Development of PD-1 and PD-L1 inhibitors as a form of cancer immunotherapy: a comprehensive review of registration trials and future considerations

Early preclinical evidence provided the rationale for programmed cell death 1 (PD-1) and programmed death ligand 1 (PD-L1) blockade as a potential form of cancer immunotherapy given that activation of the PD-1/PD-L1 axis putatively served as a mechanism for tumor evasion of host tumor antigen-specific T-cell immunity. Early-phase studies investigating several humanized monoclonal IgG4 antibodies targeting PD-1 and PD-L1 in advanced solid tumors paved way for the development of the first PD-1 inhibitors, nivolumab and pembrolizumab, approved by the Food and Drug Administration (FDA) in 2014. The number of FDA-approved agents of this class is rapidly enlarging with indications for treatment spanning across a spectrum of malignancies. The purpose of this review is to highlight the clinical development of PD-1 and PD-L1 inhibitors in cancer therapy to date. In particular, we focus on detailing the registration trials that have led to FDA-approved indications of anti-PD-1 and anti-PD-L1 therapies in cancer. As the number of PD-1/PD-L1 inhibitors continues to grow, predictive biomarkers, mechanisms of resistance, hyperprogressors, treatment duration and treatment beyond progression, immune-related toxicities, and clinical trial design are key concepts in need of further consideration to optimize the anticancer potential of this class of immunotherapy.

Baseline neutrophil-to-lymphocyte ratio (NLR) and derived NLR could predict overall survival in patients with advanced melanoma treated with nivolumab

Background

Previous studies have suggested that elevated neutrophil-to-lymphocyte ratio (NLR) is prognostic for worse outcomes in patients with a variety of solid cancers, including those treated with immune checkpoint inhibitors.

Methods

This was a retrospective analysis of 97 consecutive patients with stage IV melanoma who were treated with nivolumab. Baseline NLR and derived (d) NLR were calculated and, along with other characteristics, correlated with progression-free survival (PFS) and overall survival (OS) in univariate and multivariate analyses. The best cutoff values for NLR and dNLR were derived using Cutoff Finder software based on an R routine which optimized the significance of the split between Kaplan-Meier survival curves.

Results

In univariate analysis, increasing absolute neutrophil count (ANC), NLR, dNLR and lactate dehydrogenase (LDH) (continuous variables) were all significantly associated with OS. Only NLR (hazard ratio [HR] = 2.85; 95% CI 1.60–5.08; p < 0.0001) and LDH (HR = 2.51; 95% CI 1.36–4.64; p < 0.0001) maintained a significant association with OS in multivariate analysis. Patients with baseline NLR ≥5 had significantly worse OS and PFS than patients with NLR < 5, as did patients with baseline dNLR ≥3 versus < 3. Optimal cut-off values were ≥ 4.7 for NLR and ≥ 3.8 for dNLR. Using this ≥4.7 cut-off for NLR, the values for OS and PFS were overlapping to the canonical cut-off for values, and dNLR< 3.8 was also associated with better OS and PFS.

Conclusion

Both Neutrophil-to-lymphocyte ratio (NLR) and derived (d) NLR were associated with improved survival when baseline levels were lower than cut-off values. NLR and dNLR are simple, inexpensive and readily available biomarkers that could be used to help predict response to immunotherapy in patients with advanced melanoma.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0383-1) contains supplementary material, which is available to authorized users.

FDA Approval Summary: Nivolumab for the Treatment of Metastatic Non-Small Cell Lung Cancer With Progression On or After Platinum-Based Chemotherapy

In the CheckMate 057 trial, an international, multicenter, open-label, randomized trial in patients with metastatic nonsquamous non-small cell lung cancer with progression on or after platinum-based chemotherapy, improved overall survival and objective response rates were demonstrated with nivolumab compared with docetaxel. Progression-free survival did not differ between the two arms of the study.

On October 9, 2015, the U.S. Food and Drug Administration expanded the nivolumab metastatic non-small cell lung cancer (NSCLC) indication to include patients with nonsquamous NSCLC after a 3.25-month review timeline. Approval was based on demonstration of an improvement in overall survival (OS) in an international, multicenter, open-label, randomized trial comparing nivolumab to docetaxel in patients with metastatic nonsquamous NSCLC with progression on or after platinum-based chemotherapy. The CheckMate 057 trial enrolled 582 patients who were randomized (1:1) to receive nivolumab or docetaxel. Nivolumab demonstrated improved OS compared with docetaxel at the prespecified interim analysis with a hazard ratio (HR) of 0.73 (p = .0015), and a median OS of 12.2 months (95% CI: 9.7–15.0 months) in patients treated with nivolumab compared with 9.4 months (95% CI: 8.0–10.7 months) in patients treated with docetaxel. A statistically significant improvement in objective response rate (ORR) was also observed, with an ORR of 19% (95% CI: 15%–24%) in the nivolumab arm and 12% (95% CI: 9%–17%) in the docetaxel arm. The median duration of response was 17 months in the nivolumab arm and 6 months in the docetaxel arm. Progression-free survival was not statistically different between arms. A prespecified retrospective subgroup analysis suggested that patients with programmed cell death ligand 1-negative tumors treated with nivolumab had similar OS to those treated with docetaxel. The toxicity profile of nivolumab was consistent with the known immune-mediated adverse event profile except for 1 case of grade 5 limbic encephalitis, which led to a postmarketing requirement study to better characterize immune-mediated encephalitis.

Implications for Practice:

Based on the results from the CheckMate 057 clinical trial, nivolumab represents a new treatment option for patients requiring second-line treatment for metastatic non-small cell lung cancer. The role of nivolumab in patients with sensitizing epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) alterations is less clear. Until dedicated studies are performed to better characterize the role and sequence of programmed cell death 1 (PD-1) therapy, patients with EGFR or ALK alterations should have progressed on appropriate targeted therapy before initiating PD-1 inhibitor therapy. Some patients whose tumors lack programmed cell death ligand 1 (PD-L1) expression also appear to have durable responses. The U.S. Food and Drug Administration granted approval to Dako’s PD-L1 test, PD-L1 IHC 28-8 pharmDx, which the applicant claimed as a nonessential complementary diagnostic for nivolumab use.

Neoadjuvant PD-1 inhibitor (Sintilimab) in NSCLC

INTRODUCTION

Programmed death receptor-1 (PD-1) inhibitors have shown efficacy in first-line treatment of NSCLC; however, evidence of PD-1 inhibitor as neoadjuvant treatment is limited. This is a phase 1b study to evaluate the safety and outcome of PD-1 inhibitor in neoadjuvant setting.

METHODS

Treatment-naive patients with resectable NSCLC (stage IA-IIIB) received two cycles of sintilimab (200 mg, intravenously, day 1 out of 22). Operation was performed between day 29 and 43. Positron emission tomography-computed tomography scans were obtained at baseline and before the operation. The primary end point was safety. Efficacy end points included rate of major pathologic response (MPR) and objective response rate. Expression of programmed cell death ligand 1 was also evaluated (registration number: ChiCTR-OIC-17013726).

RESULTS

A total of 40 patients enrolled, all of whom received two doses of sintilimab and 37 underwent radical resection. A total of 21 patients (52.5%) experienced neoadjuvant treatment-related adverse events (TRAEs). Four patients (10.0%) experienced grade 3 or higher neoadjuvant TRAEs, and one patient had grade 5 TRAE. Eight patients achieved radiological partial response, resulting in an objective response rate of 20.0%. Among 37 patients, 15 (40.5%) achieved MPR, including six (16.2%) with a pathologic complete response in primary tumor and three (8.1%) in lymph nodes as well. Squamous cell NSCLC exhibited superior response compared with adenocarcinoma (MPR: 48.4% versus 0%). Decrease of maximum standardized uptake values after sintilimab treatment correlated with pathologic remission (p < 0.00001). Baseline programmed cell death ligand 1 expression of stromal cells instead of tumor cells was correlated with pathologic regression (p = 0.0471).

CONCLUSIONS

Neoadjuvant sintilimab was tolerable for patients with NSCLC, and 40.5% MPR rate is encouraging. The decrease of maximum standardized uptake values after sintilimab might predict pathologic response.

A review on the evolution of PD-1/PD-L1 immunotherapy for bladder cancer: The future is now

The treatment of bladder cancer has evolved over time to encompass not only the traditional modalities of chemotherapy and surgery, but has been particularly impacted by the use of immunotherapy. The first immunotherapy was the live, attenuated bacterial Bacillus Calmette-Guérin vaccine, which has been the standard of care non-muscle-invasive bladder cancer since 1990. Modern immunotherapy has focused on inhibitors of checkpoint proteins, which are molecules that impede immune function, thereby allowing tumor cells to grow and proliferate unregulated. Several checkpoint targets (programmed death ligand-1 [PD-L1] programmed cell death protien-1 [PD-1], and cytotoxic T-lymphocyte associated protein 4 [CTLA4]) have received the most attention in the treatment of bladder cancer, and have inhibitor agents either approved or in late-stage development. This review describes the most recent data on agents that inhibit PD-L1, found on the surface of tumor cells, and PD-1 found on activated T and B cells and macrophages. Atezolizumab is the only member of this class currently approved for the treatment of bladder cancer, but nivolumab, pembrolizumab, durvalumab, and avelumab all have positive results for this indication, and approvals are anticipated in the near future. The checkpoint inhibitors offer an effective alternative for patients for whom previously there were few options for durable responses, including those who are ineligible for cisplatin-based regimens or who are at risk of significant toxicity. Research is ongoing to further categorize responses, define ideal patient populations, and investigate combinations of checkpoint inhibitors to address multiple pathways in immune system functioning.

Immune checkpoint inhibitor-related dermatologic adverse events

Immune checkpoint inhibitors have emerged as a pillar in the management of advanced malignancies. However, nonspecific immune activation may lead to immune-related adverse events, wherein the skin and its appendages are the most frequent targets. Cutaneous immune-related adverse events include a diverse group of inflammatory reactions, with maculopapular rash, pruritus, psoriasiform and lichenoid eruptions being the most prevalent subtypes. Cutaneous immune-related adverse events occur early, with maculopapular rash presenting within the first 6 weeks after the initial immune checkpoint inhibitor dose. Management involves the use of topical corticosteroids for mild to moderate (grades 1-2) rash, addition of systemic corticosteroids for severe (grade 3) rash, and discontinuation of immunotherapy with grade 4 rash. Bullous pemphigoid eruptions, vitiligo-like skin hypopigmentation/depigmentation, and psoriasiform rash are more often attributed to programmed cell death-1/programmed cell death ligand-1 inhibitors. The treatment of bullous pemphigoid eruptions is similar to the treatment of maculopapular rash and lichenoid eruptions, with the addition of rituximab in grade 3-4 rash. Skin hypopigmentation/depigmentation does not require specific dermatologic treatment aside from photoprotective measures. In addition to topical corticosteroids, psoriasiform rash may be managed with vitamin D₃ analogues, narrowband ultraviolet B light phototherapy, retinoids, or immunomodulatory biologic agents. Stevens-Johnson syndrome and other severe cutaneous immune-related adverse events, although rare, have also been associated with checkpoint blockade and require inpatient care as well as urgent dermatology consultation.

Toripalimab plus chemotherapy in treatment-naïve, advanced esophageal squamous cell carcinoma (JUPITER-06): A multi-center phase 3 trial

Platinum-based chemotherapy is the standard first-line treatment for advanced esophageal squamous cell carcinoma (ESCC). In this phase 3 study (ClinicalTrial.gov: NCT03829969), 514 patients with treatment-naïve advanced ESCC were randomized (1:1) to receive toripalimab or placebo in combination with paclitaxel plus cisplatin (TP) every 3 weeks for up to 6 cycles, followed by toripalimab or placebo maintenance. At the prespecified final analysis of progression-free survival (PFS), a significant improvement in PFS is observed for the toripalimab arm over the placebo arm (hazard ratio [HR] = 0.58; 95% CI, 0.46-0.74; p < 0.0001). The prespecified interim analysis of overall survival (OS) also reveals a significant OS improvement for patients treated with toripalimab plus TP over placebo plus TP (HR = 0.58; 95% CI, 0.43-0.78; p = 0.0004). The incidences of grade ≥3 treatment-emergent adverse events are similar between the two arms. Toripalimab plus TP significantly improves PFS and OS in patients with treatment-naïve, advanced ESCC, with a manageable safety profile.

Third-Line Nivolumab Monotherapy in Recurrent SCLC: CheckMate 032

Introduction:

For patients with recurrent SCLC, topotecan remains the only approved second-line treatment, and the outcomes are poor. CheckMate 032 is a phase 1/2, multicenter, open-label study of nivolumab or nivolumab plus ipilimumab in SCLC or other advanced/metastatic solid tumors previously treated with one or more platinum-based chemotherapies. We report results of third- or later-line nivolumab monotherapy treatment in SCLC.

Methods:

In this analysis, patients with limited-stage or extensive-stage SCLC and disease progression after two or more chemotherapy regimens received nivolumab monotherapy, 3 mg/kg every 2 weeks, until disease progression or unacceptable toxicity. The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival, overall survival, and safety.

Results:

Between December 4, 2013, and November 30, 2016, 109 patients began receiving third- or later-line nivolumab monotherapy. At a median follow-up of 28.3 months (from first dose to database lock), the objective response rate was 11.9% (95% confidence interval: 6.5–19.5) with a median duration of response of 17.9 months (range 3.0–42.1). At 6 months, 17.2% of patients were progression-free. The 12-month and 18-month overall survival rates were 28.3% and 20.0%, respectively. Grade 3 to 4 treatment-related adverse events occurred in 11.9% of patients. Three patients (2.8%) discontinued because of treatment-related adverse events.

Conclusions:

Nivolumab monotherapy provided durable responses and was well tolerated as a third- or later-line treatment for recurrent SCLC. These results suggest that nivolumab monotherapy is an effective third- or later-line treatment for this patient population.

Association of Acute Interstitial Nephritis With Programmed Cell Death 1 Inhibitor Therapy in Lung Cancer Patients

Immune checkpoint inhibitors that target the programmed death 1 (PD-1) signaling pathway have recently been approved for use in advanced pretreated non-small cell lung cancer and melanoma. Clinical trial data suggest that these drugs may have adverse effects on the kidney, but these effects have not been well described. We present 6 cases of acute kidney injury in patients with lung cancer who received anti-PD-1 antibodies, with each case displaying evidence of acute interstitial nephritis (AIN) on kidney biopsy. All patients were also treated with other drugs (proton pump inhibitors and nonsteroidal anti-inflammatory drugs) linked to AIN, but in most cases, use of these drugs long preceded PD-1 inhibitor therapy. The association of AIN with these drugs in our patients raises the possibility that PD-1 inhibitor therapy may release suppression of T-cell immunity that normally permits renal tolerance of drugs known to be associated with AIN.

PD-1/PD-L1 Checkpoint Inhibitors in Tumor Immunotherapy

Programmed death protein 1 (PD1) is a common immunosuppressive member on the surface of T cells and plays an imperative part in downregulating the immune system and advancing self-tolerance. Its ligand programmed cell death ligand 1 (PDL1) is overexpressed on the surface of malignant tumor cells, where it binds to PD1, inhibits the proliferation of PD1-positive cells, and participates in the immune evasion of tumors leading to treatment failure. The PD1/PDL1-based pathway is of great value in immunotherapy of cancer and has become an important immune checkpoint in recent years, so understanding the mechanism of PD1/PDL1 action is of great significance for combined immunotherapy and patient prognosis. The inhibitors of PD1/PDL1 have shown clinical efficacy in many tumors, for example, blockade of PD1 or PDL1 with specific antibodies enhances T cell responses and mediates antitumor activity. However, some patients are prone to develop drug resistance, resulting in poor treatment outcomes, which is rooted in the insensitivity of patients to targeted inhibitors. In this paper, we reviewed the mechanism and application of PD1/PDL1 checkpoint inhibitors in tumor immunotherapy. We hope that in the future, promising combination therapy regimens can be developed to allow immunotherapeutic tools to play an important role in tumor treatment. We also discuss the safety issues of immunotherapy and further reflect on the effectiveness of the treatment and the side effects it brings.

Preoperative pembrolizumab combined with chemoradiotherapy for oesophageal squamous cell carcinoma (PALACE-1)

BACKGROUND

To investigate the safety and activity of preoperative pembrolizumab combined with chemoradiotherapy for resectable oesophageal squamous cell carcinoma (ESCC) (ClinicalTrials.gov number, NCT03792347).

METHODS

Twenty resectable ESCC patients, regardless of programmed death ligand-1 status, received preoperative pembrolizumab with concurrent chemoradiotherapy (PPCT). Preoperative therapy includes carboplatin (area under the curve of 2 mg per milliliter per minute, once a week for 5 weeks), paclitaxel (50 mg/m², once a week for 5 weeks), radiotherapy (23 fractions of 1.8 Gy, 5 fraction a week) and pembrolizumab (2 mg/kg) on days 1 and 22. Within 4-6 weeks after preoperative therapy, patients underwent surgery. The primary end-point was safety and secondary outcome measures were feasibility, pathologic complete response (pCR) rate and radiographic response. Immune signature of CD8⁺ T cells was evaluated in surgical specimens using immunohistochemistry and immunofluorescence.

RESULTS

All patients have received PPCT successfully, except one patient who missed the last dose of chemotherapy due to leukopenia. Grade III and higher adverse events (AEs) were observed in 13 patients (13/20, 65%), and one patient had a grade V AE. The most frequent grade III AE was lymphopenia (12/13, 92%). Eighteen patients underwent surgery within 4-9 weeks after PPCT and the pCR rate was 55.6% (10/18). The percentage of transcription factor 1 positive cells was significantly higher in specimens of pCR group than those of non-pCR group (p value = 0.010).

CONCLUSIONS

PPCT was safe, did not delay surgery, and induced a pCR in 55.6% of resected tumours. A phase II multicentre study is undergoing for further confirmation of efficacy (NCT04435197).

Relationships between lymphocyte counts and treatment-related toxicities and clinical responses in patients with solid tumors treated with PD-1 checkpoint inhibitors

The relationships between absolute lymphocyte counts (ALC), drug- related toxicities, and clinical responses remain unclear in cancer patients treated with PD-1 (programmed cell death 1) inhibitors. We performed a retrospective review of 167 adult solid tumor patients treated with nivolumab or pembrolizumab at a single institution between January 2015 and November 2016. Patients with an ALC >2000 at baseline had an increased risk of irAE (OR 1.996, p<0.05) on multivariate analysis. In a multivariate proportional hazards model, a shorter time to progression was noted in patients who were lymphopenic at baseline (HR 1.45 (p<0.05)) and at three months (HR 2.01 (p<0.05)). Patients with baseline lymphopenia and persistent lymphopenia at month 3 had a shorter time to progression compared to those who had baseline lymphopenia but recovered with ALC > 1000 at 3 months (HR 2.76, p<0.05). Prior radiation therapy was the characteristic most strongly associated with lymphopenia at 3 months (OR 2.24, p<0.001). These data suggest that patients with higher baseline lymphocyte counts have a greater risk for irAE, whereas patients with lymphopenia at baseline and persistent lymphopenia while on therapy have a shorter time to progression on these agents. These associations require further validation in additional patient cohorts.

Nivolumab in advanced hepatocellular carcinoma: Sorafenib-experienced Asian cohort analysis

BACKGROUND & AIMS

Nivolumab, an immune checkpoint inhibitor, is approved in several countries to treat sorafenib-experienced patients with HCC, based on results from the CheckMate 040 study (NCT01658878). Marked differences exist in HCC clinical presentation, aetiology, treatment patterns and outcomes across regions. This analysis assessed the safety and efficacy of nivolumab in the Asian cohort of CheckMate 040.

METHODS

CheckMate 040 is an international, multicentre, open-label, phase I/II study of nivolumab in adults with advanced HCC, regardless of aetiology, not amenable to curative resection or local treatment and with/without previous sorafenib treatment. This analysis included all sorafenib-experienced patients in the intent-to-treat (ITT) overall population and Asian cohort. The analysis cut-off date was March 2018.

RESULTS

There were 182 and 85 patients in the ITT population and Asian cohort, respectively. In both populations, most patients were older than 60 years, had BCLC (Barcelona Clinic Liver Cancer) Stage C disease, and had received previous systemic therapy. A higher percentage of Asian patients had HBV infections, extrahepatic metastases and prior therapies. Median follow-up was 31.6 and 31.3 months for the ITT and Asian patients, respectively. Objective response rates were 14% and 15% in the ITT population and Asian cohort, respectively. In the Asian cohort, patients with HBV, HCV or those who were uninfected had objective response rates of 13%, 14% and 21%, respectively. The median duration of response was longer in the ITT (19.4 months) vs. Asian patients (9.7 months). Median overall survival was similar between the ITT (15.1 months) and Asian patients (14.9 months), and unaffected by aetiology in Asian patients. The nivolumab safety profile was similar and manageable across both populations.

CONCLUSION

Nivolumab safety and efficacy are comparable between sorafenib-experienced ITT and Asian patients.

LAY SUMMARY

The CheckMate 040 study evaluated the safety and efficacy of nivolumab in patients with advanced hepatocellular carcinoma who were refractory to previous sorafenib treatment or chemotherapy. This subanalysis of the data showed that treatment responses and safety in patients in Asia were similar to those of the overall treatment population, providing support for nivolumab as a treatment option for these patients. Clinical trial number: NCT01658878.

Programmed cell death protein-1 (PD-1) inhibitor therapy in patients with advanced melanoma and preexisting autoimmunity or ipilimumab-triggered autoimmunity

AIM

Programmed cell death protein 1 (PD-1) inhibitors are a common treatment strategy for metastatic melanoma and other tumour entities. Clinical trials usually exclude patients with preexisting autoimmune diseases, thus experience with PD-1 inhibitor (PD-1i) in this patient population is limited.

PATIENTS AND METHODS

Metastatic melanoma patients with preexisting autoimmune disorders or previous ipilimumab-triggered immune-related adverse events (irAE) undergoing treatment with PD-1i from seven German skin cancer centres were evaluated retrospectively with regard to flare of the preexisting autoimmunity and development of new, not preexisting irAE as well as response to PD-1i therapy.

RESULTS

In total, 41 patients had either preexisting autoimmunity (n=19, group A, including two patients with additional ipilimumab-triggered autoimmune colitis) or ipilimumab-triggered irAE (n=22, group B). At PD-1i therapy initiation, six patients in group A and two patients in group B required immunosuppressive therapy. In group A, a flare of preexisting autoimmune disorders was seen in 42% of patients, new irAE in 16%. In group B, 4.5% of patients showed a flare of ipilimumab-triggered irAE and 23% new irAE. All flares of preexisting autoimmune disorders or irAE were managed by immunosuppressive and/or symptomatic therapy and did not require termination of PD-1i therapy. tumour responses (32% in group A and 45% in group B) were unrelated to occurrence of autoimmunity.

CONCLUSION

While preexisting autoimmunity commonly showed a flare during PD-1i therapy, a flare of ipilimumab-triggered irAE was rare. Response rates were above 30% and unrelated to irAE. PD-1i therapy can be considered in patients with autoimmune disorders depending on severity and activity of autoimmunity.

Severe cytokine release syndrome in a patient receiving PD-1-directed therapy

Cytokine release syndrome (CRS) is a phenomenon of immune hyperactivation described in the setting of cellular and bispecific T-cell engaging immunotherapy. Checkpoint blockade using anti-programmed cell death 1 (anti-PD-1) inhibitors is an approach to antitumor immune system stimulation. A 29-year-old female with alveolar soft part sarcoma developed severe CRS after treatment with anti-PD-1 therapy. CRS was characterized by high fevers, encephalopathy, hypotension, hypoxia, hepatic dysfunction, and evidence of coagulopathy, and resolved after infusion of the interleukin-6 inhibitor tocilizumab and corticosteroids.

Cutaneous adverse effects of targeted therapies: Part II: Inhibitors of intracellular molecular signaling pathways

The last decade has spawned an exciting new era of oncotherapy in dermatology, including the development of targeted therapies for metastatic melanoma and basal cell carcinoma. Along with skin cancer, deregulation of the PI3K-AKT-mTOR and RAS-RAF-MEK-ERK intracellular signaling pathways contributes to tumorigenesis of a multitude of other cancers, and inhibitors of these pathways are being actively studied. Similar to other classes of targeted therapies, cutaneous adverse effects are among the most frequent toxicities observed with mitogen-activated protein kinase pathway inhibitors, PI3K-AKT-mTOR inhibitors, hedgehog signaling pathway inhibitors, and immunotherapies. Given the rapid expansion of these families of targeted treatments, dermatologists will be essential in offering dermatologic supportive care measures to cancer patients being treated with these agents. Part II of this continuing medical education article reviews skin-related adverse sequelae, including the frequency of occurrence and the implications associated with on- and off-target cutaneous toxicities of inhibitors of the RAS-RAF-MEK-ERK pathway, PI3K-AKT-mTOR pathway, hedgehog signaling pathway, and immunotherapies.

Predictive factors for hyperprogressive disease during nivolumab as anti-PD1 treatment in patients with advanced gastric cancer

BACKGROUND

Hyperprogressive disease (HPD) during treatment with anti-programmed death-1/programmed death-ligand 1 monoclonal antibodies has anecdotally been reported in some types of cancers, but is not well-characterized in patients with advanced gastric cancer (AGC).

METHODS

Total 62 AGC patients treated with nivolumab in a single institution from September 2017 to April 2018 were enrolled in this study. Tumor responses were assessed according to Response Evaluation Criteria in Solid Tumors version 1.1, and HPD was defined as ≥ two fold increase in tumor growth rate. Clinicopathological and molecular characteristics associated with HPD were also investigated.

RESULTS

Thirteen of 62 patients (21%) developed HPD after nivolumab treatment. Overall survival (OS) and progression-free survival (PFS) were significantly shorter in patients with HPD than in patients without HPD (median OS: 2.3 months vs. not reached, P < 0.001; median PFS: 0.7 months vs. 2.4 months, P < 0.001). Liver metastases (77% vs. 41%), Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 1 or 2 (77% vs. 29%), and a large sum of target lesion diameters at baseline (median 104.2 mm vs. 44.9 mm) were significantly associated with HPD. Absolute neutrophil count (ANC) and C-reactive protein (CRP) level significantly increased in the first 4 weeks in only patients with HPD.

CONCLUSIONS

HPD was observed in AGC patients treated with nivolumab and correlated with some clinicopathological characteristics. Elevations in ANC and CRP levels upon treatment might indicate HPD.

Safety evaluation of nivolumab added concurrently to radiotherapy in a standard first line chemo-radiotherapy regimen in stage III non-small cell lung cancer-The ETOP NICOLAS trial

OBJECTIVES

Chemo-radiotherapy (CRT) and concurrent PD-1 inhibition has shown promising results in pre-clinical models. So far, the feasibility of delivering concurrent CRT and PD-1/PD-L1 inhibition has never been assessed in a clinical trial.

MATERIAL AND METHODS

NICOLAS is a phase-II trial evaluating the safety and efficacy of nivolumab combined with CRT in stage III NSCLC. Patients received 3 cycles of platinum-based chemotherapy and concurrent RT (66 Gy/33fractions). Nivolumab started concurrently with RT. The primary endpoint was 6-month post-RT rate of grade-≥3-pneumonitis. A formal interim safety analysis (IA) was scheduled when the first 21 patients reached 3 months follow-up post-RT. An early positive safety conclusion would be reached at IA if there were no grade ≥3-pneumonitis in those patients. Efficacy evaluation was planned provided the safety conclusion was reached.

RESULTS AND CONCLUSION

As of 13 December 2018, 82 patients were recruited with median follow-up of 13.4 months. The most frequent adverse events (AEs) were anaemia, fatigue and pneumonitis. No unexpected AEs or increased toxicities were observed. For the first 21 patients, no grade-≥3-pneumonitis was observed by the end of the 3-month post-RT follow-up period. The early safety IA provides evidence that the addition of nivolumab to concurrent CRT is safe and tolerable regarding the 6-month rate of pneumonitis grade ≥3 at the one-sided significance level of 5%. Following that, the 1-year progression-free survival will be evaluated in an expanded patient cohort. NICOLAS trial creates the opportunity for assessing the activity of the combination of checkpoint with concurrent CRT in larger prospective trials for locally advanced NSCLC.

Clinicopathological and molecular features of responders to nivolumab for patients with advanced gastric cancer

Background

Clinicopathological and molecular features of responders to nivolumab for advanced gastric cancer (AGC) are not well understood.

Methods

Patients (pts) with AGC who were treated with nivolumab after two or more chemotherapy regimens in a single institution from September 2017 to May 2018 were enrolled in this study. PD-L1 expression in tumor cells (TC) and mismatch repair (MMR) were analyzed by immunohistochemistry. Epstein-Barr virus (EBV) was detected by in situ hybridization. Cancer genome alterations were evaluated by a next-generation sequencing-based panel. High tumor mutation burden (TMB) was defined as more than 10 mutations/megabase.

Results

A total of 80 pts were analyzed in this study. Tumor response was evaluated in 72 pts with measurable lesions and 14 pts (19%) had an objective response. Overall response rate (ORR) was significantly higher in pts with ECOGPS 0 in those with PS 1 or 2, MMR-deficient (MMR-D) in those with MMR-proficient (MMR-P), PD-L1+ in TC in those with PD-L1- in TC and PIK3CA mutation in those with PIK3CA wild-type. ORR was 31% in pts with at least one of the following factors; MMR-D, high TMB, EBV+ and PD-L1+ in TC vs. 0% in those without these factors. Progression-free survival was significantly longer in pts with PS 0 than in those with PS 1 or 2, MMR-D than in those with MMR-P, and PD-L1+ in TC than in those with PD-L1- in TC.

Conclusions

Some features were associated with favorable response to nivolumab for AGC. Combining these features might be useful to predict efficacy.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0514-3) contains supplementary material, which is available to authorized users.

Transarterial Chemoembolization Combined With Lenvatinib Plus PD-1 Inhibitor for Advanced Hepatocellular Carcinoma: A Retrospective Cohort Study

PURPOSE

To investigate the efficacy and safety of transarterial chemoembolization (TACE) combined with lenvatinib plus PD-1 inhibitor (TACE-L-P) versus TACE combined with lenvatinib (TACE-L) for patients with advanced hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Data of advanced HCC patients treated with TACE-L-P (TACE-L-P group) or TACE-L (TACE-L group) from January 2019 to December 2020 were prospectively collected and retrospectively analyzed. The differences in overall survival (OS), progression-free survival (PFS), tumor responses (based on modified Response Evaluation Criteria in Solid Tumors) and adverse events (AEs) were compared between the two groups. Potential factors affecting OS and PFS were determined.

RESULTS

A total of 81 patients were included in this study. Among them, 41 received TACE-L-P and 40 received TACE-L. The patients in TACE-L-P group had prolonged OS (median, 16.9 vs. 12.1 months, P=0.009), longer PFS (median, 7.3 vs. 4.0 months, P=0.002) and higher objective response rate (56.1% vs. 32.5%, P=0.033) and disease control rate (85.4% vs. 62.5%, P=0.019) than those in TACE-L group. Multivariate analyses revealed that the treatment option of TACE-L, main portal vein invasion and extrahepatic metastasis were the independent risk factors for OS, while TACE-L and extrahepatic metastasis were the independent risk factors for PFS. In subgroup analyses, a superior survival benefit was achieved with TACE-L-P in patients with extrahepatic metastasis or tumor number >3 but not in those with main portal vein invasion. The incidence and severity of AEs in TACE-L-P group were comparable to those in TACE-L group (any grade, 92.7% vs. 95.0%, P=1.000; grade 3, 36.6% vs. 32.5%, P=0.699).

CONCLUSION

TACE-L-P significantly improved survival over TACE-L with an acceptable safety profile in advanced HCC patients, especially those with extrahepatic metastasis or tumor number >3 but without main portal vein invasion.

High neutrophil-to-lymphocyte ratio (NLR) is associated with treatment failure and death in patients who have melanoma treated with PD-1 inhibitor monotherapy

BACKGROUND

An elevated neutrophil-to-lymphocyte ratio (NLR) is associated with poor survival in patients with cancer, including those who receive immunotherapies. The authors sought to investigate NLR as a biomarker of treatment outcomes in patients with melanoma who were treated with PD-1 inhibition.

METHODS

Patients undergoing initial treatment with PD-1 inhibitor monotherapy for stage IV melanoma at a single center from 2012 to 2015 were included. Clinical characteristics and the NLR at baseline and before subsequent treatment cycles were collected. The time to treatment failure (TTF) and overall survival (OS) were evaluated using Kaplan-Meier and landmark analyses.

RESULTS

Among 224 study patients, 63 (28%) had a baseline NLR ≥5. The baseline NLR was significantly associated with Eastern Cooperative Oncology Group performance status and the number of involved metastatic sites. With a median follow-up of 39 months in survivors, a baseline NLR ≥5 was independently associated with shorter OS (hazard ratio, 2.0; 95% CI, 1.3-2.9) and TTF (hazard ratio, 1.7; 95% CI, 1.2-2.4). An NLR increase ≥30% during the first 2 cycles of treatment was associated with worse OS (median, 47 vs 13.5 months; P < .001) and a trend toward shorter TTF (12.8 vs 5.9 months; P = .05). A combined baseline NLR ≥5 and an NLR increase ≥30% identified a small cohort with markedly shortened OS (median, 5.8 months) and TTF (median, 1.8 months).

CONCLUSIONS

Elevated baseline NLR and an increased NLR early during treatment are prognostic for TTF and OS in patients who have melanoma treated with PD-1 inhibitor monotherapy. Combined, these biomarkers can widely risk-stratify patients for treatment failure and survival.

PD-1/PD-L1 checkpoint inhibitors in advanced hepatocellular carcinoma immunotherapy

Hepatocellular carcinoma (HCC) has a high prevalence and mortality rate worldwide. Sorafenib monotherapy has been the standard of first-line treatment for advanced HCC for a long time, but there are still many shortcomings. In recent years, with the deepening of research on tumor immune microenvironment, researchers have begun to explore new approaches in immunotherapy, and the introduction of immune checkpoint inhibitors has brought fundamental changes to the treatment of HCC. Programmed cell death protein 1 (PD-1) is an immune checkpoint molecule that plays an important role in down-regulating immune system function and promoting tolerance. Programmed cell death ligand 1 (PDL-1) is involved in tumor immune evasion by binding to PD-1, resulting in failure of treatment. Currently, immunotherapy targeting the PD-1/PD-L1 axis has achieved unprecedented success in HCC, but it also faces great challenges, with its low remission rate still to be solved. For most patients with HCC, the PD-1/PD-L1 pathway is not the only rate limiting factor of antitumor immunity, and blocking only the PD-1/PD-L1 axis is not enough to stimulate an effective antitumor immune response; thus, combination therapy may be a better option. In this study, changes in the immune microenvironment of HCC patients were reviewed to clarify the feasibility of anti-PD-1/PD-L1 therapy, and a series of monotherapy and combination therapy clinical trials were summarized to verify the safety and efficacy of this newly developed treatment in patients with advanced HCC. Furthermore, we focused on hyperprogressive disease and drug resistance to gain a better understanding of PD-1/PD-L1 blockade as a promising treatment.

Fatal orthotopic liver transplant organ rejection induced by a checkpoint inhibitor in two patients with refractory, metastatic hepatocellular carcinoma

Although checkpoint inhibitor therapies have demonstrated significant efficacy in many malignancies, they have not been well studied in patients with a history of solid organ transplant. We describe two patients with recurrent, refractory, and progressive advanced fibrolamellar hepatocellular carcinoma (HCC) following orthotopic liver transplantation who received programmed cell death protein 1 (PD-1) inhibitor, nivolumab, on a patient access, off-label basis. Both rapidly developed irreversible acute liver rejection shortly after starting therapy, and ultimately died. While checkpoint inhibitors clearly have tremendous potential as a targeted therapy, they should be avoided or used with extreme caution in the context of an organ transplant.

Tumor Mutational Burden and Efficacy of Immune Checkpoint Inhibitors: A Systematic Review and Meta-Analysis

Tumor mutational burden (TMB) is a genomic biomarker that predicts favorable responses to immune checkpoint inhibitors (ICIs). Here, we set out to assess the predictive value of TMB on long-term survival outcomes in patients undergoing ICIs. We systematically searched PubMed, Embase, CENTRAL and clinicaltrials.gov from inception to 6 August 2019. We included retrospective studies or clinical trials of ICIs that reported hazard ratios (HRs) for overall survival (OS) and/or progression-free survival (PFS) according to TMB. Data on 5712 patients from 26 studies were included. Among patients who received ICIs, high TMB groups showed better OS (HR 0.53, 95% CI 0.42 to 0.67) and PFS (HR 0.52, 95% CI 0.40 to 0.67) compared to low TMB groups. In patients with high TMB, those who received ICIs had a better OS (HR 0.69, 95% CI 0.50 to 0.95) and PFS (HR = 0.66, 95% CI = 0.47 to 0.92) compared to those who received chemotherapy alone, while in patients with low TMB, such ICI benefits of OS or PFS were not statistically significant. In conclusion, TMB may be an effective biomarker to predict survival in patients undergoing ICI treatment. The role of TMB in identifying patient groups who may benefit from ICIs should be determined in future randomized controlled trials.

Correlation of Neutrophil to Lymphocyte Ratio and Absolute Neutrophil Count With Outcomes With PD-1 Axis Inhibitors in Patients With Advanced Non-Small-Cell Lung Cancer

INTRODUCTION

Programmed death-1 (PD-1) axis inhibitors have become standard therapy in advanced non-small-cell lung cancer (NSCLC). Response might be delayed and pseudo-progression occasionally occurs in patients who eventually benefit from treatment. Additional markers beyond programmed death ligand 1 (PD-L1) expression are needed to assist in patient selection, response evaluation, and treatment decisions.

MATERIALS AND METHODS

The relationship between prospectively collected clinical outcomes (response, disease control rate [DCR], treatment duration, overall survival) and hematologic parameters (neutrophil to lymphocyte ratio [NLR], absolute neutrophil count [ANC], and platelet to lymphocyte ratio [PLR]) was explored retrospectively in advanced NSCLC patients treated with PD-1 axis inhibitors at a major cancer center from May 2013 to August 2016. Hematologic parameters at baseline and during treatment (week 2 or 3 and week 8) were included.

RESULTS

Of 88 patients treated with PD-1 axis inhibitors, 22 (25%) experienced partial response. Baseline NLR ≤4 was associated with superior DCR (74% vs. 50%; P = .025), treatment duration (P = .037), time to progression (P = .053), and overall survival (P = .019), with no differential association according to PD-L1 tumor expression. Lower NLR and ANC during treatment were also associated with response to treatment (P = .025 and P = .017, respectively), and treatment duration (P = .036 and P = .008). No association was found between baseline PLR and DCR, response, treatment duration, nor overall survival.

CONCLUSION

Baseline NLR ≤4 and lower NLR and ANC during treatment might correlate with disease control and treatment response and should be explored further as potential predictors of treatment benefit in larger studies.