Janssen has reported new data for its B-cell maturation antigen (BCMA) directed CAR T therapy ciltacabtagene autoleucel (cilta-cel) in heavily pretreated relapsed/refractory multiple myeloma (RRMM) patients.

The updated results – from the Phase Ib/II CARTITUDE-1 study – showed an overall response rate (ORR) of 98% with a longer-term follow-up at a median of 18 months.

In addition, 80% of patients achieved a stringent complete response (sCR), increasing from the 67% sCR rate presented last year at the American Society of Hematology (ASH) 2020 annual meeting.

The new results also showed that 66% of patients were progression free and alive at 18 months, with an overall survival of 81%.

Response rates were also comparable across the prespecified subgroups and lines of treatment, according to Janssen.

The CARTITUDE-1 study included patients who had received a median of six prior treatment regimens, with all patients being triple-class exposed – this includes to an immunomodulatory agent (IMiD), a proteasome inhibitor (PI) and an anti-CD38 antibody.

On top of that, 42% were penta-drug refractory and 99% of patients were also refractory to their last line of therapy.

Among these heavily pretreated patients, 14% achieved a very good partial response (VGPR) and 3% achieved a partial response (PR).

The median time to response was one month, with responses deepening over time – among the 61 minimal residual disease (MRD) evaluable patients, 92% of patients achievef MRD negativity status at a median of one month post infusion.

On the safety front, cilta-cel’s safety profile was consistent with previously reported finding and no new safety signals were observed.

The most common haematologic adverse events include neutropenia, anaemia, thrombocytopenia, leukopenia and lymphopenia.

In addition, cytokine release syndrome (CRS) of any grade was seen in 95% of patients with a median duration of four days and 99% of which resolved within 14 days.

The data from the CARTITUDE-1 study has been used to support Janssen’s US Food and Drug Administration (FDA) biologics license application (BLA) for cilta-cel, which has already been accepted for priority review.