Abstract P2-13-21: Improved central nervous system outcomes in patients with early-stage HER2-positive breast cancer who receive neratinib for the recommended duration: Findings from the phase 3 ExteNET trial

Background: Non-adherence or early discontinuation from systemic adjuvant therapy is associated with an increased risk of disease recurrence and mortality. In the phase 3 ExteNET trial, neratinib (NERLYNX®), an oral irreversible pan-HER tyrosine kinase inhibitor, significantly improved invasive disease-free survival (iDFS) when given for 12 months in patients with early-stage HER2-positive (HER2+) breast cancer after trastuzumab-based therapy. Anti-diarrheal prophylaxis was not mandated by protocol and 17% of patients discontinued neratinib early because of diarrhea. Improved iDFS, distant disease-free survival, and overall survival (OS) have since been reported in patients who completed the planned duration of neratinib therapy compared with all randomized patients [ASCO 2021]. Here we assess central nervous system disease-free survival (CNS-DFS) in 3 discrete groups of patients who completed planned therapy with neratinib in ExteNET: intent-to-treat (ITT) population; patients with hormone receptor-positive disease who initiated neratinib within 1 year after prior trastuzumab (HR+/≤1 year, the population for which neratinib is approved in the EU); and HR+/≤1 year with residual disease post-neoadjuvant therapy (i.e. no pathologic complete response [pCR]). Methods: Patients with early-stage HER2+ breast cancer received oral neratinib 240 mg/day or placebo after trastuzumab-based (neo)adjuvant therapy for 12 months. Patients who completed neratinib therapy (defined as treatment duration ≥11 months or cessation of neratinib if recurrence occurred prior to 11 months) were compared with placebo (all randomized patients). CNS-DFS was defined as time from randomization to any CNS recurrence or death from any cause (exploratory endpoint). Kaplan-Meier methods were used to estimate CNS-DFS and OS rates. Hazard ratios (HR) with 95% confidence intervals (CI) for neratinib versus placebo were estimated using a Cox proportional hazards model. Data cutoffs: March 2017 (CNS-DFS); July 2019 (OS); median follow-up 8.0 (range 0-9.8) years. Results: 2840 patients were included in the ITT population (1420 per group). Among patients who completed neratinib therapy, CNS-DFS was improved versus placebo in each of the 3 patient groups (see Table). For CNS-DFS, the magnitude of effect of neratinib versus placebo was consistently greater in patients who completed neratinib therapy than in the corresponding overall randomized patient group: ITT HR, 0.70 vs 0.73; HR+/≤1 year HR, 0.27 vs 0.41; HR+/≤ 1 year no pCR HR: 0.16 vs 0.24, respectively.

Conclusions: These descriptive findings suggest that, in addition to improved OS, patients who receive the recommended 12-month course of neratinib may have improved CNS outcomes. A dose-escalation strategy, which was shown to improve the tolerability of neratinib, decrease the proportion of patients who discontinue treatment due to diarrhea (3.3%), and allow more patients to stay on treatment for 11 months or longer in the CONTROL trial (NCT02400476) compared with ExteNET, may help to realize these benefits in the real-world setting.

Table: CNS-DFS and OS in patients who completed planned therapy with neratinib (ITT, HR+/≤1 year and HR+/≤1 year no pCR)NCNS-DFS rate (5 years)OS rateaPopulation/group NeratinibPlaceboDifference, %bHR (95% CI)Difference, %bHR (95% CI)ITT14201420+1.10.73 (0.45-1.17)-0.10.95 (0.75-1.21)cCompleted therapyd8721420+1.20.70 (0.40-1.19)+2.00.78 (0.58-1.04)HR+/≤1 yeare670664+2.70.41 (0.18-0.85)+2.10.79 (0.55-1.13)Completed therapyd402664+3.20.27 (0.08-0.69)+5.80.49 (0.29-0.78)HR+/≤1 yearb no pCRf131164+6.40.24 (0.04-0.92)+9.10.47 (0.23-0.92)Completed therapyd92164+6.90.16 (0.01-0.81)+13.20.29 (0.10-0.68)aOS analysis after a median follow-up of 8.0 (range 0-9.8) years; bDifference (neratinib vs placebo); cStratified by randomization stratification factors; dDefined as ≥11 months of therapy or ended treatment due to disease recurrence (neratinib arm), and all randomized subjects (placebo arm); eHR+ and ≤1 year after prior trastuzumab; fResidual disease post-neoadjuvant therapy. Abbreviations: CI, confidence interval; CNS-DFS, central nervous system disease-free survival; HR, hazard ratio; HR+, hormone receptor-positive; OS, overall survival; pCR, pathologic complete response.

Citation Format: Frankie Ann Holmes, Debra Patt, Yvonne Manalo, Julie C Smith, Steven W Papish, Noa Efrat, Ana Arance, Bo Zhang, Deepa Lalla, Alvin Wong, Miguel Martin. Improved central nervous system outcomes in patients with early-stage HER2-positive breast cancer who receive neratinib for the recommended duration: Findings from the phase 3 ExteNET trial [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-21.

Bendamustine, bortezomib and rituximab produces durable complete remissions in patients with previously untreated, low grade lymphoma

This Phase II trial evaluated the efficacy of bendamustine, bortezomib and rituximab in patients with previously untreated low-grade lymphoma. Eligible patients had low grade lymphoma with no previous systemic disease treatment. Treatment for all patients was given in 28-day cycles for a maximum of 6 cycles. Patients received rituximab 375 mg/m² intravenously (IV) on days 1, 8 and 15 of cycle 1 and day 1 of cycles 2-6; bendamustine 90 mg/m² IV on days 1 and 2; and bortezomib 1·6 mg/m² IV on days 1, 8 and 15. Patients were permitted to begin maintenance treatment with rituximab 6 months after completion of study treatment and after 6-month follow-up assessments had been conducted. Fifty-four eligible patients were enrolled. The most common grade 3/4 toxicities were leucopenia (28%), neutropenia (30%) and lymphopenia (17%). There were no treatment-related deaths and 1 unrelated death on study (embolic stroke). The overall response rate was 94% for all patients. The median follow-up was 54 months. Kaplan-Meier estimates of progression-free survival and overall survival at 36 months were 75% and 88%, respectively. The treatment regimen was well tolerated and produced high response rates. Further study of this regimen in patients with previously untreated lymphoma is warranted.

Randomized Phase II Study of R-CHOP With or Without Bortezomib in Previously Untreated Patients With Non-Germinal Center B-Cell-Like Diffuse Large B-Cell Lymphoma

Purpose To evaluate the impact of the addition of bortezomib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on outcomes in previously untreated patients with non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). Patients and Methods After real-time determination of non-GCB DLBCL using the Hans immunohistochemistry algorithm, 206 patients were randomly assigned (1:1; stratified by International Prognostic Index [IPI] score) to six 21-day cycles of standard R-CHOP alone or R-CHOP plus bortezomib 1.3 mg/m² intravenously on days 1 and 4 (VR-CHOP). The primary end point, progression-free survival (PFS), was evaluated in 183 patients with centrally confirmed non-GCB DLBCL who received one or more doses of study drug (91 R-CHOP, 92 VR-CHOP). Results After a median follow-up of 34 months, with 25% (R-CHOP) and 18% (VR-CHOP) of patients having had PFS events, the hazard ratio (HR) for PFS was 0.73 (90% CI, 0.43 to 1.24) with VR-CHOP ( P = .611). Two-year PFS rates were 77.6% with R-CHOP and 82.0% with VR-CHOP; they were 65.1% versus 72.4% in patients with high-intermediate/high IPI (HR, 0.67; 90% CI, 0.34 to 1.29), and 90.0% versus 88.9% (HR, 0.85; 90% CI, 0.35 to 2.10) in patients with low/low-intermediate IPI. Overall response rate with R-CHOP and VR-CHOP was 98% and 96%, respectively. The overall survival HR was 0.75 (90% CI, 0.38 to 1.45); 2-year survival rates were 88.4% and 93.0%, respectively. In the safety population (100 R-CHOP and 101 VR-CHOP patients), grade ≥ 3 adverse events included neutropenia (53% v 49%), thrombocytopenia (13% v 29%), anemia (7% v 15%), leukopenia (26% v 25%), and neuropathy (1% v 5%). Conclusion Outcomes for newly diagnosed, prospectively enrolled patients with non-GCB DLBCL were more favorable than expected with R-CHOP and were not significantly improved by adding bortezomib.

Scalp Cooling Alopecia Prevention trial (SCALP) for patients with early stage breast cancer

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Background: Adjuvant chemotherapy decreases the risk of recurrence. However, it has distressing side effects, including alopecia. There are no randomized trials assessing modern scalp cooling to prevent alopecia, and success rates in non-randomized trials have varied. Methods: We conducted a multi-center randomized trial to evaluate the safety and efficacy of the Orbis Paxman Hair Loss Prevention System (OPHLPS) in reducing chemotherapy-induced alopecia. Women with stage I-II breast cancer planned to receive anthracycline- or taxane- based chemotherapy for at least four cycles were eligible and randomized in a 2:1 ratio to scalp-cooling or control. Scalp-cooling was done with the OPHLPS 30 minutes prior to, during and 90 minutes after each chemotherapy. The primary efficacy endpoints were hair preservation and device safety. We planned to enroll 235 subjects to provide 85% power to detect a 20% difference in hair preservation. Secondary endpoints included wig/scarf use and quality of life assessed by the EORTC QLQ-30, HADS and BIS. Subjects will be followed for 5 years for recurrence, overall survival, and site of recurrence. One interim analysis was planned to allow the study to stop early for efficacy after 142 subjects were enrolled and evaluable for the primary endpoint. To maintain the overall type 1 error rate, an O’Brien-Fleming spending function was used (interim boundary p = 0.0061). Results: This is the first randomized trial with modern scalp cooling in the world. For the interim analysis, 142 subjects were evaluable. Among them, 48 (50.5%) out of 95 in the cooling group and 0 (0%) out of 47 in the control group had hair preservation. The one-tailed p-value from the Fisher’s exact test is < 0.0001, which crosses the superiority boundary (p = 0.0061). Thus on 9/26/2016 the DSMB stopped the study early. The interim analysis was presented at SABCS 2016. There are 195 subjects enrolled on this clinical trial, and the final subject will be evaluable for the primary outcome February 2017. The final analysis will be presented. Conclusions: Our trial showed that scalp cooling using OPHLPS is highly effective in hair retention. Paxman Coolers has applied for FDA clearance for the OPHLPS based on the results of the interim analysis. Clinical trial information: NCT01986140.

CODBLAM IV chemotherapy for large cell lymphoma: sequential use of infusional vincristine and bleomycin and "high dose" consolidation

BACKGROUND

Based on prior results in large cell lymphoma (LCL) with COPBLAM (Cyclophosphamide, Oncovin, Prednisone, Bleomycin, Adriamycin, Matulane) I and COPBLAM III, CODBLAM (Cyclophosphamide, Oncovin, Dexamethasone, Bleomycin, Adriamycin, Matulane) IV was developed to intensify treatment further by utilizing four sequential cycles of infusional chemotherapy followed by high-dose chemotherapy and cycle active agents.

METHODS

Sixty-one patients with LCL, mostly B-cell lymphoma, with 54% >60 years of age, were treated with daily continuous infusion of vincristine 1.0 mg/m2 days 1-2, bleomycin 4 mg/m2 i.v. push x 1 only followed by daily infusion 4 mg/m2 days 1-5, dexamethasone 10 mg/m2 days 1-5, procarbazine 100 mg/m2 orally days 1-5, doxorubicin 35 mg/m2 i.v. push day 1 (escalated), and cyclophosphamide 350 mg/m2 i.v. push day 1 (escalated), all given every 3 weeks for four cycles. After infusions, patients were restaged and treated with single courses of doxorubicin 90 mg/ m2 i.v. push followed at 3 weeks with cyclophosphamide 1500 mg/m2 i.v. push (both with concomitant vincristine 1 mg/m2 i.v. push and dexamethasone 10 mg/m2 p.o. daily for 5 days). Remaining treatment consisted of methotrexate 120 mg/m2 i.v. push with citrovorum rescue, cytarabine 250 mg/m2 i.v. push, and etoposide 100 mg/m2 i.v. infusion over 1 h, all given every 10 days for six cycles.

RESULTS

The overall complete response (CR) rate was 88%. Of all patients, 36 (59%) are sustained disease free at a median follow-up time of 55 months. In patients age < or = 60 years, 89% achieved CR and 85% of patients age >60 years attained CR. CR was achieved in 83% of patients with constitutional B-type symptoms, 69% of patients with bulky adenopathy, and 86% of patients with immunoblastic histology. Toxicity was primarily pulmonary, occuring in 15% of patients. One toxic death was observed.

CONCLUSIONS

Infusional CODBLAM IV may represent an effective and unique treatment for LCL.

COPBLAM III: infusional combination chemotherapy for diffuse large-cell lymphoma

COPBLAM III, a polychemotherapy regimen consisting of cyclophosphamide, infusional vincristine, prednisone, infusional bleomycin, doxorubicin, and procarbazine, was administered to 51 patients with diffuse large-cell lymphoma. Ninety-six percent of patients age 60 or younger achieved a complete response (CR); none have relapsed. Overall, 88% of patients are alive and well and potentially in the survival plateau. For patients greater than 60 years, CR was obtained in 73%, with 42% potentially in the survival plateau, the difference resulting in part from four relapses, three toxic deaths, and one presumed unrelated death. These results in the elderly were paralleled by a relatively reduced ability to tolerate therapy. Toxicity was primarily pulmonary, occurring in 39% of patients, two of whom died. With an overall CR rate of 84%, of which 92% are sustained at a median follow-up of 40 months, COPBLAM III represents a highly effective treatment in a sizeable cohort of patients.