Mantle Cell, Follicular, and Other Indolent B-Cell Lymphoma—Clinical Studies: Novel Therapies and Prognostic Assessment in Hairy Cell Leukemia and Indolent Non-Hodgkin Lymphoma

391  Treatment with Combination of Dabrafenib and Trametinib in Patients with Recurrent/Refractory BRAF V600E–Mutated Hairy Cell Leukemia (HCL)

Robert J. et al.

The Abstract concludes: Dabrafenib + trametinib was well tolerated and demonstrated a high rate of durable responses in patients with heavily pretreated recurrent/refractory BRAF V600E–mutated HCL.

392  Acquired Resistance to BRAF Inhibition in Hcl Is Rare and Retreatment with Vemurafenib at Relapse Can Induce High Response Rates: Final Results of a Phase II Trial of Vemurafenib in Relapsed Hcl

Jae H. Park, et al.

The Abstract concludes: With a longer follow-up duration of up to 64 months, we confirm the high response rates with vemurafenib monotherapy in pts with R/R HCL and a favorable safety profile. While relapses were common, all cases of relapse retained BRAF V600E mutation and acquired resistance to vemurafenib was rare, observed in only 1 pt with KRAS mutation. Re-treatment with vemurafenib at relapse was highly effective with 85% ORR confirming the retained high sensitivity of HCL to repeated BRAF inhibition. Based on the high anti-tumor efficacy and tolerability of BRAF inhibition with vemurafenib, we are now investigating the combination of vemurafenib and an anti-CD20 antibody, obinutuzumab, as a frontline therapy in a phase II trial in pts with previously untreated HCL (NCT03410875).

393  Early Progression As a Predictor of Survival in Marginal Zone Lymphomas: An Analysis from the Prospective International NF10 Study By Fondazione Italiana Linfomi

Stefano Luminari, et al.

The Abstract concludes: Assessment of PFS24 predicts subsequent outcome in MZL. The prognostic role of PFS is confirmed in both ENMZL and SMZL. Similarly to FL also in MZL, PFS24 should be considered as a surrogate for OS in clinical research and for patients management.

394  A Randomized, Double-Blind Efficacy and Safety Study of PF-05280586 (a Potential Rituximab Biosimilar) Compared with Rituximab Reference Product (MabThera^®) in Subjects with Previously Untreated CD20-Positive, Low Tumor Burden Follicular Lymphoma (LTB-FL)

Jeff Sharman, et al.

The Abstract concludes: Efficacy, safety and immunogenicity, PK and PD of PF‑05280586 and rituximab-EU were similar up to Week 26 in subjects with previously untreated CD20-positive, LTB-FL.

395  Outcomes for Patients with High-Risk Relapsed or Refractory Indolent B-Cell Lymphoma Treated with Copanlisib in the CHRONOS-1 Study

Armando Santoro, et al.

The Abstract concludes: Two-thirds of patients treated with copanlisib in the CHRONOS-1 study were considered high-risk based on POD in less than 24 months after first-line therapy, yet the efficacy of copanlisib in both groups was similar. These results suggest that copanlisib treatment should be explored as treatment for patients failing to achieve durable responses in the first-line setting.

396  Minimal Residual Disease Response at End of Induction and during Maintenance Correlates with Updated Outcome in the Phase III GALLIUM Study of Obinutuzumab- or Rituximab-Based Immunochemotherapy in Previously Untreated Follicular Lymphoma Patients

Christiane Pott, et al.

The Abstract concludes: These data confirm the prognostic value of MRD status at EOI in previously untreated FL pts receiving immunochemotherapy. Analysis of MRD kinetics revealed that most of the pts who achieved MRD negativity at EOI sustained their responses during maintenance. The majority of pts who were MRD positive at EOI achieved MRD negativity during the first 4 months of maintenance. While this is likely to be indicative of the efficacy of continued treatment, it also suggests that response kinetics can be slower than in those pts who have an early MRD response at MI, and that responses that are beyond the sensitivity of the MRD assay may be less deep. Importantly, pts who failed to achieve MRD negativity at EOI or during early maintenance had a high chance of experiencing early progression or death. These data demonstrate the prognostic value of MRD response assessments in previously untreated FL pts receiving immunochemotherapy.