Dose escalation phase 1 study of radiotherapy in combination with anti-cytotoxic-T-lymphocyte-associated antigen 4 monoclonal antibody ipilimumab in patients with metastatic melanoma

Radiation and Melanoma: Where Are We Now?

PURPOSE OF REVIEW

This review summarizes the current role of radiotherapy for the treatment of cutaneous melanoma in the definitive, adjuvant, and palliative settings, and combinations with immunotherapy and targeted therapies.

RECENT FINDINGS

Definitive radiotherapy may be considered for lentigo maligna if surgery would be disfiguring. High risk, resected melanoma may be treated with adjuvant radiotherapy, but the role is poorly defined since the advent of effective systemic therapies. For patients with metastatic disease, immunotherapy and targeted therapies can be delivered safely in tandem with radiotherapy to improve outcomes. Radiotherapy and modern systemic therapies act in concert to improve outcomes, especially in the metastatic setting. Further prospective data is needed to guide the use of definitive radiotherapy for lentigo maligna and adjuvant radiotherapy for high-risk melanoma in the immunotherapy era. Current evidence does not support an abscopal response or at least identify the conditions necessary to reliably produce one with combinations of radiation and immunotherapy.

Recent advances in immunotherapy and its combination therapies for advanced melanoma: a review

The incidence of melanoma is increasing year by year and is highly malignant, with a poor prognosis. Its treatment has always attracted much attention. Among the more clinically applied immunotherapies are immune checkpoint inhibitors, bispecific antibodies, cancer vaccines, adoptive cell transfer therapy, and oncolytic virotherapy. With the continuous development of technology and trials, in addition to immune monotherapy, combinations of immunotherapy and radiotherapy have shown surprising efficacy. In this article, we review the research progress of immune monotherapy and combination therapy for advanced melanoma, with the aim of providing new ideas for the treatment strategy for advanced melanoma.

Immunotherapy in melanoma: Can we predict response to treatment with circulating biomarkers?

Melanoma is the most aggressive form of skin cancer, representing approximately 4% of all cutaneous neoplasms and accounting for up to 80% of deaths. Advanced stages of melanoma involve metastatic processes and are associated with high mortality and morbidity, mainly due to the rapid dissemination and heterogeneous responses to current therapies, including immunotherapy. Immune checkpoint inhibitors (ICIs) are currently used in the treatment of metastatic melanoma (MM) and despite being linked to an increase in patient survival, a high percentage of them still do not benefit from it. Accordingly, the number of therapeutic regimens for MM patients using ICIs either alone or in combination with other therapies has increased, together with the need for reliable biomarkers that can both predict and monitor response to ICIs. In this context, circulating biomarkers, such as DNA, RNA, proteins, and cells, have emerged due to their ability to reflect disease status. Moreover, blood tests are minimally invasive and provide an attractive option to detect biomarkers, avoiding stressful medical procedures. This systematic review aims to evaluate the possibility of a non-invasive biomarker signature that can guide therapeutic decisions. The studies reported here offer valuable insight into how circulating biomarkers can have a role in personalized treatments for melanoma patients receiving ICIs therapy, emphasizing the need for rigorous clinical trials to confirm findings and establish standardized procedures.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Management of metastatic bone disease of melanoma

One of the most aggressive tumors arising from the skin, mucosa, and uvea is malignant melanoma, which easily metastasizes. Bone tissue is one of the most typical locations for distant metastasis, and around 5%-20% of patients eventually acquired skeletal metastases. For decades, the incidence of bone metastases was higher, bringing greater burden on the family, society, and healthcare system owing to the progress of targeted therapy and immunotherapy, which prolonging the survival time substantially. Moreover, bone metastases result in skeletal-related events, which influence the quality of life, obviously. Appropriate intervention is therefore crucial. To obtain the optimum cost-effectiveness, existing treatment algorithm must be integrated, which is still controversial. We have aimed to throw light on current views concerning the formation, biological and clinical features, and treatment protocol of melanoma bone metastases to guide the decision-making process.

Immunotherapy targeting different immune compartments in combination with radiation therapy induces regression of resistant tumors

Radiation therapy (RT) increases tumor response to CTLA-4 inhibition (CTLA4i) in mice and in some patients, yet deep responses are rare. To identify rational combinations of immunotherapy to improve responses we use models of triple negative breast cancer highly resistant to immunotherapy in female mice. We find that CTLA4i promotes the expansion of CD4+ T helper cells, whereas RT enhances T cell clonality and enriches for CD8+ T cells with an exhausted phenotype. Combination therapy decreases regulatory CD4+ T cells and increases effector memory, early activation and precursor exhausted CD8+ T cells. A combined gene signature comprising these three CD8+ T cell clusters is associated with survival in patients. Here we show that targeting additional immune checkpoints expressed by intratumoral T cells, including PD1, is not effective, whereas CD40 agonist therapy recruits resistant tumors into responding to the combination of RT and CTLA4i, indicating the need to target different immune compartments.

Five-year overall survival with ipilimumab and stereotactic ablative radiotherapy for metastatic disease

PURPOSE

Ipilimumab plus stereotactic ablative radiotherapy (SABR) demonstrate satisfactory short-term clinical benefit and low toxicities in metastatic cancers. Here, we report the 5-year overall survival (OS) rates for patients with metastatic disease treated with this combined-modality therapy in a phase II trial (NCT02239900).

METHODS AND MATERIALS

SABR was delivered to patients with metastatic lesions in the liver and lung either during the first dose (concurrent) or 1 week after the second dose (sequential) of ipilimumab (every 3 weeks for 4 cycles). SABR was administered to liver or lung metastases as 50 Gy in 4 fractions or 60 Gy in 10 fractions, considering the tumor location. The OS rates at 12, 36, and 60 months were estimated by the Kaplan-Meier method; subgroup analyses of progression-free survival (PFS) and OS by SABR-targeted lesions (liver/lung) were performed by log-rank tests.

RESULTS

A total of 106 patients were enrolled in this long-term follow-up analysis. At the median follow-up time of 15.32 months (range, 0.97-82.13 months), the median PFS was 6.52 months (95% CI, 5.86-7.14) and the median OS was 15.32 months (95% CI,13.03-17.23). The 12-, 36-, and 60-month OS rates were 61%, 23%, and 15%, respectively. There was a significant difference in OS between cohorts (P = 0.039), with a stronger response observed in lung-treated subgroups. Patients who had received sequential fractions (50 Gy/4f) to the lung had improved OS compared to those who had received sequential fractions (18.29 vs 8.9 months, P = 0.043) to the liver. Subgroup analysis of SABR-targeted lesions showed that lung-targeted groups had significantly longer PFS (6.87 months vs. 5.63 months, P = 0.034) and OS (18.67 months vs. 13.63 months, P = 0.013) compared to liver-targeted groups. The sequence did not affect the outcomes of PFS and OS. Exploratory analyses showed that SABR-targeted lesions and smoking history comprised an independent risk factor for OS.

CONCLUSIONS

Updated 5-year OS data from the phase II trial demonstrate the long-term clinical benefit of ipilimumab and SABR, which warrants further research and cumulative data.

Dose Limiting Pulmonary Toxicity in a Phase 1/2 Study of Radiation and Chemotherapy with Ipilimumab Followed by Nivolumab for Patients With Stage 3 Unresectable Non-Small Cell Lung Cancer

PURPOSE

We hypothesized that concurrent ipilimumab with chemoradiationtherapy (chemoRT) followed by maintenance nivolumab would be safe for patients with unresectable stage III non-small cell lung cancer (NSCLC). We aimed to assess the safety (phase 1) and the 12-month progression-free survival (PFS) (phase 2) in a multi-institution prospective trial.

METHODS AND MATERIALS

Eligible patients had unresectable stage III NSCLC. The treatment included platinum doublet chemotherapy with concurrent thoracic radiation therapy to 60 Gy in 30 fractions and ipilimumab (1 mg/kg) delivered during weeks 1 and 4. After chemoRT, maintenance nivolumab (480 mg) was given every 4 weeks for up to 12 cycles. Adverse events (AEs) were assessed according to the Common Terminology Criteria for Adverse Events, version 5.0. Survival analyses were performed with Kaplan Meier (KM) methods and log-rank tests.

RESULTS

The trial was discontinued early after enrolling 19 patients without proceeding to the phase 2 component because of unacceptable toxicity. Sixteen patients (84%) had grade ≥3 (G3+) possible treatment-related toxicity, most commonly pulmonary AEs (n = 8, 42%). Fourteen patients (74%) discontinued study therapy early because of AEs (n = 12, 63%) or patient choice (n = 2, 11%). Eleven patients (58%) experienced G2+ pulmonary toxicity with median time to onset 4.1 months (95% CI 2.6-not reached [NR]), and 12-month freedom from G2+ pulmonary toxicity 37% (95% CI, 16-59). Five patients had G5 AEs, including 3 with G5 pulmonary AEs (1 respiratory failure with pneumonitis and pulmonary embolism, 1 pneumonia/chronic obstructive pulmonary disease exacerbation, 1 pulmonary fibrosis). Despite toxicities, the median PFS was 19.2 months (95% CI 6.1-NR) and the median overall survival was NR (95% CI 6.1-NR) with median follow-up of 30.1 months by the reverse KM method.

CONCLUSIONS

Concurrent ipilimumab with chemoRT for unresectable stage III NSCLC is associated with pulmonary toxicity that may limit opportunities for improved outcomes. Future studies aiming to incorporate ipilimumab or other anti-CTLA4 therapies into management of unresectable stage III NSCLC should consider careful measures to minimize toxicity risk.

Induction chemoimmunotherapy followed by CD8+ immune cell-based patient selection for chemotherapy-free radioimmunotherapy in locally advanced head and neck cancer

PURPOSE

The first aim of the trial is to study feasibility of combined programmed death protein ligand 1/cytotoxic T-lymphocyte-associated protein 4 inhibition concomitant to radiotherapy. In addition, efficacy of the entire treatment scheme consisting of induction chemoimmunotherapy followed by chemotherapy-free radioimmunotherapy (RIT) after intratumoral CD8 +immune cell-based patient selection will be analyzed.

METHODS

Patients with stage III-IVB head and neck squamous cell carcinoma were eligible for this multicenter phase II trial. Treatment consisted of a single cycle of cisplatin 30 mg/m² days 1-3, docetaxel 75 mg/m² day 1, durvalumab 1500 mg fix dose day 5 and tremelimumab 75 mg fix dose day 5. Patients with increased intratumoral CD8 +immune cell density or pathological complete response (pCR) in the rebiopsy entered RIT up to a total dose of 70 Gy. Patients received further three cycles of durvalumab/tremelimumab followed by eight cycles of durvalumab mono (every 4 weeks). The intended treatment for patients not meeting these criteria was standard radiochemotherapy outside the trial. Primary endpoint was a feasibility rate of patients entering RIT to receive treatment until at least cycle 6 of immunotherapy of ≥80%.

RESULTS

Between September 2018 and May 2020, 80 patients were enrolled (one excluded). Out of these, 23 patients had human papilloma virus (HPV)-positive oropharyngeal cancer. Median follow-up was 17.2 months. After induction chemoimmunotherapy 41 patients had pCR and 31 had increased intratumoral CD8 +immune cells. Of 60 patients entering RIT (primary endpoint cohort), 10 experienced imiting toxic (mainly hepatitis) and four discontinued for other reasons, resulting in a feasibility rate of 82%. The RIT cohort (n=60) had a progression-free survival (PFS) rate at one and 2 years of 78% and 72%, respectively, and an overall survival rate at one and 2 years of 90% and 84%, respectively. Patients with HPV-positive oropharyngeal cancers had greater benefit from RIT with a 2-year PFS rate of 94% compared with 64% for HPV-negative oropharyngeal cancers and other locations. In the entire study cohort (n=79) the 2-year PFS rate was 68% (91% for HPV-positive oropharynx vs 59% for others). Toxicity grade 3-4 mainly consisted of dysphagia (53%), leukopenia (52%) and infections (32%).

CONCLUSIONS

The trial met the primary endpoint feasibility of RIT. Induction chemo-immunotherapy followed by chemotherapy-free RIT after intratumoral CD8 +immune cell-based patient selection has promising PFS.

TRIAL REGISTRATION NUMBER

The trial was registered with ClinicalTrials.gov (identifier: NCT03426657). The trial was conducted as investigator-sponsored trial (IST).

Effectiveness and safety of immune checkpoint inhibitors in combination with palliative radiotherapy in advanced melanoma: A systematic review

BACKGROUND

Radiotherapy is frequently added to immune checkpoint inhibitors (ICI) when treating melanoma. We sought to describe the efficacy of combination ICI and palliative radiotherapy (pRT) and assess safety, focusing on immune related adverse events (irAE).

METHODS

A systematic search for studies investigating the combination of pRT and ICI was conducted.

RESULTS

Five hundred-two articles were identified; nine met inclusion criteria. Improvements in objective response rate (p = 0.02), complete response (p = 0.04), and one-year local control (p < 0.005) were demonstrated when pRT was added to ICI. While some studies revealed improved overall and progression free survival, findings were mixed. No significant increases in adverse events or irAE were seen with the combined treatment compared with ICI alone.

CONCLUSION

The included studies revealed that the addition of pRT to ICI is effective and safe in patients with advanced melanoma. Measures of survival varied. More studies are warranted to identify optimal conditions for combination treatment.

Kickstarting Immunity in Cold Tumours: Localised Tumour Therapy Combinations With Immune Checkpoint Blockade

Cancer patients with low or absent pre-existing anti-tumour immunity ("cold" tumours) respond poorly to treatment with immune checkpoint inhibitors (ICPI). In order to render these patients susceptible to ICPI, initiation of de novo tumour-targeted immune responses is required. This involves triggering of inflammatory signalling, innate immune activation including recruitment and stimulation of dendritic cells (DCs), and ultimately priming of tumour-specific T cells. The ability of tumour localised therapies to trigger these pathways and act as in situ tumour vaccines is being increasingly explored, with the aspiration of developing combination strategies with ICPI that could generate long-lasting responses. In this effort, it is crucial to consider how therapy-induced changes in the tumour microenvironment (TME) act both as immune stimulants but also, in some cases, exacerbate immune resistance mechanisms. Increasingly refined immune monitoring in pre-clinical studies and analysis of on-treatment biopsies from clinical trials have provided insight into therapy-induced biomarkers of response, as well as actionable targets for optimal synergy between localised therapies and ICB. Here, we review studies on the immunomodulatory effects of novel and experimental localised therapies, as well as the re-evaluation of established therapies, such as radiotherapy, as immune adjuvants with a focus on ICPI combinations.

Radiotherapy-Immunotherapy Combination: How Will We Bridge the Gap Between Pre-Clinical Promise and Effective Clinical Delivery?

Radiotherapy (RT) is highly effective at directly killing tumor cells and plays an important part in cancer treatments being delivered to around 50% of all cancer patients. The additional immunomodulatory properties of RT have been investigated, and if exploited effectively, have the potential to further improve the efficacy of RT and cancer outcomes. The initial results of combining RT with immunomodulatory agents have generated promising data in pre-clinical studies, which has in turn led to a large number of RT and immunotherapy clinical trials. The overarching aim of these combinations is to enhance anti-tumor immune responses and improve responses rates and patient outcomes. In order to maximize this undoubted opportunity, there remain a number of important questions that need to be addressed, including: (i) the optimal RT dose and fractionation schedule; (ii) the optimal RT target volume; (iii) the optimal immuno-oncology (IO) agent(s) to partner with RT; (iv) the optimal site(s)/route(s) of administration of IO agents; and finally, the optimal RT schedule. In this review, we will summarize progress to date and identify current gaps in knowledge that need to be addressed in order to facilitate effective clinical translation of RT and IO agent combinations.

Fine-Tuning the Tumour Microenvironment: Current Perspectives on the Mechanisms of Tumour Immunosuppression

Immunotherapy has revolutionised the treatment of cancers by harnessing the power of the immune system to eradicate malignant tissue. However, it is well recognised that some cancers are highly resistant to these therapies, which is in part attributed to the immunosuppressive landscape of the tumour microenvironment (TME). The contexture of the TME is highly heterogeneous and contains a complex architecture of immune, stromal, vascular and tumour cells in addition to acellular components such as the extracellular matrix. While understanding the dynamics of the TME has been instrumental in predicting durable responses to immunotherapy and developing new treatment strategies, recent evidence challenges the fundamental paradigms of how tumours can effectively subvert immunosurveillance. Here, we discuss the various immunosuppressive features of the TME and how fine-tuning these mechanisms, rather than ablating them completely, may result in a more comprehensive and balanced anti-tumour response.