality of life due to symptoms such as shortness of breath, cough, pain, fatigue, and the inability to eat.
Mesothelioma is fairly resistant to most therapies, including surgery, chemotherapy, and radiation therapy. Therefore, finding a chemotherapy regimen or new therapeutic approaches that can improve quality of life or survival is essential for improving care in this population.
ONCONASE is an agent that is meant to target cancerous cells while sparing healthy cells from side effects. ONCONASE is taken into cancerous cells, where it kills the cell through various processes. ONCONASE is not yet approved by the U.S. Food and Drug Administration (FDA).
Researchers recently conducted a clinical trial to evaluate the addition of ONCONASE to doxorubicin compared with doxorubicin alone in the treatment of inoperable mesothelioma. This trial included 143 patients. Results are below:
Median survival was improved by two months with the addition of ONCONASE (12 months for patients treated with ONCONASE/doxorubicin compared with only 10 months for those treated with doxorubicin alone). At one year 47% of patients treated with ONCONASE/doxorubicin were alive compared with only 36% of patients treated with doxorubicin only.
The median duration of disease regression or disease stabilization was improved by seven months in the group of patients treated with ONCONASE/doxorubicin (17 months) compared to those treated with doxorubicin alone (10 months).
The researchers concluded that the addition of ONCONASE to doxorubicin improves outcomes compared to doxorubicin alone in the treatment of inoperable malignant mesothelioma. Future trials evaluating the addition of ONCONASE to more effective chemotherapy agents in the treatment of mesothelioma are warranted to determine its true clinical effectiveness.
Reference: Alfacell Corporation. Alfacell Provides Update on ONCONASE Phase IIIb Confirmatory Registration Trial; Releases First Interim Analysis Data. Available at: http://www.snl.com/irweblinkx/file.aspx?IID=4104784&FID=2237286. Accessed May 2006
Ranpirnase Effective in Malignant Mesothelioma
According to a recent article published in the Journal of Clinical Oncology, ranpirnase (Onconase) appears to be an effective novel treatment option for malignant mesothelioma.
Malignant pleural mesothelioma is a rare cancer that develops in the tissues that comprise the lining of a lung (pleura). The majority of individuals who develop malignant pleural mesothelioma have experienced chronic exposure to asbestos during the course of their lives. This type of cancer is considered to be resistant to standard therapies, which consist of surgery, chemotherapy and/or radiation therapy. The majority of available chemotherapeutic regimens produce an anti-cancer response rate of approximately 20% or less, with a minority of patients surviving one year following diagnosis. Due to these poor survival statistics, researchers are continually evaluating new treatment approaches in an ongoing attempt to improve upon present treatment outcomes.
Ranpirnase, a ribonuclease, is a novel therapeutic agent that is entering the final phases of clinical trials prior to FDA approval for evaluation of the treatment of malignant mesothelioma. Ranpirnase is a small protein that is isolated from the eggs of Rana pipiens - a leopard frog. Ranpirnase initially binds to the surface of cells in the body and becomes internalized into the cells. It works by degrading a protein (tRNA) that is produced more readily when cells are growing and replicating. The irreparable degradation of tRNA can directly kill a cell or can signal a cell to stop replicating. Since cancer cells replicate more frequently and tend to have higher levels of tRNA than normal cells in the body, they are more susceptible to the effects of ranpirnase.
A multi-institutional clinical trial was recently conducted to evaluate ranpirnase in 81 patients with malignant mesothelioma. All patients had cancer that was considered inoperable and was progressing at the time of initiation of the trial. Thirty-five patients experienced a stabilization of their cancer and six patients had a regression of their cancer. Survival rates for all patients at one and two years following therapy were 42% and 26.8%, respectively. Importantly, the 41 patients who responded to therapy had one and two year survival rates of 61% and 40.8%, respectively. Ranpirnase was given once a week on an outpatient basis. Treatment was generally well tolerated, with the most common side effects being weakness, swelling of the hands and feet and joint pain.
These results indicate that ranpirnase appears to be an effective and safe treatment option for patients with malignant mesothelioma. This is an important finding as patients with progressive and/or inoperable malignant mesothelioma have limited treatment options and dismal long-term outcomes following standard therapies. A clinical trial is currently ongoing to directly compare doxorubicin, a commonly used chemotherapy agent, to ranpirnase plus doxorubicin in patients with inoperable or progressing malignant mesothelioma. Patient with malignant mesothelioma may wish to speak with their physician about the risks and benefits of participation in a clinical trial further evaluating ranpirnase. Two sources of information regarding ongoing clinical trials include the National Cancer Institute ( cancer.gov) and www.eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients. (Mikulski S, Costanzi J, Vogelzang N, et al. Phase II trial of single weekly intravenous dose of ranpirnase in patients with unresectable malignant mesothelioma. Journal of Clinical Oncology. 2002;20:274-281.)
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