LY-06. Dual resistance to bortezomib and lenalidomide frequency in patients with multiple myeloma. A single center experience
Vsevolod G. Potapenko, Roman V. Vashchenkov, Natalia V. Dorofeeva, Elmira N. Dulaeva, Julia V. Zabutova, Anna V. Klimovich, Natalia A. Kotova, Maria I. Nabilkova, Olga V. Nebelitskaya, Victoria V. Ryabchikova, Irina A. Samorodova, Alexander V. Serkov, Irina A. Skorokhod, Ksenia А. Skoryukova, Daria A. Chaginskaya, Nadezhda V. Medvedeva
Municipal Clinical Hospital No.31, St. Petersburg, Russia
Dr. Vsevolod G. Potapenko, phone: +7 (905) 284-51-38, e-mail: firstname.lastname@example.org
Multiple myeloma (MM) is one of the most common malignant blood disorders. First- and second-line therapy includes lenalidomide- and bortezomib-containing regimens. The inevitable development of refractoriness refers to unresolved problems. Our aim was to evaluate efficacy of treatment and the frequency of development of double resistance to bortezomib and lenalidomide in patients with multiple myeloma (DRMM) in a single-center patient cohort.
Patients and methods
The data of 41 patients (random selection from 576), the median age 69 (56-80) years, 22 women and 19 men were retrospectively analyzed. The treatment was carried out from 01.2011 to 03.2020. A total of 95.1% (n=39) pts received first-line therapy with bortezomib. With progression, lenalidomide-containing courses were conducted. The cohort characteristics are provided in Table 1.
Table 1. Patient characteristics
The first-line chemotherapy effectiveness was 97.5%. Progression was observed in 63.4% (n=26) patients, the median time from the first therapy course to progression was 24 (3-63) months. Second-line therapy with lenalidomide was performed in 58.5% (n=24) cases, the effectiveness was 100%. The incidence of DRMM was 17% (n=7), the median from the second-line therapy initiation to progression was 21.5 (7-26) months, the median of the total disease duration from primary treatment initiation to double resistance development was 46 (11-77) months. The third-line therapy efficacy was 57.1% (n=4). In three patients (75%) progression occurred after 2 months (n=2) and 3 months (n=1). One patient remains in response for 17 months. The differences in progression-free survival (PFS) between all groups is statistically significant. PFS after three lines of therapy is shown in the figure. With a median follow-up of 43.5 (16-95) months the overall survival rate in the whole group was 58.5% (n=24). The mortality rate was 41.5% (n=17), of which 41.2% (n=7) patients died due to disease progression, 41.2% (n=7) of infectious complications and 17.6% due to cardiovascular events (n=3).
Figure 1. Progression-free survival after three different lines of therapy
The analysis of the small cohort data showed the importance of problem with DRMM. There is a need to identify its predictors within patents and disease characteristics, response to initial therapy.
Myeloma, double refractory, bortezomib, lenalidomide.