Background PI-based therapy is a standard of care for non-transplant NDMM pts. However, long-term treatment, which is associated with improved outcomes, is often challenging in the RW. This may be due to a number of factors, including the burden of repeated intravenous (IV)/subcutaneous (SC) administration, distance from treatment center, comorbidities, and toxicity (e.g. peripheral neuropathy [PN] with btz). With the aim of increasing PI-based treatment adherence and duration while maintaining quality of life (QoL), the US MM-6 RW, community-based study (NCT03173092) investigates a transition from IV/SC btz-based induction to all-oral ixazomib-based therapy (ixazomib-lenalidomide-dexamethasone, IRd). We report efficacy and safety, plus adherence and electronic pt-reported outcomes (ePRO) compliance data, for the first 55 pts. Methods Non-transplant NDMM pts (transplant-ineligible or transplant delayed >24 mos) with ≥stable disease (SD) after 3 cycles of a btz-based induction are being enrolled at 23 community sites to receive IRd (ixazomib 4 mg, d 1, 8, 15; lenalidomide 25 mg, d 1-21; dexamethasone 40 mg [20 mg in pts aged >75 yrs], d 1, 8, 15, 22) for up to 26 x 28-d cycles or until progression/toxicity. Pts complete ePROs every cycle to assess QoL/treatment satisfaction, and a monthly medication adherence survey via a wearable device/smartphone. The primary endpoint is progression-free survival (PFS); key secondary endpoints include partial (PR), very good partial (VGPR), and complete (CR) response rates, and duration of therapy. Results As of April 1 2019, 55 pts had been enrolled at 16 sites. Median age was 72 (range 49-90) yrs, with 76% classified as elderly (≥65 yrs); 47% were male. Key characteristics of this RW population are summarized in Table 1. Comorbidities/concurrent medical conditions at the start of IRd therapy were extensive and included hypertension (51%), anemia (44%), fatigue (42%), renal and urinary disorders (36%), gastroesophageal reflux disease (31%), cardiac disorders (27%), constipation (27%), nausea (24%), and PN (16%); 91% of pts were receiving concomitant medications. At data cutoff, with 40 (73%) pts remaining on therapy, median duration of PI therapy, including prior btz-based induction, was 6.9 mos (mean 8.4 mos) (Table 2). Median duration of IRd treatment was 4.0 mos (median 5 cycles; mean 5.6 mos, 6.6 cycles), with pts having received up to 17.3 mos (18 cycles) of therapy to date. After 3 cycles of btz-based induction, the ≥VGPR rate was 27%, with 4% ≥CR; overall response rate (ORR) was 62%. With IRd therapy, the ≥VGPR rate was 40%, with 22% ≥CR; ORR was 65% (15% not evaluable). Following transition from btz-based induction to IRd, 21 pts (36%) had deepened responses (18% increase in ≥CR rate), including 3 VGPR to CR, 3 PR to CR, 1 MR to CR, 4 SD to CR, 3 PR to VGPR, 1 SD to VGPR, 5 SD to PR, and 1 SD to MR (Figure). With limited follow-up, and enrollment ongoing, 3 pts had progressed and one had died at data cutoff. The preliminary 6-mo PFS rate (95% CI) was 91% (74-97%) from start of IRd and 96% (84-99%) from start of btz-based induction. Average compliance with completing issued ePRO questionnaires during IRd treatment was 96% (61 pts; data cutoff July 8, 2019). Patients recorded their monthly medication adherence for the previous 4 weeks; 81% of evaluable pts (n=32) in cycle 1, 81% in cycle 2 (n=27), 77% in cycle 3 (n=22), 96% in cycle 4 (n=24), and 94% in cycle 5 (n=18) (n2 pts. AEs led to study drug modification in 47% and discontinuation in 4% of pts; 29% had serious AEs. PN occurred in 25% (4% grade 3) and led to dose modification in 13% of pts. There were no on-study deaths (i.e. occurring Conclusions These preliminary data in mostly elderly, comorbid, NDMM pts treated in the RW, community setting indicate the feasibility, tolerability, and efficacy of transitioning to IRd after 3 cycles of btz-based induction. Toxicities appeared similar to previous ixazomib studies. With 73% of pts remaining on therapy and enrollment continuing, duration of therapy is promising, substantial improvements in response have been seen, and ePRO compliance/ medication adherence is high, indicating the feasibility and value of these evaluations. Disclosures Rifkin: Amgen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Noga:Takeda: Employment. Yimer:Amgen: Consultancy; Puma Biotechnology: Equity Ownership; Clovis Oncology: Equity Ownership; Celgene: Honoraria; Seattle Genetics: Honoraria; Janssen: Speakers Bureau; AstraZeneca: Speakers Bureau. Girnius:Takeda: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Genentech: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Birhiray:Puma: Consultancy, Research Funding, Speakers Bureau; Alexion: Consultancy; Kite Pharma: Honoraria; Bayer: Honoraria; Helsin: Honoraria; Incyte: Research Funding, Speakers Bureau; Seattle Genetics: Honoraria; Pfizer: Speakers Bureau; Abbvie: Consultancy, Honoraria; Celgene: Honoraria; AstraZeneca: Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Sanofi Oncology: Speakers Bureau; Lilly: Speakers Bureau; Genomic Health: Speakers Bureau; Amgen: Honoraria, Speakers Bureau; BMS: Speakers Bureau; Tessaro: Speakers Bureau; Exelexis: Speakers Bureau; Clovis Oncology: Speakers Bureau; Jansen Bioncology: Consultancy, Speakers Bureau; Coheris: Honoraria; Takeda: Research Funding, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau. Yasenchak:Seattle Genetics: Consultancy; BMS: Consultancy. Lyons:Texas Oncology: Equity Ownership; Amgen: Consultancy; McKesson: Other: Leadership. Whidden:Takeda: Employment. Schlossman:Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Wang:Millennium Pharmaceuticals, Inc., Cambridge, MA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Employment. Boccia:DSI: Speakers Bureau; AstraZeneca: Speakers Bureau; Amgen: Speakers Bureau; Celgene: Speakers Bureau; Genentech: Speakers Bureau; AMAG: Consultancy.