SUMMARY

• TECVAYLI is not approved by the regulatory agencies for the treatment of patients with plasma cell leukemia (PCL).
• Johnson & Johnson does not recommend any practices, procedures, or usage that deviate from the product labeling or are not approved by the regulatory agencies.
• MajesTEC-1 is a phase 1/2, multicohort study evaluating the safety and efficacy of TECVAYLI in patients with relapsed or refractory multiple myeloma (RRMM).¹
  • Per protocol, patients with PCL (>2.0 x 10⁹/L plasma cells by standard differential), were excluded from enrollment.²
• Shrestha et al (2025)² published a retrospective study of 16 patients with secondary PCL (sPCL) treated with ≥1 full dose of TECVAYLI at 3 US academic centers.
• Mohan et al (2024)³ published a retrospective, real-world study of 110 patients with RRMM treated with TECVAYLI at 5 US academic centers.
• Grajales-Cruz et al (2023)⁴ presented a single-center, retrospective chart review of 22 patients with prior B-cell maturation antigen (BCMA) targeted therapy treated with TECVAYLI.
• Bardenbacher et al (2024)⁵ reported a case of a 59-year-old female patient with PCL.

CLINICAL DATA - Retrospective studies

Shrestha et al (2025)² published a retrospective study of 16 patients with secondary PCL (sPCL) treated with ≥1 full dose of TECVAYLI at 3 US academic centers.

Results

Baseline Characteristics

• The median circulating plasma cells (CPCs) level was 7.45% (range, 5%-82%).
• All enrolled patients exhibited high‑risk cytogenetic profiles, including multiple chromosomal translocations t(4;14), t(14;16), del(17p), gain(1q21), del(1p).
• Patients received a median of 4.5 prior lines of therapy (range, 2-10), and 87% had previously undergone autologous stem cell transplantation.
• A total of 25% of patients (n=4) had been exposed to BCMA‑directed therapies before receiving TECVAYLI.

Efficacy

• The overall response rate (ORR) was 31% (5/16), including 1 patient with a complete response and 4 patients with a partial response.
• No response to TECVAYLI was observed in patients who had previously received BCMA‑directed therapy.
• The median progression-free survival (PFS) for responders was 4.6 months (95% confidence interval [CI], 0.6-not evaluable [NE]).
• At a median follow‑up duration of 61 days (95% CI, 12-543), all patients had experienced either disease progression or death by the time of the last assessment.
• At a median follow-up of 14 months, median overall survival (OS) was not reached in patients who achieved a response. Median OS among nonresponders was 1.13 months (95% CI, 0.43-NE).
• Assessment of absolute lymphocyte count (ALC) as a predictor of response in sPCL showed no significant difference between responders (median, 0.5×10³/µL; range, 0.2×10³/µL to 1.3×10³/µL) and nonresponders (median, 0.7×10³/µL; range, 0.2×10³/µL to 6.5×10³/µL), with an odds ratio (OR) of 0.32 (95% CI, 0.02-3.87; P=0.37).
• CPC levels were not significantly correlated with treatment response (OR, 1.006; 95% CI, 0.95-1.05; P=0.79) or PFS (hazard ratio, 0.98; 95% CI, 0.96-1.01; P=0.38).

Safety

• Grade 1/2 cytokine release syndrome (CRS) was observed in 56% of patients, and 55% of these patients received tocilizumab. No grade 3/4 CRS was observed.
• Immune cell-associated neurotoxicity syndrome (ICANS) was reported in 2 patients (grade 2, n=1; grade 3, n=1).

Mohan et al (2024)³ published a retrospective, real-world study of 110 patients with RRMM treated with TECVAYLI at 5 US academic centers. Two patients included in this study had sPCL. Both patients experienced fulminant disease relapse after the first full dose of TECVAYLI.

Grajales-Cruz et al (2023)⁴ presented a single-center, retrospective chart review of 22 patients with prior BCMA targeted therapy treated with TECVAYLI; 5% of patients had PCL for which efficacy and safety outcomes were not disclosed.

CLINICAL DATA – case report

Bardenbacher et al (2024)⁵ reported a case of a 59-year-old female patient with PCL who was refractory to several LOTs before achieving a complete remission to TECVAYLI, daratumumab and lenalidomide and consolidating allogeneic hematopoietic stem cell (allo-HSCT) transplantation. Prior to allo-HSCT transplantation, TECVAYLI was administered for 10 weeks and 8 weeks in combination with daratumumab and lenalidomide due to a slow clinical response. A 4-month complete remission was reported.

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 04 February 2026.