Immune Checkpoint Inhibitors and the Exposome: Host-Extrinsic Factors Determine Response, Survival, and Toxicity

Cancer immunotherapy, largely represented by immune checkpoint inhibitors (ICI), has led to substantial changes in preclinical cancer research and clinical oncology practice over the past decade. However, the efficacy and toxicity profiles of ICIs remain highly variable among patients, with only a fraction achieving a significant benefit. New combination therapeutic strategies are being investigated, and the search for novel predictive biomarkers is ongoing, mainly focusing on tumor- and host-intrinsic components. Less attention has been directed to all the external, potentially modifiable factors that compose the exposome, including diet and lifestyle, infections, vaccinations, and concomitant medications, that could affect the immune system response and its activity against cancer cells. We hereby provide a review of the available clinical evidence elucidating the impact of host-extrinsic factors on ICI response and toxicity.

What to do after immune-checkpoint inhibitors failure in advanced non-small cell lung cancer: an expert opinion and review

INTRODUCTION

Immune-checkpoint inhibitors (IO) have significantly improved outcomes of patients with non-oncogene-addicted non-small cell lung cancer (NSCLC), becoming the first-line agents for advanced disease. However, resistance remains a significant clinical challenge, limiting their effectiveness.

AREAS COVERED

Hereby, we addressed standard and innovative therapeutic approaches for NSCLC patients experiencing progression after IO treatment, discussing the emerging resistance mechanisms and the ongoing efforts to overcome them. In order to provide a complete overview of the matter, we performed a comprehensive literature search across prominent databases, including PubMed, EMBASE (Excerpta Medica dataBASE), and the Cochrane Library, and a research of the main ongoing studies on clinicaltrials.gov.

EXPERT OPINION

The dynamics of progression to IO, especially in terms of time to treatment failure and burden of progressive disease, should guide the best subsequent management, together with patient clinical conditions. Long-responders to IO might benefit from continuation of IO beyond-progression, in combination with other treatments. Patients who experience early progression should be treated with salvage CT in case of preserved clinical conditions. Finally, patients who respond to IO for a considerable timeframe and who later present oligo-progression could be treated with a multimodal approach in order to maximize the benefit of immunotherapy.

Immune checkpoint inhibitors for unresectable malignant pleural mesothelioma

Unresectable malignant pleural mesothelioma (MPM) is an aggressive disease with a 5-year survival rate of approximately 10%. Recent data suggest that MPM is an immunologically active tumor, in which checkpoint inhibition through the blockade of the anti-cytotoxic T lymphocyte antigen-4 (-CTLA-4) or anti-programmed cell death 1 (PD-1) could play a major therapeutic role. Initially, clinical trials evaluated immune checkpoint inhibitors (ICIs) in the salvage setting after platinum-based chemotherapy with mixed results in terms of efficacy. More recently, the combination of the anti-CTLA-4 agent ipilimumab plus the anti-PD-1 agent nivolumab was tested in the front-line setting, and reported a superior survival as compared to platinum/pemetrexed. While other clinical trials ore ongoing in order to investigate ICIs for MPM, it seems now evident that we have entered a new "era" for the treatment of MPM. In the future, a few issues need to be solved with regard to the use of ICIs for MPM. Among them, there is the identification of biomarkers of sensitivity to immunotherapy that may help enrich the patient population who could benefit the most from treatment, while avoiding for some other patients the potential occurrence of immune-related side effects from therapies that are anticipated to be ineffective.

Liquid Biopsy for Small Cell Lung Cancer either De Novo or Transformed: Systematic Review of Different Applications and Meta-Analysis

BACKGROUND

The potential added value of liquid biopsy (LB) is not well determined in the case of small cell lung cancer (SCLC), an aggressive tumor that can occur either de novo or from the histologic transformation of non-small cell lung cancer (NSCLC).

METHODS

A systematic review of studies adopting LB in patients with SCLC have been performed to assess the clinical utility of circulating tumor DNA (ctDNA) or circulating tumor cells (CTCs).

RESULTS

After a screening of 728 records, 62 studies (32 evaluating CTCs, 27 ctDNA, and 3 both) met predetermined eligibility criteria. Only four studies evaluated LB in the diagnostic setting for SCLC, while its prognostic significance was evaluated in 38 studies and prominently supported by both ctDNA and CTCs. A meta-analysis of 11 studies as for CTCs enumeration showed an HR for overall survival of 2.63 (1.71-4.05), with a potential publication bias. The feasibility of tumor genomic profiling and the predictive role of LB in terms of response/resistance to chemotherapy was assessed in 11 and 24 studies, respectively, with greater consistency for those regarding ctDNA. Intriguingly, several case reports suggest that LB can indirectly capture the transition to SCLC in NSCLC treated with EGFR tyrosine kinase inhibitors.

CONCLUSIONS

While dedicated trials are needed, LB holds potential clinical roles in both de novo and transformed SCLC. CtDNA analysis appears the most valuable and practicable tool for both disease monitoring and genomic profiling.

Pooled Analysis of Clinical Outcome of Patients with Chemorefractory Metastatic Colorectal Cancer Treated within Phase I/II Clinical Studies Based on Individual Biomarkers of Susceptibility: A Single-Institution Experience

Background

Patients with metastatic colorectal cancer (mCRC) refractory to standard therapies have a poor prognosis. In this setting, recruitment into clinical trials is warranted, and studies driven by selection according to individual tumor molecular characteristics are expected to provide added value.

Objective

We retrospectively analyzed data from patients with mCRC refractory to or following failure of standard therapies who were enrolled into phase I/II clinical studies at the Niguarda Cancer Center based on the presence of a specific molecular profile expected to represent the target of susceptibility to the experimental drug(s).

Patients and Methods

From June 2011 to May 2016, 2044 patients with mCRC underwent molecular screening. Eighty patients (3.9%) were enrolled in ad hoc studies; the median age was 60 years (range 36–86) and the median number of previous treatment lines was five (range 2–8). Molecular characteristics exploited within these studies were MGMT promoter hypermethylation (48.7%), HER2 amplification (28.8%), BRAF^V600E mutation (20%), and novel gene fusions involving ALK or NTRK (2.5%).

Results

One patient (1%) had RECIST (Response Evaluation Criteria In Solid Tumors) complete response (CR), 13 patients (16.5%) experienced a partial response (PR), and 28 (35%) stable disease (SD). Median progression-free survival (PFS) was 2.8 months (range 2.63–3.83), with 24% of patients displaying PFS >5 months. Median growth modulation index (GMI) was 0.85 (range 0–15.61) and 32.5% of patients had GMI >1.33. KRAS exon 2 mutations were found in 38.5% of patients, and among the 78 patients with known KRAS status, those with wild-type tumors had longer PFS than those with mutated tumors (3.80 [95% CI 2.80–5.03] vs. 2.13 months [95% CI 1.77–2.87], respectively, p = 0.001). Median overall survival (OS) was 7.83 months (range 7.17–9.33) for all patients, and patients with KRAS wild-type tumors had longer OS than those with mutated tumors (7.83 [95% CI 7.33–10.80] vs. 7.18 months [95% CI 5.63–9.33], respectively, p = 0.06).

Conclusions

This single-institution retrospective study indicates that in a heavily pretreated population approximately 4% of mCRC tumors display a potential actionable molecular context suitable for therapeutic intervention. Application of molecular selection is challenging but improves clinical outcome even in later lines of treatment.

Safety and Antitumor Activity of the Multitargeted Pan-TRK, ROS1, and ALK Inhibitor Entrectinib: Combined Results from Two Phase I Trials (ALKA-372-001 and STARTRK-1)

Entrectinib, a potent oral inhibitor of the tyrosine kinases TRKA/B/C, ROS1, and ALK, was evaluated in two phase I studies in patients with advanced or metastatic solid tumors, including patients with active central nervous system (CNS) disease. Here, we summarize the overall safety and report the antitumor activity of entrectinib in a cohort of patients with tumors harboring NTRK1/2/3, ROS1, or ALK gene fusions, naïve to prior TKI treatment targeting the specific gene, and who were treated at doses that achieved therapeutic exposures consistent with the recommended phase II dose. Entrectinib was well tolerated, with predominantly Grades 1/2 adverse events that were reversible with dose modification. Responses were observed in non-small cell lung cancer, colorectal cancer, mammary analogue secretory carcinoma, melanoma, and renal cell carcinoma, as early as 4 weeks after starting treatment and lasting as long as >2 years. Notably, a complete CNS response was achieved in a patient with SQSTM1-NTRK1-rearranged lung cancer.Significance: Gene fusions of NTRK1/2/3, ROS1, and ALK (encoding TRKA/B/C, ROS1, and ALK, respectively) lead to constitutive activation of oncogenic pathways. Entrectinib was shown to be well tolerated and active against those gene fusions in solid tumors, including in patients with primary or secondary CNS disease. Cancer Discov; 7(4); 400-9. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 339.

Efficacy and safety of rechallenge treatment with gefitinib in patients with advanced non-small cell lung cancer

OBJECTIVES

Although patients with advanced non-small cell lung cancer (NSCLC) and an activating epidermal growth factor receptor (EGFR) mutation benefit from the use of EGFR-tyrosine kinase inhibitors (TKI), most of them progress within 12 months from treatment start due to acquired resistance. In clinical practice, many physicians frequently offer these patients retreatment with EGFR-TKIs after a chemotherapy break, based on small or retrospective studies.

MATERIALS AND METHODS

A phase II trial was conducted in patients with stage III/IV NSCLC, to assess the efficacy, safety and impact on quality of life (QoL) and disease-related symptoms of gefitinib rechallenge. Eligible patients had initially responded to first-line gefitinib and progressed after second-line chemotherapy.

RESULTS

Of 61 enrolled patients, 73.8% were female, 100% had EGFR-mutated adenocarcinoma and 67.2% were never-smokers. Thirty-two (52.5%) patients obtained a clinical benefit, with 3 (4.9%) achieving a partial response and 29 (47.5%) having stable disease. Median progression-free survival was 2.8 months, overall survival 10.2 months and duration of gefitinib treatment 3.6 months. The most common all grade-adverse events were diarrhea (27.6%), nausea and/or vomiting (20.3%), rash (14.7%) and dyspnea (10.3%); no new toxicities were apparent.

CONCLUSION

Findings from this study indicate that gefitinib rechallenge offers modest benefit and may be taken into consideration only for patients for whom no other treatment option exists.

Correlation between variation in quality of life and change in hemoglobin level after treatment with epoetin alfa 40,000 IU administered once-weekly

INTRODUCTION

Anemia is frequently associated with cancer due to the disease itself and antineoplastic treatments. This open-label, uncontrolled, multi-center study evaluated the effects of once-weekly (qw) epoetin alfa 40,000 IU on hemoglobin (Hb) levels and quality of life (QoL) in anemic patients receiving chemotherapy for solid tumors.

MATERIALS AND METHODS

A total of 522 patients with Hb level < or =12 g/dL received epoetin alfa 40,000 IU qw subcutaneously for 9-20 weeks to reach and maintain Hb range of 12-14 g/dL. QoL was assessed with the Functional Assessment of Cancer Therapy-Anemia (FACT-An [anemia sub-scale]) and Cancer Linear Analogue Scale (CLAS) at study entry, after two chemotherapy cycles, and at study end.

RESULTS

Mean baseline Hb was 10.43 g/dL. Hb increases (g/dL) from baseline after 4, 8, 12 weeks and at study end were 1.07, 1.77, 1.92 and 1.71 g/dL, respectively. Response rates (Hb increase > or =1 and > or =2 g/dL during trial) were 81% and 61%, respectively. Mean increases in the FACT-An score from baseline (mean 55.4) were 3.1 after two chemotherapy cycles and 3.3 at study end; mean increases in the CLAS score from baseline (58.4 mm) were 5.9 mm after two chemotherapy cycles and 6.5 mm at study end.

DISCUSSION

The greatest QoL increase was recorded when patients approached Hb level of 12 g/dL, independent of the baseline Hb level. Hb changes from baseline to trial end were related to corresponding changes in the FACT-An score. A positive correlation was also observed in patients with progressive disease. Adverse events were essentially those associated with chemotherapy. Incidence of thrombovascular events (6.7%) did not differ from the expected standard treatment in cancer patients. Epoetin alfa 40,000 IU qw increased Hb levels and improved or preserved QoL.

Phase II study of cetuximab in combination with FOLFIRI in patients with untreated advanced gastric or gastroesophageal junction adenocarcinoma (FOLCETUX study)

BACKGROUND

The purpose of this phase II study was to evaluate the efficacy and safety of cetuximab combined with FOLFIRI as a first-line treatment of advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma.

PATIENTS AND METHODS

Untreated patients with confirmed advanced gastric or gastroesophageal adenocarcinoma received cetuximab at an initial dose of 400 mg/m(2) intravenously (i.v.) followed by weekly doses of 250 mg/m(2), CPT 11 180 mg/m(2) i.v. on day 1, LFA 100 mg/m(2) i.v. followed by 5-FU 400 mg/m(2) i.v. bolus, and 600 mg/m(2) i.v. 22-h continuous infusion on days 1 and 2 (FOLFIRI) every 2 weeks, for a maximum of 24 weeks, then cetuximab alone was allowed in patients with a complete response, partial response, or stable disease. Antitumor activity was assessed by computed tomography (CT) and positron emission tomography (PET) at baseline and after 6 weeks, and further by CT alone or CT and PET every 6 weeks.

RESULTS

Thirty-eight patients were enrolled (median age 63.5 years, range 39-83; median Karnofsky performance status 90, range 70-100; stomach 89.5% and GEJ 10.5%; locally advanced disease 13.2% and metastatic disease 86.8%). All 38 patients were assessed for safety and survival, and 34 patients were assessed for overall response rates (ORR). The ORR was 44.1% [95% confidence interval (CI) 27.5% to 60.9%]. The median time-to-progression was 8 months (95% CI 7-9). At the median follow-up time of 11 months, 55.3% of patients were alive, with a median expected survival time of 16 months (95% CI 9-23). Grade 3-4 toxicity included neutropenia (42.1%), acne-like rash (21.1%), diarrhea (7.9%), asthenia (5.3%), stomatitis (5.3%), and hypertransaminasemia (5.3%). There was one (2.6%) treatment-related death.

CONCLUSIONS

The combination of cetuximab and FOLFIRI is active in gastric and GEJ adenocarcinoma. The higher toxicity appears to be limited to neutropenia.

Treatment of metastatic neuroendocrine carcinomas based on WHO classification

A single institution prospective trial was conducted to evaluate the efficacy of biotherapy or chemotherapy in metastatic neuroendocrine carcinomas (NECs). The choice of therapy was based on the revised histological classification criteria of the WHO in an effort to define a standardized protocol for therapy of these cancers. Patients with well-differentiated NECs (WD-NECs; n=11) received therapy with octreotide long-acting release and interferon-alpha-2b for a maximum of 1 year; cases with poorly-differentiated NECs (PD-NECs; n=8) were given combination cisplatin, L-leucovorin and 5-fluorouracil chemotherapy for a maximum of 9 cycles. Five patients (4 with WD-NECs) had carcinoid syndrome. Among the patients with WD-NECs (median follow-up 20 months, range 4-40), 4 had partial responses and 7 had stable disease. In patients with PD-NECs (median follow-up 10.5 months, range 3-30), 3 had partial response, 2 stable disease, and the disease progressed in 3 cases. The 2-year survival rate in WD-NECs and PD-NECs was 88% and 66%, respectively. Grade 3-4 side-effects were limited to 9% thrombocytopenia and 12.5% neutropenia. Both these treatment regimens had a good therapeutic index and compared favourably with those previously reported for metastatic WD-NECs and PD-NECs.

Optimising management of neutropenia and anaemia in cancer chemotherapy-advances in cytokine therapy

Neutropenia and anaemia are serious complications of myelosuppressive chemotherapy. They have a negative impact on patient quality of life and may reduce response to treatment. Febrile neutropenia, a potentially life-threatening complication of neutropenia, frequently requires hospital admission, while fatigue and weakness from anaemia reduce patient's capacity for activity. Pegfilgrastim and darbepoetin alfa, were designed to simplify and optimise treatment for patients with cancer. Once-per-cycle pegfilgrastim is as effective as daily filgrastim with respect to duration of severe neutropenia (DSN) and may have a lower incidence of febrile neutropenia than filgrastim. Darbepoetin alfa has enhanced biological activity and a serum terminal half-life three-fold longer than that of erythropoietin (EPO), which translates into rapid and sustained correction of anaemia with less frequent dosing. These novel cytokines have the potential to simplify the management of neutropenia and anaemia with fewer injections and less disruption to patients daily lives.

Second-line chemotherapy with bleomycin, methotrexate, and vinorelbine (BMV) for patients with squamous cell carcinoma of the head, neck and esophagus (SCC-HN&E) pretreated with a cisplatin-containing regimen: a phase II study

We evaluated the toxicity and activity of bleomycin, methotrexate and vinorelbine (BMV) combination chemotherapy in cisplatin-pretreated patients with squamous cell carcinoma of the head, neck and esophagus (SCC-HN&E) with the aim of identifying a second-line therapy combination and schedule that might offer an improved therapeutic index. BMV (bleomycin 15 I.U., total dose, methotrexate 30 mg/m2, and vinorelbine 30 mg/m2) was administered intravenously every 2 weeks until disease progression, to 26 consecutive patients. Clinical and CT-scan evaluations revealed 7 partial responses (PR) 127%, 95% confidence interval: 9.6%-44.4%], and 13 patients with stable disease (SD) [50%]. The mean progression-free survival for patients who achieved a PR or SD was 6.47 months (range 4-13 months), with 75% of these patients experiencing partial relief of symptoms, mainly pain and dysphagia. BMV, administered second-line in an outpatient setting, has activity similar to that of the taxanes, but with a more acceptable toxicity profile including an absence of alopecia.

Controversies in the management of brain metastases: the role of chemotherapy

The role of chemotherapy (CT) for brain metastases (BrM) is still controversial. Limited life expectancy and presence of the blood-brain barrier (BBB) have been considered as contraindications for relatively aggressive therapies, such as CT. Nevertheless, more recent studies emphasise the possibility that in addition to historical nitrosoureas, also platinum derivatives, etoposide, teniposide, gemcitabine, irinotecan, topotecan and temozolomide can pass the BBB as they are active against selected BrM. Interaction of cytotoxic agents with other drugs may represent a problem in the treatment of BrM. By far, the most important factor conditioning the response to cytotoxic agents is the chemosensitivity of different tumours. CT proved to be effective in patients with BrM from lung cancer, mainly small cell lung cancer, breast cancer, choriocarcinoma and germ cell tumours. In these malignancies the responses to CT are similar to those observed in other metastatic sites. This observation, confirmed by many studies, contrasts with the theory, emphasised in the past, of the brain as a sanctuary. In fact BBB may be important in protecting normal brain tissue and micrometastases from CT, but not when BrM are symptomatic and clinically evident. The clue to the treatment of chemosensitive tumours is to assess the most active drugs and combinations. Cisplatin and etoposide was confirmed to be the treatment of choice in many situations (BrM from lung and also from breast cancer). Newer drugs are now on study: topotecan and temozolomide seem to be particularly promising (alone or in association with other drugs) in the treatment of various BrM (also from melanoma) and could represent an alternative to more widely-used drugs or as second-line treatments.