Polatuzumab Vedotin in Previously Untreated Diffuse Large B-Cell Lymphoma.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is typically treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). However, only 60% of patients are cured with R-CHOP. Polatuzumab vedotin is an antibody-drug conjugate targeting CD79b, which is ubiquitously expressed on the surface of malignant B cells. METHODS: We conducted a double-blind, placebo-controlled, international phase 3 trial to evaluate a modified regimen of R-CHOP (pola-R-CHP), in which vincristine was replaced with polatuzumab vedotin, as compared with standard R-CHOP, in patients with previously untreated intermediate-risk or high-risk DLBCL. Patients 18 to 80 years of age were randomly assigned in a 1:1 ratio to receive six cycles of either pola-R-CHP or R-CHOP, plus two cycles of rituximab alone. The primary end point was investigator-assessed progression-free survival. Secondary end points included overall survival and safety. RESULTS: Overall, 879 patients underwent randomization: 440 were assigned to the pola-R-CHP group and 439 to the R-CHOP group. After a median follow-up of 28.2 months, the percentage of patients surviving without progression was significantly higher in the pola-R-CHP group than in the R-CHOP group (76.7% [95% confidence interval (CI), 72.7 to 80.8] vs. 70.2% [95% CI, 65.8 to 74.6] at 2 years; stratified hazard ratio for progression, relapse, or death, 0.73 by Cox regression; 95% CI, 0.57 to 0.95; P = 0.02). Overall survival at 2 years did not differ significantly between the groups (88.7% [95% CI, 85.7 to 91.6] in the pola-R-CHP group and 88.6% [95% CI, 85.6 to 91.6] in the R-CHOP group; hazard ratio for death, 0.94; 95% CI, 0.65 to 1.37; P = 0.75). The safety profile was similar in the two groups. CONCLUSIONS: Among patients with previously untreated intermediate-risk or high-risk DLBCL, the risk of disease progression, relapse, or death was lower among those who received pola-R-CHP than among those who received R-CHOP. (Funded by F. Hoffmann-La Roche/Genentech; POLARIX ClinicalTrials.gov number, NCT03274492.).

Polatuzumab vedotin in previously untreated DLBCL: an Asia subpopulation analysis from the phase 3 POLARIX trial.

In the phase 3 POLARIX study in previously untreated diffuse large B-cell lymphoma, polatuzumab vedotin combined with rituximab plus cyclophosphamide, doxorubicin, and prednisone (Pola-R-CHP) significantly improved progression-free survival (PFS) compared with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) with similar safety. Patients were randomized 1:1 to 6 cycles of Pola-R-CHP or R-CHOP plus 2 cycles of rituximab alone. For registration of POLARIX in China, consistency of PFS in an Asia subpopulation (defined as ≥50% of the risk reduction in PFS expected in the global population) was evaluated. Overall, 281 patients were analyzed: 160 patients from Asia in the intention-to-treat (ITT) population of the global study and 121 from an ITT China extension cohort. Of these, 141 were randomized to Pola-R-CHP and 140 to R-CHOP. At data cutoff (28 June 2021; median follow-up 24.2 months), PFS met the consistency definition with the global population, and was superior with Pola-R-CHP vs R-CHOP (hazard ratio, 0.64; 95% confidence interval [CI], 0.40-1.03). Two-year PFS was 74.2% (95% CI, 65.7-82.7) and 66.5% (95% CI, 57.3-75.6) with Pola-R-CHP and R-CHOP, respectively. Safety was comparable between Pola-R-CHP and R-CHOP, including rates of grade 3 to 4 adverse events (AEs; 72.9% vs 66.2%, respectively), serious AEs (32.9% vs 32.4%), grade 5 AEs (1.4% vs 0.7%), AEs leading to study treatment discontinuation (5.0% vs 7.2%), and any-grade peripheral neuropathy (44.3% vs 50.4%). These findings demonstrate consistent efficacy and safety of Pola-R-CHP vs R-CHOP in the Asia and global populations in POLARIX. This trial was registered at https://clinicaltrials.gov/ct2/home as # NCT03274492.

Polatuzumab vedotin plus bendamustine and rituximab or obinutuzumab in relapsed/refractory follicular lymphoma: a phase Ib/II study.

Follicular lymphoma (FL) is the most common type of indolent non-Hodgkin lymphoma. Despite treatment advances that have improved outcomes for patients with relapsed or refractory (R/R) FL, many patients still die from progressive disease or treatment-related toxicities. In the phase Ib/II GO29365 study (clinicaltrials.gov 02257567), the safety and efficacy of polatuzumab vedotin plus bendamustine and rituximab (Pola-BR) versus bendamustine and rituximab (BR) alone, and polatuzumab vedotin plus bendamustine and obinutuzumab (Pola-BG) as a single-arm cohort were evaluated in patients with R/R FL. Following the phase Ib safety run-in, patients were randomized 1:1 to receive Pola-BR or BR alone in the phase II stage; a separate non-randomized Pola-BG cohort was examined in the phase Ib/II expansion stage. Primary endpoints included safety and tolerability (phase Ib) and positron emission tomography complete response (PET-CR) rate by independent review committee (phase II). Overall, 112 patients were enrolled (phase Ib safety run-in: Pola-BR, N=6; phase II randomized cohort: Pola-BR, N=39; BR, N=41; phase Ib/II expansion cohort: Pola-BG, N=26). PET-CR rates were 66.7% (phase Ib safety run-in, Pola-BR); 69.2% (phase II randomized, Pola-BR); 63.4% (phase II randomized, BR); and 65.4% (phase Ib/II expansion Pola-BG). There was a higher occurrence of cytopenias with Pola-BR and Pola-BG than with BR; serious adverse events were more frequent with Pola-BR (61.4%) and Pola-BG (46.2%) than with BR (29.3%). Overall, this analysis does not demonstrate a benefit of adding Pola to BR or BG regimens for patients with R/R FL.

Polatuzumab vedotin, venetoclax, and an anti-CD20 monoclonal antibody in relapsed/refractory B-cell non-Hodgkin lymphoma.

The Phase 2 portion of this study evaluated safety and efficacy of polatuzumab vedotin 1.8 mg/kg and venetoclax 800 mg, plus fixed-dose obinutuzumab 1000 mg or rituximab 375 mg/m2 in patients with relapsed/refractory (R/R) follicular lymphoma (FL) or diffuse large B-cell lymphoma (DLBCL), respectively. Patients with complete response (CR) or partial response (PR)/stable disease (FL) or CR/PR (DLBCL) at end of induction (EOI; six 21-day cycles) received post-induction therapy with venetoclax and obinutuzumab or rituximab, respectively. Primary endpoint was CR rate at EOI. Safety-evaluable populations included 74 patients (FL cohort; median age 64 years; progression of disease within 24 months on first-line treatment, 25.7%; FL International Prognostic Index 3-5, 54.1%; ≥2 previous therapies, 74.3%) and 57 patients (DLBCL cohort; median age 65 years; International Prognostic Index 3-5, 54.4%; ≥2 previous therapies, 77.2%). The most common non-hematologic adverse events (mostly Grades 1-2) in the FL and DLBCL cohorts were diarrhea (55.4% and 47.4%, respectively) and nausea (47.3% and 36.8%); neutropenia was the most common Grades 3-4 toxicity (39.2% and 52.6%). Efficacy-evaluable populations included patients treated at the recommended Phase 2 dose (FL, n = 49; DLBCL, n = 48). CR rates at EOI were 59.2% (FL) and 31.3% (DLBCL); median progression-free survival was 22.8 months (95% confidence interval [CI], 14.5-not evaluable) and 4.6 months (95% CI, 3.6-8.1), respectively. Polatuzumab vedotin plus venetoclax and obinutuzumab/rituximab had acceptable safety in patients with R/R FL or DLBCL, with promising response rates in R/R FL, including high-risk patients.

Targeting MCL-1 and BCL-2 with polatuzumab vedotin and venetoclax overcomes treatment resistance in R/R non-Hodgkin lymphoma: Results from preclinical models and a Phase Ib study.

The treatment of patients with relapsed or refractory lymphoid neoplasms represents a significant clinical challenge. Here, we identify the pro-survival BCL-2 protein family member MCL-1 as a resistance factor for the BCL-2 inhibitor venetoclax in non-Hodgkin lymphoma (NHL) cell lines and primary NHL samples. Mechanistically, we show that the antibody-drug conjugate polatuzumab vedotin promotes MCL-1 degradation via the ubiquitin/proteasome system. This targeted MCL-1 antagonism, when combined with venetoclax and the anti-CD20 antibodies obinutuzumab or rituximab, results in tumor regressions in preclinical NHL models, which are sustained even off-treatment. In a Phase Ib clinical trial (NCT02611323) of heavily pre-treated patients with relapsed or refractory NHL, 25/33 (76%) patients with follicular lymphoma and 5/17 (29%) patients with diffuse large B-cell lymphoma achieved complete or partial responses with an acceptable safety profile when treated with the recommended Phase II dose of polatuzumab vedotin in combination with venetoclax and an anti-CD20 antibody.

Application of a Two-Analyte Integrated Population Pharmacokinetic Model to Evaluate the Impact of Intrinsic and Extrinsic Factors on the Pharmacokinetics of Polatuzumab Vedotin in Patients with Non-Hodgkin Lymphoma.

PURPOSE: The established two-analyte integrated population pharmacokinetic model was applied to assess the impact of intrinsic/extrinsic factors on the pharmacokinetics (PK) of polatuzumab vedotin (pola) in patients with non-Hodgkin lymphoma (NHL) following bodyweight-based dosing. METHODS: Model simulations based on individual empirical Bayes estimates were used to evaluate the impact of intrinsic/extrinsic factors as patient subgroups on Cycle 6 exposures. Intrinsic factors included bodyweight, age, sex, hepatic and renal functions. Extrinsic factors included rituximab/obinutuzumab or bendamustine combination with pola and manufacturing process. The predicted impact on exposures along with the established exposure-response relationships were used to assess clinical relevance. RESULTS: No clinically meaningful differences in Cycle 6 pola exposures were found for the following subgroups: bodyweight 100-146 kg versus 38-<100 kg, age ≥ 65 years versus <65 years, female versus male, mild hepatic impairment versus normal, mild-to-moderate renal impairment versus normal. Co-administration of rituximab/obinutuzumab or bendamustine, and change in the pola manufacturing process, also had no meaningful impact on PK. CONCLUSIONS: In patients with NHL, bodyweight-based dosing is adequate, and no further dose adjustment is recommended for the heavier subgroup (100-146 kg). In addition, no dose adjustments are recommended for other subgroups based on intrinsic/extrinsic factors evaluated.

Polatuzumab vedotin in combination with immunochemotherapy in patients with previously untreated diffuse large B-cell lymphoma: an open-label, non-randomised, phase 1b-2 study.

BACKGROUND: Polatuzumab vedotin, an antibody-drug conjugate targeting the CD79b component of the B-cell receptor, has demonstrated activity as a single agent and in combination with rituximab in relapsed or refractory diffuse large B-cell lymphoma. In this study, we evaluated the safety and preliminary activity of polatuzumab vedotin in combination with rituximab or obinutuzumab and cyclophosphamide, doxorubicin, and prednisone (CHP) in patients with previously untreated diffuse large B-cell lymphoma. METHODS: This was an open-label, non-randomised study composed of a phase 1b dose escalation and a phase 2 dose expansion at 11 hospitals and health centres in the USA and France. Patients aged 18 years or older with B-cell non-Hodgkin lymphoma were eligible. Exclusion criteria included peripheral neuropathy with grade greater than 1, major surgery within 4 weeks before enrolment, known CNS involvement of lymphoma, and uncontrolled heart disease. Phase 1b dose escalation had a three-plus-three design and established the recommended phase 2 dose. Phase 2 expansion evaluated the recommended phase 2 dose of polatuzumab vedotin in patients with newly diagnosed diffuse large B-cell lymphoma with an International Prognostic Index (IPI) of 2-5. Patients received cyclophosphamide 750 mg/m2 on day 1 intravenously, doxorubicin 50 mg/m2 on day 1 intravenously, and prednisone 100 mg once daily on days 1-5 of each 21-day cycle orally (CHP), plus either rituximab 375 mg/m2 intravenously on day 1 of each cycle (R-CHP) or obinutuzumab 1000 mg intravenously on days 1, 8, and 15 of cycle 1 and on day 1 of the following cycles (G-CHP). Polatuzumab vedotin was administered on day 2 of cycles 1 and 2, and on day 1 of the following cycles at 1·0-2·4 mg/kg during the escalation phase and at the recommended phase 2 dose during the expansion phase. Treatment could last six or eight cycles, depending on investigator preference. The primary endpoints of the study were safety and tolerability, and determination of the maximum tolerated dose (or recommended phase 2 dose) of polatuzumab vedotin. All endpoints were analysed per protocol in the safety evaluable population, defined as all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT01992653. FINDINGS: Between Dec 4, 2013, and July 26, 2016, 85 patients were enrolled. 82 patients were included in the safety and activity evaluable populations, 25 in phase 1b and 57 in phase 2. In light of information from other studies using polatuzumab vedotin reported during this study, in which the safety profile associated with exposure to polatuzumab vedotin at doses higher than 1·8 mg/kg every 3 weeks was not outweighed by any clinical benefit, the recommended phase 2 dose was set to 1·8 mg/kg in the R-CHP cohort and no higher doses were explored in this study. 66 patients with newly diagnosed diffuse large B-cell lymphoma received the polatuzumab vedotin recommended phase 2 dose (45 R-CHP; 21 G-CHP). In 66 patients with diffuse large B-cell lymphoma who received the recommended phase 2 dose, the most common adverse events of grade 3 or worse were neutropenia (20 [30%]), febrile neutropenia (12 [18%]), and thrombocytopenia (six [9%]). Among the 70 patients (any histology) who received the recommended phase 2 dose, 19 (27%) had grade 1 peripheral neuropathy, eight (11%) grade 2, and two (3%) grade 3. Four deaths were reported during follow-up: two treatment-related (one complication of atrial fibrillation and one septic shock) and two due to disease progression. As of the cutoff date of Dec 29, 2017, median follow-up time was 21·5 months (IQR 16·7-24·3) for the untreated diffuse large B-cell lymphoma cohort treated at the polatuzumab vedotin recommended phase 2 dose. 59 (89%) patients achieved an overall response at end of treatment (51 [77%] patients had a complete response, and eight [12%] patients had a partial response). INTERPRETATION: The safety of incorporating polatuzumab vedotin to R-CHP or G-CHP was as expected and managable. Preliminary clinical activity in newly diagnosed diffuse large B-cell lymphoma seems promising and encouraged a phase 3 trial comparing polatuzumab vedotin with R-CHP to R-CHOP. FUNDING: F Hoffmann-La Roche/Genentech.

Randomized phase 2 study of obinutuzumab monotherapy in symptomatic, previously untreated chronic lymphocytic leukemia.

Obinutuzumab is a glycoengineered, type 2 anti-CD20 humanized antibody with single-agent activity in relapsed chronic lymphocytic leukemia (CLL). With other CD20 antibodies, a dose-response relationship has been shown. We therefore performed a randomized phase 2 study in symptomatic, untreated CLL patients to evaluate if an obinutuzumab dose response exists. Obinutuzumab was given at a dose of 1000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 8 and day 15 of cycle 1; 1000 mg day 1 of cycles 2-8) or 2000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 3, 2000 mg day 8 and day 15 of cycle 1; 2000 mg day 1 of cycles 2-8). The primary end point was overall response rate (ORR). Eighty patients were enrolled with similar demographics: median age 67 years, 41% high-risk Rai disease, and 10% del(17p)(13.1). ORR (67% vs 49%, P = .08) and complete response (CR) or CR with incomplete cytopenia response (20% vs 5%) favored 2000 mg obinutuzumab. Overall, therapy was well tolerated, and infusion events were manageable. This study demonstrates significant efficacy of obinutuzumab monotherapy, for 1000 mg as well as for 2000 mg, in untreated CLL patients with acceptable toxicity. Although exploratory, a dose-response relationship may exist, but its relevance to improving progression-free survival is uncertain and will require further follow-up. This trial was registered at www.clinicaltrials.gov as #NCT01414205.

Obinutuzumab plus fludarabine/cyclophosphamide or bendamustine in the initial therapy of CLL patients: the phase 1b GALTON trial.

Obinutuzumab is a type 2, glycoengineered, anti-CD20 antibody recently approved with chlorambucil for the initial therapy of chronic lymphocytic leukemia (CLL). In this nonrandomized, parallel-cohort, phase 1b, multicenter study, we explored the safety and preliminary efficacy of obinutuzumab-bendamustine (G-B) or obinutuzumab fludarabine cyclophosphamide (G-FC) for the therapy of previously untreated fit patients with CLL. Patients received up to 6 cycles of G-B (n = 20) or G-FC (n = 21). The primary end point was safety, with infusion-related reactions (88%, grade 3-4 20%) being the most common adverse event and grade 3-4 neutropenia in 55% on G-B and 48% on G-FC. Mean cycles completed were 5.7 for G-B and 5.1 for G-FC, with 2 and 7 early discontinuations, respectively. The objective response rate (ORR) for G-B was 90% (18/20) with 20% complete response (CR) and 25% CR with incomplete marrow recovery (CRi). The ORR for G-FC was 62% (13/21), with 10% CR and 14% CRi, including 4 patients not evaluable. With a median follow-up of 23.5 months in the G-B cohort and 20.7 months in the G-FC cohort, no patient has relapsed or died. We conclude that obinutuzumab with either B or FC shows manageable toxicity and has promising activity. This study was registered at www.clinicaltrials.gov as #NCT01300247.

Polatuzumab vedotin plus rituximab and lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma: a cohort of a multicentre, single-arm, phase 1b/2 study.

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: This completed phase 1b/2, open-label, multicentre, single-arm study (GO29834) evaluated the safety and efficacy of Pola+R+Len in patients with relapsed or refractory diffuse large B-cell lymphoma at 19 sites in three countries (USA, Spain, and UK). Patients (≥18 years old) were eligible for inclusion if they had histologically documented CD20-positive relapsed or refractory diffuse large B-cell lymphoma and Eastern Cooperative Oncology Group performance status of 2 or lower, had received at least one previous line of chemoimmunotherapy, including an anti-CD20 agent, and were ineligible for stem-cell transplantation. The dose-escalation phase (1b) used escalating doses of lenalidomide to find the recommended phase 2 dose. Patients received six 28-day cycles of induction treatment with intravenous rituximab 375 mg/m2 and intravenous polatuzumab vedotin 1·8 mg/kg (all cohorts) plus oral lenalidomide at the following doses: 10 mg (cohort A); 15 mg (cohort B); and 20 mg (cohort C). Rituximab and polatuzumab vedotin were administered on day 1 and lenalidomide on days 1-21 of each 28-day cycle. During the dose-expansion phase (2), patients received six 28-day cycles of Pola+R+Len at the recommended phase 2 dose established during dose escalation. In both phases, patients with a complete response or partial response at the end of induction were eligible for post-induction therapy with rituximab 375 mg/m2 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: 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: 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: Genentech/F Hoffmann-La Roche.

Population pharmacokinetics and exposure-response analyses of polatuzumab vedotin in patients with previously untreated DLBCL from the POLARIX study.

Polatuzumab vedotin is a CD79b-directed antibody-drug conjugate that targets B cells and delivers the cytotoxic payload monomethyl auristatin E (MMAE). The phase III POLARIX study (NCT03274492) evaluated polatuzumab vedotin in combination with rituximab, cyclophosphamide, doxorubicin, and prednisone (R-CHP) as first-line treatment of diffuse large B-cell lymphoma (DLBCL). To examine dosing decisions for this regimen, population pharmacokinetic (popPK) analysis, using a previously developed popPK model, and exposure-response (ER) analysis, were performed. The popPK analysis showed no clinically meaningful relationship between cycle 6 (C6) antibody-conjugated (acMMAE)/unconjugated MMAE area under the concentration-time curve (AUC) or maximum concentration, and weight, sex, ethnicity, region, mild or moderate renal impairment, mild hepatic impairment, or other patient and disease characteristics. In the ER analysis, C6 acMMAE AUC was significantly associated with longer progression-free and event-free survival (both p = 0.01). An increase of <50% in acMMAE/unconjugated MMAE exposure did not lead to a clinically meaningful increase in adverse events of special interest. ER data and the benefit-risk profile support the use of polatuzumab vedotin 1.8 mg/kg once every 3 weeks with R-CHP for six cycles in patients with previously untreated DLBCL.

Clinical pharmacology strategies to accelerate the development of polatuzumab vedotin and summary of key findings.

The favorable benefit-risk profile of polatuzumab vedotin, as demonstrated in a pivotal Phase Ib/II randomized study (GO29365; NCT02257567), coupled with the need for effective therapies in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), prompted the need to accelerate polatuzumab vedotin development. An integrated, fit-for-purpose clinical pharmacology package was designed to support regulatory approval. To address key clinical pharmacology questions without dedicated clinical pharmacology studies, we leveraged non-clinical and clinical data for polatuzumab vedotin, published clinical data for brentuximab vedotin, a similar antibody-drug conjugate, and physiologically based pharmacokinetic and population pharmacokinetic modeling approaches. We review strategies and model-informed outcomes that contributed to regulatory approval of polatuzumab vedotin plus bendamustine and rituximab in R/R DLBCL. These strategies made polatuzumab vedotin available to patients earlier than previously possible; depending on the strength of available data and the regulatory/competitive environment, they may also prove useful in accelerating the development of other agents.

Ethnic sensitivity assessment: Polatuzumab vedotin pharmacokinetics in Asian and non-Asian patients with previously untreated diffuse large B-cell lymphoma in POLARIX.

This ethnic sensitivity analysis used data from the phase III POLARIX study (NCT03274492) to assess polatuzumab vedotin pharmacokinetics (PKs) in Asian versus non-Asian patients with previously untreated diffuse large B-cell lymphoma and examined the appropriateness of extrapolating global study findings to Asian patients. PK and population PK (PopPK) analyses assessed polatuzumab vedotin analyte exposures by ethnicity (Asian [n = 84] vs. non-Asian [n = 345] patients) and region (patients enrolled from Asia [n = 80] vs. outside Asia [n = 349]). In patients from Asia versus outside Asia, observed mean antibody-conjugated monomethyl auristatin E (acMMAE) concentrations were comparable (1.2% lower at cycle [C]1 postdose, 4.4% higher at C4 predose; and 6.8% lower at C4 postdose in patients from Asia). Observed mean unconjugated MMAE was lower in patients from Asia by 6.5% (C1 postdose), 20.0% (C4 predose), and 15.3% (C4 postdose). In the PopPK analysis, C6 area under the curve and peak plasma concentrations were also comparable for acMMAE (6.3% and 3.0% lower in Asian vs. non-Asian patients, respectively) and lower for unconjugated MMAE by 19.1% and 16.7%, respectively. By region, C6 mean acMMAE concentrations were similar, and C6 mean unconjugated MMAE concentrations were lower, in patients enrolled from Asia versus outside Asia, by 3.9%-7.0% and 17.3%-19.7%, respectively. In conclusion, polatuzumab vedotin PKs were similar between Asian and non-Asian patients by ethnicity and region, suggesting PKs are not sensitive to Asian ethnicity and dose adjustments are not required in Asian patients to maintain efficacy and safety.

Racial differences in presentation and management of follicular non-Hodgkin lymphoma in the United States: report from the National LymphoCare Study.

BACKGROUND: Racial differences in follicular lymphoma (FL) in the United States have not been investigated. METHODS: The National LymphoCare Study is a multicenter, longitudinal, observational cohort study collecting data on treatment patterns and outcomes for patients with newly diagnosed FL in the United States between 2004 and 2007 without any predefined, study-specific intervention. The authors investigated differences between white (W) patients, African American (AA) patients, and Hispanic (H) patients. RESULTS: Among 2744 enrolled patients, there were 95 (3%) AA patients, 125 (5%) H patients, and 2476 (90%) W patients. Compared with W patients, more AA and H patients were diagnosed at age <45 years (P < .0001). H patients more commonly were diagnosed with grade 3 FL compared with AA and W patients (29%, 13%, and 18%, respectively; P = .019) and more commonly received rituximab plus chemotherapy as initial therapy compared with W patients (66% vs 50%; P = .036), while AA patients less commonly received anthracyclines (49% vs 64% in W patients; P = .027). H and AA patients who received rituximab plus chemotherapy were less likely than W patients to receive maintenance rituximab (27% vs 31% vs 40%, respectively; P = .031). At a median follow-up of 52 months, progression-free survival was similar between AA and W patients but was longer in H patients, and there was no difference in overall survival. CONCLUSIONS: In the largest prospective cohort to date of AA and H patients with FL in the United States, AA and H patients were younger at presentation. Although racial differences in treatment patterns for FL were noted, additional follow-up is needed to determine the impact of these differences on survival.

Polatuzumab vedotin plus bendamustine and rituximab in relapsed/refractory DLBCL: survival update and new extension cohort data.

Polatuzumab vedotin plus bendamustine and rituximab (pola + BR) received regulatory approvals for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL) based on primary results from the randomized arms of the GO29365 study. After the randomized phase, 106 additional patients received pola + BR in a single-arm extension cohort. We report updated results from the randomized arms and results of the extension cohort. In this phase 1b/2 study, patients with R/R DLBCL who were transplant ineligible received up to six 21-day cycles of pola + BR or BR. The primary end point of the randomized arms was the complete response (CR) rate at end of treatment. Primary objectives of the extension cohort were safety, pharmacokinetic profile, and efficacy of pola + BR. As of 7 July 2020, a total of 192 patients with R/R DLBCL were enrolled in the pola + BR cohort (n = 152 [safety run-in, n = 6; randomized, n = 40; extension cohort, n = 106]) or the BR cohort (n = 40). Significant survival benefit with pola + BR vs BR persisted in the randomized arms (median progression-free survival, 9.2 vs 3.7 months [hazard ratio, 0.39; 95% confidence interval, 0.23-0.66]; median overall survival, 12.4 vs 4.7 months [hazard ratio, 0.42; 95% confidence interval, 0.24-0.72]). In the extension cohort, the independent review committee-assessed objective response rate was 41.5%, and the CR rate was 38.7%; median independent review committee-assessed progression-free survival and overall survival were 6.6 months and 12.5 months, respectively. No new safety signals with pola + BR were identified. Pola + BR is an effective treatment option for patients with R/R DLBCL, with a well-characterized and manageable safety profile. This trial was registered at www.clinicaltrials.gov as #NCT02257567.

Polatuzumab vedotin plus obinutuzumab and lenalidomide in patients with relapsed or refractory follicular lymphoma: a cohort of a multicentre, single-arm, phase 1b/2 study.

BACKGROUND: Obinutuzumab with polatuzumab vedotin or lenalidomide showed tolerability and activity in phase 1b/2 trials that recruited patients with relapsed or refractory follicular lymphoma. We aimed to examine whether the novel polatuzumab vedotin-obinutuzumab-lenalidomide (Pola-G-Len) combination might enhance antitumour response in patients with relapsed or refractory follicular lymphoma. METHODS: This multicentre, single-arm phase 1b/2 study tested Pola-G-Len in patients with relapsed or refractory follicular lymphoma, and polatuzumab vedotin in combination with rituximab and lenalidomide in patients with relapsed or refractory diffuse large B-cell lymphoma. Here we report the results from the cohort of patients with follicular lymphoma. The trial was done in 18 cancer centres across three countries (Spain, UK, and USA). Patients (≥18 years old) with CD20-positive relapsed or refractory follicular lymphoma (excluding grade 3b) and Eastern Cooperative Oncology Group performance status of 2 or less who had previously received anti-CD20-containing chemotherapy were eligible for inclusion. During the dose-escalation phase, patients received six 28-day cycles of induction treatment with intravenous obinutuzumab 1000 mg (all cohorts), and intravenous polatuzumab vedotin and oral lenalidomide (Celgene, Summit, NJ, USA) in the following doses: 1·4 mg/kg polatuzumab vedotin and 10 mg lenalidomide (cohort 1); 1·8 mg/kg polatuzumab vedotin and 10 mg lenalidomide (cohort 2); 1·4 mg/kg polatuzumab vedotin and 15 mg lenalidomide (cohort 3); 1·8 mg/kg polatuzumab vedotin and 15 mg lenalidomide (cohort 4); 1·4 mg/kg polatuzumab vedotin and 20 mg lenalidomide (cohort 5); and 1·8 mg/kg polatuzumab vedotin and 20 mg lenalidomide (cohort 6). Polatuzumab vedotin was administered on day 1, lenalidomide on days 1-21, and obinutuzumab on days 1, 8, and 15 of cycle one and day 1 of cycles two to six of each 28-day cycle. During phase 2 (dose expansion phase), patients received six cycles of induction with Pola-G-Len at the recommended phase 2 dose established during dose-escalation. Patients who had a response or stable disease at the end of induction were eligible to enter the maintenance phase, in which they received obinutuzumab for 24 months at 1000 mg on day 1 of every other 28-day cycle for a total of 12 doses, and lenalidomide for 12 months at 10 mg on days 1-21 of each 28-day cycle for a maximum of 12 cycles. The primary activity endpoint was complete response at the end of induction. Adverse events were monitored throughout the study. The primary safety objective was to determine the maximum tolerated dose of Pola-G-Len. Analyses were in the safety population, which included all patients that received at least one dose of any of the component drugs (ie, all patients who entered the induction phases in both the escalation and expansion phases), and activity-evaluable population, which included all patients who received at least one dose of any of the component drugs at the recommended phase 2 dose (ie, all patients who received the recommended phase 2 dose in the dose escalation investigation and all patients who entered induction in the dose expansion investigation). This ongoing trial is registered at ClinicalTrials.gov, NCT02600897. FINDINGS: Between March 24, 2016, and August 23, 2018, 56 patients (33 [59%] men and 23 [41%] women; 49 [88%] non-Hispanic or Latino) were enrolled. Two of four patients in cohort 2 reported dose-limiting toxicity events during dose escalation (one patient had grade 4 amylase and lipase elevation and one patient had grade 4 neutropenia and grade 3 thrombocytopenia), and there were no dose-limiting toxicities observed in cohorts 3 or 5; therefore, the recommended phase 2 dose for the dose-expansion was 1·4 mg/kg polatuzumab vedotin plus 20 mg lenalidomide. 46 (82%) patients were included in the activity-evaluable population. After a median follow up of 26·7 months (IQR 22·2-31·3) the objective response rate was 76% (90% CI 64-86) and complete response rate was 63% (90 CI 50-75). After a median follow-up of 27·0 months (IQR 18·7-34·0), the most common grade 3-4 adverse events were neutropenia (31 [55%] of 56 patients) and thrombocytopenia (14 [25%] patients). 61 serious adverse events were reported in 35 (63%) patients; the most common of which were febrile neutropenia (five [9%] patients; a sixth patient had febrile neutropenia, but this was not considered serious by the investigator), pneumonia (four [7%] patients), and pyrexia (four [7%] patients). One fatal adverse event (grade 5 septic shock) occurred in a patient who had discontinued study treatment due to disease progression and had initiated a new anti-lymphoma tyrosine kinase inhibitor treatment. This was not considered related to study treatment by the investigator. INTERPRETATION: Pola-G-Len showed high complete response rates, although it did not reached the prespecified threshold for activity, in patients who were heavily pretreated with refractory follicular lymphoma. Our findings compare favourably with available therapies and support future investigation of Pola-G-Len in a larger patient population. FUNDING: Genentech/F Hoffmann-La Roche.

Integrated Two-Analyte Population Pharmacokinetic Model of Polatuzumab Vedotin in Patients With Non-Hodgkin Lymphoma.

A two-analyte integrated population pharmacokinetic (PK) model that simultaneously describes concentrations of antibody-conjugated monomethyl auristatin E (acMMAE) and unconjugated MMAE following repeated administrations of polatuzumab vedotin (pola) was developed based on data from four clinical studies of pola in patients with non-Hodgkin lymphoma. A two-compartment model with a nonspecific, time-dependent linear clearance, a linear time-dependent exponentially declining clearance, and a Michaelis-Menten clearance provided a good fit of the acMMAE plasma PK profiles. All three acMMAE elimination pathways contributed to the input to the central compartment of unconjugated MMAE, which was also described by a two-compartment model. Population PK parameters, covariate effects, and interindividual variability of model parameters were estimated. The impact of clinically relevant covariates on PK exposures of each analyte were quantified and reported to support key label claims.

Exposure-safety and exposure-efficacy analyses of polatuzumab vedotin in patients with relapsed or refractory diffuse large B-cell lymphoma.

Exposure-response relationships were investigated to assess the risk/benefit of polatuzumab vedotin (pola) + bendamustine-rituximab (pola + BR) in relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). Analyses were conducted in pivotal study GO29365 (NCT02257567; BR/pola + BR/pola + BG [BG: bendamustine-obinutuzumab]; 1.8 mg/kg pola, every 3 weeks [Q3W], six cycles), and supportive studies DCS4968g (NCT01290549) and GO27834 (NCT01691898) (pola/pola + R/pola + G; 0.1-2.4 mg/kg pola Q3W; eight-cycle landmark), separately. Exposure was characterized as simulated cycle-6 AUC and Cmax for antibody-conjugated mono-methyl auristatin E (acMMAE) and unconjugated MMAE. Supportive studies showed response rate and safety risk (grade ≥2 peripheral neuropathy; grade ≥3 anemia) increased with exposure, suggesting not to dose below 1.8 mg/kg (up to eight-cycle) for balancing safety and efficacy. Pivotal study with limited exposure range showed no exposure-safety relationship and slightly positive exposure (acMMAE)-efficacy relationship for overall survival. The exposure-response analyses and the observed risk/benefit characteristics in pivotal study supported pola (1.8 mg/kg) +BR Q3W for six cycles in R/R DLBCL patients.