Background: Teclistamab is the first B-cell maturation antigen (BCMA) bispecific antibody approved for the treatment of relapsed/refractory multiple myeloma (RRMM) at a dose of 1.5 mg/kg weekly (QW) given subcutaneously. A less frequent dosing schedule offers added convenience and flexibility to patients, physicians, and caregivers. We evaluated the ability of patients to maintain their responses after transitioning from QW to every other week (Q2W) dosing schedules in the pivotal phase 1/2 MajesTEC-1 trial (NCT03145181/NCT04557098). Methods: Eligible patients had RRMM and received ≥3 prior lines of therapy including a proteasome inhibitor, immunomodulatory drug, and anti-CD38 antibody. Prior BCMA-targeted therapy was not allowed in this cohort. Patients received the recommended phase 2 dose (RP2D) of 1.5 mg/kg teclistamab QW, with the option to switch to Q2W dosing if patients achieved a confirmed partial response or better after ≥4 cycles of treatment (phase 1) or a confirmed complete response (CR) or better for ≥6 months (phase 2). Response was assessed per IMWG 2016 criteria. Results: As of Dec 9, 2022, 165 patients in the pivotal cohort had received teclistamab at the RP2D. Of 104 responders, 60 patients switched to Q2W dosing; 50 met the protocol-defined criteria for switching, and 10 switched who did not meet the criteria (4 due to adverse events [AEs]; 6 due to other reasons). Patients who switched had a median age of 64 years, 58% were male, 25% had high-risk cytogenetics, 7% had extramedullary plasmacytomas, and 3% had International Staging System stage III disease at baseline. Patients received a median of 4 prior lines of therapy, and 75% were triple-class refractory. At the time of switch, 49 (82%) patients achieved ≥CR, and 11 (18%) had a very good partial response. Median time to switch from QW to Q2W dosing was 11.1 months (range, 3–20). At median 11.1-month (range, 2–24) follow-up since switching, the median duration of response from the date of switch was 20.5 months (range, 1–23), with 40/60 patients still in response and ongoing treatment. Of the remaining patients, 13/60 have progressed (median time from switch to progression not estimable), 2 discontinued due to AEs, 1 discontinued for other reason, and 4 died. Additional results will be presented. Conclusions: Overall, patients from the MajesTEC-1 study who transitioned from QW to less frequent Q2W dosing of teclistamab had sustained remission, with a median duration of response of 20.5 months from the date of switch. Clinical trial information: NCT03145181, NCT04557098.