LA JOLLA, CALIF. — Prolonged exposure to mogamulizumab can improve responses without compromising safety in patients with cutaneous T-cell lymphoma (CTCL), according to a post hoc analysis of the MAVORIC trial.
Investigators found that exposure to mogamulizumab correlated with response. The highest response rate — 75.6% — was observed in patients exposed to the drug for at least 351 days, and the lowest — 1.9% — was observed in patients exposed to mogamulizumab for less than 72 days.
On the other hand, rates of adverse events (AEs) were similar regardless of how long patients were treated with mogamulizumab.
, MD, of Stanford Cancer Institute at Stanford (Calif.) University, and her colleagues presented these findings at the annual T-cell Lymphoma Forum.
The phase 3 MAVORIC trial () included 372 adults with CTCL who had failed at least one systemic therapy. The patients were randomized to treatment with mogamulizumab or vorinostat.
Results from this comparison were previously reported at the 10th annual T-cell Lymphoma Forum.
At this year’s meeting, Dr. Kim and her colleagues reported results in 184 patients who were randomized to mogamulizumab — 105 of whom had mycosis fungoides (MF) and 79 of whom had Sézary syndrome (SS).
Patients were exposed to mogamulizumab for a mean of 275.2 days and a median of 170.0 days (range, 1-1,617 days).
The investigators divided patients into the following quartiles according to mogamulizumab exposure:
- Less than 72 days — 52 patients (28%)
- 72-170 days — 40 patients (22%)
- 171-351 days — 47 patients (26%)
- More than 351 days — 45 patients (24%).
Patients exposed to mogamulizumab for longer were more likely to have SS, stage III/IV disease, blood involvement, and a performance status of 0.
Dr. Kim said the SS patients “benefited a lot” from mogamulizumab and therefore remained on treatment longer.
As expected, patients exposed to mogamulizumab for the longest period had the highest global response rates. Confirmed response rates according to drug exposure were as follows:
- Less than 72 days: 1.9% overall, 0% for SS, and 2.9% for MF
- 72-170 days: 10% overall, 18.8% for SS, and 4.2% for MF
- 171-351 days: 29.8% overall, 36.4% for SS, and 24% for MF
- More than 351 days: 75.6% overall, 83.3% for SS, and 66.7% for MF.
In addition, rates of complete response (CR) and partial response (PR) tended to increase with mogamulizumab exposure. Rates of CR, PR, and stable disease (SD) according to exposure time were as follows:
- Less than 72 days: 0% CR, 7.7% PR, and 38.5% SD
- 72-170 days: 2.5% CR, 20% PR, and 62.5% SD
- 171-351 days: 2.1% CR, 34% PR, and 57.4% SD
- More than 351 days: 6.7% CR, 71.1% PR, and 17.8% SD.