Response to brentuximab vedotin versus physician's choice by CD30 expression and large cell transformation status in patients with mycosis fungoides: An ALCANZA sub-analysis

INTRODUCTION

Mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma, can lead to disfiguring lesions, debilitating pruritus and frequent skin infections. This study assessed response to brentuximab vedotin in patients with MF in the phase III ALCANZA study.

METHODS

Baseline CD30 levels and large-cell transformation (LCT) status were centrally reviewed in patients with previously-treated CD30-positive MF using ≥2 skin biopsies obtained at screening; eligible patients required ≥1 biopsy with ≥10% CD30 expression. Patients were categorised as CD30_min < 10% (≥1 biopsy with <10% CD30 expression), or CD30_min ≥ 10% (all biopsies with ≥10% CD30 expression) and baseline LCT present or absent. Efficacy analyses were the proportion of patients with objective response lasting ≥4 months (ORR4) and progression-free survival (PFS).

RESULTS

Clinical activity with brentuximab vedotin was observed across all CD30 expression levels in patients with ≥1 biopsy showing ≥10% CD30 expression. Superior ORR4 was observed with brentuximab vedotin versus physician's choice in patients: with CD30_min < 10% (40.9% versus 9.5%), with CD30_min ≥ 10% (57.1% versus 10.3%), with LCT (64.7% versus 17.6%) and without LCT (38.7% versus 6.5%). Brentuximab vedotin improved median PFS versus physician's choice in patients: with CD30_min < 10% (16.7 versus 2.3 months), with CD30_min ≥ 10% (15.5 versus 3.9 months), with LCT (15.5 versus 2.8 months) and without LCT (16.1 versus 3.5 months). Safety profiles were generally comparable across subgroups.

CONCLUSION

These exploratory analyses demonstrated that brentuximab vedotin improved rates of ORR4 and PFS versus physician's choice in patients with CD30-positive MF and ≥1 biopsy showing ≥10% CD30 expression, regardless of LCT status.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT01578499.

Tucatinib, Trastuzumab, and Capecitabine for HER2-Positive Metastatic Breast Cancer

BACKGROUND

Patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer who have disease progression after therapy with multiple HER2-targeted agents have limited treatment options. Tucatinib is an investigational, oral, highly selective inhibitor of the HER2 tyrosine kinase.

METHODS

We randomly assigned patients with HER2-positive metastatic breast cancer previously treated with trastuzumab, pertuzumab, and trastuzumab emtansine, who had or did not have brain metastases, to receive either tucatinib or placebo, in combination with trastuzumab and capecitabine. The primary end point was progression-free survival among the first 480 patients who underwent randomization. Secondary end points, assessed in the total population (612 patients), included overall survival, progression-free survival among patients with brain metastases, confirmed objective response rate, and safety.

RESULTS

Progression-free survival at 1 year was 33.1% in the tucatinib-combination group and 12.3% in the placebo-combination group (hazard ratio for disease progression or death, 0.54; 95% confidence interval [CI], 0.42 to 0.71; P<0.001), and the median duration of progression-free survival was 7.8 months and 5.6 months, respectively. Overall survival at 2 years was 44.9% in the tucatinib-combination group and 26.6% in the placebo-combination group (hazard ratio for death, 0.66; 95% CI, 0.50 to 0.88; P = 0.005), and the median overall survival was 21.9 months and 17.4 months, respectively. Among the patients with brain metastases, progression-free survival at 1 year was 24.9% in the tucatinib-combination group and 0% in the placebo-combination group (hazard ratio, 0.48; 95% CI, 0.34 to 0.69; P<0.001), and the median progression-free survival was 7.6 months and 5.4 months, respectively. Common adverse events in the tucatinib group included diarrhea, palmar-plantar erythrodysesthesia syndrome, nausea, fatigue, and vomiting. Diarrhea and elevated aminotransferase levels of grade 3 or higher were more common in the tucatinib-combination group than in the placebo-combination group.

CONCLUSIONS

In heavily pretreated patients with HER2-positive metastatic breast cancer, including those with brain metastases, adding tucatinib to trastuzumab and capecitabine resulted in better progression-free survival and overall survival outcomes than adding placebo; the risks of diarrhea and elevated aminotransferase levels were higher with tucatinib. (Funded by Seattle Genetics; HER2CLIMB ClinicalTrials.gov number, NCT02614794.).

Anti-CD22 and anti-CD79B antibody drug conjugates are active in different molecular diffuse large B-cell lymphoma subtypes

Antibody drug conjugates (ADCs), in which cytotoxic drugs are linked to antibodies targeting antigens on tumor cells, represent promising novel agents for the treatment of malignant lymphomas. Pinatuzumab vedotin is an anti-CD22 ADC and polatuzumab vedotin an anti-CD79B ADC that are both linked to the microtubule-disrupting agent monomethyl auristatin E (MMAE). In the present study, we analyzed the activity of these agents in different molecular subtypes of diffuse large B-cell lymphoma (DLBCL) both in vitro and in early clinical trials. Both anti-CD22-MMAE and anti-CD79B-MMAE were highly active and induced cell death in the vast majority of activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL cell lines. Similarly, both agents induced cytotoxicity in models with and without mutations in the signaling molecule CD79B. In line with these observations, relapsed and refractory DLBCL patients of both subtypes responded to these agents. Importantly, a strong correlation between CD22 and CD79B expression in vitro and in vivo was not detectable, indicating that patients should not be excluded from anti-CD22-MMAE or anti-CD79B-MMAE treatment because of low target expression. In summary, these studies suggest that pinatuzumab vedotin and polatuzumab vedotin are active agents for the treatment of patients with different subtypes of DLBCL.

Genetic analysis of long-term Barrett's esophagus epithelial cultures exhibiting cytogenetic and ploidy abnormalities

BACKGROUND & AIMS

Progression to cancer in Barrett's esophagus occurs through an accumulation of cell cycle and genetic abnormalities that have been documented in vivo. To better study neoplastic evolution in Barrett's esophagus, the aim of this study was to establish in vitro cultures from preneoplastic tissues.

METHODS

Mechanical and enzymatic dissociation methods were used to initiate Barrett's epithelial cultures from endoscopic biopsy specimens, and the cells were characterized using flow-cytometric, cytogenetic, and molecular genetic analyses.

RESULTS

Four long-term cultures were established from 39 attempts. All cultures contain cytogenetic abnormalities and elevated flow-cytometric 4N DNA content fractions. Molecular genetic abnormalities detected include the following: 9p and/or CDKN2/p16 abnormalities in 4 of 4 cultures, 17p loss of heterozygosity and p53 mutation in 3 of 4 cultures, and 5q loss of heterozygosity in 1 of 4 cultures. Inactivation of p53 was statistically associated with successful long-term culture.

CONCLUSIONS

These cultures contain cell cycle and molecular genetic abnormalities that closely parallel those previously documented to occur early in cancer development in Barrett's esophagus in vivo. These alterations also appear to be associated with successful growth in vitro. The cultures may provide a premalignant in vitro system in which to test potential therapies for Barrett's esophagus as well as to examine etiologic factors and genetic intermediates important in neoplastic progression.