The MDS Beacon™

Several important myelodysplastic syndromes (MDS) studies were presented at the annual American Society of Clinical Oncology (ASCO) annual meeting on June 7. The meeting was held June 4 to 8 in Chicago.

Monday, June 7

As part of Monday’s morning session about leukemia, myelodysplasia, and transplantation, two important studies were presented and then discussed.

The first study, which looked at Vidaza (azacitidine) treatment in high-risk patients, was presented by Dr. Alan List of the Lee Moffitt Cancer Center and Research Institute. The results showed that Vidaza significantly prolongs overall survival as compared to conventional care. Patients who achieved at least stable disease had longer survival than patients who progressed.

Among patients who achieved a complete response or improved blood cell counts (known as a hematological improvement), Vidaza extended survival compared to conventional care. However, for patients with stable disease, survival was similar between the two treatment groups.

The study showed that some patients with stable disease are able to achieve hematological improvement with continued Vidaza treatment. For patients who have stable disease after 3 months of Vidaza treatment, 21 percent can achieve hematological improvement by 6 months treatment, and for patients who still have stable disease at 6 months, 14 percent can achieve a higher response by 9 months.

Therefore, Dr. List recommended that patients with stable disease be treated with Vidaza for six months. Then the physician should decide on a case-by-case basis, whether a stable patient should continue Vidaza treatment.

Results from a second study that compared two doses of Clolar (clofarabine) in high-risk patients were presented by Elias Jabbour of M.D. Anderson Cancer Center. Patients were treated with either 15 mg/m² or 30 mg/m² Clolar for 5 days each cycle. The overall response rate was higher in the low-dose group (41 percent vs. 29 percent), and mortality was lower in the low-dose group (14 percent at 8 weeks vs. 29 percent).

Duration of response was similar for both doses (8.8 months), and survival was higher among patients who responded to treatment (13.4 months vs. 7.4 months).

Dr. Jabbour concluded that 15 mg/m² Clolar was more active and less toxic than 30 mg/m² Clolar, and he said that future trials will further explore the lower dose.

Dr. Jeffrey Lancet of Lee Moffitt Cancer Center and Research Institute then discussed whether researchers are making progress in the treatment of high-risk MDS and acute myeloid leukemia patients.

He said that progress is being made by studies like the two that were just previously presented. Dr. List’s study showed that a response is not necessarily needed: even stable disease is associated with higher survival. Additionally, Dr. Jabbour’s study showed that response rates can be achieved in patients previously treated with Vidaza and Dacogen (decitabine).

However, Dr. Lancet said that physicians need to look beyond age and physical health of patients. They need to determine which patients are high-risk based on chromosomal abnormalities and who is likely to respond to treatment.

Dr. Lancet suggested that survival is higher among elderly patients who receive intensive therapy than those who do not and that subgroups of elderly patients should be identified to receive targeted therapy.

According to Dr. Lancet, there are several critical questions that need to be addressed by MDS researchers: Can we compare intensive versus non-intensive chemotherapy? How can we design effective trials with limited patients?

In an afternoon poster session, results were presented from a Phase 2 study of sapacitabine in MDS patients resistant to Vidaza or Dacogen (see related Beacon news). Among the three doses tested, patients responded best (35 percent response rate) to 300 mg sapacitabine twice daily for 7 days per cycle.