Novel treatment approaches for HER2 positive solid tumors (excluding breast cancer).

PURPOSE OF REVIEW: Human epidermal growth factor 2 (HER2) alterations (protein overexpression, gene amplification and mutation) play a key role in oncogenesis and are more likely correlated to poorer outcome in solid tumors. We reviewed recently published studies in the last 18 months on novel treatment approaches for HER2 positive solid tumors (excluding breast cancer). RECENT FINDINGS: Results of clinical studies assessing anti-HER2 therapies have been recently issued.One of the most promising drugs is transtuzumab deruxtecan, an antibody-drug conjugate which demonstrated clinically meaningful activity in gastric or gastroesophageal junction cancer and colorectal cancers.Small molecules such as poziotinib, pyrotinib, neratinib, which target both epidermal growth factor receptor (EGFR) and HER2 also showed promising activity, especially in heavily pretreated ERRB2-mutated non-small cell lung cancer (NSCLC) cancer patients. Yet, these findings need to be confirmed in confirmatory randomized trials with larger cohorts.Trastuzumab-based combinations with chemotherapy or immune checkpoint inhibitors are under development with promising results, but not in all HER2 tumors. Emerging adverse events with anti-HER2 are interstitial pneumopathy and diarrhea. SUMMARY: Tyrosine kinase inhibitors, antibody drug conjugate in monotherapy and combinations are emerging strategies in many HER2-positive cancers; HER2 therapies are now part of standard of care of HER2-amplified gastric or gastroesophageal junction cancer. Data are pending on several unmet medical needs.

Duration of nivolumab for pretreated, advanced non-small-cell lung cancer.

BACKGROUND: A standard of care for pretreated, advanced non-small-cell lung cancers (NSCLCs), nivolumab has demonstrated long-term benefit when administered for 2 years. We aimed to better discern an optimized administration duration by retrospectively analyzing real-life long-term efficacy in a prospective cohort. METHODS: All nivolumab-treated adults with advanced NSCLCs (01/09/2015 to 30/09/2016) from nine French centers were eligible. On 31/12/2018, patients who are alive ≥ 2 years after starting nivolumab were defined as long-term survivors (LTSs) and were divided into three nivolumab treatment groups: <2, 2, or > 2 years. Co-primary endpoints were LTSs' progression-free survival (PFS) and overall survival (OS). RESULTS: The median follow-up was 32 months (95% CI, 31.0 to 34.0). The 3-year OS rate for the 259 cohort patients was 16.6%. Among them, 65 were LTSs: 47 treated < 2 years, 7 for 2 years, and 11 > 2 years. Their respective characteristics were: median age: 59, 52, and 58 years; smoking history: 92.9, 100, and 100%; adenocarcinomas: 66, 57.1, and 54.5%. LTSs' median (m)PFS was 28.4 months; mOS was not reached. LTSs' objective response rate was 61.6%. mOS was 32.7 months for those treated < 2 years and not reached for the others. The > 2-year group's 3-year OS was longer. Twenty-eight LTSs experienced no disease progression; 7 had durable complete responses. However, LTSs had more frequent and more severe adverse events. CONCLUSION: In real-life, prolonged nivolumab use provided long-term benefit with 16.6% 3-year OS and 25% LTSs. Survival tended to be prolonged with nivolumab continued beyond 2 years. Prospective randomized trials with adequate design are needed.

Intra-cranial efficacy of brigatinib in an ALK-positive non-small cell lung cancer patient presenting leptomeningeal carcinomatosis.

OBJECTIVES: Brigatinib is a second-generation ALK inhibitor which demonstrated activity over crizotinib-resistance, especially on brain metastasis by increased blood-brain penetration. However, its activity on lepto-meningeal disease is unknown and scarcely reported. MATERIALS AND METHODS: We hereby report the case of lepto-meningeal disease in crizotinib- and ceretinib- treated patient who was successfully treated by brigatinib. RESULTS: The patient achieved intracranial response to brigatinib more than 14 months. CONCLUSION: Our case provides additional data on brigatinib's intracranial activity, not only on brain metastasis but also on leptomeningeal disease, after experiencing resistance to both crizotinib and ceretinib, 1st and 2nd generation ALK inhibitors.

HER-Family Ligands Promote Acquired Resistance to Trastuzumab in Gastric Cancer.

Despite the clinical benefit of trastuzumab, eventually all HER2-amplified gastric cancer tumors develop drug resistance. We aimed to identify molecular mechanisms of acquired resistance to trastuzumab in gastric cancer by using well-established cell line-based preclinical models, as well as samples from patients with HER2-positive gastric cancer treated with trastuzumab. We studied trastuzumab resistance in NCI-N87 and OE19, two gastric cancer cell lines that overexpress HER2 receptor and are trastuzumab sensitive. Differences at protein, DNA, and RNA levels between the parental and resistant cells were characterized and functional studies were performed. Paired pre- and post-trastuzumab blood and tissue samples from patients with gastric cancer treated with trastuzumab were analyzed. We found that resistant cells were associated with increased activation of MAPK/ERK and PI3K/mTOR pathways driven by SRC activation. Upstream, resistant cells showed increased coexpression of multiple HER-family ligands that allowed for compensatory activation of alternative HER receptors upon HER2 blockade. Simultaneous inhibition of EGFR, HER2, and HER3 by the novel antibody mixture, Pan-HER, effectively reverted trastuzumab resistance in vitro and in vivo Similarly, an increase in HER-family ligands was observed in serum and tumor from patients with gastric cancer after trastuzumab therapy. We propose that trastuzumab resistance in gastric cancer is mediated by HER-family ligand upregulation that allows a compensatory activation of HER receptors and maintains downstream signaling activation despite trastuzumab therapy. Resistance is reverted by simultaneous inhibition of EGFR, HER2, and HER3, thereby revealing a potential therapeutic strategy to overcome trastuzumab resistance in patients with gastric cancer.