Revisiting the concept of neoadjuvant and induction therapy in head and neck cancer with the advent of immunotherapy

The treatment of locally advanced (LA) Head and Neck Squamous Cell Carcinoma (HNSCC) is based on surgery followed by (chemo)radiation or on curative (chemo)radiation, depending on site and stage. Despite optimal locoregional treatment, about 50% of patients recur, with a huge impact on prognosis and substantial morbidity. The advent of immunotherapy (IT) with immune checkpoint inhibitors (ICIs) changed the paradigm of systemic treatment for recurrent/metastatic (RM) disease, showing activity, efficacy, and safety in both platinum-resistant and platinum-naïve patients. Such data led clinicians to design clinical trials to investigate early administration of IT even in the neoadjuvant or window of opportunity setting. In this review, we examine the published and ongoing trials investigating IT in the neoadjuvant setting for LA HNSCC. We address the current challenges of this treatment modality: optimal patient selection for neoadjuvant IT; choosing the appropriate systemic approach to enhance response without compromising tolerability; determining the ideal study endpoint, with a focus on major pathological response as a potential surrogate for overall survival; evaluating treatment response through imaging, considering the discordance between radiological and pathological assessments; and the influence of neoadjuvant IT response on locoregional treatment de-escalation strategies.

A systematic review of neoadjuvant and definitive immunotherapy in locally advanced head and neck squamous cell carcinoma

BACKGROUND

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) require multi-modality treatment. Immune checkpoint inhibitors (ICIs) are now standard of care in management of recurrent/metastatic HNSCC. However, its role in the definitive and neoadjuvant setting remains unclear.

METHODS

A literature search was conducted that included all articles investigating ICI in untreated locally advanced (LA) HNSCC. Data was extracted and summarised and rated for quality using the Cochrane risk of bias tool.

RESULTS

Of 1086 records, 29 met the final inclusion criteria. In both concurrent and neoadjuvant settings, the addition of ICI was safe and did not delay surgery or reduce chemoradiotherapy completion. In the concurrent setting, although ICI use demonstrates objective responses in all published trials, there has not yet been published data to with PFS or OS benefit. In the neoadjuvant setting, combination ICI resulted in superior major pathological response rates compared to ICI monotherapy without a significant increase adverse event profiles, but its value in improving survival is not clear. ICI efficacy appears to be affected by tumour characteristics, in particular PD-L1 combined positive score, HPV status and the tumour microenvironment.

CONCLUSIONS

There is significant heterogeneity of ICI use in untreated LA HNSCC with multiple definitive concurrent and neoadjuvant protocols used. Resultantly, conclusions regarding the survival benefits of adding ICI to standard-of-care regimens cannot be made. Further trials and translational studies are required to elucidate optimal ICI sequencing in the definitive setting as well as better define populations more suited for neoadjuvant protocols.

First-in-human phase 1/1b study to evaluate sitravatinib in patients with advanced solid tumors

Sitravatinib (MGCD516), a spectrum-selective receptor tyrosine kinase inhibitor targeting TAM (TYRO3, AXL, MERTK) and split kinase family receptors, has demonstrated preclinical anti-tumor activity and modulation of tumor microenvironment. This first-in-human phase 1/1b study included sitravatinib dose exploration and anti-tumor activity evaluation in selected patients with advanced solid tumors. Primary objectives included assessment of safety, pharmacokinetics and clinical activity of sitravatinib. Secondary objectives included identifying doses for further investigation and exploring molecular markers for patient selection. In phase 1, 32 patients received 10-200 mg, while phase 1b dose expansion comprised 161 patients (150 mg n = 99, 120 mg n = 62). Maximum tolerated dose was determined as 150 mg daily. Dose-limiting toxicity was reported in 4/28 evaluable phase 1 patients (three at 200 mg, one at 80 mg). In phase 1b, 120 mg was defined as the recommended dose due to tolerability. Treatment-related adverse events (TRAEs) were experienced by 174/193 patients (90.2%); grade ≥ 3 TRAEs in 103 patients (53.4%). Most common TRAEs were diarrhea, fatigue, hypertension and nausea; TRAEs led to treatment discontinuation in 26 patients (13.5%) and death in one patient. Sitravatinib was steadily absorbed and declined from plasma with a terminal elimination half-life of 42.1-51.5 h following oral administration. Overall objective response rate was 11.8% in phase 1b, 13.2% in patients with non-small cell lung cancer (NSCLC) and 4.2% in patients with NSCLC with prior checkpoint inhibitor experience. Sitravatinib demonstrated manageable safety and modest clinical activity in solid tumors. NCT02219711 (first posted August 14, 2014).

Neoadjuvant immunotherapy in head and neck cancer: Rationale, current evidence and future perspective

Immune-checkpoint inhibitors (ICIs) have shown to improve survival in the first- and second-line settings of recurrent/metastatic squamous cell carcinoma of the head and neck (SCCHN). In the past two years more than a dozen neoadjuvant IO studies have been reported in SCCHN, demonstrating the feasibility of one or a few doses of single agent or combination ICIs. This approach seems safe with no surgical delays due to toxicity in most of the studies with no new safety signals. Efficacy in terms of pathologic response appears promising both with single-agent ICIs and especially with chemo-IO combinations. The scientific rationale and current clinical evidence of neoadjuvant IO trials in SCCHN will be reviewed, including currently debated aspects such as the methodology for radiological and pathological evaluation as well as types and criteria for biomarker use in this setting. Finally, the future perspective of neoadjuvant IO in SCCHN will be approached.

Immunotherapy for head and neck cancer: from recurrent/metastatic disease to (neo)adjuvant treatment in surgically resectable tumors

PURPOSE OF REVIEW

We aim to summarize the current evidence on the role of immune checkpoint inhibitors in the (neo)adjuvant treatment of squamous cell carcinoma of the head and neck (HNSCC), with a particular focus on surgically treated patients.

RECENT FINDINGS

Pembrolizumab +/- chemotherapy improves the outcome in patients with previously untreated recurrent/metastatic HNSCC. Nivolumab is superior to chemotherapy after platinum failure. The addition of avelumab to chemoradiation failed to improve the outcome in patients with locally advanced HNSCC. Neoadjuvant presurgical programmed cell death 1 receptor (PD-1) blockade is safe and associated with encouraging overall response rate. KEYNOTE-689 randomizes patients with resectable stage III/IVA HNSCC to surgery and adjuvant standard of care +/- neoadjuvant and adjuvant pembrolizumab. ADHERE assigns surgically treated HNSCC at high risk of recurrence to chemoradiotherapy (CRT) and either durvalumab or placebo. MK-3475-689 evaluates the role of pembrolizumab in patients with resectable HNSCC. NIVOPOSTOP evaluates the addition of nivolumab to CRT in patients with surgically treated pStage III/IV HNSCC or pT3N1/pT4N1 oropharyngeal cancer with at least 20 packs/year at high risk of relapse.

SUMMARY

Multiple trials are currently evaluating the role of immunotherapy in HNSCC amenable to surgery. Neoadjuvant presurgical PD-1 blockade is feasible and safe and is associated with an encouraging overall response rate.