Phase II trial of dasatinib for recurrent or metastatic c-KIT expressing adenoid cystic carcinoma and for nonadenoid cystic malignant salivary tumors

BACKGROUND

Adenoid cystic carcinoma (ACC) is a subtype of malignant salivary gland tumors (MSGT), in which 90% of cases express cKIT. Dasatinib is a potent and selective inhibitor of five oncogenic protein tyrosine kinases (PTKs)/kinase families including cKIT. We conducted a phase II study to determine the antitumor activity of dasatinib in ACC and non-ACC MSGT.

PATIENTS AND METHODS

In a two-stage design, patients with progressive, recurrent/metastatic ACC (+cKIT) and non-ACC MSGT (separate cohort) were treated with dasatinib 70 mg p.o. b.i.d. Response was assessed every 8 weeks using RECIST.

RESULTS

Of 54 patients: 40 ACC, 14 non-ACC (1, ineligible excluded); M:F = 28 : 26, median age 56 years (range 20-82 years), ECOG performance status 0 : 1 : 2 = 24 : 28 : 2, prior radiation: 44, prior chemotherapy: 21. The most frequent adverse events (AEs) (as % of patients, worst grade 2 or higher) were: fatigue (28%), nausea (19%), headache (15%), lymphopenia (7%), dyspnea (11%), alanine aminotransferase increased (7%), anorexia (7%), vomiting (7%), alkaline phosphatase increased (6%), diarrhea (6%), neutropenia (6%), and noncardiac chest pain (6%). No grade 4 AE occurred, 15 patients experienced a grade 3 AE, primarily dyspnea (5) and fatigue (4), and cardiac toxicity (1 prolonged QTc). Among ACC patients, best response to dasatinib: 1 patient (2.5%) had partial response, 20 patients (50%) had stable disease (SD) (3-14 months), 12 patients (30%) had PD, 2 withdrew, 3 discontinued therapy due to AE, and 2 died before cycle 2. Median progression-free survival was 4.8 months. Median overall survival was 14.5 months. For 14 assessable non-ACC patients, none had objective response, triggering early stopping rule. Seven had SD (range 1-7 months), 4 PD, 2 discontinued therapy due to AE, and 1 died before cycle 2.

CONCLUSION

Although there was only one objective response, dasatinib is well tolerated, with tumor stabilization achieved by 50% of ACC patients. Dasatinib demonstrated no activity in non-ACC MSGT.

Serum C-Telopeptide Collagen Crosslinks and Plasma Soluble VEGFR2 as Pharmacodynamic Biomarkers in a Trial of Sequentially Administered Sunitinib and Cilengitide

PURPOSE

Fit-for-purpose pharmacodynamic biomarkers could expedite development of combination antiangiogenic regimens. Plasma sVEGFR2 concentrations ([sVEGFR2]) mark sunitinib effects on the systemic vasculature. We hypothesized that cilengitide would impair microvasculature recovery during sunitinib withdrawal and could be detected through changes in [sVEGFR2].

EXPERIMENTAL DESIGN

Advanced solid tumor patients received 50 mg sunitinib daily for 14 days. For the next 14 days, patients were randomized to arm A (cilengitide 2,000 mg administered intravenously twice weekly) or arm B (no treatment). The primary endpoint was change in [sVEGFR2] between days 14 and 28. A candidate pharmacodynamic biomarker of cilengitide inhibition of integrin αvβ3, serum c-telopeptide collagen crosslinks (CTx), was also measured.

RESULTS

Of 21 patients, 14 (7 per arm) received all treatments without interruption and had all blood samples available for analysis. The mean change and SD of [sVEGFR2] for all sunitinib-treated patients was consistent with previous data. There was no significant difference in the mean change in [sVEGFR2] from days 14 to 28 between the arms [arm A: 2.8 ng/mL; 95% confidence interval (CI), 2.1-3.6 vs. arm B: 2.0 ng/mL; 95% CI, 0.72-3.4; P = 0.22, 2-sample t test]. Additional analyses suggested (i) prior bevacizumab therapy to be associated with unusually low baseline [sVEGFR2] and (ii) sunitinib causes measurable changes in CTx.

CONCLUSIONS

Cilengitide had no measurable effects on any circulating biomarkers. Sunitinib caused measurable declines in serum CTx. The properties of [sVEGFR2] and CTx observed in this study inform the design of future combination antiangiogenic therapy trials.

Lenvatinib in Advanced, Radioactive Iodine-Refractory, Differentiated Thyroid Carcinoma

Management options are limited for patients with radioactive iodine refractory, locally advanced, or metastatic differentiated thyroid carcinoma. Prior to 2015, sorafenib, a multitargeted tyrosine kinase inhibitor, was the only approved treatment and was associated with a median progression-free survival (PFS) of 11 months and overall response rate (ORR) of 12% in a phase III trial. Lenvatinib, a multikinase inhibitor with high potency against VEGFR and FGFR demonstrated encouraging results in phase II trials. Recently, the pivotal SELECT trial provided the basis for the FDA approval of lenvatinib as a second targeted therapy for these patients. Median PFS of 18.3 months in the lenvatinib group was significantly improved from 3.6 months in the placebo group, with an HR of 0.21 (95% confidence interval, 0.4-0.31; P < 0.0001). ORR was also significantly increased in the lenvatinib arm (64.7%) compared with placebo (1.5%). In this article, we will review the molecular mechanisms of lenvatinib, the data from preclinical studies to the recent phase III clinical trial, and the biomarkers being studied to further guide patient selection and predict treatment response.

Integrated genomic analysis suggests MLL3 is a novel candidate susceptibility gene for familial nasopharyngeal carcinoma

BACKGROUND

Little is known about genetic factors associated with nasopharyngeal carcinoma (NPC). To gain insight into NPC etiology, we performed whole exome sequencing on germline and tumor DNA from three closely related family members with NPC.

METHODS

The family was ascertained through the Pediatric Familial Cancer Clinic at The University of Chicago (Chicago, IL). The diagnosis of NPC was confirmed pathologically for each individual. For each sample sequenced, 97.3% of the exome was covered at 5×, with an average depth of 44×. Candidate germline and somatic variants associated with NPC were identified and prioritized using a custom pipeline.

RESULTS

We discovered 72 rare deleterious germline variants in 56 genes shared by all three individuals. Of these, only three are in previously identified NPC-associated genes, all of which are located within MLL3, a gene known to be somatically altered in NPC. One variant introduces an early stop codon in MLL3, which predicts complete loss-of-function. Tumor DNA analysis revealed somatic mutations and Epstein-Barr virus (EBV) integration events; none, however, were shared among all three individuals.

CONCLUSIONS

These data suggest that inherited mutations in MLL3 may have predisposed these three individuals from a single family to develop NPC, and may cooperate with individually acquired somatic mutations or EBV integration events in NPC etiology.

IMPACT

Our finding is the first instance of a plausible candidate high penetrance inherited mutation predisposing to NPC.

Ex vivo antibody-dependent cellular cytotoxicity inducibility predicts efficacy of cetuximab

We conducted in vitro studies and a clinical trial for patients with squamous cell carcinoma of the head and neck (SCCHN) to study the relationship between FcγRIIIa polymorphisms and antibody-dependent cellular cytotoxicity (ADCC). In vitro, FcγRIIIa genotype was correlated with ADCC and innate cytotoxicity using natural killer (NK) cells harvested from healthy donors. In the phase II study, patients with recurrent or metastatic SCCHN were treated with cetuximab (500 mg/m(2) i.v. every 2 weeks) and lenalidomide (25 mg daily). FcγRIIIa genotype and ex vivo ADCC were correlated with clinical response, progression-free survival (PFS), and overall survival (OS). In vitro, healthy donors with a FcγRIIIa 158-V allele demonstrated more effective ADCC against two colon cancer cell lines HT29 and SW480, mean cytotoxicity: FF 16.1%, VF/VV 24.3% (P = 0.015) and FF 11.7%, VF/VV 21.0% (P = 0.008), respectively. We observed a linear relationship between ADCC response and innate cytotoxicity. In the phase II trial, 40 patients received cetuximab and lenalidomide with median PFS of 7.2 weeks and OS of 16.4 weeks. Thirty-six patients had FcγRIIIa genotype: VV (2), VF (20), and FF (14), and 25 patients had sufficient NK-cell yield to perform ex vivo ADCC. FcγRIIIa genotype was not associated with any clinical outcomes. Patients mounting ex vivo ADCC response had a higher likelihood of stable disease (P = 0.01) and showed a trend toward increased PFS: 14 weeks versus 6.8 weeks, respectively (P = 0.13). Enhanced ex vivo ADCC and innate immunity responses were more predictive of clinical response than FcγRIIIa and may offer a functional assay to select patients suitable for cetuximab therapy.

Mechanisms of and therapeutic approaches for overcoming resistance to epidermal growth factor receptor (EGFR)-targeted therapy in squamous cell carcinoma of the head and neck (SCCHN)

The majority of squamous cell carcinoma of the head and neck (SCCHN) overexpress epidermal growth factor receptor (EGFR), which has been associated with poor treatment response and survival. However, only modest success has been achieved with the use of single agents that target EGFR, possibly due to primary and acquired resistance. This review will discuss key mechanisms of and therapeutic approaches to overcoming resistance to EGFR-targeted therapy in SCCHN. Recent preclinical and clinical investigations have demonstrated that other ErbB family receptors (eg, HER2 and HER3) and other horizontal resistance mechanisms, as well as activation of downstream signaling pathways, epigenetic events, and nuclear EGFR, are possible mediators of resistance to anti-EGFR therapeutics. Key downstream pathways that may be implicated in EGFR resistance include phosphatidylinositol-3-kinase/protein kinase B, vascular endothelial growth factor (VEGF), and mammalian target of rapamycin (mTOR). Multiple agents that target EGFR and other ErbB family members (ie, lapatinib, afatinib, and dacomitinib), as well as combination therapies that target EGFR and selected other pathways (eg, VEGF, mTOR, and c-Met) are being investigated clinically. In addition, several phase II and III trials continue to investigate strategies to enhance the efficacy of EGFR-targeted therapy in SCCHN.

Genetic profiling of advanced radioactive iodine-resistant differentiated thyroid cancer and correlation with axitinib efficacy

Biomarkers predicting which patients with advanced radioiodine-resistant differentiated thyroid cancer (DTC) may benefit from multi-kinase inhibitors are unavailable. We aimed to describe molecular markers in DTC that correlate with clinical outcome to axitinib. Pretreatment thyroid cancer blocks from 18 patients treated with axitinib were collected and genomic DNA was isolated. The OncoCarta™ Mutation Panel was used to test for 238 oncogenic mutations. Copy number of VEGFR1-3 and PIK3CA was determined using qPCR on enriched tumor samples. Genomic DNA was analyzed for all coding regions of VEGFR1-3 with custom primers. Protein expressions of VEGFR1-3, c-Met, and PIK3CA were evaluated with immunohistochemistry. Clinical response to axitinib, including best response (BR) and progression free survival (PFS), was ascertained from corresponding patients. Fisher's exact test and logistic regression models were used to correlate BR with molecular findings. Cox proportional hazards regression was used to correlate PFS with molecular defects. A total of 22 pathology samples (10 primary, 12 metastatic) were identified. In patients with 2 samples (n = 4), genetic results were concordant and only included once for analysis. Tumors from 4 patients (22%) harbored BRAF V600E mutations, 2 (11%) had KRAS mutations (G12A, G13D) and 2 (11%) had HRAS mutations (Q61R, Q61K). One metastatic sample with mutated KRAS also harbored a PIK3CA (H1047R) mutation. qPCR showed increased copy numbers of PIK3CA in 6 (33%) tumors, VEGFR1 in 0 (0%) tumors, VEGFR2 in 4 (22%) tumors, and VEGFR3 in 6 (33%) tumors. VEGFR sequencing was significant for a possibly damaging non-synonymous SNP in VEGFR2 (G539R) in 2 samples (11%), a possibly damaging SNP in VEGFR3 (E350V) in 1 sample (6%), and a potentially novel mutation in VEGFR2 (T439I) in 2 samples (11%). Immunohistochemistry (VEGFR1, -2, -3; c-MET; PIK3CA) revealed positive staining in the majority of samples. No significant relationship was seen between BR or PFS and the presence of molecular alterations. Molecular evaluation of DTC specimens did not predict clinical response to axitinib but our data were limited by sample size. We did identify molecular changes in VEGFR that should be further explored. While DTC is genetically heterogeneous, primary and metastatic lesions showed identical oncogenic alterations in four cases.

Afatinib efficacy against squamous cell carcinoma of the head and neck cell lines in vitro and in vivo

Epidermal growth factor receptor (EGFR) inhibitors have demonstrated efficacy in squamous cell carcinoma of the head and neck (SCCHN). In addition to EGFR, other ErbB family members are expressed and activated in SCCHN. Afatinib is an ErbB family blocker that has been approved for treating patients with EGFR-mutated nonsmall cell lung cancer. We sought to determine the efficacy of afatinib in preclinical models and compare this to other EGFR-targeted agents. Afatinib efficacy was characterized in a panel of ten SCCHN cell lines and found to be most effective against cell lines amplified for EGFR. Afatinib had lower IC(50) values than did gefitinib against the same panel. Two EGFR-amplified cell lines that are resistant to gefitinib are sensitive to afatinib. Cetuximab was not found to have a synergistic effect with afatinib either in vitro or in vivo. Both afatinib and cetuximab were effective in tumor xenograft model. Afatinib is an effective agent in SCCHN especially in models with EGFR amplification.

Comparison of outcomes of locoregionally advanced oropharyngeal and non-oropharyngeal squamous cell carcinoma over two decades

BACKGROUND

Human papillomavirus (HPV) has emerged as a causative agent and positive prognostic factor for oropharyngeal (OP) head and neck squamous cell cancer (HNSCC). This prompts inquiry into whether therapy improvements or increasing incidence of HPV drives the apparent improvements in HNSCC outcomes observed in non-randomized clinical trials.

PATIENTS AND METHODS

We reviewed all locoregionally advanced HNSCC patients treated with chemotherapy and radiation in prospective institutional trials at a single institution. Patients were divided into three groups (1, 2, 3) according to treatment time period (1993-1998, 1999-2003, 2004-2010, respectively). We reasoned that if a favorable trend was observed over time in OP but not non-OP patients, HPV status may be confounding treatment effects, whereas this would be unlikely if both subgroups improved over time.

RESULTS

Four hundred and twenty-two patients were identified with OP (55.7%) and non-OP (44.3%) HNSCC. Five-year OP overall survival (OS) improved from 42.3% (group 1) to 72.5% (group 2), and 78.4% (group 3), adjusted P = 0.0084. Non-OP 5-year OS was 51.0% (group 1), 58.8% (group 2), and 66.3% (group 3), adjusted P = 0.51. Five-year recurrence-free survival (RFS) improved for OP groups from 42.3% to 68.4% to 75.8% (adjusted P = 0.017). Non-OP 5-year RFS was 42.9%, 53.6%, and 61.7% for sequential groups (adjusted P = 0.30). Five-year OP distant failure-free survival (DFFS) improved from 42.3% to 71.1% to 77.8% (adjusted P = 0.011). Five-year non-OP DFFS was 46.9%, 57.1%, and 66.0% for sequential groups (adjusted P = 0.38).

CONCLUSIONS

Over the past two decades, OP HNSCC outcomes improved significantly, while non-OP outcomes only trended toward improvement. Although our patients are not stratified by HPV status, improving OP outcomes are likely at least partly due to the increasing HPV incidence. These data further justify trial stratification by HPV status, investigations of novel approaches for carcinogen-related HNSCC, and current de-intensification for HPV-related HNSCC.

Aspiration pneumonia after concurrent chemoradiotherapy for head and neck cancer

BACKGROUND

Aspiration pneumonia represents an under-reported complication of chemoradiotherapy in patient with head and neck cancer. The objective of the current study was to evaluate the incidence, risk factors, and mortality of aspiration pneumonia in a large cohort of patients with head and neck cancer who received concurrent chemoradiotherapy.

METHODS

Patients who had head and neck cancer diagnosed between 2000 and 2009 were identified from the Surveillance, Epidemiology, and End Results-Medicare database. Aspiration pneumonia was identified from Medicare billing claims. The cumulative incidence, risk factors, and survival after aspiration pneumonia were estimated and compared with a noncancer population.

RESULTS

Of 3513 patients with head and neck cancer, 801 developed aspiration pneumonia at a median of 5 months after initiating treatment. The 1-year and 5-year cumulative incidence of aspiration pneumonia was 15.8% and 23.8%, respectively, for patients with head and neck cancer and 3.6% and 8.7%, respectively, for noncancer controls. Among the patients with cancer, multivariate analysis identified independent risk factors (P < .05) for aspiration pneumonia, including hypopharyngeal and nasopharyngeal tumors, male gender, older age, increased comorbidity, no surgery before radiation, and care received at a teaching hospital. Among the patients with cancer who experienced aspiration pneumonia, 674 (84%) were hospitalized; and, of these, 301 (45%) were admitted to an intensive care unit. The 30-day mortality rate after hospitalization for aspiration pneumonia was 32.5%. Aspiration pneumonia was associated with a 42% increased risk of death (hazard ratio, 1.42; P < .001) after controlling for confounders.

CONCLUSIONS

The current results indicated that nearly 25% of elderly patients will develop aspiration pneumonia within 5 years after receiving chemoradiotherapy for head and neck cancer. A better understanding of mitigating factors will help identify patients who are at risk for this potentially lethal complication.

Targeting the PI3K/AKT/mTOR pathway in squamous cell carcinoma of the head and neck

Despite recent advances in novel therapies, the prognosis for patients with squamous cell carcinoma of the head and neck (SCCHN) remains poor. Progress in understanding the biology of cancer has led to the development of personalized therapy targeted at blocking defective signaling pathways of cancer cells. These drugs aim to act selectively to reduce the adverse effects associated with systemic therapy. Cetuximab (Erbitux®), an anti-epidermal growth factor receptor gene (EGFR)-targeted agent, is the only approved targeted therapy for patients with SCCHN. However, resistance to EGFR therapy remains a major obstacle to achieving a positive clinical outcome with cetuximab. Other therapies that offer better clinical outcomes in patients with advanced SCCHN are urgently needed. The phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin pathway, which is downstream of EGFR, has also been implicated in SCCHN development and progression, and therefore, targeting this pathway offers another rational treatment approach. This review discusses the potential role of PI3K pathway inhibitors in the treatment of patients with advanced SCCHN, both alone and in combination with other therapies.

Integrative analysis of head and neck cancer identifies two biologically distinct HPV and three non-HPV subtypes

PURPOSE

Current classification of head and neck squamous cell carcinomas (HNSCC) based on anatomic site and stage fails to capture biologic heterogeneity or adequately inform treatment.

EXPERIMENTAL DESIGN

Here, we use gene expression-based consensus clustering, copy number profiling, and human papillomavirus (HPV) status on a clinically homogenous cohort of 134 locoregionally advanced HNSCCs with 44% HPV(+) tumors together with additional cohorts, which in total comprise 938 tumors, to identify HNSCC subtypes and discover several subtype-specific, translationally relevant characteristics.

RESULTS

We identified five subtypes of HNSCC, including two biologically distinct HPV subtypes. One HPV(+) and one HPV(-) subtype show a prominent immune and mesenchymal phenotype. Prominent tumor infiltration with CD8(+) lymphocytes characterizes this inflamed/mesenchymal subtype, independent of HPV status. Compared with other subtypes, the two HPV subtypes show low expression and no copy number events for EGFR/HER ligands. In contrast, the basal subtype is uniquely characterized by a prominent EGFR/HER signaling phenotype, negative HPV-status, as well as strong hypoxic differentiation not seen in other subtypes.

CONCLUSION

Our five-subtype classification provides a comprehensive overview of HPV(+) as well as HPV(-) HNSCC biology with significant translational implications for biomarker development and personalized care for patients with HNSCC.

A Phase II trial of axitinib in patients with various histologic subtypes of advanced thyroid cancer: long-term outcomes and pharmacokinetic/pharmacodynamic analyses

PURPOSE

Axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors, has shown activity in advanced thyroid cancer in a Phase II study. We report updated overall survival and pharmacokinetic/pharmacodynamic (PK/PD) analyses from the study.

METHODS

Patients (N = 60) with advanced thyroid cancer of any histology for whom iodine-131 ((131)I) failed to control the disease or (131)I was not appropriate therapy were administered axitinib 5 mg twice daily. Objective response rate (primary endpoint), duration of response, progression-free survival, overall survival, safety, and PK/PD relationships were assessed.

RESULTS

Objective response rate was 38 % [23 partial responses; 95 % confidence interval (CI) 26-52], and 18 (30 %) patients had stable disease lasting ≥16 weeks. Responses occurred in all histologic subtypes. With median follow-up of 34 months (95 % CI 32-37), median overall survival was 35 months (95 % CI 19-not estimable), median progression-free survival was 15 months (95 % CI 10-20), and median duration of response was 21 months (95 % CI 13-46). Most common Grade 3/4 treatment-related adverse events included hypertension (13 %), proteinuria (8 %), diarrhea (7 %), weight decrease (7 %), and fatigue (5 %). PK/PD analyses revealed trends toward greater tumor size reduction and response probability with higher axitinib plasma exposures.

CONCLUSIONS

Axitinib appears active and well tolerated in patients with various histologic subtypes of advanced thyroid cancer, demonstrating durable responses and long overall survival. Axitinib may be useful for the treatment of advanced thyroid cancer.

Rare occurrence of EGFRvIII deletion in head and neck squamous cell carcinoma

BACKGROUND

The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor and is overexpressed in up to 90% of head and neck squamous cell carcinoma (HNSCC) cases. The EGFR truncation mutation, EGFR variant III (EGFRvIII), harbors an in-frame deletion of exons 2-7 (801 bp) that leads to the constitutive activation of downstream signaling. EGFRvIII has been reported in ∼40% of glioblastomas (GBM), but its presence in HNSCC remains controversial.

METHODS

EGFRvIII deletion in 638 HNSCC samples was analyzed using: (i) quantitative Real-Time polymerase chain reaction (qRT-PCR) on 108 HNSCC samples with direct detection of the EGFRvIII breakpoint, (ii) RNA-Seq analysis on 7 HNSCC tumor tissues and 425 The Cancer Genome Atlas (TCGA) HNSCC samples, and (iii) immunohistochemistry (IHC) for EGFRvIII using an established antibody (L8A4) on a tissue microarray of 105 HNSCC samples.

RESULTS

qRT-PCR did not show the presence of EGFRvIII in any of the samples analyzed. Furthermore, we could not detect any EGFRvIII transcripts in the RNA-Seq data of the seven HNSCC samples. However, 2 samples out of 425 TCGA HNSCC samples had EGFRvIII specific reads. EGFRvIII IHC results were assessed as negative for all samples.

CONCLUSION

Our results firmly establish that EGFRvIII is very rare in HNSCC as only 2 out of 638 (0.31%) samples we analyzed overall, or 2 out of 540 (0.37%) using mRNA based approaches, were positive for EGFRvIII. EGFRvIII is extremely rare in HNSCC and the clinical significance remains unclear. We propose not to include EGFRvIII testing in regular diagnostic tests for HNSCC.

A randomized, phase II study of afatinib versus cetuximab in metastatic or recurrent squamous cell carcinoma of the head and neck

BACKGROUND

Afatinib is an oral, irreversible ErbB family blocker that has shown activity in epidermal growth factor receptor (EGFR)-mutated lung cancer. We hypothesized that the agent would have greater antitumor activity compared with cetuximab in recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) patients, whose disease has progressed after platinum-containing therapy.

PATIENTS AND METHODS

An open-label, randomized, phase II trial was conducted in 43 centers; 124 patients were randomized (1 : 1) to either afatinib (50 mg/day) or cetuximab (250 mg/m(2)/week) until disease progression or intolerable adverse events (AEs) (stage I), with optional crossover (stage II). The primary end point was tumor shrinkage before crossover assessed by investigator (IR) and independent central review (ICR).

RESULTS

A total of 121 patients were treated (61 afatinib, 60 cetuximab) and 68 crossed over to stage II (32 and 36 respectively). In stage I, mean tumor shrinkage by IR/ICR was 10.4%/16.6% with afatinib and 5.4%/10.1% with cetuximab (P = 0.46/0.30). Objective response rate was 16.1%/8.1% with afatinib and 6.5%/9.7% with cetuximab (IR/ICR). Comparable disease control rates were observed with afatinib (50%) and cetuximab (56.5%) by IR; similar results were seen by ICR. Most common grade ≥3 drug-related AEs (DRAEs) were rash/acne (18% versus 8.3%), diarrhea (14.8% versus 0%), and stomatitis/mucositis (11.5% versus 0%) with afatinib and cetuximab, respectively. Patients with DRAEs leading to treatment discontinuation were 23% with afatinib and 5% with cetuximab. In stage II, disease control rate (IR/ICR) was 38.9%/33.3% with afatinib and 18.8%/18.8% with cetuximab.

CONCLUSION

Afatinib showed antitumor activity comparable to cetuximab in R/M HNSCC in this exploratory phase II trial, although more patients on afatinib discontinued treatment due to AEs. Sequential EGFR/ErbB treatment with afatinib and cetuximab provided sustained clinical benefit in patients after crossover, suggesting a lack of cross-resistance.