Ibrutinib/Rituximab Approved in Canada for CLL

Matthew Kang, MD, FRCPC

Health Canada has approved the combination of ibrutinib (Imbruvica) and rituximab (Rituxan) for use in patients with treatment-naïve chronic lymphocytic leukemia (CLL), according to an announcement from The Janssen Pharmaceutical Companies of Johnson & Johnson.¹

The regulatory decision is based on data from the phase 3 ECOG1912 trial, which showed that the doublet significantly improved progression-free survival (PFS) over fludarabine, cyclophosphamide, and rituximab (FCR) in newly diagnosed patients with CLL who were aged 70 years or older. At a median follow-up of 37 months, treatment with the regimen resulted in a 66% reduction in the risk of disease progression or death compared with FCR (HR, 0.34; 95% CI, 0.22-0.52; P <.0001).

“For younger patients, chemoimmunotherapy is a common first-line treatment,” Matthew Kang, MD, FRCPC, hematologist at Joseph Brant Hospital Oncology Clinic and assistant clinical professor at McMaster University, stated in a press release. “With this new indication for [ibrutinib], we have entered a new treatment era, one that is targeted, chemotherapy-free, and shown to help patients live longer without disease progression.”

In the multicenter, open-label, phase 3 trial, investigators enrolled a total of 529 patients with previously untreated CLL who were aged 70 years and older. Participants were randomized to receive the combination of ibrutinib and rituximab (n = 354) or FCR (n = 175). The primary objective of the trial was PFS per independent review committee and in accordance with the International Workshop on CLL.

Additional results revealed that at a median follow-up of 49 months, the median overall survival had not yet been reached. A total of 23 deaths were reported, with 3% (n = 11) occurring in the doublet arm and 7% (n = 12) occurring in the FCR arm.

Previous data showed that at a median follow-up of 33.6 months, the PFS rate was 89.4% versus 72.9% in the investigational and control arms, respectively (HR, 0.35; 95% CI, 0.22-0.56; P <.001).² Moreover, OS was also found to favor the doublet over FCR, at 98.8% versus 91.5%, respectively (HR, 0.17; 95% CI, 0.05-0.54; P <.001).

In patients with IGHV-mutated disease, the 3-year PFS rates with ibrutinib/rituximab and FCR were 87.7% and 88%, respectively (HR, 0.44; 95% CI, 0.14-0.36).

Regarding safety, the most frequent toxicities reported in patients with CLL who received ibrutinib included neutropenia, diarrhea, fatigue, musculoskeletal pain, rash, thrombocytopenia, anemia, bruising, nausea, hemorrhage, cough, pyrexia, arthralgia, headache, upper-respiratory tract infection, and hypertension.

References

1. Health Canada approves IMBRUVICA (ibrutinib) plus rituximab for the treatment of patients with chronic lymphocytic leukemia (CLL). News release. The Janssen Pharmaceutical Companies of Johnson & Johnson. January 13, 2021. Accessed January 13, 2021. http://bit.ly/3bCCQwi.
2. Shanafelt TD, Wang XV, Kay NE, et al. Ibrutinib-rituximab or chemoimmunotherapy for chronic lymphocytic leukemia. N Eng J Med. 2019;381(5):432-443. doi:10.1056/NEJMoa1817073