Three-year follow-up analysis of axicabtagene ciloleucel in relapsed/refractory indolent non-Hodgkin lymphoma (ZUMA-5).

ABSTRACT: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) follicular lymphoma (FL). Approval was supported by the phase 2, multicenter, single-arm ZUMA-5 study of axi-cel for patients with R/R indolent non-Hodgkin lymphoma (iNHL; N = 104), including FL and marginal zone lymphoma (MZL). In the primary analysis (median follow-up, 17.5 months), the overall response rate (ORR) was 92% (complete response rate, 74%). Here, we report long-term outcomes from ZUMA-5. Eligible patients with R/R iNHL after ≥2 lines of therapy underwent leukapheresis, followed by lymphodepleting chemotherapy and axi-cel infusion (2 × 106 CAR T cells per kg). The primary end point was ORR, assessed in this analysis by investigators in all enrolled patients (intent-to-treat). After median follow-up of 41.7 months in FL (n = 127) and 31.8 months in MZL (n = 31), ORR was comparable with that of the primary analysis (FL, 94%; MZL, 77%). Median progression-free survival was 40.2 months in FL and not reached in MZL. Medians of overall survival were not reached in either disease type. Grade ≥3 adverse events of interest that occurred after the prior analyses were largely in recently treated patients. Clinical and pharmacokinetic outcomes correlated negatively with recent exposure to bendamustine and high metabolic tumor volume. After 3 years of follow-up in ZUMA-5, axi-cel demonstrated continued durable responses, with very few relapses beyond 2 years, and manageable safety in patients with R/R iNHL. The ZUMA-5 study was registered at www.clinicaltrials.gov as #NCT03105336.

Comparative effectiveness of ZUMA-5 (axi-cel) vs SCHOLAR-5 external control in relapsed/refractory follicular lymphoma.

In the pivotal ZUMA-5 trial, axicabtagene ciloleucel (axi-cel; an autologous anti-CD19 chimeric antigen receptor T-cell therapy) demonstrated high rates of durable response in relapsed/refractory (r/r) follicular lymphoma (FL) patients. Here, outcomes from ZUMA-5 are compared with the international SCHOLAR-5 cohort, which applied key ZUMA-5 trial eligibility criteria simulating randomized controlled trial conditions. SCHOLAR-5 data were extracted from institutions in 5 countries, and from 1 historical clinical trial, for r/r FL patients who initiated a third or higher line of therapy after July 2014. Patient characteristics were balanced through propensity scoring on prespecified prognostic factors using standardized mortality ratio (SMR) weighting. Time-to-event outcomes were evaluated using weighted Kaplan-Meier analysis. Overall response rate (ORR) and complete response (CR) rate were compared using weighted odds ratios. The 143 ScHOLAR-5 patients reduced to an effective sample of 85 patients after SMR weighting vs 86 patients in ZUMA-5. Median follow-up time was 25.4 and 23.3 months for SCHOLAR-5 and ZUMA-5. Median overall survival (OS) and progression-free survival (PFS) in SCHOLAR-5 were 59.8 months and 12.7 months and not reached in ZUMA-5. Hazard ratios for OS and PFS were 0.42 (95% confidence interval [CI], 0.21-0.83) and 0.30 (95% CI, 0.18-0.49). The ORR and CR rate were 49.9% and 29.9% in SCHOLAR-5 and 94.2% and 79.1% in ZUMA-5, for odds ratios of 16.2 (95% CI, 5.6-46.9) and 8.9 (95% CI, 4.3-18.3). Compared with available therapies, axi-cel demonstrated an improvement in meaningful clinical endpoints, suggesting axi-cel addresses an important unmet need for r/r FL patients. This trial was registered at www.clinicaltrials.gov as #NCT03105336.

A Phase 1 study evaluating AMG 337 in Asian patients with advanced solid tumors.

AMG 337, a selective small-molecule MET inhibitor, was evaluated in Asian patients with advanced solid tumors. Eligible patients orally self-administered AMG 337; the initial dose of 150 mg once daily (QD) was escalated to 300 mg QD (modified 3+3+3 design). Treatment continued until disease progression, intolerability, or death. The primary endpoint was adverse events (AEs) and clinical abnormalities defined as dose-limiting toxicities (DLTs). Secondary endpoints included other AEs, pharmacokinetics and tumor response. Eleven patients were enrolled. No DLTs occurred. The most common treatment-emergent AEs were headache (73%) and nausea (45%). Cmax and AUC0-24 exposures increased proportionally with dose; t1/2 was comparable between groups; plasma accumulation was minimal over 28 days. One patient (150 mg) had partial response; one patient (300 mg) had stable disease. Safety, tolerability, pharmacokinetics and efficacy of AMG 337 in Asian patients were consistent with those observed in Western patient populations. The study was terminated early.

A Phase 1/1b tolerability study of rilotumumab alone or in combination with cisplatin and capecitabine in Japanese patients with gastric cancer.

OBJECTIVE: To evaluate the safety (including adverse events and dose-limiting toxicities [DLTs]), tolerability, pharmacokinetics and antitumor activity of the investigational MET inhibitor rilotumumab alone in patients with advanced solid tumors (Part 1) or in combination with cisplatin plus capecitabine (CX) in patients with MET-positive advanced gastric or gastroesophageal junction cancer (Part 2). METHODS: Adult patients received 10 or 20 mg/kg intravenous (IV) rilotumumab every 2 weeks (Part 1) or 15 mg/kg IV rilotumumab every 3 weeks plus 80 mg/m2 cisplatin on Day 1 and 1000 mg/m2 capecitabine twice daily on Days 1-14 of every 21-day cycle (Part 2). RESULTS: Nine patients enrolled in Part 1; 12 patients enrolled in Part 2. One DLT occurred (Grade 3 decreased appetite and stomatitis [Part 2]). Adverse events related to any treatment occurred in 17 patients (81%) and were Grade ≥3 in nine patients (43%). Rilotumumab pharmacokinetics appeared linear, and exposure was unaffected by CX. No patient who received rilotumumab monotherapy in Part 1 had a response. In Part 2, five of eight patients (63%) with measureable disease at baseline had a partial response and two patients (25%) had stable disease; median (95% CI) progression-free survival was 7.0 (2.4-15.4) months; overall survival was 18.2 (5.6-20.4) months. CONCLUSIONS: In combination with CX, rilotumumab appeared tolerable and showed antitumor activity in Japanese patients with MET-positive gastric/gastroesophageal junction cancer. However, owing to the results of recent Phase 3 trials of MET inhibitors (including rilotumumab), further development of rilotumumab in this setting is not being pursued. ClinicalTrials.gov Identifier: NCT01791374.

A phase 3 trial evaluating panitumumab plus best supportive care vs best supportive care in chemorefractory wild-type KRAS or RAS metastatic colorectal cancer.

BACKGROUND: We assessed the treatment effect of panitumumab plus best supportive care (BSC) vs BSC on overall survival (OS) in patients with chemorefractory wild-type KRAS exon 2 metastatic colorectal cancer (mCRC) and report the first prospective extended RAS analysis in a phase 3 trial. METHODS: Patients with wild-type KRAS exon 2 mCRC were randomised 1 : 1 to panitumumab (6 mg kg-1 Q2W) plus BSC or BSC. On-study crossover was prohibited. RAS mutation status was determined by central laboratory testing. The primary endpoint was OS in wild-type KRAS exon 2 mCRC; OS in wild-type RAS mCRC (KRAS and NRAS exons 2, 3, and 4) was a secondary endpoint. RESULTS: Three hundred seventy seven patients with wild-type KRAS exon 2 mCRC were randomised. Median OS was 10.0 months with panitumumab plus BSC vs 7.4 months with BSC (HR=0.73; 95% CI=0.57-0.93; P=0.0096). RAS ascertainment was 86%. In wild-type RAS mCRC, median OS for panitumumab plus BSC was 10.0 vs 6.9 months for BSC (HR=0.70; 95% CI=0.53-0.93; P=0.0135). Patients with RAS mutations did not benefit from panitumumab (OS HR=0.99; 95% CI=0.49-2.00). No new safety signals were observed. CONCLUSIONS: Panitumumab significantly improved OS in wild-type KRAS exon 2 mCRC. The effect was more pronounced in wild-type RAS mCRC, validating previous retrospective analyses.

Open-Label, phase 2 study of blinatumomab as second salvage therapy in adults with relapsed/refractory aggressive B-cell non-Hodgkin lymphoma.

The phase 2 portion of this open-label phase 2/3 study assessed the efficacy and safety of blinatumomab as second salvage for aggressive relapsed or refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL) following platinum-based first salvage chemotherapy. Forty-one patients with aggressive disease (32% relapsed; 68% refractory) enrolled and received stepwise blinatumomab (9-28-112 µg/day) in a 70-day cycle 1 and an optional 28-day cycle 2; 19 (46%) completed cycle 1 and 3 (7%) completed cycle 2. The overall response rate after 12 weeks was 37%, including 9 (22%) complete metabolic responses. Eight (20%) patients (all responders) subsequently received stem cell transplants. Grade ≥3 adverse events were reported in 29 (71%) patients. Grade 3 cytokine release syndrome occurred in one patient. Grade 3 neurologic events occurred in 10 (24%) patients; all resolved. Blinatumomab monotherapy appears effective as second salvage therapy in patients with r/r aggressive B-NHL. Trial registration: NCT02910063.

Clinical validation of the next-generation sequencing-based Extended RAS Panel assay using metastatic colorectal cancer patient samples from the phase 3 PRIME study.

PURPOSE: To validate a next-generation sequencing (NGS)-based companion diagnostic using the MiSeqDx® sequencing instrument to simultaneously detect 56 RAS mutations in DNA extracted from formalin-fixed paraffin-embedded metastatic colorectal cancer (mCRC) tumor samples from the PRIME study. The test's ability to identify patients with mCRC likely to benefit from panitumumab treatment was assessed. METHODS: Samples from PRIME, which compared first-line panitumumab + FOLFOX4 with FOLFOX4, were processed according to predefined criteria using a multiplex assay that included input DNA qualification, library preparation, sequencing, and the bioinformatics reporting pipeline. NGS mutational analysis of KRAS and NRAS exons 2, 3, and 4 was performed and compared with Sanger sequencing. RESULTS: In 441 samples, positive percent agreement of the Extended RAS Panel with Sanger sequencing was 98.7% and negative percent agreement was 97.6%. For clinical validation (n = 528), progression-free survival (PFS) and overall survival (OS) were compared between patients with RAS mutations (RAS Positive) and those without (RAS Negative). Panitumumab + FOLFOX4 improved PFS in RAS Negative patients (P = 0.02). Quantitative interaction testing indicated the treatment effect (measured by the hazard ratio of panitumumab + FOLFOX4 versus FOLFOX4) differed for RAS Negative versus RAS Positive for PFS (P = 0.0038) and OS (P = 0.0323). CONCLUSIONS: NGS allows for broad, rapid, highly specific analyses of genomic regions. These results support use of the Extended RAS Panel as a companion diagnostic for selecting patients for panitumumab, and utilization is consistent with recent clinical guidelines regarding mCRC RAS testing. Overall, approximately 13% more patients were detected with the Extended RAS Panel versus KRAS exon 2 alone. CLINICAL TRIAL REGISTRY IDENTIFIER: NCT00364013 (ClinicalTrials.gov).

Final Analysis of Outcomes and RAS/BRAF Status in a Randomized Phase 3 Study of Panitumumab and Best Supportive Care in Chemorefractory Wild Type KRAS Metastatic Colorectal Cancer.

INTRODUCTION: Tumor rat sarcoma gene (RAS) status is a negative predictive biomarker for anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer (mCRC). We analyzed outcomes according to RAS and v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutational status, and evaluated early tumor shrinkage (ETS) and depth of response (DpR) for patients with wild type RAS. PATIENTS AND METHODS: Patients with confirmed metastatic colon or rectum adenocarcinoma, wild type Kristen rat sarcoma gene tumor exon 2 status, clinical/radiologic disease progression or toxicity during irinotecan or oxaliplatin treatment, and no previous anti-EGFR therapy were randomized 1:1 to receive best supportive care (BSC) with or without panitumumab (6.0 mg/kg, intravenously, on day 1 of each 14-day cycle) in this open-label, multicenter, phase III study (20100007). RAS and BRAF mutation status were determined using Sanger sequencing. ETS was evaluated as maximum percentage change from baseline to week 8; DpR was calculated as the percentage change for tumor shrinkage at nadir versus baseline. RESULTS: Overall, 270 patients had RAS wild type mCRC (panitumumab with BSC, n = 142; BSC, n = 128). For patients with wild type RAS tumors, median overall survival (OS; hazard ratio [HR], 0.72; P = .015) and progression-free survival (PFS; HR, 0.45; P < .0001) were improved with panitumumab with BSC versus BSC. Similar improvements were seen for patients with wild type RAS, and wild type BRAF tumors (OS: HR, 0.75; P = .04; PFS: HR, 0.45; P < .0001). Median DpR was 16.9% for the evaluable panitumumab with BSC wild type RAS population. Overall, 69.5% experienced any type of tumor shrinkage at week 8; 38.2% experienced ≥ 20% shrinkage. Similar improvements in OS and PFS were seen with stratification according to ETS. CONCLUSION: This analysis showed that panitumumab improved outcomes in wild type RAS mCRC and indicated that ETS and DpR could be used as additional efficacy markers.

Combined BRAF, EGFR, and MEK Inhibition in Patients with BRAFV600E-Mutant Colorectal Cancer.

Although BRAF inhibitor monotherapy yields response rates >50% in BRAFV600-mutant melanoma, only approximately 5% of patients with BRAFV600E colorectal cancer respond. Preclinical studies suggest that the lack of efficacy in BRAFV600E colorectal cancer is due to adaptive feedback reactivation of MAPK signaling, often mediated by EGFR. This clinical trial evaluated BRAF and EGFR inhibition with dabrafenib (D) + panitumumab (P) ± MEK inhibition with trametinib (T) to achieve greater MAPK suppression and improved efficacy in 142 patients with BRAFV600E colorectal cancer. Confirmed response rates for D+P, D+T+P, and T+P were 10%, 21%, and 0%, respectively. Pharmacodynamic analysis of paired pretreatment and on-treatment biopsies found that efficacy of D+T+P correlated with increased MAPK suppression. Serial cell-free DNA analysis revealed additional correlates of response and emergence of KRAS and NRAS mutations on disease progression. Thus, targeting adaptive feedback pathways in BRAFV600E colorectal cancer can improve efficacy, but MAPK reactivation remains an important primary and acquired resistance mechanism.Significance: This trial demonstrates that combined BRAF + EGFR + MEK inhibition is tolerable, with promising activity in patients with BRAFV600E colorectal cancer. Our findings highlight the MAPK pathway as a critical target in BRAFV600E colorectal cancer and the need to optimize strategies inhibiting this pathway to overcome both primary and acquired resistance. Cancer Discov; 8(4); 428-43. ©2018 AACR.See related commentary by Janku, p. 389See related article by Hazar-Rethinam et al., p. 417This article is highlighted in the In This Issue feature, p. 371.