Long-term results from a clinical study of xevinapant plus chemoradiotherapy in people with high-risk locally advanced squamous cell carcinoma of the head and neck: a plain language summary.

WHAT IS THIS SUMMARY ABOUT?: Squamous cell carcinoma of the head and neck (SCCHN) is the most common type of head and neck cancer. About half of the people with locally advanced (LA) SCCHN will have surgery to remove their cancer. For people who do not have surgery, chemoradiotherapy is the standard treatment, with the aim of fully removing the cancer. However, in many people, this treatment does not completely kill the cancer. This summary presents the main results of a phase 2 study of a medicine called xevinapant, which is under investigation as a potential future medicine for people with this type of cancer. WHAT DID THE RESEARCHERS WANT TO FIND OUT?: In this study, researchers wanted to find out whether xevinapant plus chemoradiotherapy could stop the cancer from growing back or getting worse in the years after treatment completion in people with LA SCCHN. They also looked at whether people with this type of cancer had side effects from taking this medicine. Short-term results were collected 18 months after treatment with chemoradiotherapy ended. These results showed that people who received xevinapant plus chemoradiotherapy were less likely to have their cancer grow back, or get worse in the part of the body where it was first found, than people who received liquid placebo-which looked and tasted the same as the active medicine (in this case, xevinapant), but did not contain any medicine-plus chemoradiotherapy. Researchers then continued to collect information for a longer amount of time (at least 3 years). They wanted to see if treatment with xevinapant plus chemoradiotherapy was stopping the cancer from growing back or getting worse and helping people live longer. After this, people were monitored for a further 2 years to see if they were alive 5 years after treatment. WHAT WERE THE MAIN FINDINGS OF THE STUDY?: The results showed that people with this type of cancer who were treated with xevinapant plus chemoradiotherapy were less likely to die, lived longer on average, and were less likely to have their cancer get worse. A phase 3 study, named TrilynX, in a larger group of people, is currently taking place to confirm the results of this study. Clinical Trial Registration: NCT02022098 (Debio 1143-201 Dose-finding and Efficacy Phase I/II Trial) (ClinicalTrials.gov).

Extended follow-up of a phase 2 trial of xevinapant plus chemoradiotherapy in high-risk locally advanced squamous cell carcinoma of the head and neck: a randomised clinical trial.

INTRODUCTION: We report long-term efficacy and overall survival (OS) results from a randomised, double-blind, phase 2 study (NCT02022098) investigating xevinapant plus standard-of-care chemoradiotherapy (CRT) vs. placebo plus CRT in 96 patients with unresected locally advanced squamous cell carcinoma of the head and neck (LA SCCHN). METHODS: Patients were randomised 1:1 to xevinapant 200 mg/day (days 1-14 of a 21-day cycle for 3 cycles), or matched placebo, plus CRT (cisplatin 100 mg/m2 every 3 weeks for 3 cycles plus conventional fractionated high-dose intensity-modulated radiotherapy [70 Gy/35 F, 2 Gy/F, 5 days/week for 7 weeks]). Locoregional control, progression-free survival, and duration of response after 3 years, long-term safety, and 5-year OS were assessed. RESULTS: The risk of locoregional failure was reduced by 54% for xevinapant plus CRT vs. placebo plus CRT but did not reach statistical significance (adjusted hazard ratio [HR] 0.46; 95% CI, 0.19-1.13; P = .0893). The risk of death or disease progression was reduced by 67% for xevinapant plus CRT (adjusted HR 0.33; 95% CI, 0.17-0.67; P = .0019). The risk of death was approximately halved in the xevinapant arm compared with placebo (adjusted HR 0.47; 95% CI, 0.27-0.84; P = .0101). OS was prolonged with xevinapant plus CRT vs. placebo plus CRT; median OS not reached (95% CI, 40.3-not evaluable) vs. 36.1 months (95% CI, 21.8-46.7). Incidence of late-onset grade ≥3 toxicities was similar across arms. CONCLUSIONS: In this randomised phase 2 study of 96 patients, xevinapant plus CRT demonstrated superior efficacy benefits, including markedly improved 5-year survival in patients with unresected LA SCCHN.

Phase I Trial of Debio 1143, an Antagonist of Inhibitor of Apoptosis Proteins, Combined with Cisplatin Chemoradiotherapy in Patients with Locally Advanced Squamous Cell Carcinoma of the Head and Neck.

PURPOSE: Debio 1143 is an oral antagonist of inhibitor of apoptosis proteins, which enhances tumor response with concomitant chemoradiotherapy. Addition of Debio 1143 to cisplatin-based chemoradiotherapy in locally advanced squamous cell carcinomas of the head and neck (LA-SCCHN) was evaluated in a phase I/II study to determine the MTD and recommended phase II dose (RP2D). Here, phase I results are reported. PATIENTS AND METHODS: Treatment-naïve patients with LA-SCCHN (stages III/IVA/IVB) received Debio 1143 (100, 200, 300 mg/day), for 14 days every 3 weeks, with cisplatin (100 mg/m², every 3 weeks), for three cycles, and concomitant conventional fractionation radiotherapy (70 Gy/7 weeks). Dose-limiting toxicity (DLT) was evaluated over 9 weeks using continual reassessment. RESULTS: Fourteen patients were treated/evaluable for DLT. Median age was 64.5 years, and all patients were current/former smokers. Primary tumors were hypopharynx, oropharynx (all human papillomavirus/p16 negative), larynx, and oral cavity. Two of six patients at 200 mg/day had DLT (grade 3 tubular necrosis, grade 3 aspartate aminotransferase/alanine aminotransferase increase, grade 4 febrile neutropenia, and grade 3 lipase increase), which was considered the MTD and RP2D. Common grade 3-4 adverse events were dysphagia (36%) and mucositis (29%). Laboratory abnormalities were frequent and generally mild, including anemia, white blood cell decrease, and increased creatinine. Addition of Debio 1143 did not compromise chemotherapy administration. Overall locoregional control rate at 18 months was 85%. Overall response rate was 85%, including 69% complete responses. Progression-free survival rate at 24 months was 74%. CONCLUSIONS: The RP2D of Debio 1143 is 200 mg/day for 14 days, every 3 weeks, when combined with concomitant high-dose cisplatin chemoradiotherapy in LA-SCCHN. Debio 1143 addition to chemoradiotherapy was safe and manageable. Preliminary efficacy is encouraging and supports further development.

Debio 1143 and high-dose cisplatin chemoradiotherapy in high-risk locoregionally advanced squamous cell carcinoma of the head and neck: a double-blind, multicentre, randomised, phase 2 study.

BACKGROUND: Debio 1143 is an orally available antagonist of inhibitor of apoptosis proteins with the potential to enhance the antitumour activity of cisplatin and radiotherapy. The radiosensitising effect of Debio 1143 is mediated through caspase activation and TNF, IFNγ, CD8 T cell-dependent pathways. We aimed to investigate the efficacy and safety of Debio 1143 in combination with standard chemoradiotherapy in patients with high-risk locally advanced squamous cell carcinoma of the head and neck. METHODS: This double-blind, multicentre, randomised, phase 2 study by the French Head and Neck Radiotherapy Oncology Group (GORTEC) was run at 19 hospitals in France and Switzerland. Eligible patients were aged 18-75 years with locoregionally advanced, squamous cell carcinoma of the head and neck (characterised as non-metastatic, measurable stage III, IVa, or IVb [limited to T ≥2, N0-3, and M0] disease), Eastern Cooperative Oncology Group performance status of 0 or 1, a history of heavy tobacco smoking (>10 pack-years) with no previous or current treatment for invasive head and neck cancer, and no previous treatment with inhibitor of apoptosis protein antagonists. Patients were randomly assigned (1:1) to receive oral Debio 1143 (200 mg per day on days 1-14 of 21-day cycles, for three cycles) or oral placebo (20 mg/mL, administered at the same dosing schedule) using a stochastic minimisation technique according to node involvement and primary tumour site, and HPV-16 status in patients with an oropharyngeal primary tumour site. All patients received standard high-dose cisplatin chemoradiotherapy. The primary endpoint was the proportion of patients with locoregional control 18 months after chemoradiotherapy, analysed in the intention-to-treat population (primary analysis), and repeated in the per-protocol population. Responses were assessed according to Response Evaluation Criteria in Solid Tumors (version 1.1). This trial is registered with ClinicalTrials.gov, NCT02022098, and is still active but not recruiting. FINDINGS: Between Jan 25, 2016, and April 24, 2017, 48 patients were randomly assigned to the Debio 1143 group and 48 to the placebo group (one patient in the placebo group did not receive the study drug and was not included in the safety analysis). Median duration of follow-up was 25·0 months (IQR 19·6-29·4) in the Debio 1143 group and 24·2 months (6·6-26·8) in the placebo group. Locoregional control 18 months after chemoradiotherapy was achieved in 26 (54%; 95% CI 39-69) of 48 patients in the Debio 1143 group versus 16 (33%; 20-48) of 48 patients in the placebo group (odds ratio 2·69 [95% CI 1·13-6·42], p=0·026). Grade 3 or worse adverse events were reported in 41 (85%) of 48 patients in the Debio 1143 group and in 41 (87%) of 47 patients in the placebo group. The most common grade 3-4 adverse events were dysphagia (in 24 [50%] patients in the Debio 1143 group vs ten [21%] in the placebo group), mucositis (in 15 [31%] vs ten [21%]), and anaemia (in 17 [35%] vs 11 [23%]). Serious treatment-emergent adverse events were recorded in 30 (63%) of 48 patients in the Debio 1143 group and 28 (60%) of 47 in the placebo group. In the placebo group, two (4%) deaths were due to adverse events (one multiple organ failure and one asphyxia; neither was considered to be related to treatment). No deaths due to adverse events occurred in the Debio 1143 group. INTERPRETATION: To our knowledge, this is the first treatment regimen to achieve superior efficacy in this disease setting against a high-dose cisplatin chemoradiotherapy comparator in a randomised trial. These findings suggest that inhibition of inhibitor of apoptosis proteins is a novel and promising approach in this poor prognostic population and warrant confirmation in a phase 3 study with the aim of expanding the therapeutic options for these patients. FUNDING: Debiopharm.

Antigen Availability and DOCK2-Driven Motility Govern CD4+ T Cell Interactions with Dendritic Cells In Vivo.

Parenchymal migration of naive CD4+ T cells in lymph nodes (LNs) is mediated by the Rac activator DOCK2 and PI3Kγ and is widely assumed to facilitate efficient screening of dendritic cells (DCs) presenting peptide-MHCs (pMHCs). Yet how CD4+ T cell motility, DC density, and pMHC levels interdependently regulate such interactions has not been comprehensively examined. Using intravital imaging of reactive LNs in DC-immunized mice, we show that pMHC levels determined the occurrence and timing of stable CD4+ T cell-DC interactions. Despite the variability in interaction parameters, ensuing CD4+ T cell proliferation was comparable over a wide range of pMHC levels. Unexpectedly, decreased intrinsic motility of DOCK2-/- CD4+ T cells did not impair encounters with DCs in dense paracortical networks and, instead, increased interaction stability, whereas PI3Kγ deficiency had no effect on interaction parameters. In contrast, intravital and whole-organ imaging showed that DOCK2-driven T cell motility was required to detach from pMHClow DCs and to find rare pMHChigh DCs. In sum, our data uncover flexible signal integration by scanning CD4+ T cells, suggesting a search strategy evolved to detect low-frequency DCs presenting high cognate pMHC levels.

CD69 modulates sphingosine-1-phosphate-induced migration of skin dendritic cells.

In this study, we have investigated the role of CD69, an early inducible leukocyte activation receptor, in murine dendritic cell (DC) differentiation, maturation, and migration. Skin DCs and DC subsets present in mouse lymphoid organs express CD69 in response to maturation stimuli. Using a contact sensitization model, we show that skin DCs migrated more efficiently to draining lymph nodes (LNs) in the absence of CD69. This was confirmed by subcutaneous transfer of CD69-/- DCs, which presented an increased migration to peripheral LNs. Two-photon microscopy analysis showed that once DCs reached the LNs, CD69 deficiency did not alter DC interstitial motility in the LNs. Chemotaxis to sphingosine-1-phosphate (S1P) was enhanced in CD69-/- DCs compared with wild-type DCs. Accordingly, we detected a higher expression of S1P receptor type-1 (S1P(1)) by CD69-/- DCs, whereas S1P(3) expression levels were similar in wild-type and CD69-/- DCs. Moreover, in vivo treatment with S1P analogs SEW2871 and FTY720 during skin sensitization reduced skin DC migration to peripheral LNs. These results suggest that CD69 regulates S1P-induced skin DC migration by modulating S1P(1) function. Together, our findings increase our knowledge on DC trafficking patterns in the skin, enabling the development of new directed therapies using DCs for antigen (Ag) delivery.

Comprehensive analysis of lymph node stroma-expressed Ig superfamily members reveals redundant and nonredundant roles for ICAM-1, ICAM-2, and VCAM-1 in lymphocyte homing.

Although it is well established that stromal intercellular adhesion molecule-1 (ICAM-1), ICAM-2, and vascular cell adhesion molecule-1 (VCAM-1) mediate lymphocyte recruitment into peripheral lymph nodes (PLNs), their precise contributions to the individual steps of the lymphocyte homing cascade are not known. Here, we provide in vivo evidence for a selective function for ICAM-1 > ICAM-2 > VCAM-1 in lymphocyte arrest within noninflamed PLN microvessels. Blocking all 3 CAMs completely inhibited lymphocyte adhesion within PLN high endothelial venules (HEVs). Post-arrest extravasation of T cells was a 3-step process, with optional ICAM-1-dependent intraluminal crawling followed by rapid ICAM-1- or ICAM-2-independent diapedesis and perivascular trapping. Parenchymal motility of lymphocytes was modestly reduced in the absence of ICAM-1, while ICAM-2 and alpha4-integrin ligands were not required for B-cell motility within follicles. Our findings highlight nonredundant functions for stromal Ig family CAMs in shear-resistant lymphocyte adhesion in steady-state HEVs, a unique role for ICAM-1 in intraluminal lymphocyte crawling but redundant roles for ICAM-1 and ICAM-2 in lymphocyte diapedesis and interstitial motility.

CCL21 mediates CD4+ T-cell costimulation via a DOCK2/Rac-dependent pathway.

CD4(+) T cells use the chemokine receptor CCR7 to home to and migrate within lymphoid tissue, where T-cell activation takes place. Using primary T-cell receptor (TCR)-transgenic (tg) CD4(+) T cells, we explored the effect of CCR7 ligands, in particular CCL21, on T-cell activation. We found that the presence of CCL21 during early time points strongly increased in vitro T-cell proliferation after TCR stimulation, correlating with increased expression of early activation markers. CCL21 costimulation resulted in increased Ras- and Rac-GTP formation and enhanced phosphorylation of Akt, MEK, and ERK but not p38 or JNK. Kinase-dead PI3Kdelta(D910A/D910A) or PI3Kgamma-deficient TCR-tg CD4(+) T cells showed similar responsiveness to CCL21 costimulation as control CD4(+) T cells. Conversely, deficiency in the Rac guanine exchange factor DOCK2 significantly impaired CCL21-mediated costimulation in TCR-tg CD4(+) T cells, concomitant with impaired Rac- but not Ras-GTP formation. Using lymph node slices for live monitoring of T-cell behavior and activation, we found that G protein-coupled receptor signaling was required for early CD69 expression but not for Ca(2+) signaling. Our data suggest that the presence of CCL21 during early TCR signaling lowers the activation threshold through Ras- and Rac-dependent pathways leading to increased ERK phosphorylation.