402MO Final results of the CARACAS study: Randomized phase II trial of avelumab alone or with cetuximab for unresectable, locally advanced or metastatic squamous cell anal carcinoma progressed to at least one line of treatment

Immunological Checkpoint Blockade in Anal Squamous Cell Carcinoma: Dramatic Responses Tempered By Frequent Resistance

PURPOSE OF REVIEW

Squamous cell carcinoma of the anus (SCCA) is an HPV-associated malignancy that has limited treatment options. Immunotherapy has expanded these options and here we review current and emerging immunotherapeutic approaches.

RECENT FINDINGS

Multiple studies of single-agent anti-PD1/PD-L1 immunotherapy have demonstrated a modest response rate of approximately 10% to 15%. While a minority of patients (~5%) with SCCA experience durable complete responses, most advanced SCCAs are resistant to anti-PD1/PD-L1 monotherapy. Given the need for more broadly effective immunotherapies, novel strategies, such as adaptive cell therapies and therapeutic vaccination, are being explored. To reduce the recurrence risk of localized high-risk SCCA, strategies combining immunotherapy with chemoradiation are also being investigated. While a small subset of patients with SCCA have prolonged responses to PD1-directed immunotherapy, the majority do not derive clinical benefit, and new immunotherapeutic strategies are needed. Better understanding of the immune microenvironment and predictive biomarkers could accelerate therapeutic advances.

Combining Anti-epidermal Growth Factor Receptor (EGFR) Therapy with Immunotherapy in Metastatic Colorectal Cancer (mCRC)

INTRODUCTION

Monoclonal antibodies binding the EGFR, such as cetuximab and panitumumab, have been extensively used as targeted therapy for the treatment of mCRC. However, in clinical practice, it has been found that these treatment options have some limitations and fail to fully exploit their immunoregulatory activities. Meanwhile, because of the limited effects of current treatments, immunotherapy is being widely studied for patients with mCRC. However, previous immunotherapy trials in mCRC patients have had unsatisfactory outcomes as monotherapy. Thus, combinatorial treatment strategies are being researched.

AREAS COVERED

The authors retrieved relevant documents of combination therapy for mCRC from PubMed and Medline. This review elaborates on the knowledge of immunomodulatory effects of anti-EGFR therapy alone and in combination with immunotherapy for mCRC.

EXPERT OPINION

Although current treatment options have improved median overall survival (OS) for advanced disease to 30 months, the prognosis remains challenging for those with metastatic disease. More recently, the combination of anti-EGFR therapy with immunotherapy has been shown activity with complementary mechanisms. Hence, anti-EGFR therapy in combination with immunotherapy may hold the key to improving the therapeutic effect of refractory mCRC.

A Phase II Study Evaluating the Interest to Combine UCPVax, a Telomerase CD4 TH1-Inducer Cancer Vaccine, and Atezolizumab for the Treatment of HPV Positive Cancers: VolATIL Study

Background

There is a strong rational of using anti–programmed cell death protein-1 and its ligand (anti–PD-1/L1) antibodies in human papillomavirus (HPV)–induced cancers. However, anti–PD-1/L1 as monotherapy induces a limited number of objective responses. The development of novel combinations in order to improve the clinical efficacy of an anti–PD-1/L1 is therefore of interest. Combining anti–PD-1/L1 therapy with an antitumor vaccine seems promising in HPV-positive (+) cancers. UCPVax is a therapeutic cancer vaccine composed of two separate peptides derived from telomerase (hTERT, human telomerase reverse transcriptase). UCPVax is being evaluated in a multicenter phase I/II study in NSCLC (non–small cell lung cancer) and has demonstrated to be safe and immunogenic. The aim of the VolATIL study is to evaluate the combination of atezolizumab (an anti-PD-L1) and UCPVax vaccine in a multicenter phase II study in patients with HPV⁺ cancers.

Methods

Patients with HPV⁺ cancer (anal canal, head and neck, and cervical or vulvar), at locally advanced or metastatic stage, and refractory to at least one line of systemic chemotherapy are eligible. The primary end point is the objective response rate (ORR) at 4 months. Patients will receive atezolizumab every 3 weeks at a fixed dose of 1,200 mg in combination with the UCPVax vaccine at 1 mg subcutaneously.

Discussion

Anti-cancer vaccines can restore cancer-immunity via the expansion and activation of tumor-specific T cells in patients lacking pre-existing anti-tumor responses. Moreover, preclinical data showed that specific T_H1 CD4 T cells sustain the quality and homing of an antigen-specific CD8⁺ T-cell immunity. In previous clinical studies, the induction of anti-hTERT immunity was significantly correlated to survival in patients with advanced squamous anal cell carcinoma. Thus, there is a strong rational to combine an anti-cancer hTERT vaccine and an immune checkpoint inhibitor to activate and promote antitumor T-cell immunity. This pivotal proof of concept study will evaluate the efficacy and safety of the combination of a telomerase-based T_H1 inducing vaccine (UCPVax) and an anti–PD-L1 (atezolizumab) immunotherapy in HPV⁺ cancers, as well as confirming their synergic mechanism, and settling the basis for a new combination for future clinical trials.

Clinical Trial Registration

https://www.clinicaltrials.gov/, identifier NCT03946358.

A phase II study of retifanlimab (INCMGA00012) in patients with squamous carcinoma of the anal canal who have progressed following platinum-based chemotherapy (POD1UM-202)

Background

Locally advanced or metastatic squamous carcinoma of the anal canal (SCAC) has poor prognosis following platinum-based chemotherapy. Retifanlimab (INCMGA00012), a humanized monoclonal antibody targeting programmed death protein-1 (PD-1), demonstrated clinical activity across a range of solid tumors in clinical trials. We present results from POD1UM-202 (NCT03597295), an open-label, single-arm, multicenter, phase II study evaluating retifanlimab in patients with previously treated advanced or metastatic SCAC.

Patients and methods

Patients ≥18 years of age had measurable disease and had progressed following, or were ineligible for, platinum-based therapy. Retifanlimab 500 mg was administered intravenously every 4 weeks. The primary endpoint was overall response rate (ORR) by independent central review. Secondary endpoints were duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety.

Results

Overall, 94 patients were enrolled. At a median follow-up of 7.1 months (range, 0.9-19.4 months), ORR was 13.8% [95% confidence interval (CI) 7.6% to 22.5%], with one complete response (1.1%) and 12 partial responses (12.8%). Responses were observed regardless of human immunodeficiency virus or human papillomavirus status, programmed death ligand 1 (PD-L1) expression, or liver metastases. Stable disease was observed in 33 patients (35.1%) for a DCR of 48.9% (95% CI 38.5% to 59.5%). Median DOR was 9.5 months (range, 5.6 months-not estimable). Median (95% CI) PFS and OS were 2.3 (1.9-3.6) and 10.1 (7.9-not estimable) months, respectively. Retifanlimab safety in this population was consistent with previous experience for the PD-(L)1 inhibitor class.

Conclusions

Retifanlimab demonstrated clinically meaningful and durable antitumor activity, and an acceptable safety profile in patients with previously treated locally advanced or metastatic SCAC who have progressed on or are intolerant to platinum-based chemotherapy.

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Retifanlimab (PD-1 inhibitor) monotherapy demonstrated encouraging results in patients with platinum-refractory SCAC.

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Clinically meaningful antitumor activity was reported with ORR of 13.8% and stable disease in 35.1%, for a DCR of 48.9%.

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Observed responses in advanced SCAC were durable (median 9.5 months).

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Acceptable safety profile consistent with that reported for the PD-(L)1 inhibitor class.

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Promising results warrant further investigation of retifanlimab in advanced SCAC as well as earlier stages of disease.

The Role of Immunotherapy in the Treatment of Anal Cancer and Future Strategies

OPINION STATEMENT

Despite being markedly sensitive to chemoradiotherapy, patients with locally advanced (T3-4 and/or node-positive) squamous cell carcinoma of the anal canal (SCCA) still present high rates of disease recurrence, which is characterized by meaningful morbidity and mortality. Abdominoperineal resection as salvage surgery may be considered for patients with local recurrence, but with an important negative impact in the quality of life. Systemic therapy of advanced SCCA is an unmet clinical need. Palliative chemotherapy for the management of unresectable or metastatic disease yields approximately 60% of objective response rate; however, it still portends a grim prognosis. Based on the recently published InterAACT trial, carboplatin plus paclitaxel has become the standard of care of advanced disease; modified DCF (docetaxel, cisplatin, and 5-fluorouracil) may also be considered for fit patients amenable to intensive therapy. There are no FDA-approved therapies for the treatment of chemorefractory patients. Nevertheless, both nivolumab and pembrolizumab may be considered for these patients with promising results, regardless of PD-L1 expression or other predictive biomarkers. It is estimated that approximately 1 out of 5 patients with SCCA will derive large benefit from PD-1 inhibitors, which may produce considerable durations of response. Ongoing clinical trials exploring the combination of chemotherapy plus immune checkpoint inhibitors in the first-line therapy, combination of anti-PD-1/PD-L1 plus anti-CTLA-4, and emerging immunotherapeutic approaches, such as adoptive T cell therapies, are eagerly awaited and may bring practice-changing results in the next few years for the treatment of this challenging disease.

Anal Cancer: Emerging Standards in a Rare Rare Disease

The social stigma surrounding an anal cancer diagnosis has traditionally prevented open discussions about this disease. However, as recent treatment options and an increasing rate of diagnoses are made worldwide, awareness is growing. In the United States alone, 9,090 individuals were expected to be diagnosed with anal cancer in 2021. The US annual incidence of squamous cell carcinoma of the anus continues to increase by 2.7% yearly, whereas the mortality rate increases by 3.1%. The main risk factor for anal cancer is a human papillomavirus infection; those with chronic immunosuppression are also at risk. Patients with HIV are 19 times more likely to develop anal cancer compared with the general population. In this review, we have provided an overview of the carcinoma of the anal canal, the role of screening, advancements in radiation therapy, and current trials investigating acute and chronic treatment-related toxicities. This article is a comprehensive approach to presenting the existing data in an effort to encourage continuous international interest in anal cancer.

Second-line treatment after docetaxel, cisplatin and 5-fluorouracil in metastatic squamous cell carcinomas of the anus. Pooled analysis of prospective Epitopes-HPV01 and Epitopes-HPV02 studies

BACKGROUND

Squamous cell carcinoma of the anus (SCCA) is a rare disease often diagnosed at a localised stage. For locally advanced recurrence or metastatic disease, DCF (docetaxel, cisplatin, 5-fluorouracil) demonstrated high efficacy and became one of the standard regimens. However, there is no standard of care in the second line.

PATIENTS AND METHODS

In the Epitopes-HPV01 and Epitopes-HPV02 prospective trials, 115 patients with advanced SCCA were treated with a DCF regimen in the first line. In these studies, second-line data were registered per protocol.

RESULTS

After a median follow-up of >40 months, at progression, 73 patients received a second-line (L2) treatment. In this L2 population, median overall survival (mOS) was 13.5 months (95%CI 9.4-19.8), and median progression-free survival (mPFS) was 5.7 months (3.4-7.3) in L2. Fourteen patients presented an oligometastatic progression and were treated with an ablative treatment (surgery or radiotherapy); mOS was 48.3 months (NE-NE), and mPFS was 31.3 months (23.2-NE). Fifty-nine patients received a systemic treatment (chemotherapy or immunotherapy); mOS was 11 months (8.4-15.4) and mPFS was 4.9 months (3.3-7). The most frequent chemotherapy regimens were the reintroduction of DCF, paclitaxel, FOLFIRI and mitomycin plus fluoropyrimidine. No significant difference was observed between regimens (p = 0.26). Six patients received anti-PD1/L1-based immunotherapy.

CONCLUSION

Second-line treatments are effective in patients with SCCA. Ablative treatment is feasible and is probably the best option for patients with oligometastatic progression. If this is not possible, systemic therapy by an anti-PD1/L1 immunotherapy or chemotherapy can be recommended. Reintroduction of DCF, paclitaxel, FOLFIRI or mitomycin-C plus fluoropyrimidine are possible options.

Present and Future Research on Anal Squamous Cell Carcinoma

Squamous cell carcinoma of the anus is an orphan disease, and after more than three decades of no substantial advances in disease knowledge and treatment, it is finally gaining momentum with the arrival of a taxane-based chemotherapy and immunotherapy. Currently, about 20 combination clinical trials with an anti-PD1/L1 are ongoing in localized and advanced stages, in association with radiotherapy, chemotherapy, tumor vaccines, anti-CTLA4, anti-EGFR, or antiangiogenic molecules. Moreover, a new biomarker with high sensitivity and specificity such as HPV circulating tumor DNA (HPV ctDNA) by liquid biopsy, is improving not only the prognostic measurement but also the treatment strategy guidance for this disease. Finally, better understanding of potential targets is reshaping the present and future clinical research in this unique, HPV genotype-16-related disease in the great majority of patients.

Anal squamous cell carcinoma: standards of care, new data and ongoing clinical trials

PURPOSE OF REVIEW

To summarize current standards of care, discuss results of recent studies and present ongoing clinical trials for anal squamous cell carcinoma (ASCC).

RECENT FINDINGS

Over the last year, no practice changing studies have been reported in the setting of localised ASCC. A number of retrospective analyses, however, have provided practice-informing data, such as those confirming the negative impact of low compliance to chemoradiotherapy (CRT) on patient outcomes. In contrast, and for the first time, randomized evidence has become available to inform the management of advanced tumours. The InterAACT trial represents a key milestone in the evidence-building process for this disease, establishing carboplatin plus paclitaxel as a new standard of care for treatment-naïve advanced ASCC patients. Furthermore, more data have accumulated about the value of triplet chemotherapy in the first-line setting and of immune checkpoint inhibitors (either as single agents or in combination with other agents) in the refractory setting.

SUMMARY

Recent findings have the potential to improve the treatment quality standards and overall outcome of patients with either localised or advanced ASCC. Results from ongoing clinical trials will hopefully provide useful insights into the management of this disease and further shape current treatment paradigms.

Emerging and Experimental Agents for Anal Cancer: What is New?

Squamous cell carcinoma of the anal canal (SCCA) is an HPV-related malignancy with rising incidence in the past few decades in the US, characterized by high rates of complete response to chemoradiotherapy with curative intent. However, in a long-term follow-up, a meaningful subgroup of patients with locally advanced disease presents disease recurrence, which demands treatments with high morbidity and important impact in the quality of life. In metastatic or unresectable disease, palliative chemotherapy is the standard of care, but it is still associated with a dismal prognosis. Novel agents are urgently needed in the systemic therapy of SCCA. From a translational standpoint, there are many hurdles to overcome, since PI3KCA mutation is the most frequent genetic abnormality and actionable mutations are rarely found in SCCA, as well as it is characterized by low tumor mutational burden and low rates of high-frequency microsatellite instability. But the latest studies of immunotherapeutic approaches have produced promising findings and this therapeutic strategy is the major path being followed in the ongoing clinical trials. The latest advances in the systemic therapy of SCCA have provided the framework for the conception of new clinical trials. Therefore, carboplatin plus paclitaxel have become the backbone for novel agents. Immune checkpoint inhibitors (ICIs), mainly anti-PD-1 monoclonal antibodies, such as retifanlimab, nivolumab, and atezolizumab have been studied in Phase III trials with chemotherapy in first-line therapy. Likewise, ICIs have been evaluated in locally advanced and refractory disease. Novel technologies, such as bispecific antibodies, and immunotherapeutic approaches, such as vaccines and adoptive T-cell therapies, have also been tested in ongoing clinical trials. Immunotherapy may bring practice-changing advances in the systemic therapy of SCCA in the next few years and it might play a larger role in the therapeutic management of this challenging disease.

Clinical Practice Guideline: Anal Cancer—Diagnosis, Treatment and Follow-up

BACKGROUND

The number of anal cancer diagnoses has been rising steadily, so that the incidence has doubled in the past 20 years. Almost all anal cancers are induced by persistent infection with human papillomaviruses. Hitherto the care of patients with anal cancer has been heterogeneous and little experience exists with the primary management of anal cancer.

METHODS

The guideline was developed in accordance with the requirements of the German Guideline Program in Oncology. In line with the GRADE approach, the certainty of the evidence was assessed on the outcome level following a systematic literature search. Interdisciplinary working groups were set up to compile suggestions for recommendations, which were discussed and agreed upon in a formal consensus conference.

RESULTS

Ninety-three recommendations and statements were developed. No high-quality evidence was available to support recommendations for or against the treatment of stage I anal cancer with local excision alone as an alternative to chemoradiotherapy. Chemoradiotherapy is the gold standard in the treatment of stages II–III. Among other aspects regarding the timing and extent of response evaluation after chemoradiotherapy, the guideline panel recommended against obtaining a biopsy in the event of complete clinical response. Owing to lack of confidence in the available evidence, only open recommendations were given for treatment of stage IV.

CONCLUSION

This evidence-based clinical practice guideline provides a sound basis for optimizing the interdisciplinary, cross-sector care of anal cancer patients. Among other areas, gaps in research were identified with respect to the care of patients with early-stage or metastatic anal cancer. Approaches such as chemoradiotherapy combined with regional deep hyperthermia require further investigation. The role for immunotherapy in the management of metastasized anal cancer has also been insufficiently explored to date.

Avelumab and cetuximab as a therapeutic combination: An overview of scientific rationale and current clinical trials in cancer

Treatment outcomes have improved with the advent of immune checkpoint inhibitors and small molecule inhibitors. However, many patients do not respond with single agents. Consequently, ongoing research is focused on the use of combination therapies to increase clinical efficacy by potential synergistic effects. Here, we outline ongoing trials and review the rationale and evidence for the combination of avelumab, an anti-programmed death ligand 1 (PD-L1) immunoglobulin G1 (IgG1) monoclonal antibody (mAb), with cetuximab, an anti-epidermal growth factor receptor (EGFR) IgG1 mAb. Avelumab is approved as a monotherapy for the treatment of Merkel cell carcinoma and urothelial carcinoma, and in combination with axitinib for renal cell carcinoma; cetuximab is approved in combination with chemotherapy for the treatment of squamous cell carcinoma of the head and neck (SCCHN) and RAS wild-type metastatic colorectal cancer, and in combination with radiation therapy for SCCHN. Avelumab binds to PD-L1 expressed on tumor cells and immune regulatory cells, thus blocking its interaction with programmed death 1 and reventing T-cell suppression; cetuximab inhibits the EGFR signaling pathway, inhibiting proliferation and inducing apoptosis. Both therapies have complementary mechanisms of action and may also activate the immune system to induce innate effector function through the binding of their Fc regions to natural killer (NK) cells. Furthermore, cetuximab combined with chemotherapy has been shown to induce immunogenic cell death and leads to an increase in tumor-infiltrating CD8+ T and NK cells, which should synergize with the immunostimulatory effects of avelumab. Prospective studies will investigate this combination and inform future treatment strategies.

[Squamous cell anal carcinoma. What's next ?]

Despite its status as a rare disease, the incidence of the squamous cell carcinoma of the anus (SCCA) is surging, especially in its metastatic form. In addition, the prognosis of initially localized diseases has not substantially changed since the 1970s with a recurrence rate of between 25-40 % after the chemoradiotherapy. The updated data from 115 patients included in the Epitopes-HPV01 and Epitopes-HPV02 trials, confirm the modified regimen of DCF (mDCF) as the treatment of choice for patients with advanced SCCA given the rate of sustained remissions and complete molecular responses observed. The carboplatin-paclitaxel regimen may be considered as an option for patients with contraindication to cisplatin or 5-FU. In chemo-refractory patients, the efficacy of anti-PD-1/PD-L1 in monotherapy is limited and only brings benefit to 10-20 % of patients, and its use cannot be generalized in the absence of an association potentiating its effectiveness. In order to better understand the immunological parameters associated with advanced SCCA, an analysis of peripheral immune responses was carried out in the Epitopes-HPV01 and 02 trials. It demonstrated the key role of CD4 Th1 specific responses of telomerase and M-MDSC as main prognostic factors for the therapeutic efficacy of DCF. Numerous combination trials are currently underway or will soon begin in localized SCCA, as well as in the first and second-line in the advanced stage. Finally, the detection of circulating tumor DNA of HPV oncoprotein E6 and E7 (HPVtc), especially by the "digital droplet PCR" technique, is highly sensitive and specific, and can be used in daily practice.