Dr. Martha Lacy: Pomalidomide+ low-dose dexamethasone in relapsed/refractory myeloma (ASH 2014)
Dr. Martha Lacy (Mayo Clinic, Rochester, Minnesota) discusses a study including long-term follow up and comparison of 2 mg vs. 4 mg doses of pomalidomide (Pomalyst/Imnovid) plus low-dose dexamethasone in relapsed lenalidomide (Revlimid) refractory myeloma patients. The study results were presented at the 56th American Society of Hematology (ASH) Annual Meeting. ASH 2014 abstract 4780.
Program: Oral and Poster Abstracts
Session: 653. Myeloma: Therapy, excluding Transplantation: Poster III
Martha Q. Lacy, MD1, Betsy R. LaPlant, MS2*, Kristina M Laumann, BA2*, Shaji Kumar, MD3, Morie A Gertz, MD, MACP3, Suzanne R Hayman, MD3, Francis Buadi, MD3, Angela Dispenzieri, M.D.3, John A Lust, MD, PhD3, Prashant Kapoor, MD3, Nelson Leung, MD4, Stephen Russell3, David Dingli, M.D., Ph.D.1, Ronald S. Go, MD5, Wilson I Gonsalves, MD3*, Rafael Fonseca, M.D.6, P. Leif Bergsagel, MD6, Vivek Roy, MD7, Taimur Sher, MD8*, Sikander Ailawadhi, MD8*, Asher Chanan-Khan, MD7, A. Keith Stewart, MD9, Craig B. Reeder, MD10, S. Vincent Rajkumar, M.D.3 and Joseph R. Mikhael, MD11
1Division of Hematology, Department of Internal Medicine, The Mayo Clinic, Rochester, MN
2Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN
3Division of Hematology, Mayo Clinic, Rochester, MN
4Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN
5Gundersen Medical Foundation, La Crosse, La Cross, WI
6Division of Hematology - Oncology, Mayo Clinic, Scottsdale, AZ
7Division of Hematology & Medical Oncology, Mayo Clinic, Jacksonville, FL
8Department of Hematology and Oncology, Mayo Clinic, Jacksonville, FL
9Division of Hematology/Oncology, Mayo Clinic, Scottsdale, AZ
10Hematology/Oncology, Mayo Clinic Arizona, Scottsdale, AZ
11Hematology and Oncology, Mayo Clinic in Arizona, Scottsdale, AZ
Background: Pomalidomide has demonstrated excellent activity in patients with relapsed, lenalidomide refractory, multiple myeloma (MM). Between November 2007 and March 2012, we enrolled 285 patients with relapsed MM on 5 sequential phase 2 trials; patients received pomalidomide at 2mg or 4 mg daily with weekly dexamethasone (Pom/dex). The approved dose of pomalidomide is 4 mg for 21 of 28 days. We wished to compare efficacy, tolerability and long-term outcomes between cohorts treated with 2 mg or 4mg daily continuously and 4mg daily for 21/28 days.
Methods: After excluding two ineligible patients, 283 patients with lenalidomide refractory, relapsed MM from 5 sequential cohorts were analyzed. These patients were divided into 3 groups: Group1 received Pom 2mg for 28/28 day cycle (N= 69), Group 2 received Pom 4 mg for 28/28 day cycle (N= 95) and Group 3 received Pom 4mg for 21/28 day cycle (N= 119). All patients received oral dexamethasone given 40 mg daily on days 1, 8, 15, and 22. Response was assessed by the IMWG Uniform Response criteria. All patients received aspirin 325 mg daily for DVT prophylaxis or full dose anticoagulation.
Results: The median age was 63 years (32-85); 35% were female. The median time from diagnosis was 53 months and the median number of prior regimens was 4. 127 (46%) had high-risk molecular markers. Prior therapies (% received) included lenalidomide (100%), thalidomide (46%), bortezomib (78%), autologous stem cell transplant (71%), and allogeneic transplant (4%). The median follow-up is 16.4 months (3.2-64.4). Forty eight percent are alive and 26% remain progression free; 15 patients are continuing to receive treatment. Frequency of AEs by groups are shown in Table 1. The most notable difference is grade 3+ neutropenia seen in 39% of group 1 and 56% and 57% of groups 2 and 3. Confirmed responses of PR or better were seen in 29% (group1), 35% (group2) and 24% (group3). Median duration of response (DOR) was 14.1 months (group1), 14.5 months (group2) and 10.2 months (group3). Median PFS was 5.5 months (group1), 6.9 months (group2) and 4.3 months (group3). Although the dose level cohorts were sequential rather than randomized, we compared OS between the dose levels in an exploratory manner. There was no significant difference in OS between dose levels (p=0.26). Median overall survival (OS) was 16.6 months (group1), 21.9 months (group2) and 16.0 months (group3).
Conclusions: Pom/dex is active and well tolerated even in heavily pretreated patients Responses are durable. Response rates and overall toxicity are similar between the 2 mg and 4 mg doses. Neutropenia is more common in those receiving doses of 4mg daily or for 21/28 days compared to those receiving 2 mg daily.
ABOUT MARTHA Q. LACY, MD
Dr. Martha Lacy is a hematologist/oncologist, Chair of Hematology and a Professor of Medicine in the department of hematology and transplant at the Mayo Clinic and the Mayo Clinic College of Medicine in Rochester, Minnesota. Her areas of research include clinical trials, immunomodulation, and virotherapy for myeloma Visit Dr. Martha Lacy’s full biography.