SUMMARY  

• Janssen does not recommend the use of TECVAYLI in a manner inconsistent with the approved labeling.
• The information presented below is limited to evaluations of primary intravenous immunoglobulin (IVIG) prophylaxis compared with patients who received no IVIG prophylaxis and infection outcomes.

Clinical Data

• MajesTEC-1 (MMY1001) is a phase 1/2, multicohort study evaluating the safety and efficacy of TECVAYLI in patients with relapsed or refractory multiple myeloma (RRMM).¹
  • Frerichs et al (2024)² evaluated the impact of IVIG supplementation on the frequency of severe infections in 52 patients treated with TECVAYLI in the MajesTEC-1 study at Amsterdam University Medical Center.
    • Primary IVIG prophylaxis referred to preemptive IVIG replacement in patients with polyclonal immunoglobulin G (IgG) <4 g/L. Secondary IVIG prophylaxis was administered at the physician’s discretion in patients who developed a severe infection with IgG <4g/L. Primary IVIG supplementation was administered to 20 patients. None of these patients discontinued IVIG while on TECVAYLI. IVIG as secondary prophylaxis was administered to 32 patients (observation group).
    • The incidence rate of infections was 0.12 per patient-year (95% confidence interval [CI], 0.014-0.42) in the primary IVIG prophylaxis group, compared to 1.36 per patient-year (95% CI, 0.84-2.03) in the observation group (incidence rate ratio, 11.6; 95% CI, 2.70-50.0; P=0.001). The cumulative incidence of serious infections at 6 months was 5.3% in the primary IVIG prophylaxis group and 54.8% in the observation group (P<0.001).
    • A total of 2 serious infections in 2 patients occurred during 204.5 months of IVIG treatment, compared to 20 infections in 18 patients not receiving IVIG during 176.8 months of observation. The most common type of grade ≥3 infections in the observation group were lower respiratory tract infections, accounting for 13 of 20 infections (65.0%).
    • Fourteen of the 18 patients in the observation group who developed a serious infection were subsequently administered IVIG (secondary prophylaxis). During 144.8 months of follow-up, 1 of these patients developed a serious infection after IVIG was initiated (incidence rate, 0.083 per patient-year; 95% CI, 0.0021-0.45). This was significantly lower than what was observed in the absence of IVIG supplementation (incidence rate ratio, 16.4; 95% CI, 2.22-125; P=0.006). Of the remaining 4 patients who were not initiated on IVIG, 3 patients died as a result of infection, and 1 patient discontinued study due to disease progression.
    • After 6 months, the cumulative frequency of serious infections after initiation of secondary IVIG prophylaxis was 0%.

additional Data

• Smits et al (2025)³ reported results from a retrospective, single center cohort study of 80 patients with RRMM treated with TECVAYLI at Amsterdam University Medical Center, Netherlands.
  • Among 80 patients with RRMM, 64% of patients (n=51) were enrolled in a clinical trial and 36% of patients (n=29) received treatment through a compassionate use program.
    • Of the 80 patients, 17% had International Staging System (ISS) stage III disease, 40% had high-risk cytogenetic abnormalities, 23% presented with extramedullary disease, and 52% were triple-class refractory. Patients had a median of 5 prior lines of therapy (LOTs).
  • All patients received cotrimoxazole and valaciclovir for antimicrobial prophylaxis. IVIG was administered either as primary prophylaxis when polyclonal IgG <4 g/L, or as secondary prophylaxis following a severe infection (CTC grade ≥3) with polyclonal IgG <4 g/L. Infections were recorded from treatment initiation until disease progression, death, or the last follow-up date.
  • At a median follow-up of 21 months, the median progression-free survival (PFS) was 18.1 months (95% confidence interval [CI], 11.8-37.6) and the median overall survival (OS) was 43.5 months (95% CI, 24.6-not estimable [NE]).
  • A total of 83% of patients (n=66) received IVIG supplementation (primary prophylaxis, n=51; secondary prophylaxis, n=15); 17% of patients (n=14) did not receive IVIG, including 13 due to early disease progression.
  • A total of 390 infections were reported, with 48 (12%) categorized as severe.
    • Infection was reported in 90% of patients (n=72), with 38% of patients (n=30) experiencing >1 severe infection.
    • A total of 5% of patients (n=4) died due to infection.
  • Of 265 infections during IVIG treatment, 82 (31%) were associated with IgG levels <4 g/L. After IVIG initiation, 56% of infections occurred within the first 3 months and 73% within the first 6 months.
  • IVIG lowered all-grade infection rate from 4.41 vs 3.15 (no IVIG vs IVIG, P=0.01) and severe infection rate from 0.93 vs 0.33 (no IVIG vs IVIG, P<0.001) per patient-year.
  • Longer dosing intervals reduced annualized rates of infections.
    • All-grade infection rate was 6.08 vs 2.25 (weekly vs bimonthly, P<0.01), and severe infection rate was 0.81 vs 0.10 (weekly vs bimonthly, P<0.05) per patient-year.
  • During IVIG, a reduced risk for severe infections was observed.
    • With IVIG, all-grade infections were 3.02 (weekly), 3.13 (biweekly), 3.22 (monthly), and 2.88 (bimonthly) per patient-year and severe infections were 0.44 (weekly), 0.31 (biweekly), 0.32 (monthly), and 0.13 (bimonthly) per patient-year.
• Mohan et al (2025)⁴ presented results from a multi-institutional study evaluating the effect of primary IVIG replacement (n=92) compared with no primary IVIG prophylaxis (n=133) in patients with RRMM who received at least one dose of TECVAYLI or an investigational B-cell maturation antigen (BCMA)-directed bispecific antibody (BsAb). 
  • Primary IVIG prophylaxis was administered following the start of BsAb therapy and prior to a documented infection, whereas secondary IVIG prophylaxis was administered following a documented infection. In patients who received TECVAYLI, 78 patients received primary IVIG prophylaxis while 82 patients received no primary IVIG prophylaxis.
  • Treatment groups were pooled, and results were provided for spectrum of infections, infection-free survival and PFS/OS and IVIG prophylaxis.
• Mohan et al (2024)⁵ conducted a retrospective cohort study on the efficacy and safety of TECVAYLI in 110 patients with RRMM across 5 United States (US) academic centers from January 2023 to August 2023.
  • Primary IVIG prophylaxis referred to preemptive IVIG replacement given in patients with hypogammaglobulinemia, regardless of any history of infection. IVIG supplementation was administered to 43% of patients (n=46) as primary prophylaxis.
  • Overall, 78 infections were diagnosed in 44 patients; all grades and grade ≥3 infections were 40% (n=44) and 26% (n=29), respectively. Recipients of IVIG had a statistically significant reduction in rates of all grades (0.95 vs 0.45; P=0.005) and grade ≥3 infections (0.61 vs 0.24; P=0.011) per 100 days compared to patients who did not receive IVIG supplementation.
  • The cumulative incidence of infections (all grades) at 3 and 6 months in patients who received primary IVIG supplementation was 35% (95% CI, 23-55) and 35% (95% CI, 23-55), respectively, compared with 44% (95% CI, 33-60) and 54% (95% CI, 41-71), respectively, in patients who did not receive IVIG supplementation. The cumulative incidence of grade ≥3 infections at 3 and 6 months in patients who received primary IVIG supplementation was 17% (95% CI, 8.7-35) each, compared to 31% (95% CI, 21-46) and 43% (95% CI, 31-61) respectively, in patients who did not receive primary IVIG prophylaxis.

Literature Search

A literature search of MEDLINE^®, Embase^®, BIOSIS Previews^®, and Derwent Drug File databases (and/or other resources, including internal/external databases) was conducted on 13 October 2025.