Erin Reid

Diffuse large B-cell lymphomas (DLBCLs) and follicular lymphoma (FL) are the most common subtypes of B-cell non-Hodgkin's lymphomas in adults. Histologic transformation of FL to DLBCL (TFL) occurs in approximately 15% of patients and is generally associated with a poor clinical outcome. Phosphatidylinositol 3-kinase (PI3K) inhibitors have shown promising results in the treatment of relapsed/refractory FL. CAR T-cell therapy (axicabtagene ciloleucel and tisagenlecleucel) has emerged as a novel treatment option for relapsed/refractory DLBCL and TFL. These NCCN Guidelines Insights highlight important updates to the NCCN Guidelines for B-Cell Lymphomas regarding the treatment of TFL and relapsed/refractory FL and DLBCL.

Non-Hodgkin’s lymphomas (NHL) are a heterogeneous group of lymphoproliferative disorders originating in B lymphocytes, T lymphocytes, or natural killer cells. Mantle cell lymphoma (MCL) accounts for approximately 6% of all newly diagnosed NHL cases. Radiation therapy with or without systemic therapy is a reasonable approach for the few patients who present with early-stage disease. Rituximab-based chemoimmunotherapy followed by high-dose therapy and autologous stem cell rescue (HDT/ASCR) is recommended for patients presenting with advanced-stage disease. Induction therapy followed by rituximab maintenance may provide extended disease control for those who are not candidates for HDT/ASCR. Ibrutinib, a Bruton tyrosine kinase inhibitor, was recently approved for the treatment of relapsed or refractory disease. This manuscript discusses the recommendations outlined in the NCCN Guidelines for NHL regarding the diagnosis and management of patients with MCL.

In the last decade, a better understanding of the molecular pathogenesis of B-cell non-Hodgkin lymphomas has resulted in the development of novel targeted therapies, such as small molecule inhibitors of select kinases in the B-cell receptor pathway, antibody-drug conjugates, and small molecules that target a variety of proteins (eg, CD-19, EZH2, and XPO-1-mediated nuclear export). Anti-CD19 CAR T-cell therapy, first approved for relapsed/refractory (R/R) diffuse large B-cell lymphoma, has also emerged as a novel treatment option for R/R follicular lymphoma and mantle cell lymphoma. These NCCN Guideline Insights highlight the new targeted therapy options included in the NCCN Guidelines for B-Cell Lymphomas for the treatment of R/R disease.

The prognosis for patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) remains poor, with a need for alternatives to current salvage therapies. Loncastuximab tesirine (ADCT-402) is an antibody-drug conjugate comprising a humanized anti-CD19 monoclonal antibody conjugated to a pyrrolobenzodiazepine dimer toxin. Presented here are final results of a phase 1 dose-escalation and dose-expansion study in patients with R/R B-NHL. Objectives were to determine the maximum tolerated dose (MTD) and recommended dose(s) for expansion and evaluate safety, clinical activity, pharmacokinetics, and immunogenicity of loncastuximab tesirine. Overall, 183 patients received loncastuximab tesirine, with 3 + 3 dose escalation at 15 to 200 µg/kg and dose expansion at 120 and 150 µg/kg. Dose-limiting toxicities (all hematologic) were reported in 4 patients. The MTD was not reached, although cumulative toxicity was higher at 200 µg/kg. Hematologic treatment-emergent adverse events were most common, followed by fatigue, nausea, edema, and liver enzyme abnormalities. Overall response rate (ORR) in evaluable patients was 45.6%, including 26.7% complete responses (CRs). ORRs in patients with diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma, and follicular lymphoma were 42.3%, 46.7%, and 78.6%, respectively. Median duration of response in all patients was 5.4 months and not reached in patients with DLBCL (doses ≥120 µg/kg) who achieved a CR. Loncastuximab tesirine had good stability in serum, notable antitumor activity, and an acceptable safety profile, warranting continued study in B-NHL. The recommended dose for phase 2 was determined as 150 µg/kg every 3 weeks for 2 doses followed by 75 µg/kg every 3 weeks. This trial was registered at www.clinicaltrials.gov as #NCT02669017.

Peripheral T-cell lymphomas (PTCLs) represent a relatively uncommon heterogeneous group of non-Hodgkin's lymphomas (NHLs) with an aggressive clinical course and poor prognosis. Anthracycline-based multiagent chemotherapy with or without radiation therapy followed by first-line consolidation with high-dose therapy followed by autologous stem cell rescue (HDT/ASCR) is the standard approach to most of the patients with newly diagnosed PTCL. Relapsed or refractory disease is managed with second-line systemic therapy followed by HDT/ASCR or allogeneic stem cell transplant, based on the patient's eligibility for transplant. In recent years, several newer agents have shown significant activity in patients with relapsed or refractory disease across all 4 subtypes of PTCL. These NCCN Guideline Insights highlight the important updates to the NCCN Guidelines for NHL, specific to the management of patients with relapsed or refractory PTCL.