LaPlant, Betsy

AbstractWaldenström macroglobulinemia (WM) is an immunoglobulin M‐associated lymphoma, with majority of cases demonstrating MYD88 locus alteration, most commonly, MYD88L265P. Owing to low prevalence of the wild‐type (WT) MYD88 genotype in WM, clinically relevant data in this patient population are sparse, with one study showing nearly a 10‐fold increased risk of mortality in this subgroup compared to patients with MYD88L265P mutation. We studied a large cohort of patients with MYD88L265P and MYD88WT WM, evaluated at Mayo Clinic, Rochester, between 1995 and 2016, to specifically assess the impact of these genotypes on clinical course. Of 557 patients, MYD88L265P mutation status, as determined by allele‐specific polymerase chain reaction, was known in 219, and 174 (79%) of those exhibited MYD88L265P, 157 of 174 patients had active disease. Of 45 (21%) patients with MYD88WT genotype, 44 had active disease. The estimated median follow‐up was 7.0 years; median overall survival was 10.2 years (95% CI: 8.4‐16.5) for MYD88L265P versus 13.9 years (95% CI: 6.4‐29.3) for the MYD88WT (P = 0.86). The time‐to‐next therapy from frontline treatment and the presenting features were similar in the two patient populations. For patients with smoldering WM at diagnosis, the median time‐to‐progression to active disease was 2.8 years (95% CI: 2.2‐3.8) in the MYD88L265P cohort and 1.9 years (95% CI: 0.7‐3.1) in the MYD88WT cohort (P = 0.21). The frequency of transformation to high‐grade lymphoma, or the development of therapy‐elated myelodysplastic syndrome was higher in the MYD88WT cohort (16% versus 4% in the MYD88L265P, P = 0.009). In conclusion, MYD88L265P mutation does not appear to be a determinant of outcome, and its presence may not be a disease‐defining feature in WM. Our findings warrant external validation, preferably through prospective studies.

Key Points Ibrutinib has modest activity in FL with low response rates in rituximab-refractory patients. CARD11 mutations predict for lack of response to ibrutinib.

Key Points PVD is an active combination in relapsed lenalidomide-refractory MM patients. PVD with weekly bortezomib offers a simpler, more convenient, and well-tolerated regimen option.

AbstractPatients with relapsed aggressive non‐Hodgkin lymphoma (NHL) are often treated with platinum‐based chemoimmunotherapy regimens in preparation for autologous stem cell transplant. We sought to reduce toxicity and maintain efficacy by using oxaliplatin with rituximab, cytarabine and dexamethasone (ROAD) in a phase II clinical trial in patients who had relapsed after one prior regimen. ROAD was delivered q21 days and consisted of rituximab 375 mg/m2 IV weekly x 4 doses (cycle 1 only); dexamethasone 40 mg PO/IV d2 – 5; oxaliplatin 130 mg/m2 IV day 2; cytarabine 2000 mg/m2 IV × two doses on days 2 to 3; and pegfilgrastim 6 mg SC on day 4. Forty‐five eligible patients were accrued between 2006 and 2008. Patient characteristics were a median age of 69 years; 96% had received prior rituximab; 53% were within one year of diagnosis. The median number of cycles received was 2 (range, 1‐6). Forty‐four % received ROAD as an outpatient. The overall response rate was 71% with 27% (12/45) CR and 44% (20/45) PR. Forty‐four % (20/45) of all patients and 69% (18/26) of patients whom responded after 2 cycles proceeded to transplant. Median overall survival was 26 mos (95% CI: 7.3 mos—not reached) and median progression‐free survival was 11 mos (95% CI: 6—104 mos). There was no grade 3/4 nephrotoxicity; the rate of grade 3/4 neuropathy was 4%. Forty‐two percent of all patients and 69% of patients transplanted remain alive at 5 years. ROAD represents an acceptable salvage therapeutic option for patients with relapsed aggressive NHL.

Key Points Pembrolizumab was first shown to be clinically active in CLL patients with RT. PD-1 and PD-L1 expression in tumor microenvironment are promising biomarkers to select RT patients for PD-1 blockade.