FDA Approves Imbruvica, Rituxan Combination in Previously Untreated Patients with CLL and SLL

The Food and Drug Administration (FDA) expanded the use of Imbruvica (ibrutinib) by approving it in combination with Rituxan (rituximab) for the treatment of previously untreated adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL).

Approval for this combination was based on results of the E1912 trial, a randomized, multi-center and open-label study of Imbruvica and Rituxan compared to fludarabine (chemotherapy for CLL), cyclophosphamide (chemotherapy for leukemia and lymphomas) and Rituxan. Imbruvica was previously approved for treatment of patients with CLL and SLL.

The study looked at 529 adult patients 70 years or younger with previously untreated CLL or SLL requiring systemic therapy and found a statistically significant improvement in progression-free survival (PFS) for patients on the Imbruvica and Rituxan combination. However, a median PFS was not reached in the combination arm nor the fludarabine, cyclophosphamide and Rituxan arm after a follow-up duration of 37 months.

“The gold-standard first-line treatment option for many patients with chronic lymphocytic leukemia who were fit enough to tolerate an aggressive treatment course had been the intravenous chemoimmunotherapy of FCR — that is, until today,” Dr. Brian Koffman, CLL Society co-founder, executive vice president and chief medical officer, said in a press release from the drug’s manufacturer. “The FDA approval of ibrutinib and rituximab regimen is welcome news for these previously untreated patients who have been looking forward to a non-chemotherapy treatment option.”

The most common side effects in CLL and SLL patients in the trial on the combination therapy included thrombocytopenia, diarrhea, fatigue, musculoskeletal pain, neutropenia, rash, anemia, bruising and nausea.

The review for this approval was done under Project Orbis, an FDA Oncology Center of Excellence initiative that allows for simultaneous submission and review of cancer treatments by the FDA and global partners. Due to the timing of the review amid the COVID-19 pandemic, a modified Project Orbis was taken as Australia, Canada and Switzerland are still reviewing the treatment for patients.

The recommended dose for Imbruvica is 420milligrams (mg) taken orally once daily with a glass of water. Rituxan is initiated in the second cycle and is administered at 50 mg/m² on Day 1, 325 mg/m² on Day 2, and 500 mg/m² on Day 1 of 5 cycles, for a total of 6 cycles.

Check back later for what you need to know about this approval.