Herceptin Plus Taxol Look Promising, Trials Underway

Herceptin and Taxol Combination Looks Promising for Prostate Cancer

In Mouse Study, Herceptin Alone Ineffective for Refractory Disease; Clinical Trials Underway

Nov 3, 1999 New York /PSA Rising/ --Before patients are enrolled in a clinical trial of a cancer therapy, laboratory studies are run to find out whether the drug has any effect on human cancer cells. Cancer cells are treated with the novel drug in a test tube and then the drug is tested on human cancer cells implanted into mice. These tests are known as preclinical studies. Patients contemplating entry into a clinical trial may need to know about the results in order to make informed treatment decisions.

Currently, a Phase II clinical trial of a monoclonal antibody called Herceptin in patients with progressive androgen-independent prostate cancer is underway at Memorial Sloan-Kettering Cancer Center. The clinical trial abstracts for patients and professionals are online at the National Cancer Institute website.

Herceptin(r) is a therapy originally developed for breast cancer and now being developed to treat prostate cancer. Last month results of preclinical mouse studies of the effects of Herceptin and Taxol were published. Human prostate tumors were grown in mice to see if the tumors would respond to Herceptin (also called trastuzumab or anti-Her-2/neu antibody) and to the chemotherapy drug Taxol(r) (paclitaxel).

The two drugs were tested in mice with both androgen-dependent tumors - tumors that need testosterone to grow - and androgen-independent tumors - recurrent tumors that grow independent of hormone stimulation. The researchers found that Herceptin(r) combined with Taxol(r) caused a marked shrinkage (regression) of tumors in both androgen-dependent and independent disease. Results of this work were published in the October 1 issue of Cancer Research.

In mice, the drug caused significant tumor regression in androgen-dependent or initial prostate cancer tumors. But with recurrent prostate cancer - or androgen independent disease, the investigators found that Herceptin(r) alone had no effect on tumor growth. It took treatment with the combination of both drugs to cause the tumors to shrink significantly in any of the androgen-independent or recurrent tumors.

"It appears that Herceptin(r) has different effects depending on whether or not testosterone is present, which means that treatment with the combination of both drugs may lead to a new way to treat the recurrence of this disease," said Dr. Agus.

Meanwhile clinical trials are underway at Memorial Sloan-Kettering to evaluate the effectiveness of Herceptin(r) alone and Taxol(r) to treat patients with androgen-dependent and independent prostate cancer.

The combination of these two drugs may turn out to be effective. In mice with recurrent prostate cancer - or androgen independent disease, - the investigators found that treatment with the combination of both drugs caused the tumors to shrink significantly.

An abstract of the report on this preclinical work on Herceptin (anti-Her-2/neu antibody) is online at NIH PubMed.

Cancer Res 1999 Oct 1;59(19):4761-4 Response of prostate cancer to anti-Her-2/neu antibody in androgen-dependent and -independent human xenograft models. Agus DB, Scher HI, Higgins B, Fox WD, Heller G, Fazzari M, Cordon-Cardo C, Golde DW Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.

A Clinical Trial Abstract for Phase II Study of Monoclonal Antibody HER2 (Herceptin) in Patients with Progressive Androgen Independent Prostate Cancer is online in the Professional Version and the Patient Version.

See also Semin Oncol 1999 Feb;26(1 Suppl 2):109-11 Paclitaxel in the treatment of hormone-refractory prostate cancer. Smith DC, Pienta KJ Division of Hematology/Oncology, The University of Michigan School of Medicine and the University of Michigan Comprehensive Cancer Center, Ann Arbor, USA.

To search for clinical trials at NCI go the Search for Clinical Trials PDQ page. For more links to clinical trial sites check our Treatment Options page. We are working on expanding this section..

Have you checked the links to online cancer journals listed on our PCa Research page? Some of them are worth a bookmark.


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