Chicago, IL—The novel immunomodulatory drug (IMiD) pomalidomide showed strong activity in patients with multiple myeloma who are not responding to current therapies, said Irene Ghobrial, MD, medical staff member in the Myeloma Program of the Dana Farber Cancer Institute, and Associate Professor of Medicine, Harvard Medical School, Boston.
“As myeloma patients live longer and longer, they need new agents of therapy, and pomalidomide may be one of those,” said Dr Ghobrial, who presented the results of this phase 2 clinical trial during ASCO 2012.
“This agent is showing responses even in patients who are resistant to bortezomib or lenalidomide,” Dr Ghobrial said, noting that adding a new IMiD to the available treatment options will be especially critical for patients with relapsed/refractory disease.
Pomalidomide plus Dexamethasone
Ravi Vij, MD, Associate Professor, Department of Medicine, Oncology Division, Bone Marrow Transplantation and Leukemia Section, Washington University School of Medicine, St Louis, MO, presented updated results of a phase 2 clinical trial of pomalidomide in combination with low-dose dexamethasone in 221 patients resistant to lenalidomide, to bortezomib, or to both. The pomalidomide/dexamethasone combination induced responses in heavily pretreated patients, including patients who had received stem-cell transplantation.
The overall response rate to the pomalidomide/dexamethasone combination was 30% compared with 9% with pomalidomide alone, after a median (number) of 5 cycles and a median (time) of 2 months. Three quarters of patients achieved stable disease or better. Median progression-free survival (PFS) was 3.5 months for the whole group.
A 1-year overall survival (OS) was reached by 59% of the patients, and median OS was similar (approximately 14 months) between the 2 arms, Dr Vij reported. Patients who had relapsed after stem-cell transplantation had a median PFS of approximately 4 months. No severe cases of peripheral neuropathy were reported.
In June, a New Drug Application for pomalidomide in combination with low-dose dexamethasone was submitted to the US Food and Drug Administration.
Adding Clarithromycin to the Mix
Another phase 2 clinical trial evaluated pomalidomide in combination with clarithromycin and dexamethasone (ClaPD) in 73 heavily pretreated patients with relapsed/refractory myeloma. The antibiotic clarithromycin has been shown to enhance the antimyeloma activity of pomalidomide/ dexamethasone.
The overall response rate was 56%. Even among the patients whose disease was refractory to lenalidomide and to bortezomib, the response rate was 58%.
Median PFS was 7.5 months, and, at a median follow-up of 12 months, 85% of the patients were alive and 42% remained progression-free.
“Response to ClaPD is rapid, well tolerated, and sustained over 7 months in most subjects,” said Adriana C. Rossi, MS, MD, Clinical Fellow, Hematology/Oncology, Weill Cornell Medical College, New York. “These data support the clinical efficacy of pomalidomide-based regimens in relapsed/refractory myeloma.”