CIT still has a role as first-line treatment
Dr. Brown suggested that a PFS benefit may not be enough to recommend targeted agents over CIT. For one thing, the PFS benefit doesn’t apply to all patients, as the IGHV-mutated subgroup does equally well with CIT and targeted agents.
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Dr. Jennifer R. Brown
In the IGHV-mutated group from the E1912 trial, the 3-year PFS was 88% for patients who received Ib-R and those who received FCR (N Engl J Med. 2019 Aug 1;381:432-43). In the A041202 study, the 2-year PFS among IGHV-mutated patients was 87% in the BR arm, 86% in the Ib arm, and 88% in the Ib-R arm (N Engl J Med. 2018; 379:2517-28).
In the CLL14 trial, PFS rates were similar among IGHV-mutated patients who received chlorambucil plus obinutuzumab and IGHV-mutated or unmutated patients who received venetoclax and obinutuzumab (N Engl J Med. 2019; 380:2225-36).
Dr. Brown also noted that the overall improvement in PFS observed with ibrutinib and venetoclax doesn’t always translate to improved OS.
In the A041202 study, there was no significant difference in OS between the Ib, Ib-R, and BR arms (N Engl J Med. 2018; 379:2517-28). There was no significant difference in OS between the ibrutinib and chlorambucil arms in the iLLUMINATE trial (Lancet Oncol. 2019 Jan;20[1]:43-56). And there was no significant difference in OS between the venetoclax and chlorambucil arms in the CLL14 trial (N Engl J Med. 2019; 380:2225-36).
However, in the RESONATE-2 trial, ibrutinib provided an OS benefit over chlorambucil. The 2-year OS was 95% and 84%, respectively (P = .0145; Haematologica. Sept 2018;103:1502-10). Dr. Brown said the OS advantage in this study was due to the “very poor comparator of chlorambucil and very limited crossover.”
As Dr. Wierda mentioned, the OS rate was higher with Ib-R than with FCR in the E1912 trial. The 3-year OS rate was 98.8% and 91.5%, respectively (P less than .001; N Engl J Med. 2019 Aug 1;381:432-43). Dr. Brown noted, however, that there were few deaths in this study, and many of them “were not clearly related to the disease or its treatment.”
Dr. Brown also pointed out that FCR has been shown to have curative potential in IGHV-mutated CLL in both the FCR300 trial (Blood. 2016 127:303-9) and the CLL8 trial (Blood. 2016 127:208-15).
Another factor to consider is the greater cost of targeted agents. One analysis suggested the per-patient lifetime cost of CLL treatment in the United States will increase from $147,000 to $604,000 as targeted therapies overtake CIT as first-line treatment (J Clin Oncol. 2017 Jan 10;35[2]:166-174).
“Given all of the above, chemoimmunotherapy is going to remain part of the treatment repertoire for CLL,” Dr. Brown said. “It’s our only known potential cure for the fit, mutated patients ... and can also result in prolonged treatment-free intervals for patients who are older. As we manage CLL as a chronic disease over a lifetime, we need to continue to have this in our armamentarium.”
Specifically, Dr. Brown said CIT is appropriate for patients who don’t have del(17p) or mutated TP53. FCR should be given to young, fit patients with IGHV-mutated CLL, and FCR or BR should be given to older patients and young, fit patients with IGHV-unmutated CLL.
Dr. Brown and Dr. Wierda reported financial ties to multiple pharmaceutical companies, including makers of CLL treatments.