The incidence of human papillomavirus (HPV)-positive oropharyngeal cancer, a disease affecting younger patients, is rapidly increasing. Cetuximab, an epidermal growth factor receptor inhibitor, has been proposed for treatment de-escalation in this setting to reduce the toxicity of standard cisplatin treatment, but no randomised evidence exists for the efficacy of this strategy. We did an open-label randomised controlled phase 3 trial at 32 head and neck treatment centres in Ireland, the Netherlands, and the UK, in patients aged 18 years or older with HPV-positive low-risk oropharyngeal cancer (non-smokers or lifetime smokers with a smoking history of <10 pack-years). Eligible patients were randomly assigned (1:1) to receive, in addition to radiotherapy (70 Gy in 35 fractions), either intravenous cisplatin (100 mg/m2 on days 1, 22, and 43 of radiotherapy) or intravenous cetuximab (400 mg/m2 loading dose followed by seven weekly infusions of 250 mg/m2). The primary outcome was overall severe (grade 3-5) toxicity events at 24 months from the end of treatment. The primary outcome was assessed by intention-to-treat and per-protocol analyses. This trial is registered with the ISRCTN registry, number ISRCTN33522080. Between Nov 12, 2012, and Oct 1, 2016, 334 patients were recruited (166 in the cisplatin group and 168 in the cetuximab group). Overall (acute and late) severe (grade 3-5) toxicity did not differ significantly between treatment groups at 24 months (mean number of events per patient 4·8 [95% CI 4·2-5·4] with cisplatin vs 4·8 [4·2-5·4] with cetuximab; p=0·98). At 24 months, overall all-grade toxicity did not differ significantly either (mean number of events per patient 29·2 [95% CI 27·3-31·0] with cisplatin vs 30·1 [28·3-31·9] with cetuximab; p=0·49). However, there was a significant difference between cisplatin and cetuximab in 2-year overall survival (97·5% vs 89·4%, hazard ratio 5·0 [95% CI 1·7-14·7]; p=0·001) and 2-year recurrence (6·0% vs 16·1%, 3·4 [1·6-7·2]; p=0·0007). Compared with the standard cisplatin regimen, cetuximab showed no benefit in terms of reduced toxicity, but instead showed significant detriment in terms of tumour control. Cisplatin and radiotherapy should be used as the standard of care for HPV-positive low-risk patients who are able to tolerate cisplatin. Cancer Research UK.

The role of adjuvant radiotherapy in stage I endometrial cancer has changed in recent years. This updated Cochrane systematic review aimed to reexamine the efficacy and toxicity of adjuvant radiotherapy vs no treatment in stage I endometrial cancer. We searched various databases including The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and the Specialised Register of the Cochrane Gynaecological Cancer Review Group (CGCRG) for randomized controlled trials that met the predefined inclusion criteria. The primary outcome was overall survival (OS); secondary outcomes were endometrial cancer-specific survival, locoregional recurrence, distant recurrence, and toxicity. Hazard ratios (HRs) were estimated and pooled if possible; otherwise, dichotomous data were extracted. All statistical tests were two-sided. Of the eight included trials, seven trials (3628 women) compared external beam radiotherapy (EBRT) and no EBRT (or vaginal brachytherapy [VBT]), and one trial (645 women) compared VBT and no additional treatment. EBRT statistically significantly reduced locoregional recurrence compared with no EBRT (or VBT alone) (HR = 0.36, 95% confidence Interval [CI] = 0.25 to 0.52; P < .001), but this did not translate into an improvement in OS (HR = 0.99, 95% CI = 0.82 to 1.20; P = .95), endometrial cancer-specific survival (HR = 0.96, 95% CI = 0.72 to 1.28; P = .80), or distant recurrence rates (risk ratio = 1.04, 95% CI = 0.80 to 1.35; P = .77). EBRT was associated with an increased risk of severe acute toxicity, severe late toxicity, and reduced quality of life scores. EBRT reduces the risk of locoregional recurrence but has no statistically significant impact on cancer-related deaths or OS. However, EBRT is associated with clinically and statistically significant morbidity and a reduction in quality of life.

Trastuzumab has been shown to improve the survival outcomes of HER2 positive breast cancer patients. However, a significant proportion of HER2-positive patients are either inherently resistant or develop resistance to trastuzumab. We assessed the effects of neratinib, an irreversible panHER inhibitor, in a panel of 36 breast cancer cell lines. We further assessed its effects with or without trastuzumab in several sensitive and resistant breast cancer cells as well as a BT474 xenograft model. We confirmed that neratinib was significantly more active in HER2-amplified than HER2 non-amplified cell lines. Neratinib decreased the activation of the 4 HER receptors and inhibited downstream pathways. However, HER3 and Akt were reactivated at 24 hours, which was prevented by the combination of trastuzumab and neratinib. Neratinib also decreased pHER2 and pHER3 in acquired trastuzumab resistant cells. Neratinib in combination with trastuzumab had a greater growth inhibitory effect than either drug alone in 4 HER2 positive cell lines. Furthermore, trastuzumab in combination with neratinib was growth inhibitory in SKBR3 and BT474 cells which had acquired resistance to trastuzumab as well as in a BT474 xenograft model. Innately trastuzumab resistant cell lines showed sensitivity to neratinib, but the combination did not enhance response compared to neratinib alone. Levels of HER2 and phospho-HER2 showed a direct correlation with sensitivity to neratinib. Our data indicate that neratinib is an effective anti-HER2 therapy and counteracted both innate and acquired trastuzumab resistance in HER2 positive breast cancer. Our results suggest that combined treatment with trastuzumab and neratinib is likely to be more effective than either treatment alone for both trastuzumab-sensitive breast cancer as well as HER2-positive tumors with acquired resistance to trastuzumab.

Herceptin (trastuzumab) is used in patients with breast cancer who have HER2 (ErbB2)–positive tumours. However, its mechanisms of action and how acquired resistance to Herceptin occurs are still poorly understood. It was previously thought that the anti-HER2 monoclonal antibody Herceptin inhibits HER2 signalling, but recent studies have shown that Herceptin does not decrease HER2 phosphorylation. Its failure to abolish HER2 phosphorylation may be a key to why acquired resistance inevitably occurs for all responders if Herceptin is given as monotherapy. To date, no studies have explained why Herceptin does not abolish HER2 phosphorylation. The objective of this study was to investigate why Herceptin did not decrease HER2 phosphorylation despite being an anti-HER2 monoclonal antibody. We also investigated the effects of acute and chronic Herceptin treatment on HER3 and PKB phosphorylation in HER2-positive breast cancer cells. Using both Förster resonance energy transfer (FRET) methodology and conventional Western blot, we have found the molecular mechanisms whereby Herceptin fails to abolish HER2 phosphorylation. HER2 phosphorylation is maintained by ligand-mediated activation of EGFR, HER3, and HER4 receptors, resulting in their dimerisation with HER2. The release of HER ligands was mediated by ADAM17 through a PKB negative feedback loop. The feedback loop was activated because of the inhibition of PKB by Herceptin treatment since up-regulation of HER ligands and ADAM17 also occurred when PKB phosphorylation was inhibited by a PKB inhibitor (Akt inhibitor VIII, Akti-1/2). The combination of Herceptin with ADAM17 inhibitors or the panHER inhibitor JNJ-26483327 was able to abrogate the feedback loop and decrease HER2 phosphorylation. Furthermore, the combination of Herceptin with JNJ-26483327 was synergistic in tumour inhibition in a BT474 xenograft model. We have determined that a PKB negative feedback loop links ADAM17 and HER ligands in maintaining HER2 phosphorylation during Herceptin treatment. The activation of other HER receptors via ADAM17 may mediate acquired resistance to Herceptin in HER2-overexpressing breast cancer. This finding offers treatment opportunities for overcoming resistance in these patients. We propose that Herceptin should be combined with a panHER inhibitor or an ADAM inhibitor to overcome the acquired drug resistance for patients with HER2-positive breast cancer. Our results may also have implications for resistance to other therapies targeting HER receptors. HER2 (ErbB2) is a surface protein and member of the epidermal growth factor receptor (EGFR) family that is overexpressed in approximately one-fifth of breast cancers. HER2-positive breast tumours tend to be very aggressive, and patients with this type of tumour have a poor prognosis. A therapeutic monoclonal antibody called trastuzumab (Herceptin) has been designed to block HER2 signalling and is used as a treatment for patients with HER2-positive breast cancer. However, recent studies have shown that Herceptin does not decrease HER2 activation. This may be why patients invariably develop resistance if treated with Herceptin monotherapy. To date, no study has explained why Herceptin cannot abolish HER2 signalling despite being an anti-HER2 monoclonal antibody. We have found that Herceptin switches on a feedback loop that increases the production of the ADAM17 protein, a protease that in turn releases the growth factors that activate HER (ErbB) receptors. These growth factors activate HER2 and also the other members of the HER receptor family—EGFR, HER3 and HER4—in such a way as to maintain HER2 activation and cell survival in HER2-positive breast cancer cells. We have found that when Herceptin is provided in combination with ADAM17 inhibitors, the feedback loop is abrogated in cells. Furthermore, a pan-HER inhibitor that decreases the activation of other HER receptors can also inhibit the feedback loop and decrease HER2 activation when used in combination with Herceptin. We further demonstrated that the combination therapy of Herceptin with a pan-HER inhibitor is more effective than Herceptin alone in an animal model of breast cancer. We believe our results offer treatment strategies that may help overcome acquired Herceptin resistance in patients with HER2-positive breast cancer.

Purpose: The prognosis for patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) is poor, and only a minority of patients benefit from checkpoint immunotherapy. Talimogene laherparepvec (T-VEC), an oncolytic immunotherapy approved for advanced melanoma, in combination with pembrolizumab may yield enhanced antitumor activity over either agent alone. Patients and Methods: This was a phase Ib/III, multicenter trial testing intratumoral T-VEC combined with intravenous pembrolizumab in R/M HNSCC refractory to platinum-based chemotherapy. For phase Ib, primary endpoint was incidence of dose-limiting toxicity (DLT). Key secondary endpoints included objective response rate and progression-free survival per irRECIST, overall survival, and safety. Results: Thirty-six patients were enrolled into the phase Ib study. The data cut-off date was August 28, 2018. Median follow-up was 5.8 months (range, 0.3–24.2). One DLT of T-VEC–related fatal arterial hemorrhage was reported. Twenty (55.6%) and 21 (58.3%) patients experienced adverse events (AE) related to T-VEC and pembrolizumab, respectively. Besides the DLT, there were no treatment-related fatal AEs. A confirmed partial response was observed in 5 (13.9%) patients. Ten (27.8%) patients were unevaluable for response due to early death. Median PFS and OS were 3.0 months [95% confidence interval (Cl), 2.0–5.8] and 5.8 months (95% Cl, 2.9–11.4), respectively. Conclusions: The combination of T-VEC and pembrolizumab demonstrated a tolerable safety profile in R/M HNSCC. The efficacy with the combination was similar to that with pembrolizumab monotherapy in historical HNSCC studies. Phase III part of this study was not further pursued (ClinicalTrials.gov Identifier: NCT02626000).

Purpose of Review: WEE1 inhibitor has been shown to potential chemotherapy or radiotherapy sensitivity in preclinical models, particularly in p53-mutated or deficient cancer cells although not exclusively. Here, we review the clinical development of WEE1 inhibitor in combination with chemotherapy or radiotherapy with concurrent chemotherapy as well as its combination with different novel agents. Recent Findings: Although several clinical trials have shown that WEE1 inhibitor can be safely combined with different chemotherapy agents as well as radiotherapy with concurrent chemotherapy, its clinical development has been hampered by the higher rate of grade 3 toxicities when added to standard treatments. A few clinical trials had also been conducted to test WEE1 inhibitor using TP53 mutation as a predictive biomarker. However, TP53 mutation has not been shown to be the most reliable predictive biomarker and the benefit of adding WEE1 inhibitor to chemotherapy has been modest, even in TP53 biomarker-driven studies. Summary: There are ongoing clinical trials testing WEE1 inhibitor with novel agents such as ATR and PAPR inhibitors as well as anti-PDL1 immunotherapy, which may better define the role of WEE1 inhibitor in the future if any of the novel treatment combination will show superior anti-tumor efficacy with a good safety profile compared to monotherapy and/or standard treatment.