The Multiple Myeloma Hub uses cookies on this website. They help us give you the best online experience. By continuing to use our website without changing your cookie settings, you agree to our use of cookies in accordance with our updated Cookie Policy

Update from the KarMMA study of CAR T-cell product, bb2121 (ide-cel)

Dec 8, 2019

On 6th December 2019, it was announced that the phase II KarMMA study met its primary endpoint of overall response rate (ORR) and key secondary endpoint of complete response (CR) rate. The KarMMA study is investigating idecabtagene vicleucel (ide-cel, also known as bb2121), in patients with relapsed/refractory multiple myeloma (RRMM). Ide-cel is a chimeric antigen receptor (CAR) T-cell therapy targeting B-cell maturation antigen (BCMA).1

The KarMMA study was initiated based on positive results from a phase I, CRB-4012 study of bb2121 in patients with RRMM, summarized by the Multiple Myeloma (MM) Hub here.

KarMMA (NCT03361748)1

  • Open-label, single arm, multicenter phase II study in patients with RRMM
    • Enrolled; n= 140
    • Treated; n= 128
  • Patients were treated at target dose between 150 and 450 x 106 CAR T cells
  • Patient characteristics:
    • Patients had received three or more prior lines of therapy including an immunomodulatory drug (IMiD), a proteasome inhibitor (PI) and an anti-CD38 antibody
      • All were refractory to last regimen
      • Refractory to anti-CD38: 94%
      • Triple refractory: 84%
  • Key efficacy results are shown in Table 1
  • The safety results were consistent with the CRB-401 study in 128 evaluable patients
    • ≥ Grade III cytokine release syndrome (CRS): 5.5%. One CRS event was fatal
    • ≥ Grade III neurotoxicity events: 3.1%. No grade IV events were reported
    • Grade III or higher CRS or neurotoxicity at each target dose was <6%

Table 1. Efficacy results from KarMMA

CAR, chimeric antigen receptor; CR, complete response; ORR, overall response rate; PFS, progression free survival

CAR T-cell dose

150 x 106

300 x 106

450 x 106

150 – 450 x 106











CR/stringent CR





Median duration of response


9.9 months

11.3 months

10.6 months

Median PFS


5.8 months

11.3 months

8.6 months

More detailed data from this trial are due to be presented at an upcoming medical congress. Meanwhile, several abstracts in the field of CAR T-cell therapy are due to be presented at the 61st American Society of Hematology (ASH) meeting in December 2019.

  1. BusinessWire. Bristol-Myers Squibb and bluebird bio Announce Positive Top-line Results from the Pivotal Phase 2 KarMMa Study of Ide-cel in Relapsed and Refractory Multiple Myeloma. Published; December 6 2019[Accessed December 08 2019 ]
  2. Raje N. et al., bb2121 anti-BCMA CAR T-cell therpy in patients with relapsed and refractory multiple myeloma: Updated results from a multicenter phase I study. Abstract  #8007. 2018 American Society of Clinical Oncology (ASCO) Annual Meeting, 2018; Chicago, IL, US

Expert Opinion