Session: 653. Myeloma: Therapy, excluding Transplantation: Immunotherapies in Plasma Cell Disorders
Hematology Disease Topics & Pathways:
antibodies, Biological, Diseases, Adult, Therapies, Biological Processes, Technology and Procedures, Study Population, Plasma Cell Disorders, Clinically relevant, Lymphoid Malignancies, immune mechanism
Methods: Patients with relapsed/refractory AL amyloidosis were enrolled and treated in a phase 1b study (N=19) using the anti-amyloid mAb CAEL-101. CAEL-101 was administered weekly for 4 weeks with sequential doses of 0.5, 5, 10, 50, 100, 250 and 500 mg/m2 in a dose-escalation design. All patients underwent transthoracic echocardiograms at screening and 12 weeks. GLS was measured using speckle-tracking (TomTec-Arena 1.2, Germany) and calculated as an average of 4-, 2-, and 3- chamber based measurements. Paired student’s t-test was used to compare echocardiographic variables at screening and 12 weeks after therapy start with CAEL-101. GLS was correlated with NT-proBNP using Pearson correlation coefficient.
Results: The median age of patients (N=19) was 63 years with 68% male and 32% female. Ten out of 19 patients had cardiac involvement with a median NT-proBNP of 1186 (range 699-3964) at screening. Six out of 10 patients (60%) with cardiac involvement met cardiac response criteria by having a decrease in NT-proBNP >30% (3). Among echocardiographic parameters, mean GLS improved significantly in 9/10 patients from -15.58 ± -4.14% at screening to -17.37 ± -3.53% at week 12, p = 0.004 (Figure 1) of the trial. One patient who did not have improvement in GLS was dosed at low dose level 2 (5mg/m2) in the study. Under the null hypothesis, the probability of 9 or more patients improving without drug effect, is ~0.0107, suggesting that improvement of GLS in 9 of 10 is a highly unlikely outcome unless the there is a drug association. In contrast to the improved GLS in cardiac patients, CAEL-101 had no significant effect (p=0.4829) on GLS in the 9 patients without cardiac involvement (GLS -22.77 ± -3.12 at screening and -22.36 ± -3.02 at end of treatment), suggesting a specific effect of CAEL-101 on cardiac amyloid deposits (Figure 2 and Table 1). Pearson correlation coefficient between NT-proBNP response and GLS response (in 8 cardiac evaluable patients) was 0.345, further confirming the efficiency of Cael-101 in amyloid resolution resulting in structural remodeling of the heart muscle.
Improvement in GLS correlates with improvement in NT-proBNP in in patients with cardiac AL Amyloidosis treated with CAEL-101. The short timeframe in which the improvement of the GLS occurred (12 weeks after entering the trial) suggests that this effect is Ab related and GLS along with NT-proBNP should be evaluated in larger studies as markers for early cardiac response in patients with AL Amyloidosis.
- Wechalekar AD, Schonland SO, Kastritis E et al. A European collaborative study of treatment outcomes in 346 patients with cardiac stage III AL amyloidosis. Blood.2013;121(17):3420-7.
- Wall JS, Kennel SJ, Stuckey AC et al. Radioimmunodetection of amyloid deposits in patients with AL amyloidosis. Blood. 2010 Sep 30;116(13):2241-4.
- Edwards CV, Gould J, Langer AL et al. Final Analysis of the Phase 1a/b Study of Chimeric Fibril-Reactive Monoclonal Antibody 11-1F4 in Patients with Relapsed or Refractory AL Amyloidosis. Blood 2017 130:509.
- Salinaro F, Meier-Ewert HK, Miller EJ et al. Longitudinal systolic strain, cardiac function improvement and survival following treatment of light-chain (AL) cardiac amyloidosis. Eur Heart J Cardiovasc Imaging.2017 Sep 1;18(9):1057-1064.
*Dr. Lentzsch recused herself from the Phase 1a/b trial in 11/2017.
Disclosures: Maurer: Glaxo Smith kline: Other: personal fees ; Eidos: Other: Personal fees, Research Funding; Pfizer: Other: Personal fees, Research Funding; Prothena: Research Funding; Alnylam: Research Funding; Ionis: Other: Personal fees, Research Funding; Akcea: Other: Personal fees. Lentzsch: BMS: Consultancy; Caelum Biosciences: Consultancy, Other: Dr. Lentzsch recused herself as an investigator from the Phase 1a/b trial testing CAEL-101 in 11/2017., Patents & Royalties: Shareholder for Caelum Biosiences; Bayer: Consultancy; Janssen: Consultancy.
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