Faculty Bibliography

Immune cells express an incredible variety of proteins; by measuring combinations of these, cell types influencing disease can be precisely identified. We developed terraFlow, a platform that defines cell subsets exhaustively by combinatorial protein expression. Using high-parameter checkpoint-focused and function-focused panels, we studied classical Hodgkin's lymphoma (cHL), where systemic T cells have not been investigated in detail. terraFlow revealed immune perturbations in patients, including elevated activated, exhausted, and interleukin (IL)-17+ phenotypes, along with diminished early, interferon (IFN)γ+, and tumor necrosis factor (TNF)+ T cells before treatment; many perturbations remained after treatment. terraFlow identified more disease-associated differences than other tools, often with better predictive power, and included a non-gating approach, eliminating time-consuming and subjective manual thresholds. It also reports a method to identify the smallest set of markers distinguishing study groups. Our results provide mechanistic support for past reports of immune deficiency in cHL and demonstrate the value of terraFlow in immunotherapy and biomarker studies.

Despite excellent cure rates with modern front-line regimens, up to 20% of patients with Hodgkin lymphoma will progress through front-line therapy or experience disease relapse. Worldwide, salvage chemotherapy followed by high-dose chemotherapy with autologous stem cell transplantation (HDT/ASCT) is considered the standard of care for these patients and can cure approximately 50% of relapsed or refractory (R/R) patients in the second line. Brentuximab vedotin (BV), an anti-CD30 antibody drug conjugate, and PD1 inhibitors like nivolumab and pembrolizumab, have high response rates in patients who recur after HDT/ASCT. When used prior to HDT/ASCT, BV and PD1 inhibitors appear to dramatically increase the effectiveness of salvage therapies with complete response rates often double those seen with historic chemotherapy-based regimens and durable progression free survival (PFS) post-HDT/ASCT. Emerging data in adults and from pediatric trials showing a durable PFS in a subset of relapsed patients raises the question of whether HDT/ASCT is essential for cure in R/R patients after PD1 based salvage. Future studies will help clarify if ASCT can omitted PD1 based salvage to avoid the potential toxicity of HDT/ASCT without compromising cure.

UNLABELLED:To investigate the cellular and molecular mechanisms associated with targeting CD30-expressing Hodgkin lymphoma (HL) and immune checkpoint modulation induced by combination therapies of CTLA4 and PD1, we leveraged Phase 1/2 multicenter open-label trial NCT01896999 that enrolled patients with refractory or relapsed HL (R/R HL). Using peripheral blood, we assessed soluble proteins, cell composition, T-cell clonality, and tumor antigen-specific antibodies in 54 patients enrolled in the phase 1 component of the trial. NCT01896999 reported high (>75%) overall objective response rates with brentuximab vedotin (BV) in combination with ipilimumab (I) and/or nivolumab (N) in patients with R/R HL. We observed a durable increase in soluble PD1 and plasmacytoid dendritic cells as well as decreases in plasma CCL17, ANGPT2, MMP12, IL13, and CXCL13 in N-containing regimens (BV + N and BV + I + N) compared with BV + I (P < 0.05). Nonresponders and patients with short progression-free survival showed elevated CXCL9, CXCL13, CD5, CCL17, adenosine-deaminase, and MUC16 at baseline or after one treatment cycle and a higher prevalence of NY-ESO-1-specific autoantibodies (P < 0.05). The results suggest a circulating tumor-immune-derived signature of BV ± I ± N treatment resistance that may be useful for patient stratification in combination checkpoint therapy. SIGNIFICANCE/UNASSIGNED:Identification of multi-omic immune markers from peripheral blood may help elucidate resistance mechanisms to checkpoint inhibitor and antibody-drug conjugate combinations with potential implications for treatment decisions in relapsed HL.

Outcomes in mature T-cell lymphomas remain poor, with previous attempts at developing mAbs compromised by limited efficacy and significant immunocompromise. Anti-killer cell lectin-like receptor G1 mAbs may have greater selectivity and specificity for malignant T cells and avoid the toxicity concerns with previous agents. See related article by Assatova et al., p. 2514.

The combination of the phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor zandelisib with the Bruton's tyrosine kinase (BTK) inhibitor zanubrutinib was hypothesized to be synergistic and prevent resistance to single-agent therapy. This phase 1 study (NCT02914938) included a dose-finding stage in patients with relapsed/refractory (R/R) B-cell malignancies (n = 20) and disease-specific expansion cohorts in follicular lymphoma (FL; n = 31) or mantle cell lymphoma (MCL; n = 19). The recommended phase 2 dose was zandelisib 60 mg on Days 1-7 plus zanubrutinib 80 mg twice daily continuously in 28-day cycle. In the total population, the most common adverse events (AEs; all grades/grade 3-4) were neutropenia (35%/24%), diarrhoea (33%/2%), thrombocytopenia (32%/8%), anaemia (27%/8%), increased creatinine (25%/0%), contusion (21%/0%), fatigue (21%/2%), nausea (21%/2%) and increased aspartate aminotransferase (24%/6%). Three patients discontinued due to AEs. The overall response rate was 87% (complete response [CR] = 33%) for FL and 74% (CR = 47%) for MCL. The median duration of response and progression-free survival (PFS) were not reached in either group. The estimated 1-year PFS was 72.3% (95% confidence interval [CI], 51.9-85.1) for FL and 56.3% (95% CI, 28.9-76.7) for MCL (median follow-up: 16.5 and 10.9 months respectively). Zandelisib plus zanubrutinib was associated with high response rates and no increased toxicity compared to either agent alone.

BACKGROUND:Mosunetuzumab is a CD20xCD3 T-cell engaging bispecific antibody approved in Europe and the United States for relapsed/refractory (R/R) follicular lymphoma (FL) after ≥ 2 prior therapies. MATERIALS AND METHODS:We present interim safety data from the mosunetuzumab GO29781 (NCT02500407) phase I/II dose-escalation study in R/R non-Hodgkin lymphoma (NHL), focusing on FL. RESULTS:Overall, 218 patients with R/R NHL, including 90 with R/R FL, received a median of eight 21-day cycles of intravenous mosunetuzumab with step-up dosing in Cycle (C) 1 (C1 Day [D] 1, 1 mg; C1D8, 2 mg; C1D15/C2D1, 60 mg; C3D1 and onwards, 30 mg). Cytokine release syndrome (CRS) was the most common adverse event (AE), occurring in 39.4% (NHL) and 44.4% (FL) of patients. Events occurred predominantly during C1 at the first loading dose; the majority were grade 1/2. CRS events were managed at the investigator's discretion with supportive care, steroids, and tocilizumab, based on protocol management guidelines. Immune effector cell-associated neurotoxicity syndrome was uncommon, reported in 0.9% (NHL) and 1.1% (FL) of patients. Neutropenia occurred in 27.5% (NHL) and 28.9% (FL) of patients (mostly grade 3/4) and could be effectively managed using granulocyte colony-stimulating factor. Tumor lysis syndrome occurred in 0.9% (NHL) and 1.1% (FL) of patients (all grade 3/4 with CRS; all resolved). CONCLUSION:Mosunetuzumab monotherapy as treatment for R/R B-cell NHL, including FL, was associated with low rates of severe AEs (including CRS) and is suitable for outpatient administration in the community setting. Adapted protocol guidance for the management of select AEs during mosunetuzumab treatment is included.

BACKGROUND:Diffuse large B-cell lymphoma comprises nearly 30% of non-Hodgkin lymphoma cases and patients with relapsed or refractory diffuse large B-cell lymphoma who are ineligible for stem-cell transplantation have few treatment options and poor prognoses. We aimed to determine whether the novel combination of polatuzumab vedotin in combination with rituximab and lenalidomide (Pola+R+Len) would provide a tolerable treatment option with enhanced antitumour response in patients with relapsed or refractory diffuse large B-cell lymphoma. METHODS:on day 1 and lenalidomide 10 mg/day on days 1-21 of each 28-day cycle for a maximum of 6 cycles. The primary safety objective of the dose-escalation phase was identification of the maximum tolerated dose through incidence of dose-limiting toxic effects. The primary efficacy outcome of the dose-expansion phase was Independent Review Committee-assessed complete response rate at end of induction, based on PET-CT. Analyses were conducted in the safety population, which included all patients who received at least one dose of any study drug, and the efficacy population, which included all patients who received at least one dose of any study drug at the recommended phase 2 dose. This study is registered with ClinicalTrials.gov, number NCT02600897. FINDINGS/RESULTS:Between July 11, 2017 and Feb 3, 2020, 57 patients were enrolled (median age 71 years [IQR 60-75]; 38 [67%] were male and 19 (33%) were female; 47 [82%] were not Hispanic or Latino; and the median previous lines of therapy was 2 [IQR 1-3]). 18 participants were included in phase 1b and 39 were included in phase 2. Phase 1b confirmed a 20 mg recommended phase 2 dose for lenalidomide. After a median follow-up of 11·8 months (IQR 4·7-25·8), the complete response rate, as assessed by the Independent Review Committee, was 31% (90% CI 20-43). The most common grade 3-4 adverse events were neutropenia (35 [61%] of 57) and thrombocytopenia (eight [14%] of 57). Serious adverse events were reported in 23 (40%) of 57 patients and one patient died due to a treatment-related adverse event (neutropenic sepsis). INTERPRETATION/CONCLUSIONS:Although the combination of Pola+R+Len did not meet the prespecified activity threshold, some patients derived clinical benefit and the regimen had a tolerable safety profile in patients with relapsed or refractory diffuse large B-cell lymphoma. FUNDING/BACKGROUND:Genentech/F Hoffmann-La Roche.

Relapsed/refractory aggressive large B cell lymphoma (LBCL) remains an area of unmet need. Here we report the primary analysis of a phase 1b/2 trial of outpatient mosunetuzumab (a CD20xCD3 T-cell-engaging bispecific antibody) plus polatuzumab vedotin (an anti-CD79B antibody-drug conjugate) in relapsed/refractory LBCL. The phase 2 component is a single arm of an ongoing multi-arm trial. The primary endpoint during dose expansion was independent review committee (IRC)-assessed best overall response rate. Secondary endpoints included investigator-assessed overall response rate, complete response, duration of response, progression-free survival and overall survival. At data cutoff, 120 patients were enrolled (22 dose escalation, 98 dose expansion). The primary endpoint was met during dose expansion, with IRC-assessed best overall response rate and complete response rates of 59.2% (58/98; 95% confidence interval (CI): 48.8-69.0) and 45.9% (45/98; 95% CI: 35.8-56.3), respectively (median follow-up, 23.9 months). Median duration of complete was not reached (95% CI: 20.5-not estimable (NE)). Median progression-free survival was 11.4 months (95% CI: 6.2-18.7). Median overall survival was 23.3 months (95% CI: 14.8-NE). Across dose escalation and expansion, the most common grade 3 or higher adverse events were neutropenia (25.0%, 30/120) and fatigue (6.7%, 8/120). Any-grade cytokine release syndrome occurred in 16.7% of patients. These data demonstrate that mosunetuzumab plus polatuzumab vedotin has a favorable safety profile with highly durable responses suitable as second-line therapy in transplant-ineligible relapsed/refractory LBCL. ClinicalTrials.gov identifier: NCT03671018 .

Immune checkpoint inhibitors (ICI) are increasingly used in combination. To understand the effects of different ICI categories, we characterized changes in circulating autoantibodies in patients enrolled in the E4412 trial (NCT01896999) of brentuximab vedotin (BV) plus ipilimumab, BV plus nivolumab, or BV plus ipilimumab-nivolumab for Hodgkin Lymphoma. Cycle 2 Day 1 (C2D1) autoantibody levels were compared to pre-treatment baseline. Across 112 autoantibodies tested, we generally observed increases in ipilimumab-containing regimens, with decreases noted in the nivolumab arm. Among 15 autoantibodies with significant changes at C2D1, all nivolumab cases exhibited decreases, with more than 90% of ipilimumab-exposed cases showing increases. Autoantibody profiles also showed differences according to immune-related adverse event (irAE) type, with rash generally featuring increases and liver toxicity demonstrating decreases. We conclude that dynamic autoantibody profiles may differ according to ICI category and irAE type. These findings may have relevance to clinical monitoring and irAE treatment.