Pomalidomide 3rd Line Versus 4th Line for RRMM
Authors: Gruchet Cécile , Guidez Stephanie , Richez Valentine , Hulin Cyrille , Voog Eric G. , Perrot Aurore , Macro Margaret , Decaux Olivier , Pauline Gueneau , Caillot Denis , Stoppa Anne-Marie , Lenain Pascal , Lebreton Pierre , Royer Bruno , Lancesseur Charles , Laribi Kamel , Le Du Katell , Moulin Charline , Montes De Oca Catalina , Jaccard Arnaud , Benboubker Lotfi , Chaleteix Carine , Systchenko Thomas , Moya Niels , Sabirou Florence , Levy Anthony , Bobin Arthur , Franques Paul , Gardeney Helene , Tomowiak Cecile , Desmier Deborah , Machet Antoine , Avet Loiseau Herve , Leleu Xavier 
Published: October 2019

Abstract
Background. Pomalidomide in association with dexamethasone is approved for RRMM in 3rd line and beyond based on the MM-003 multicenter international phase 3 study that demonstrated greater efficacy for Pomalidomide plus dexamethasone over high dose dexamethasone. However, MM-003 mainly recruited advanced RRMM with a median of 5 prior lines. Few data is available regarding real life Pomalidomide-based treatment in 3rd and 4th line RRMM.
The aim of this study was to study efficacy and safety of Pomalidomide-based treatment in 3rd and 4th line RRMM.
Methods. We studied 108 consecutive RRMM treated with Pomalidomide-based treatment in 3rd and 4th line in a multicenter-based study. All assessment made according to IMWG.
Results. The median age was 62.5 (range, 30-86), with 36% older than 65 years, sex ratio M/F 1.25 and ISS disease stage 2 or 3 in 58%. 100% were exposed to bortezomib and refractory to Lenalidomide. 52 patients (48%) had pomalidomide-based therapy as 3rd, and 56 (52%) as 4th line. 73% of patients received a double-based therapy (Pomalidomide plus Dexamethasone) and 27% received a triple based therapy (Pomalidomide, Cyclophosphamide and Dexamethasone).
Overall ORR was 55%, with 20% ≥VGPR including 5% CR, and was not statistically different in 3rd versus 4th line, and with PCd versus Pd, although the former was always better.
With a median f-up of 45 months, overall 77% and 49% had relapsed and died, respectively, with significantly less in benefit to combination and 3rd line compared to Pd and 4th line (p=0.020). The median PFS was 6 (CI95% 2.3;9.6) and 9 (5.5;12.5) months in 3rd and 4th line (p=0.04), and 6 (CI95% 2.8;9.2) and 12 (8.5;15.5) months in Pd and PCd (p=0.04), respectively. Interestingly, the estimated 3 years PFS for 3rd line and PCd was 34% and 32% respectively, greatly superior to 4th line and Pd, 13% and 18%, respectively. Similarly, the median OS from start of Pomalidomide was not reached in 3rd and in PCd lines versus 23months (5;49), (p=0.04), and 32 months (5;-) for 4th line and Pd use, respectively.
Pomalidomide was never permanently discontinued for safety issues, but 30 (28% of patients had to reduced pomalidomide dose, 25% to N-1 that is 3mg/d and 3% at N-2 that is 2mg/d. Expectedly, more patients (increased by 10%) had to reduce pomalidomide dose in 4th line compared to 3rd line, although it was not statistically significant, but not with PCd versus Pd. Indeed Cyclophosphamide but not pomalidomide is reduced in modified in dose or scheme when facing safety issues. No patient died related to adverse events. AEs leading to pomalidomide-based modification in schema included hematological in 40% and non hematological AEs in 12% of patients. Overall, the most common adverse events grade 3 or 4 were neutropenia (22%), anemia (11%), thrombocytopenia (7%) and infectious disease (5%).
Conclusion. Pomalidomide-based therapy demonstrates efficacy in the real life with a manageable safety profile. We demonstrate herein that early use and combination improves MM on pomalidomide in the real life. Further prospective studies are warranted to confirm this data on a larger MM population.

Disclosures
Hulin: Janssen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Perrot:Janssen: Honoraria; Amgen: Honoraria; Takeda: Honoraria; Sanofi: Honoraria; Celgene: Honoraria. Macro:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Financial support for congress; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Financial support for congress; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Financial support for congress; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Financial support for congress. Laribi:Hospira: Other: Grant; Amgen: Other: Personal fees; Novartis: Other: Grant and personal fees; Gilead: Other: Personal fees; Roche: Other: Grant; Takeda: Other: Grant and personal fees; Sandoz: Other: Grant; Teva: Other: Grant. Leleu:Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Mundipharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.