By Amy D’Orazio, PhD

The annual meeting of the American Society of Clinical Oncology was held in Orlando in May. The gathering of over 28,000 cancer researchers, physicians and representatives from pharmaceutical and biotechnology industries reported a series of breakthroughs in treatments for patients with lung, breast, kidney, colon and other cancers. Some data are covered in Drugs in the News, and others are summarized below.

Sutent in First-Line Advanced Kidney Cancer

Effective new drugs offer hope for patients with kidney cancer. One such drug, Sutent (SU11248), directly inhibits tumor cell growth by blocking the formation of new blood vessels within the tumor. In two phase II trials in previously treated patients with advanced kidney cancer, treatment with Sutent led to tumor shrinkage in about 40 percent of patients in each trial, with clinical benefit (shrinkage or disease stabilization) in nearly two thirds in each trial. The antitumor effects lasted about nine months. The main side effects of Sutent, an oral medication, were high blood pressure, nausea and fatigue. From these data, a phase III trial has been launched with newly diagnosed kidney cancer patients. This trial will compare treatment with Sutent to interferon treatment. For more information, visit www.pfizer.com.

Proteasome Inhibitors in NHL

Velcade® (bortezomib) is well known for its activity in myeloma, but data presented at this year’s ASCO meeting show this drug offers hope for patients with mantle cell lymphoma, a subtype of non-Hodgkin’s lymphoma (NHL) that can be poorly responsive to various types of treatment. In this trial, which enrolled patients who relapsed after prior therapy, 42 percent of patients showed disease remission. Velcade is being studied in other NHL types, such as follicular and indolent lymphomas, and is co-administered with Rituxan in some trials. For more information, visit www.velcade.com.

SAHA in Cutaneous Lymphomas

SAHA (suberoylanilide hydroxamic acid) is a member of a new class of drugs that stop tumor growth by altering the mechanisms that allow the tumor cells to grow and divide. The oral drug is being studied in numerous tumor types, including cutaneous T-cell lymphoma (CTCL). In a phase II study presented at ASCO, SAHA showed the ability to cause tumor regression in eight of 33 patients with a rare type of skin lymphoma called mycosis fungoides (a type of CTCL). Patients had a significant reduction in skin rash and itching. A larger trial is under way. MGCD0103, a similar drug also taken by mouth, is currently being studied in NHL and solid tumors.

Vitamin D derivative enhances the activity of Taxotere in prostate cancer
Last year’s ASCO meeting revealed exciting advances in prostate cancer therapy with Taxotere® (docetaxel), a drug well known in lung and breast cancers. The drug has also been shown to increase the potential for survival in men with advanced prostate cancer. Further improving this regimen is DN-101, a derivative of vitamin D. In a randomized 250-patient study in advanced prostate cancer patients, treatment with Taxotere plus DN-101 was compared with Taxotere treatment alone. Despite similar numbers regarding disease remission, survival was prolonged in patients receiving DN-101, with a 49 percent improvement in survival. For more information, visit www.novacea.com.

New Treatment Effective Against Sarcoma

More than one third of sarcoma patients (37 percent) had their tumors stabilize or shrink in response to a new type of cancer therapy known as an mTOR inhibitor. The drug, called AP23573, halts the tumor cells’ internal signals that cause the cancer to grow uncontrollably. Additional benefit with the drug was seen in 72 percent of patients who experienced relief of pain or other tumor symptoms. For information about ongoing trials, go to www.ariad.com.

Chemotherapy for Early-Stage Colon Cancer

In 2004, treatment of early-stage colon cancer was advanced with the use of Eloxatin™ (oxaliplatin), a drug that improved overall survival in patients with metastatic disease and lengthened the time early-stage patients remained disease-free after surgery. These data, seen in two clinical trials called MOSAIC and NSABP C-07, were re-evaluated with longer follow-up at the 2005 ASCO meeting. As in earlier analyses, benefits were seen in stage 3 colon cancer patients in terms of disease remission times, but the benefit to stage 2 patients is still not proven. More time is needed before it is known if patients are living longer on the new regimens. Studies were also reported that compared treatment with 5-FU/leucovorin with and without Camptosar® (irinotecan). In the PETACC3 study, an improvement in disease-free remission time was seen with the inclusion of Camptosar. But in a second study, adding Camptosar did not improve efficacy of the therapy. Camptosar is not currently approved for use in colorectal cancer patients who have undergone surgical resection, but the drug is approved for use with Avastin™ (bevacizumab) or Erbitux® (cetuximab) and with other chemotherapy drugs in patients with advanced colorectal cancer.

Drug Combination Boosts Survival in Head and Neck Cancer

Adding a third drug to standard chemotherapy can dramatically improve the survival of patients with advanced head and neck cancer. Previous studies have shown that using combination chemotherapy of cisplatin and 5-FU yields a 25 to 50 percent rate of complete responses (the tumor disappeared). Researchers found that adding Taxotere to the cisplatin/5-FU regimen significantly increased the complete response rate to 89 percent. For more about head and neck cancer, visit www.spohnc.org, and watch for the Fall 2005 issue of CURE, which will feature oral cavity cancer.

Aspirin Use May Protect Against Colon Cancer Recurrence

While previous studies have shown that aspirin use provides a preventive benefit by lowering the risk of developing colon cancer and intestinal polyps, a new study is the largest to demonstrate that aspirin has a potential treatment benefit in people already diagnosed with colon cancer. The researchers found that regular aspirin users had a 55 percent lower risk of colon cancer recurrence and a 48 percent lower risk of death compared to non-users. The benefit of aspirin was independent of the dose, as long as the patient consistently took the painkiller throughout the follow-up period. Studies are currently under way to examine the addition of COX-2 inhibitors to chemotherapy in patients with advanced colon cancer.