Kyle, RA

Abstract Measurable residual disease (MRD) assessment has become central to risk-adapted treatment strategies in multiple myeloma, yet the prognostic value of MRD negativity following autologous stem cell transplantation (ASCT) across individual high-risk cytogenetic abnormalities (HRCAs) remains unclear. We analyzed 351 newly diagnosed patients who achieved MRD negativity (sensitivity 2.4×10 − 6 ) at Day 100 following ASCT and had baseline cytogenetic data available. Median follow-up was 50.4 months. Standard-risk cytogenetics were present in 46% (n = 162), while 34% (n = 118) had one HRCA and 20% (n = 71) had ≥ 2 HRCAs. Despite uniform MRD negativity, several HRCAs continued to confer inferior progression-free survival (PFS). Compared with the standard-risk group (4-year PFS 84%), patients with del(17p), 1q21+, t(4;14), or MAF translocations [t(14;16)/t(14;20)] had significantly lower 4-year PFS rates: 56% (HR 2.89; p = 0.0001), 60% (HR 2.46; p = 0.0001), 43% (HR 3.50; p = 0.0001), and 58% (HR 2.51; p = 0.01), respectively. Isolated del(17p) and 1q21 + also conferred inferior PFS. The 4-year PFS was 65% for patients with one HRCA (HR 2.31; p = 0.0004) and 55% for those with ≥ 2 HRCAs (HR 2.75; p = 0.0001). In this large MRD-negative post-ASCT cohort, several HRCAs, including isolated HRCAs, remained clinically meaningful drivers of inferior PFS, highlighting that early MRD negativity does not uniformly mitigate the impact of high-risk biology.

Abstract The plasma cell labeling index (PCLI) and serum beta 2-microglobulin (beta 2M) are independent prognostic factors in multiple myeloma (MM). Recently, levels of thymidine kinase (TK) and C-reactive protein (CRP) have been shown to have prognostic value. We studied 107 patients with newly diagnosed myeloma to determine whether TK and CRP values added prognostic information not already available using the PCLI and beta 2M. Univariate survival analysis showed prognostic significance for the PCLI, TK, beta 2M, age, serum albumin, and CRP. Multivariate analysis showed that only PCLI and beta 2M have independent prognostic significance. The survival curves were better separated using the PCLI and beta 2M than with other combinations of variables. Among nine patients under age 65 with low PCLI and low beta 2M, eight were alive almost 6 years after starting chemotherapy. These good-risk patients could not be identified by standard clinical features. Although creatinine and calcium were normal, other features such as bone lesions, osteoporosis, fracture, and anemia were present and stage distribution was similar to other patients in the study. In conclusion, PCLI and beta 2M measured at diagnosis are independent prognostic factors. They must be considered when interpreting the results of clinical trials and should be helpful in counseling patients and in designing new trials. When the PCLI and beta 2M values are known, the TK and CRP values do not add useful additional prognostic information.

Beta 2-microglobulin (beta 2M) has been proposed as a prognostic factor in multiple myeloma (MM), but beta 2M levels are reported to correlate with other prognostic indicators such as stage and creatinine level. This study addressed the independent prognostic values of these and other variables, including plasma cell labeling indices (LI), in patients with newly diagnosed MM. beta 2M levels were measured with an enzyme-linked immunosorbent assay. LI were determined with a [3H]thymidine autoradiography method. By multivariate analysis and Kaplan-Meier survival analysis, the uncorrected beta 2M level remained the most significant prognostic factor after adjustment for age. Stage and creatinine level were closely related to beta 2M level and were no longer predictive of outcome after adjustment for age and beta 2M. Plasma cell LI varied independently of beta 2M level and remained predictive. A subset of patients with plasma-blastic myeloma had poor survival since beta 2M level and plasma cell LI were high. By using beta 2M level and LI, three risk groups were defined: low (beta 2M less than 4 micrograms/mL and LI less than 0.4%, median survival 48 months); intermediate (beta 2M less than 4 micrograms/mL and LI greater than or equal to 0.4%, median survival 29 months); and high (beta 2M greater than or equal to 4 micrograms/mL, median survival 12 months). Such grouping may better identify MM patients who might benefit from new treatment regimens.

Background:Venetoclax is a B cell lymphoma 2 (BCL‐2) inhibitor that has shown activity as a single agent and in combination with other therapies in patients with multiple myeloma, particularly those harboring t(11;14) associated with high BCL‐2 expression. Although early clinical trial data is encouraging (monotherapy response rate of 21% and 40% amongst t(11;14) and a response rate of 97% when used in combination with bortezomib and dexamethasone), data on outcomes in patients treated outside of clinical trial setting are sparse.Aims:We aimed to identify the efficacy of venetoclax in patients with multiple myeloma treated outside clinical trial.Methods:We conducted a retrospective review of all patients with multiple myeloma treated with venetoclax between December 2016 and February of 2019 at the Mayo Clinic outside of a clinical trial setting.Results:A total of 29 patients that were treated with venetoclax for relapsed or refractory multiple myeloma were identified. Characteristics of the cohort are reported in Table 1. Two thirds of the cohort had t(11;14) detected on cytogenetic studies and 48% (n = 14) had presence of high risk abnormalities. Median number of prior therapies was 6 (range 1–15) and 21% (n = 6) of patients had received ≥10 prior lines of therapy. Eighty three percent (n = 24) of patients had received prior autologous transplant and 76% (n = 22) were penta refractory or exposed. Median time from diagnosis of myeloma to initiation of venetoclax therapy was 5.3 years (range 0.8–23.6 years).Venetoclax used as monotherapy or a doublet in combination with dexamethasone in 59% (n = 17) of patients and a triplet or quadruplet in 41% (n = 12) given at 800 mg (55%) or 400 mg (35%) daily. Triplet and quadruplet regimens combined venetoclax with a variety of proteasome inhibitors or daratumumab. One patient had a quadruplet of venetoclax, carfilzomib, pomalidomide and dexamethasone. 93% (n = 27) patients were refractory to at least on proteasome inhibitor and immunomodulatory drug. Dose titration and escalation was used in 31% (n = 9) of patients. None of the patients experienced tumor lysis syndrome. At last follow‐up 55% (n = 16) of patients remain on venetoclax therapy. Overall response rate in the 24 patients evaluable for response was 46% (21% CR, 8% VGPR, 17% PR). Patients with t(11;14) had a numerically higher response rate than those without (50% vs 33%, p = 0.64). Patients with high risk cytogenetic abnormalities were less likely to respond (ORR 69% for standard risk vs 18% for high risk, p = 0.019). Median time to response was 2.6 months (range 1.1–6.9 months). Median duration of response was 5.2 months (range 2.2–12.9 months). After a median follow‐up time of 7.2 months for the cohort, the median PFS and OS are 5.8 and 14.6 months, respectively, Figure 1A/B. High risk cytogenetic abnormalities were associated with a shorter PFS (median PFS 3 months vs 14 months for standard risk, p = 0.002). The outcomes with venetoclax monotherapy and combination therapies are reported separately in the Table.Summary/Conclusion:Venetoclax is an effective oral agent in relapsed and/or refractory myeloma and can produce deep and durable responses in heavily pretreated patients. Further studies are needed to elucidate its role earlier in the disease and its effectiveness in combination with other anti‐myeloma therapies.image