Study: Paclitaxel Best for HIV-Related Kaposi's Sarcoma

AMSTERDAM – People infected with HIV and diagnosed with advanced Kaposi's sarcoma were more likely to achieve long-term progression-free survival on a chemotherapy treatment regimen led by paclitaxel (Taxol) versus other agents, researchers reported here.

In a late-breaker oral presentation, Susan Krown, MD, a member of the leadership group of the AIDS Malignancy Consortium, said that 63% of the patients on paclitaxel plus combination antiretroviral achieved progression-free survival at 2 years.

That compared to 43% of the patients assigned to the chemotherapy treatment with bleomycin and vincristine, and 19% of the patients assigned to treatment with etoposide, Krown said at the 22nd International AIDS Society.

The study was truncated twice. The trial's Data Monitoring and Safety Board first recommended stopping the etoposide arm of the trial for inferiority, and then did the same after it was found that the bleomycin/vincristine arm of the trial was also unlikely to achieve non-inferiority, Krown explained.

"Paclitaxel plus antiretroviral therapy is established as a standard of care for initial treatment of advanced AIDS Kaposi's sarcoma in resource limited settings," she said. In addition to a similar adverse effect profile, she said that paclitaxel treatment was associated with longer progression-free survival.

She suggested that the similar profiles for CD4-positive cell counts and similar levels of viral suppression indicated that the chemotherapy treatment did not interfere with the antiretroviral treatment aspect. All 3 arms of the study appeared to have similar rates of HIV suppression, she said.

The researchers assigned 59 patients to the etoposide arm of the study; 125 patients were taking the bleomycin/vincristine arms of the study and 132 patients were taking paclitaxel, she said. About 23% of the patients in the trial were women; the average age of all the patients was 35 years; about 57% of the patients were in 90% or greater in performance status; 21% of the patients had suppressed viral loads.

Krown said the research team was "considering an ad hoc cost-effectiveness analysis to further inform drug policy now that paclitaxel is more readily available and because the price has come down. We also have several analyses to conduct."

When asked about costs of paclitaxel, Krown said that "it depends where you are."

She said in Zimbabwe the cost of the paclitaxel regimen is 2-3 times the cost of the bleomycin/vincristine regimen; but in South Africa paclitaxel costs less. "I think that right now, price is a moving target," Krown said. "There is a generic paclitaxel that is now available."

The protocol for the trial was set up in 2010, but patients weren't enrolled until 2013, delayed because of early interest in using the anti-cancer agent liposomal doxorubicin – but the depletion of the world supply of the agent and its slow recovery to the marketplace led the researchers to use other drugs.

Priscilla Hsue, MD, of the University of California San Francisco, told MedPage Today, "These were compelling results. Paclitaxel has to be given through an infusion which may limit its practicality in some areas in resource limited setting, but it certainly may be more practical than using liposomal doxorubicin."

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