Effect of Age on Efficacy and Safety Outcomes in Patients (Pts) with Newly Diagnosed Multiple Myeloma (NDMM) Receiving Lenalidomide and Low-Dose Dexamethasone (Rd): The First Trial
Authors: Hulin Cyrille , Facon Thierry , Shustik Chaim , Belch Andrew , Petrucci Maria Teresa , Dührsen Ulrich , Lu Jin , Song Kevin , Rodon Philippe , Pegourie Brigitte , Garderet Laurent , Hunter Hannah , Azais Isabelle , Eek Richard , Macro Margaret , Dakhil Shaker , Houck Vanessa , Chen Guang , Ervin-Haynes Annette , Offner Fritz 
Published: October 2019

Abstract
Background: In the pivotal FIRST trial, a randomized, international, multicenter phase 3 study, continuous Rd compared with melphalan-prednisone-thalidomide (MPT) improved progression-free survival (PFS) which was the primary endpoint (HR = 0.72; P < 0.01). The interim overall survival (OS) analysis showed a 22% reduction in risk of death with continuous Rd vs. MPT (HR = 0.78; P = 0.02) (Facon, Blood 2013). This analysis evaluates outcomes based on age, which was a stratification parameter, and compared pts aged ≤ 75 yrs and > 75 yrs.
Methods: Pts with NDMM were randomized to continuous Rd until progressive disease (PD) (N = 535); 18 cycles (72 weeks [wks]) of Rd (Rd18; N = 541); or 12 cycles (72 wks) of MPT (N = 547). Starting doses were reduced in pts aged > 75 yrs: dexamethasone (20 vs. 40 mg), melphalan (0.20 vs. 0.25 mg/kg), and thalidomide (100 vs 200 mg). The primary endpoint was PFS (continuous Rd vs. MPT) and the secondary endpoint were OS, overall response rate, time to response, duration of response, time to Tx failure, time to 2nd AMT, health-related quality of life, safety.
Results: The proportion of pts aged > 75 yrs was > 34% across treatment (Tx) arms. In pts ≤ 75 yrs, 37% had ISS stage III vs. 51% in > 75 yrs. ECOG score ≥ 1 was observed in 74% and 69% of pts aged > 75 and ≤ 75 yrs, respectively. Severe renal impairment (CrCl < 30 mL/min) was observed in 14% of pts > 75 vs. 7% in ≤ 75 yrs. PFS and OS outcomes favored continuous Rd over MPT in both age groups. With a median follow-up of 37 months (mos), PFS was 27.4 mos in continuous Rd pts vs. 21.8 mos in MPT pts aged ≤ 75 yrs (HR = 0.68; P < 0.001); a trend for improved PFS was also seen for pts aged > 75 yrs (HR = 0.81; P = 0.11) (Table 1). PFS for continuous Rd vs. Rd18 pts was also increased in both age groups (HR = 0.68; P < 0.001 and HR = 0.75; P = 0.03, respectively). Response rates were consistently higher with continuous Rd vs. MPT in pts aged ≤ 75 yrs (77% vs. 66%; P < 0.001) and > 75 yrs (71% vs. 55%; P < 0.001). Duration of response with continuous Rd was longer vs. MPT in pts aged ≤ 75 yrs (40 vs. 22 mos) and pts > 75 yrs (31 vs. 24 mos). The interim analysis of OS showed an improved trend for continuous Rd vs. MPT in pts aged ≤ 75 yrs (HR = 0.77; P = 0.06) and > 75 yrs (HR = 0.80; P= 0.16). Grade 3–4 adverse events (AEs) in ≥ 10% of pts were similar across age subgroups (Table 2). Tx discontinuation due to AEs was comparable across the Tx groups and independent of age.
Conclusions:Regardless of age (≤ 75 vs. > 75 yrs), continuous Rd was effective, increased PFS and interim OS, and was generally well tolerated vs. MPT in NDMM pts. Duration of response was improved with continuous Rd vs. MPT and Rd18, irrespective of age, and with a more profound benefit observed in younger pts. Continuous Rd represents a new clinical option and standard of care for these pts in the first-line setting.
Abstract 81. Table 1 PFS, OS and Response Aged ≤ 75 yrs Aged > 75 yrs All pts ITT population Continuous Rd (n = 349) Rd18 (n = 348) MPT (n = 359) Continuous Rd (n = 186) Rd18 (n = 193) MPT (n = 188) Continuous Rd (n = 535) Rd18 (n = 541) MPT (n = 547) Median PFS, mos 27.4 21.3 21.8 21.2 19.4 19.2 25.5 20.7 21.2 PFS HR (95% CI); P-value Continuous Rd vs. Rd18 0.68 (0.55–0.83); P < 0.01 0.75 (0.58–0.98); P = 0.03 0.70 (0.60–0.82); P < 0.01 Continuous Rd vs. MPT 0.68 (0.56–0.83); P < 0.01 0.81 (0.62–1.05); P = 0.11 0.72 (0.61–0.85); P < 0.01 4-yr OS, % 66 61 58 47 47 39 59 56 51 OS HR (95% CI); P-value Continuous Rd vs. Rd18 0.88 (0.67–1.16); P = 0.36 0.94 (0.69–1.29); P = 0.70 0.90 (0.73–1.10); P = 0.31 Continuous Rd vs. MPT 0.77 (0.59–1.01); P = 0.06 0.80 (0.59–1.09); P = 0.16 0.78 (0.64–0.96); P = 0.02 Response rate (≥ PR), % 77 77 66 71 66 55 75 73 62 Duration of response (≥ PR), mos 40 23 22 31 20 24 35 22 22 CI, confidence interval; ITT, intent to treat; PR, partial response.
Table 2 Grade 3–4 AEs Observed in ≥ 10% of Pts Aged ≤ 75 yrs Aged > 75 yrs Safety population, % Continuous Rd (n = 347) Rd18 (n = 348) MPT (n = 357) Continuous Rd (n = 185) Rd18 (n = 192) MPT (n = 184) Neutropenia 28 25 47 28 29 40 Thrombocytopenia 8 9 13 9 7 7 Anemia 18 12 20 19 23 17 Leukopenia 5 6 11 4 5 8 Infections 29 21 16 29 23 20 DVT and/or PE 10 6 8 7 8 4 Peripheral sensory neuropathy 1 1 10 1 0 8 Tx discontinuation due to AEs 28 18 28 32 25 30 DVT, deep-vein thrombosis; PE, pulmonary embolism.

Disclosures
Hulin: Celgene: Honoraria. Off Label Use: Lenalidomide used in newly diagnosed multiple myeloma patients. Facon:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Belch:Janssen, Celgene, Onyx: Honoraria. Petrucci:Celgene, Janssen-Cilag, Sanofi, Bristol-Myers Squibb: Honoraria. Dührsen:Celgene: Honoraria, Research Funding. Song:Celgene: Consultancy, Honoraria, Research Funding. Houck:Celgene: Employment. Chen:Celgene: Employment. Ervin-Haynes:Celgene: Employment.