Neoantigen-targeted CD8+ T cell responses with PD-1 blockade therapy.

Neoantigens are peptides derived from non-synonymous mutations presented by human leukocyte antigens (HLAs), which are recognized by antitumour T cells1-14. The large HLA allele diversity and limiting clinical samples have restricted the study of the landscape of neoantigen-targeted T cell responses in patients over their treatment course. Here we applied recently developed technologies15-17 to capture neoantigen-specific T cells from blood and tumours from patients with metastatic melanoma with or without response to anti-programmed death receptor 1 (PD-1) immunotherapy. We generated personalized libraries of neoantigen-HLA capture reagents to single-cell isolate the T cells and clone their T cell receptors (neoTCRs). Multiple T cells with different neoTCR sequences (T cell clonotypes) recognized a limited number of mutations in samples from seven patients with long-lasting clinical responses. These neoTCR clonotypes were recurrently detected over time in the blood and tumour. Samples from four patients with no response to anti-PD-1 also demonstrated neoantigen-specific T cell responses in the blood and tumour to a restricted number of mutations with lower TCR polyclonality and were not recurrently detected in sequential samples. Reconstitution of the neoTCRs in donor T cells using non-viral CRISPR-Cas9 gene editing demonstrated specific recognition and cytotoxicity to patient-matched melanoma cell lines. Thus, effective anti-PD-1 immunotherapy is associated with the presence of polyclonal CD8+ T cells in the tumour and blood specific for a limited number of immunodominant mutations, which are recurrently recognized over time.

Long-term avelumab in advanced non-small-cell lung cancer: summaries and post hoc analyses from JAVELIN Solid Tumor.

Background: This study examined patients with advanced non-small-cell lung cancer who received long-term avelumab (anti-PD-L1) in a large phase Ib trial (JAVELIN Solid Tumor). Methods: Patients receiving >2 years of avelumab were reviewed and exploratory descriptive analyses were conducted. Results: Individuals with varying baseline characteristics who had received up to 6 years of avelumab were reviewed. Overall, 37/340 (10.9%) had received ≥2 years of treatment; in this subgroup, best response was complete response in 5.4%, partial response in 59.5% and stable disease in 29.7%; 51.4% had continued treatment beyond disease progression. Conclusions: In this study, 11% of patients with advanced non-small-cell lung cancer received ≥2 years of avelumab treatment and experienced prolonged response or continued clinical benefit. Clinical Trial Registration: NCT02395172 (ClinicalTrials.gov).

Pembrolizumab plus cetuximab in patients with recurrent or metastatic head and neck squamous cell carcinoma: an open-label, multi-arm, non-randomised, multicentre, phase 2 trial.

BACKGROUND: Pembrolizumab (PD-1 inhibitor) and cetuximab (EGFR inhibitor) are active as single agents and in combination with cytotoxic chemotherapy for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). Given each drug's single agent activity and unique mechanism of action, we aimed to evaluate the anti-tumour activity of PD-1 blockade with EGFR inhibition in recurrent or metastatic HNSCC. METHODS: This study is an open-label, non-randomised, multi-arm, phase 2 trial done at four academic centres in the USA. Participants were required to have platinum-resistant or platinum-ineligible, recurrent or metastatic HNSCC, be at least 18 years old, have an Eastern Cooperative Oncology Group performance status 0-1, have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, and to have received no previous immunotherapy or EGFR inhibition. All participants received pembrolizumab 200 mg intravenously every 3 weeks, combined with an initial loading dose of cetuximab 400 mg/m2 intravenously followed by 250 mg/m2 intravenously weekly (21 day cycle). The primary endpoint was overall response rate defined as the proportion of participants with a partial or complete responses (per RECIST version 1.1) by 6 months in the intention-to-treat population. The safety population included all participants who received at least one dose of pembrolizumab. Herein, the final analysis of cohort 1 (no previous PD-1, PD-L1, or EGFR inhibition for recurrent or metastatic HNSCC) is reported. Three additional cohorts (two for participants with a previous response to immunotherapy followed by relapse or progression, with or without previous cetuximab exposure, and one for cutaneous HNSCC) will be reported separately once fully accrued. This study is registered with ClinicalTrials.gov, NCT03082534, and remains open as the three additional cohorts are actively accruing participants. FINDINGS: Between March 22, 2017, and July 16, 2019, 33 participants were enrolled to cohort 1. All 33 participants received at least one dose of pembrolizumab. Median follow-up duration was 7·3 months (IQR 3·9-10·9). By 6 months, the overall response rate was 45% (95% CI 28-62), with 15 of 33 participants achieving a partial response. The most common grade 3-4 treatment-related adverse event was oral mucositis (three [9%] of 33 participants), and serious treatment-related adverse events occurred in five (15%) participants. No treatment-related deaths occurred. INTERPRETATION: Pembrolizumab combined with cetuximab shows promising clinical activity for recurrent or metastatic HNSCC, and merits further investigation. FUNDING: Merck Sharp & Dohme.

Pegilodecakin as monotherapy or in combination with anti-PD-1 or tyrosine kinase inhibitor in heavily pretreated patients with advanced renal cell carcinoma: Final results of cohorts A, G, H and I of IVY Phase I study.

Interleukin (IL)-10 has anti-inflammatory and CD8+ T-cell-stimulating properties. Pegilodecakin (pegylated recombinant human IL-10) induces intratumoral antigen-specific CD8 + T-cells and upregulates IFNγ and major histocompatibility complexes (MHC) I and II. Pegilodecakin has single-agent activity with manageable toxicity in advanced renal cell carcinama (aRCC) (data cutoff 24 March 2016). Pegilodecakin with pembrolizumab or nivolumab revealed clinical activity in aRCC (data cutoff 1 July 2018). Here, we report for the first time the results of pegilodecakin+ pazopanib, and final results for monotherapy and long-term follow-up with pegilodecakin + anti-programmed cell death 1 (anti-PD-1) inhibitors (data cutoff 19 February 2019). Phase 1/1b multi-cohort dose escalation IVY study enrolled 353 patients. Sixty-six patients with aRCC were treated with pegilodecakin alone or with pazopanib or anti-PD-1 inhibitor in cohorts A, G, H and I (data cutoff 19 February 2019). Primary endpoints included safety and tolerability. Secondary endpoint was tumor response by immune-related response criteria (irRC). Pegilodecakin plus nivolumab or pembrolizumab yielded median progression-free survival (mPFS) of 13.9 months and 6-month PFS probability of 60%, 76% 1-year overall survival (OS) probability and 61% 2-year OS probability. Pegilodecakin monotherapy produced mPFS of 1.8 months, 6-month PFS probability 25%, 1-year OS 50%, and 2-year OS 17%. Median OS was not reached in both combinations. Objective response rates (ORRs) were 33% with pazopanib and 43% with anti-PD-1. Most common Grade 3/4 treatment-related adverse events included anemia, thrombocytopenia and hypertriglyceridemia. In these heavily pretreated renal cell carcinama cohorts of IVY, pegilodecakin+anti-PD-1 inhibitor showed promising clinical activity. Safety profile of pegilodecakin alone and with anti-PD-1 inhibitors was consistent as previously reported.

Immunologic and tumor responses of pegilodecakin with 5-FU/LV and oxaliplatin (FOLFOX) in pancreatic ductal adenocarcinoma (PDAC).

Background Treatment options for pancreatic ductal adenocarcinoma (PDAC) are limited and checkpoint blockade inhibitors have been disappointing in this disease. Pegilodecakin has demonstrated single agent anti-tumor activity in immune-sensitive tumors. Phase 1 and preclinical data indicate synergy of pegilodecakin with 5-FU and platins. We assessed the safety and activity of pegilodecakin+FOLFOX in patients with PDAC. Methods IVY (NCT02009449) was an open-label phase 1b trial in the United States. Here we report on all enrolled patients from cohort C. Heavily pretreated patients were treated with pegilodecakin (self-administered subcutaneously daily at 2.5, 5, or 10 µg/kg) + 5-flurouracil/leucovorin/oxaliplatin (FOLFOX), dosed per manufacturers prescribing information, until tumor progression. Eligible patients had measurable disease per immune-related response criteria (irRC), were ≥ 18 years of age, and had ECOG performance status of 0 or 1. Patients were evaluated for primary(safety) and secondary (tumor response per irRC) endpoints. Results From 5 August 2014-12 July 2016, 39 patients enrolled in cohort C. All patients were evaluable for safety. In this advanced population, regimen had manageable toxicities with no immune-related adverse events (irAEs) greater than grade 1. The most common grade 3/4/5 TEAEs were thrombocytopenia (21[53.8%] of 39) and anemia (17[43.6%] of 39). In evaluable PDAC patients, the best overall response of pegilodecakin+FOLFOX was 3(14%) with CRs in 2(9%) patients. Conclusions Pegilodecakin+FOLFOX had an acceptable tolerability profile in PDAC, with no substantial irAEs seen, and promising efficacy with the combination yielding a 2-year OS of 24% (95% CI 10-42). These data led to the phase 3 study with pegilodecakin+FOLFOX as second-line therapy of PDAC (SEQUOIA).

Cemiplimab in locally advanced cutaneous squamous cell carcinoma: results from an open-label, phase 2, single-arm trial.

BACKGROUND: Cemiplimab has shown substantial antitumour activity in patients with metastatic cutaneous squamous cell carcinoma. Patients with locally advanced cutaneous squamous cell carcinoma have poor prognosis with conventional systemic therapy. We present a primary analysis of the safety and antitumour activity of cemiplimab in patients with locally advanced cutaneous squamous cell carcinoma. METHODS: This pivotal open-label, phase 2, single-arm trial was done across 25 outpatient clinics, primarily at academic medical centres, in Australia, Germany, and the USA. Eligible patients (aged ≥18 years with histologically confirmed locally advanced cutaneous squamous cell carcinoma and an Eastern Cooperative Oncology Group performance status of 0-1) received cemiplimab 3 mg/kg intravenously over 30 min every 2 weeks for up to 96 weeks. Tumour measurements were done every 8 weeks. The primary endpoint was objective response, defined as the proportion of patients with complete or partial response, according to independent central review as per Response Evaluation Criteria in Solid Tumors version 1.1 for radiological scans and WHO criteria for medical photography. Data cutoff was Oct 10, 2018, when the fully enrolled cohort reached the prespecified timepoint for the primary analysis. Analyses were done as per the intention-to-treat principle. The safety analysis comprised all patients who received at least one dose of cemiplimab. This study is registered with ClinicalTrials.gov, number NCT02760498. FINDINGS: Between June 14, 2016, and April 25, 2018, 78 patients were enrolled and treated with cemiplimab. The median duration of study follow-up was 9·3 months (IQR 5·1-15·7) at the time of data cutoff. An objective response was observed in 34 (44%; 95% CI 32-55) of 78 patients. The best overall response was ten (13%) patients with a complete response and 24 (31%) with a partial response. Grade 3-4 treatment-emergent adverse events occurred in 34 (44%) of 78 patients; the most common were hypertension in six (8%) patients and pneumonia in four (5%). Serious treatment-emergent adverse events occurred in 23 (29%) of 78 patients. One treatment-related death was reported that occurred after onset of aspiration pneumonia. INTERPRETATION: Cemiplimab showed antitumour activity and an acceptable safety profile in patients with locally advanced cutaneous squamous cell carcinoma for whom there was no widely accepted standard of care. FUNDING: Regeneron Pharmaceuticals and Sanofi.

Tipifarnib in recurrent, metastatic HRAS-mutant salivary gland cancer.

BACKGROUND: To the authors' knowledge, there are no approved therapies for recurrent, metastatic (R/M) salivary gland carcinoma (SGC), but molecularly targeted therapies warrant ongoing investigation. In the current study, the authors have reported on the efficacy of tipifarnib in patients with aggressive HRAS-mutant, R/M SGC. METHODS: The current prospective, nonrandomized, multicenter, international cohort study involved 8 centers and was conducted from May 2015 to June 2019. The median follow-up was 22 months (range, 6-55 months). Subjects with HRAS-mutant R/M SGC (any histology) and disease progression within the last 6 months were enrolled. Tipifarnib was dosed orally twice daily. The authors determined the objective response rate using Response Evaluation Criteria in Solid Tumors (version 1.1), duration of response, and molecular predictors of response. RESULTS: A total of 13 patients with R/M SGC were enrolled; all had received prior systemic therapy (1-3 regimens). One objective response was observed; an additional 7 of 12 evaluable patients (58%) had stable disease as their best response with a median duration of 9 months (range, 3-14 months). Five of 7 patients had >10% tumor regression and 6 of 7 had stable disease lasting >6 months. Q61R was the most frequent activating HRAS mutation noted (7 of 13 patients; 54%), but gene variant and allele frequency did not correlate with outcomes. The median progression-free survival was 7 months (95% confidence interval, 5.9-10.1 months), and the median overall survival was 18 months (95% confidence interval, 9.6-22.4 months) with approximately 58.6% of patients alive at 1 year. Survival was similar regardless of HRAS mutant variant or co-occurring PIK3CA alterations. No participant discontinued treatment because of toxicity. CONCLUSIONS: Tipifarnib resulted in modest clinical activity with a promising disease control rate among patients with HRAS-mutant, R/M SGC who developed disease progression within the last 6 months.

Pegilodecakin combined with pembrolizumab or nivolumab for patients with advanced solid tumours (IVY): a multicentre, multicohort, open-label, phase 1b trial.

BACKGROUND: IL-10 has anti-inflammatory and CD8+ T-cell stimulating activities. Pegilodecakin (pegylated IL-10) is a first-in-class, long-acting IL-10 receptor agonist that induces oligoclonal T-cell expansion and has single-agent activity in advanced solid tumours. We assessed the safety and activity of pegilodecakin with anti-PD-1 monoclonal antibody inhibitors in patients with advanced solid tumours. METHODS: We did a multicentre, multicohort, open-label, phase 1b trial (IVY) at 12 cancer research centres in the USA. Patients were assigned sequentially into cohorts. Here, we report on all enrolled patients from two cohorts treated with pegilodecakin combined with anti-PD-1 inhibitors. Eligible patients were aged at least 18 years with histologically or cytologically confirmed advanced malignant solid tumours refractory to previous therapies, and an Eastern Cooperative Oncology Group performance status of 0 or 1. Patients with uncontrolled infectious diseases were excluded. Pegilodecakin was provided in single-use 3 mL vials and was self-administered subcutaneously by injection at home at 10 µg/kg or 20 µg/kg once per day in combination with pembrolizumab (2 mg/kg every 3 weeks or 200 mg every 3 weeks) or nivolumab (3 mg/kg every 2 weeks or 240 mg every 2 weeks or 480 mg every 4 weeks at the approved dosing), both of which were given intravenously at the study site. Patients received pembrolizumab or nivolumab with pegilodecakin until disease progression, toxicity necessitating treatment discontinuation, patient withdrawal of consent, or study end. The primary endpoints were safety and tolerability, assessed in all patients enrolled in the study who received any amount of study medication including at least one dose of pegilodecakin, and pharmacokinetics (previously published). Secondary endpoints included objective response by immune-related response criteria in all patients who were treated and had evaluable measurements. The study is active but no longer recruiting, and is registered with ClinicalTrials.gov, NCT02009449. FINDINGS: Between Feb 13, 2015, and Sept 12, 2017, 111 patients were enrolled in the two cohorts. 53 received pegilodecakin plus pembrolizumab, and 58 received pegilodecakin plus nivolumab. 34 (31%) of 111 patients had non-small-cell lung cancer, 37 (33%) had melanoma, and 38 (34%) had renal cell carcinoma; one (<1%) patient had triple-negative breast cancer and one (<1%) had bladder cancer. Data cutoff was July 1, 2018. Median follow-up was 26·9 months (IQR 22·3-31·5) for patients with non-small-cell lung cancer, 33·0 months (29·2-35·1) for those with melanoma, and 22·7 months (20·9-27·0) for those with renal cell carcinoma. At least one treatment-related adverse event occurred in 103 (93%) of 111 patients. Grade 3 or 4 events occurred in 73 (66%) of 111 patients (35 [66%] of 53 in the pembrolizumab group and 38 [66%] of 58 in the nivolumab group), the most common of which were anaemia (12 [23%] in the pembrolizumab group and 16 [28%] in the nivolumab group), thrombocytopenia (14 [26%] in the pembrolizumab group and 12 [21%] in the nivolumab group), fatigue (11 [21%] in the pembrolizumab group and 6 [10%] in the nivolumab group) and hypertriglyceridaemia (three [6%] in the pembrolizumab group and eight [14%] in the nivolumab group). There were no fatal adverse events determined to be related to the study treatments. Of the patients evaluable for response, objective responses were 12 (43%) of 28 (non-small-cell lung cancer), three (10%) of 31 (melanoma), and 14 (40%) of 35 (renal cell carcinoma). INTERPRETATION: In this patient population, pegilodecakin with anti-PD-1 monoclonal antibodies had a manageable toxicity profile and preliminary antitumour activity. Pegilodecakin with pembrolizumab or nivolumab could provide a new therapeutic opportunity for previously treated patients with renal cell carcinoma and non-small-cell carcinoma. FUNDING: ARMO BioSciences, a wholly owned subsidiary of Eli Lilly and Company.

Safety profile of avelumab in patients with advanced solid tumors: A pooled analysis of data from the phase 1 JAVELIN solid tumor and phase 2 JAVELIN Merkel 200 clinical trials.

BACKGROUND: Antibodies targeting the programmed death-ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) checkpoint may cause adverse events (AEs) that are linked to the mechanism of action of this therapeutic class and unique from those observed with conventional chemotherapy. METHODS: Patients with advanced solid tumors who were enrolled in the phase 1 JAVELIN Solid Tumor (1650 patients) and phase 2 JAVELIN Merkel 200 (88 patients) trials received avelumab, a human anti-PD-L1 IgG1 antibody at a dose of 10 mg/kg every 2 weeks. Treatment-related AEs (TRAEs) were graded using the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0). In post hoc analyses, immune-related AEs (irAEs) were identified via an expanded AE list and medical review, and infusion-related reactions (IRRs) occurring ≤2 days after infusion and symptoms occurring ≤1 day after infusion and resolving ≤2 days after onset were identified based on prespecified Medical Dictionary for Regulatory Activities (MedDRA) terms. RESULTS: Of the 1738 patients analyzed, grade ≥3 TRAEs occurred in 177 (10.2%); the most common were fatigue (17 patients; 1.0%) and IRR (10 patients; 0.6%). TRAEs led to discontinuation in 107 patients (6.2%) and death in 4 patients (0.2%). Grade ≥3 irAEs occurred in 39 patients (2.2%) and led to discontinuation in 34 patients (2.0%). IRRs or related symptoms occurred in 439 patients (25.3%; grade 3 in 0.5% [9 patients] and grade 4 in 0.2% [3 patients]). An IRR occurred at the time of first infusion in 79.5% of 439 patients who had an IRR, within the first 4 doses in 98.6% of 439 patients who had an IRR, and led to discontinuation in 35 patients (2.0%). CONCLUSIONS: Avelumab generally was found to be well tolerated and to have a manageable safety profile. A minority of patients experienced grade ≥3 TRAEs or irAEs, and discontinuation was uncommon. IRRs occurred mainly at the time of first infusion, and repeated events were infrequent. Cancer 2018;124:2010-7. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

Avelumab for patients with previously treated metastatic or recurrent non-small-cell lung cancer (JAVELIN Solid Tumor): dose-expansion cohort of a multicentre, open-label, phase 1b trial.

BACKGROUND: Avelumab, a human Ig-G1 monoclonal antibody targeting PD-L1 and approved in the USA for the treatment of metastatic Merkel cell carcinoma, has shown antitumour activity and an acceptable safety profile in patients with advanced solid tumours in a dose-escalation phase 1a trial. In this dose-expansion cohort of that trial, we assess avelumab treatment in a cohort of patients with advanced, platinum-treated non-small-cell lung cancer (NSCLC). METHODS: In this dose-expansion cohort of a multicentre, open-label, phase 1 study, patients with progressive or platinum-resistant metastatic or recurrent NSCLC were enrolled at 58 cancer treatment centres and academic hospitals in the USA. Eligible patients had confirmed stage IIIB or IV NSCLC with squamous or non-squamous histology, measurable disease by Response Evaluation Criteria In Solid Tumors version 1.1 (RECIST v1.1), tumour biopsy or archival sample for biomarker assessment, and Eastern Cooperative Oncology Group performance status 0 or 1, among other criteria. Patient selection was not based on PD-L1 expression or expression of other biomarkers, including EGFR or KRAS mutation or ALK translocation status. Patients received infusional avelumab monotherapy 10 mg/kg every 2 weeks until disease progression or toxicity. The primary objective was to assess safety and tolerability. This trial is registered with ClinicalTrials.gov, number NCT01772004; enrolment in this cohort is closed and the trial is ongoing. FINDINGS: Between Sept 10, 2013, and June 24, 2014, 184 patients were enrolled and initiated treatment with avelumab. Median follow-up duration was 8·8 months (IQR 7·2-11·9). The most common treatment-related adverse events of any grade were fatigue (46 [25%] of 184 patients), infusion-related reaction (38 [21%]), and nausea (23 [13%]). Grade 3 or worse treatment-related adverse events occurred in 23 (13%) of 184 patients; the most common (occurring in more than two patients) were infusion-related reaction (four [2%] patients) and increased lipase level (three [2%]). 16 (9%) of 184 patients had a serious adverse event related to treatment with avelumab, with infusion-related reaction (in four [2%] patients) and dyspnoea (in two [1%]) occurring in more than one patient. Serious adverse events irrespective of cause occurred in 80 (44%) of 184 patients. Those occurring in more than five patients (≥3%) were dyspnoea (ten patients [5%]), pneumonia (nine [5%]), and chronic obstructive pulmonary disease (six [3%]). Immune-related treatment-related events occurred in 22 patients (12%). Of 184 patients, 22 (12% [95% CI 8-18]) achieved a confirmed objective response, including one complete response and 21 partial responses. 70 (38%) had stable disease. Overall, 92 (50%) of 184 patients achieved disease control (they had a confirmed response or stable disease as their best overall response). One patient was initially thought to have died from grade 5 radiation pneumonitis during the study; however, this adverse event was subsequently regraded to grade 3 and the death was attributed to disease progression. INTERPRETATION: Avelumab showed an acceptable safety profile and antitumour activity in patients with progressive or treatment-resistant NSCLC, providing a rationale for further studies of avelumab in this disease setting. FUNDING: Merck KGaA and Pfizer.

Non-small cell lung cancer clinical trials requiring biopsies with biomarker-specific results for enrollment provide unique challenges.

BACKGROUND: Clinical trials in lung cancer increasingly require patients to provide fresh tumor tissue as a prerequisite to enrollment. The effects of this requirement on enrollment rates, enrollment durations, and patient selection have not been fully elucidated. METHODS: The authors retrospectively reviewed data generated by patients who consented to 1 or more interventional lung cancer clinical trials at the University of California-Los Angeles Jonsson Comprehensive Cancer Center between January 2013 and December 2014. Trials were considered to require a biopsy when enrollment was conditional on the procurement of tissue without intervening therapy between procurement and enrollment. RESULTS: In total, 311 patients underwent 368 screening incidents for 1 or more of 19 trials. Trials that required a new biopsy had a longer median screening duration (34 vs 14 days) than trials that did not require a biopsy (P < .001). Trials that required a biopsy had a greater screen failure rate (49.1% vs 26.5%; P < .001), which was largely driven by patients who did not undergo the required biopsy or lacked the required biomarker. Worsening performance status led to the majority of screen failures (56.5%) among biomarker-eligible patients. CONCLUSIONS: Although the scientific benefits of obtaining a new biopsy and requiring specific results for trial enrollment are clear, these requirements lead to a lengthening of the screening period, which, in some patients, is associated with clinical decline before enrollment. Implications for the interpretation of data from studies of this design should be explored. Cancer 2017;123:4800-7. © 2017 American Cancer Society.

Targeted Therapy for Melanoma.

Vemurafenib and dabrafenib, two potent tyrosine kinase inhibitors (TKIs) of the BRAF(V600E) kinase, are highly effective in the treatment of a BRAF (V600) -mutant metastatic melanoma. These are selective type I inhibitors (functional against the active conformation of the kinase) of the RAF kinases, which are key players in the mitogen-activated protein kinase (MAPK) pathway. BRAF (V600) mutations are present in approximately 7 % of all cancers, including high frequencies of mutations reported in 50 % of advanced melanomas and 100 % of hairy cell leukemias. As with most targeted therapies, resistance to BRAF inhibitors is an issue, and mechanisms of resistance are varied. Combining BRAF inhibitors with MEK inhibitors such as trametinib delays the development of resistance. Rationally combining targeted therapies to address the mechanism of resistance or combining BRAF inhibitors with other effective therapies such as immunotherapy may result in further improvement in outcomes for patients.

Combination of pan-RAF and MEK inhibitors in NRAS mutant melanoma.

BACKGROUND: Approximately 20% of melanomas contain a mutation in NRAS. However no direct inhibitor of NRAS is available. One of the main signaling pathways downstream of NRAS is the MAPK pathway. In this study we investigated the possibility of blocking oncogenic signaling of NRAS by inhibiting two signaling points in the MAPK pathway. METHODS: Fourteen NRAS mutated human melanoma cell lines were treated with a pan-RAF inhibitor (PRi, Amgen Compd A), a MEK inhibitor (MEKi, trametinib) or their combination and the effects on proliferation, cell cycle progression, apoptosis, transcription profile and signaling of the cells were investigated. RESULTS: The majority of the cell lines showed a significant growth inhibition, with high levels of synergism of the PRi and MEKi combination. Sensitive cell lines showed induction of apoptosis by the combination treatment and there was a correlation between p-MEK levels and synergistic effect of the combination treatment. Proliferation of sensitive cell lines was blocked by the inhibition of the MAPK pathway, which also blocked expression of cyclin D1. However, in resistant cell lines, proliferation was blocked by combined inhibition of the MAPK pathway and cyclin D3, which is not regulated by the MAPK pathway. Resistant cell lines also showed higher levels of p-GSK3ß and less perturbation of the apoptotic profile upon the treatment in comparison with the sensitive cell lines. CONCLUSIONS: The combination of PRi + MEKi can be an effective regimen for blocking proliferation of NRAS mutant melanomas when there is higher activity of the MAPK pathway and dependence of proliferation and survival on this pathway.

Antitumor activity of the ERK inhibitor SCH772984 [corrected] against BRAF mutant, NRAS mutant and wild-type melanoma.

BACKGROUND: In melanoma, dysregulation of the MAPK pathway, usually via BRAF(V600) or NRAS(Q61) somatic mutations, leads to constitutive ERK signaling. While BRAF inhibitors are initially effective for BRAF-mutant melanoma, no FDA-approved targeted therapies exist for BRAF-inhibitor-resistant BRAF(V600), NRAS mutant, or wild-type melanoma. METHODS: The 50% inhibitory concentration (IC50) of SCH772984, a novel inhibitor of ERK1/2, was determined in a panel of 50 melanoma cell lines. Effects on MAPK and AKT signaling by western blotting and cell cycle by flow cytometry were determined. RESULTS: Sensitivity fell into three groups: sensitive, 50% inhibitory concentration (IC50) < 1 µM; intermediately sensitive, IC50 1-2 µM; and resistant, >2 µM. Fifteen of 21 (71%) BRAF mutants, including 4 with innate vemurafenib resistance, were sensitive to SCH772984. All three (100%) BRAF/NRAS double mutants, 11 of 14 (78%) NRAS mutants and 5 of 7 (71%) wild-type melanomas were sensitive. Among BRAF(V600) mutants with in vitro acquired resistance to vemurafenib, those with MAPK pathway reactivation as the mechanism of resistance were sensitive to SCH772984. SCH772984 caused G1 arrest and induced apoptosis. CONCLUSIONS: Combining vemurafenib and SCH722984 in BRAF mutant melanoma was synergistic in a majority of cell lines and significantly delayed the onset of acquired resistance in long term in vitro assays. Therefore, SCH772984 may be clinically applicable as a treatment for non-BRAF mutant melanoma or in BRAF-mutant melanoma with innate or acquired resistance, alone or in combination with BRAF inhibitors.

A Phase II Trial of Rivoceranib, an Oral Vascular Endothelial Growth Factor Receptor 2 Inhibitor, for Recurrent or Metastatic Adenoid Cystic Carcinoma.

PURPOSE: This open-label, single-arm, phase II study evaluated the vascular endothelial growth factor receptor 2 (VEGFR2) tyrosine kinase inhibitor (TKI) rivoceranib in patients with recurrent or metastatic (R/M) adenoid cystic carcinoma (ACC). PATIENTS AND METHODS: Eligible patients had confirmed disease progression per Response Evaluation Criteria in Solid Tumors (RECIST) with ≥20% increase in radiologically or clinically measurable lesions or appearance of new lesions within the preceding 6 months. Patients received oral rivoceranib 700 mg once daily. Primary outcomes were objective response rate (ORR) by investigator review and by blinded independent review committee (BIRC). RESULTS: Eighty patients were enrolled and 72 were efficacy evaluable. Seventy-four patients had distant metastases and 49 received prior systemic treatment (14 received VEGFR TKIs). Per investigator and BIRC, respectively, ORR was 15.3% [95% confidence interval (95% CI), 7.9-25.7] and 9.7% (95% CI, 4.0-19.0); median duration of response was 14.9 months (95% CI, 4.9-17.3) and 7.2 months (95% CI, 3.5-8.4); and median progression-free survival was 9.0 months (95% CI, 7.3-11.5) and 9.0 months (95% CI, 7.7-11.5). Grade ≥3 treatment-related adverse events occurred in 56 patients (70.0%); the most common were hypertension (34, 42.5%) and stomatitis (6, 7.5%). Four grade 5 events occurred with one attributed to rivoceranib (epistaxis). Sixty-eight patients (85.0%) had ≥1 dose modifications and 16 patients (20.0%) discontinued rivoceranib for toxicity. CONCLUSIONS: In patients with progressing R/M ACC, rivoceranib demonstrated antitumor activity and a manageable safety profile consistent with other VEGFR TKIs.

A Phase 1 First-in-Human Study of FS118, a Tetravalent Bispecific Antibody Targeting LAG-3 and PD-L1 in Patients with Advanced Cancer and PD-L1 Resistance.

PURPOSE: This phase 1 study (NCT03440437) evaluated the safety, tolerability, pharmacokinetics (PK), and activity of FS118, a bispecific antibody-targeting LAG-3 and PD-L1, in patients with advanced cancer resistant to anti-PD-(L)1 therapy. PATIENTS AND METHODS: Patients with solid tumors, refractory to anti-PD-(L)1-based therapy, received intravenous FS118 weekly with an accelerated dose titration design (800 µg to 0.3 mg/kg) followed by 3+3 ascending dose expansion (1 to 20 mg/kg). Primary objectives were safety, tolerability, and PK. Additional endpoints included antitumor activity, immunogenicity, and pharmacodynamics. RESULTS: Forty-three patients with a median of three prior regimens in the locally advanced/metastatic setting, including at least one anti-PD-(L)1 regimen, received FS118 monotherapy. FS118 was well tolerated, with no serious adverse events relating to FS118 reported. No dose-limiting toxicities (DLT) were observed, and an MTD was not reached. The recommended phase 2 dose of FS118 was established as 10 mg/kg weekly. The terminal half-life was 3.9 days. Immunogenicity was transient. Pharmacodynamic activity was prolonged throughout dosing as demonstrated by sustained elevation of soluble LAG-3 and increased peripheral effector cells. The overall disease control rate (DCR) was 46.5%; this disease control was observed as stable disease, except for one late partial response. Disease control of 54.8% was observed in patients receiving 1 mg/kg or greater who had acquired resistance to PD-(L)1-targeted therapy. CONCLUSIONS: FS118 was well tolerated with no DLTs observed up to and including 20 mg/kg QW. Further studies are warranted to determine clinical benefit in patients who have become refractory to anti-PD-(L)1 therapy. See related commentary by Karapetyan and Luke, p. 835.

Durable response of anaplastic thyroid carcinoma to FS118, a bispecific LAG-3/PD-L1 antibody, after checkpoint inhibitor progression: a case report.

Anaplastic thyroid cancer represents a rare, highly aggressive form of thyroid cancer with a poor prognosis and an overall survival ranging from 5 to 12 months. Unfortunately, treatment options remain limited, even for patients with a targetable driver mutation. Here, we present a case of a patient with a BRAF V600E-mutated, PD-L1 positive (tumor proportion score of 95%) anaplastic thyroid cancer refractory to standard therapies, including debulking surgery, followed by chemoradiation, who had further progressed on PD-1 monotherapy, and was unable to tolerate BRAF/MEK inhibition. Ongoing treatment with FS118, a bispecific LAG-3/PD-L1 antagonist, has afforded 3 years of disease control, including a late confirmed partial response, with excellent tolerability. Given this response, further investigation is required to delineate the mechanism by which dual PD-L1/LAG-3 blockade by FS118 overcomes initial PD-1 pathway resistance, and therefore, identify which patients are most likely to benefit. Simultaneously, expanded use should be considered for those with refractory disease, especially if PD-L1 positive. Insights Dual PD-L1/LAG-3 blockade may be an effective treatment strategy for refractory metastatic tumors, including anaplastic thyroid cancer.

Safety and Clinical Activity of Atezolizumab Plus Ipilimumab in Locally Advanced or Metastatic Non-Small Cell Lung Cancer: Results From a Phase 1b Trial.

BACKGROUND: This phase 1b study investigated safety and activity of combined checkpoint inhibition (CPI) with programmed death-ligand 1 (PD-L1) antibody atezolizumab plus cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor ipilimumab in NSCLC. PATIENTS AND METHODS: Eligible patients had previously treated locally advanced or metastatic non-small cell lung cancer (NSCLC) or melanoma. A standard 3+3 dose escalation investigated atezolizumab (600-1200 mg IV every 3 weeks) plus ipilimumab starting at 1 mg/kg, administered as a single dose or 4 doses, administered every 3 weeks. The expansion stage included a cohort previously treated with atezolizumab. Patients were monitored for safety and tolerability; response was evaluated every 6 weeks. RESULTS: Twenty-seven patients were enrolled, 4 with melanoma and 23 with NSCLC; here, we focus on data for the NSCLC population. Three of 23 patients (13.0%) received prior CPI. No dose-limiting toxicities were reported during dose escalation; dose expansion occurred with atezolizumab 1200 mg plus 1 cycle of ipilimumab 1 mg/kg. Most common treatment-emergent adverse events were dyspnea (39%) and cough (35%); treatment-related Grade ≥3 adverse events occurred in 11 patients (48%), most frequently pneumonitis (17%) and amylase or lipase elevation (9% each). Six of 23 NSCLC patients (26%) achieved confirmed responses, 5 of whom (25%) were CPI naive. Median duration of response was 23.0 (95% CI, 3.2-36.9) months overall and 36.9 (95% CI, 2.9-36.9) months in CPI-naive patients. CONCLUSION: Preliminary efficacy of atezolizumab plus ipilimumab was observed in metastatic NSCLC. The combination had manageable toxicity, with a safety profile consistent with those of the individual agents.

Genomic Immune Evasion: Diagnostic and Therapeutic Opportunities in Head and Neck Squamous Cell Carcinomas.

Head and neck squamous cell cancers (HNSCCs) represent a diverse group of tumors emerging within different mucosal surfaces of the oral cavity, nasopharynx, oropharynx, larynx, and hypopharynx. HNSCCs share common clinical risk factors and genomic features, including smoking, alcohol, age, male sex, aneuploidy, and TP53 mutations. Viral initiating and contributing events are increasingly recognized in HNSCCs. While both Epstein-Barr Virus (EBV) and human papilloma virus (HPV) are observed, EBV is more frequently associated with nasopharyngeal cancers whereas HPV is associated with oropharyngeal cancers. HNSCCs are associated with high tumor mutational burden and loss of tumor suppressor gene function, especially in TP53 and X-linked genes. Multiple lines of evidence suggest that HNSCCs are subject to immunologic surveillance and immune-induced evolutionary pressure that correlate with negative clinical outcomes. This review will discuss genomic mechanisms related to immune-mediated pressures and propose prognostic and therapeutic implications of detectable immune escape mechanisms that drive tumorigenesis and disease progression.

Impact of early detection on cancer curability: A modified Delphi panel study.

Expert consensus on the potential benefits of early cancer detection does not exist for most cancer types. We convened 10 practicing oncologists using a RAND/UCLA modified Delphi panel to evaluate which of 20 solid tumors, representing >40 American Joint Committee on Cancer (AJCC)-identified cancer types and 80% of total cancer incidence, would receive potential clinical benefits from early detection. Pre-meeting, experts estimated how long cancers take to progress and rated the current curability and benefit (improvement in curability) of an annual hypothetical multi-cancer screening blood test. Post-meeting, experts rerated all questions. Cancers had varying estimates of the potential benefit of early cancer detection depending on estimates of their curability and progression by stage. Cancers rated as progressing quickly and being curable in earlier stages (stomach, esophagus, lung, urothelial tract, melanoma, ovary, sarcoma, bladder, cervix, breast, colon/rectum, kidney, uterus, anus, head and neck) were estimated to be most likely to benefit from a hypothetical screening blood test. Cancer types rated as progressing quickly but having comparatively lower cure rates in earlier stages (liver/intrahepatic bile duct, gallbladder, pancreas) were estimated to have medium likelihood of benefit from a hypothetical screening blood test. Cancer types rated as progressing more slowly and having higher curability regardless of stage (prostate, thyroid) were estimated to have limited likelihood of benefit from a hypothetical screening blood test. The panel concluded most solid tumors have a likelihood of benefit from early detection. Even among difficult-to-treat cancers (e.g., pancreas, liver/intrahepatic bile duct, gallbladder), early-stage detection was believed to be beneficial. Based on the panel consensus, broad coverage of cancers by screening blood tests would deliver the greatest potential benefits to patients.