Witzig, Thomas E.

AbstractMantle cell lymphoma (MCL) is a type of non‐Hodgkin lymphoma (NHL) with aggressive disease characteristics resulting in multiple relapses after initial treatment. Lenalidomide is an immunomodulatory agent approved in the US for patients with relapsed/refractory MCL following bortezomib based on results from 3 multicenter phase II studies (2 including relapsed/refractory aggressive NHL and 1 focusing on MCL post‐bortezomib). The purpose of this report is to provide longer follow‐up on the MCL‐001 study (follow‐ups were 6.8 [NHL‐002], 7.6 [NHL‐003], and 52.2 [MCL‐001] months). The 206 relapsed MCL patients treated with single‐agent lenalidomide (25 mg/day PO, days 1 to 21 every 28‐days) had a median age of 67 years (63% ≥65 years), 91% with stage III/IV disease, and 50% with ≥4 previous treatment regimens. With a median follow‐up of X, the combined best overall response rate (ORR) was 33% (including 11% with complete remission [CR]/CR unconfirmed CRu). Lenalidomide produced rapid and durable responses with a median time to response of 2.2 months and median duration of response (DOR) of 16.6 months (95% CI: 11.1%‐29.8%). The safety profile was consistent and manageable; myelosuppression was the most common adverse event (AE). Overall, single‐agent lenalidomide showed consistent efficacy and safety in multiple phase II studies of heavily pretreated patients with relapsed/refractory MCL, including those previously treated with bortezomib.

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.

SummaryHistological transformation (HT) of follicular lymphoma (FL) to an aggressive lymphoma after chemotherapy remains a key issue. The incidence of HT after radioimmunotherapy (RIT) is unknown. This single institution study analysed the risk of HT in FL after treatment with yttrium‐90 ibritumomab tiuxetan in 115 consecutive patients treated during 1987–2012. RIT was administered for progressive FL in 111 (97%) patients and as first‐line therapy in the remaining 4. 28% (n = 32) had HT, occurring at a median of 60 months from diagnosis and 20 months after RIT. 48% (12/25) of patients who received fludarabine developed HT. The estimated 10‐year risk of HT in the fludarabine and non‐fludarabine groups was 67% and 26% respectively (P = 0·015). Only prior fludarabine was significantly associated with predicting the risk of HT after RIT. 8% (9/115) of patients developed therapy‐related myelodysplastic syndrome/acute myeloid leukaemia (tMDS/AML) at a median of 41·4 months (range, 5–89). The estimated 10‐year risk of tMDS/AML in non‐fludarabine treated patients (n = 90) versus fludarabine treated (n = 25) was 13% and 29%, respectively. The estimated overall risk of FL undergoing HT at 10 years without fludarabine exposure appears similar to patients reported in the literature that have not received RIT. Patients with prior purine‐analogue therapy are at significantly higher risk of HT.

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.