Source: Arthroscopy  |  Posted 5 years ago

By Ed Susman

ORLANDO, FL -- December 14, 2006 -- The immunoconjugate gemtuzumab ozogamicin in addition to standard chemotherapy appears to improve outcomes in patients with acute myeloid leukemia (AML), researchers said here at the American Society of Hematology (ASH) 48[^]th[] Annual Meeting and Exhibition.

Alan Burnett, MD, head of the department of hematology at the Welsh Medical School, Cardiff, Wales, United Kingdom, presented the findings in an oral session on December 10[^]th[].

In a large trial involving 1,115 patients who were followed for 3 years, relapses occurred in 52% of patients who were given gemtuzumab compared with 37% of patients who
did not receive the drug, a risk reduction of 30% that was statistically significant at the []P[] = .01 level.

"This preliminary analysis indicates that the addition of gemtuzumab to induction chemotherapy can reduce the relapse risk without adding significant extra toxicity and this
has significantly improved disease free survival," Dr. Burnett said.

After 3 years, 51% of patients receiving gemtuzumab were alive and free of disease compared with 40% of patients who did not received the extra treatment in their regimens. The difference was statistically significant at the []P[] = .008 level, Dr. Burnett said.

Dr. Burnett said AML is the most common form of acute leukemia that occurs in adults. About 10,400 new cases are diagnosed in the United States each year and more than half of those cases occur in people more than 64 years of age.

In the study, patients were treated with gemtuzumab in addition to 1 of 3 standard chemotherapy regimens: 1. daunorubicin and cytarabine; 2. cytarabine, daunorubicin and etoposide; 3. fludarabine, cytarabine, idarubicin and granulocyte-colony stimulating factor. The regimens were consolidated with amsacrine and etoposide or with high dose cytarabine.

Dr. Burnett said the 85% rate of remissions was the same with or without gemtuzumab. About 8% of patients in the gemtuzumab and 7% in the non-gemtuzumab died during the induction stage of treatment; 7% of the gemtuzumab group and 8% of those who did not receive gemtuzumab had resistant disease following induction.

Overall survival between the 2 arms was not statistically different, Dr. Burnett said. About 53% of patients in the gemtuzumab arm were alive at 3 years compared with 43% of patients who did not receive gemtuzumab ([]P[] = .40).

"Longer follow up is required to determine the impact [of gemtuzumab] on survival," he said.

The study was sponsored Wyeth Pharmaceuticals, Collegeville, Pennsylvania.

[Presentation title: The Addition of Gemtuzumab Ozogamicin to Induction Chemotherapy for AML Improves Disease Free Survival Without Extra Toxicity: Preliminary Analysis of 1115 Patients in the MRC AML15 Trial. Abstract 13]