Experimental investigation of skin toxicity after immune checkpoint inhibition in combination with radiation therapy

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy. However, structured knowledge to mitigate a patient's specific risk of developing adverse events are limited. Nevertheless, there is an exponential growth of clinical studies combining conventional therapies such as radiation therapy (RT) with ICIs. Cutaneous reactions are amongst the most common adverse events after monotherapy with either ICIs or RT. So far, little is known about inter-individual differences in the risk of developing severe tissue toxicity after the combination of RT with ICIs, and the underlying biological mechanisms are ill defined. We used experimental models of RT-induced skin injury to analyze skin toxicity after simultaneous application of ICIs. We compared different RT regimens such as fractionated or stereotactic RT with varying dose intensity. Strikingly, we found that simultaneous application of RT and ICIs did not significantly aggravate acute skin injury in two different mouse strains. Detailed examination of long-term tissue damage of the skin revealed similar signs of epidermal hyperplasia, dermal fibrosis, and adnexal atrophy. In summary, we here present the first experimental study demonstrating excellent safety profiles of concurrent treatment with RT and ICIs. These findings will help to interpret the development of adverse events of the skin after radioimmunotherapy and guide the design of new clinical trials and clinical decision making in individual cases. This article is protected by copyright. All rights reserved.

Safety and Tolerability of Metastasis Directed Radiotherapy in the Era of Evolving Systemic, Immune and Targeted Therapies

AbstractPurpose

Systemic, immune, and target therapies are growing in use in the management of metastatic cancers. The aim of this review was to describe up-to-date published data on the safety and tolerability of metastasis-directed hypofractionated radiation therapy (RT) when combined with newer systemic, immune, and targeted therapies and to provide suggested strategies to mitigate potential toxicities in the clinical setting.

Methods and Materials

A comprehensive search was performed for the time period between 1946 and August 2021 using predetermined keywords describing the use of noncentral nervous system palliative RT with commonly used targeted systemic therapies on PubMed and Medline databases. A total of 1022 articles were screened, and 130 met prespecified criteria to be included in this review.

Results

BRAF and MEK inhibitors are reported to be toxic when given concurrently with RT; suspension 3 days and 1 to 2 days, respectively, prior and post-RT is suggested. Cetuximab, erlotinib/gefitinib, and osimertinib were generally safe to use concomitantly with conventional radiation. But in a palliative/hypofractionated RT setting, suspending cetuximab during radiation week, erlotinib/gefitinib 1 to 2 days, and osimertinib ≥2 days pre- and post-RT is suggested. Vascular endothelial growth factor inhibitors such as bevacizumab reported substantial toxicities, and the suggestion is to suspend 4 weeks before and after radiation. Less data exist on sorafenib and sunitinib; 5 to 10 days suspension before and after RT should be considered. As a precaution, until further data are available, for cyclin-dependent kinase 4-6 inhibitors, consideration of suspending treatment 1 to 2 days before and after RT should be given. Ipilimumab should be suspended 2 days before and after RT, and insufficient data exist for other immunotherapy agents. Trastuzumab and pertuzumab are generally safe to use in combination with RT, but insufficient data exist for other HER2 target therapy.

Conclusions

Suggested approaches are described, using up-to-date literature, to aid clinicians in navigating the integration of newer targeted agents with hypofractionated palliative and/or ablative metastatic RT. Further prospective studies are required.

Targeting RAS–RAF–MEK–ERK signaling pathway in human cancer: Current status in clinical trials

Molecular target inhibitors have been regularly approved by Food and Drug Administration (FDA) for tumor treatment, and most of them intervene in tumor cell proliferation and metabolism. The RAS-RAF-MEK-ERK pathway is a conserved signaling pathway that plays vital roles in cell proliferation, survival, and differentiation. The aberrant activation of the RAS-RAF-MEK-ERK signaling pathway induces tumors. About 33% of tumors harbor RAS mutations, while 8% of tumors are driven by RAF mutations. Great efforts have been dedicated to targeting the signaling pathway for cancer treatment in the past decades. In this review, we summarized the development of inhibitors targeting the RAS-RAF-MEK-ERK pathway with an emphasis on those used in clinical treatment. Moreover, we discussed the potential combinations of inhibitors that target the RAS-RAF-MEK-ERK signaling pathway and other signaling pathways. The inhibitors targeting the RAS-RAF-MEK-ERK pathway have essentially modified the therapeutic strategy against various cancers and deserve more attention in the current cancer research and treatment.

Brain metastases: An update on the multi-disciplinary approach of clinical management

IMPORTANCE

Brain metastasis (BM) is the most common malignant intracranial neoplasm in adults with over 100,000 new cases annually in the United States and outnumbering primary brain tumors 10:1.

OBSERVATIONS

The incidence of BM in adult cancer patients ranges from 10-40%, and is increasing with improved surveillance, effective systemic therapy, and an aging population. The overall prognosis of cancer patients is largely dependent on the presence or absence of brain metastasis, and therefore, a timely and accurate diagnosis is crucial for improving long-term outcomes, especially in the current era of significantly improved systemic therapy for many common cancers. BM should be suspected in any cancer patient who develops new neurological deficits or behavioral abnormalities. Gadolinium enhanced MRI is the preferred imaging technique and BM must be distinguished from other pathologies. Large, symptomatic lesion(s) in patients with good functional status are best treated with surgery and stereotactic radiosurgery (SRS). Due to neurocognitive side effects and improved overall survival of cancer patients, whole brain radiotherapy (WBRT) is reserved as salvage therapy for patients with multiple lesions or as palliation. Newer approaches including multi-lesion stereotactic surgery, targeted therapy, and immunotherapy are also being investigated to improve outcomes while preserving quality of life.

CONCLUSION

With the significant advancements in the systemic treatment for cancer patients, addressing BM effectively is critical for overall survival. In addition to patient's performance status, therapeutic approach should be based on the type of primary tumor and associated molecular profile as well as the size, number, and location of metastatic lesion(s).

Phase I/II trial of concurrent extracranial palliative radiation therapy with Dabrafenib and Trametinib in metastatic BRAF V600E/K mutation-positive cutaneous Melanoma

Background

Concurrent treatment with BRAF inhibitors and palliative radiation therapy (RT) could be associated with increased toxicity, especially skin toxicity. Current Eastern Cooperative Oncology Group (ECOG) consensus guideline recommend ceasing BRAF inhibitors during RT. There is a lack of data regarding concurrent RT with combined BRAF and MEK inhibitors. This single-arm phase I/II trial was designed to assess the safety and tolerability of palliative RT with concurrent Dabrafenib and Trametinib in patients with BRAF-mutant metastatic melanoma.

Materials and methods

Patients received Dabrafenib and Trametinib before and during palliative RT to soft tissue, nodal or bony metastases. The RT dose was escalated stepwise during the study period. Toxicity data including clinical photographs of the irradiated area was collected for up to 12 months following completion of RT.

Results

Between June 2016 to October 2019, ten patients were enrolled before the study was stopped early due to low accrual rate. Six patients were treated at level 1 (20 Gy in 5 fractions, any location) and 4 patients at level 2a (30 Gy in 10 fractions with no abdominal viscera exposed). All alive patients completed one year of post-RT follow-up. Of the 82 adverse events (AEs) documented, the majority (90%) were grade 1 and 2. Eight grade 3 events (10%) occurred in five patients, only one was treatment-related (grade 3 fever due to Dabrafenib and Trametinib). No patients experienced grade 3 or 4 RT related toxicities, including skin toxicities. One serious AE was documented in relation to a grade 3 fever due to Dabrafenib and Trametinib requiring hospitalisation.

Conclusions

The lack of grade 3 and 4 RT-related toxicities in our study suggests that Dabrafenib and Trametinib may be continued concurrently during fractionated non-visceral palliative RT to extracranial sites.

Toxicity of combined targeted therapy and concurrent radiotherapy in metastatic melanoma patients: a single-center retrospective analysis

Supplemental Digital Content is available in the text.

The Eastern Cooperative Oncology Group consensus guidelines from 2016 recommend interruption of targeted therapy with BRAF- and MEK-inhibitors during radiotherapy with data being based mostly on BRAF monotherapy. The aim of this study is to provide data on the safety of concurrent radiotherapy and combination targeted therapy with BRAF- and MEK-inhibitors. A total of 32 patients with 51 sessions of radiotherapy from one center receiving concurrent radiotherapy and BRAF- and MEK- inhibitors were included. Radiotherapy-associated toxicities were retrospectively collected. Incidence was compared between three groups: (A) targeted therapy during radiotherapy with and, (B) without interruption, and (C) radiotherapy before the start of targeted therapy. Survival and local disease control were examined. Targeted therapy was interrupted during radiotherapy in 16, not interrupted in 14, and only started after radiotherapy in 21 sessions. Stereotactic radiotherapy was applied in 28 sessions, conventionally fractionated radiotherapy in 23. The brain was the most common site of irradiation (n = 36). Radiotherapy-associated toxicities occurred in 41.2% (n = 21) of sessions and did not differ significantly among the groups. Overall survival was 11.7 months and progression-free survival was 8.4 months. No increase in radiotherapy-associated toxicity was seen where combination targeted therapy was not interrupted during radiotherapy. Prospective clinical trials are warranted to support our findings.

Kinase Inhibitors of DNA-PK, ATM and ATR in Combination with Ionizing Radiation Can Increase Tumor Cell Death in HNSCC Cells While Sparing Normal Tissue Cells

(1) Kinase inhibitors (KI) targeting components of the DNA damage repair pathway are a promising new type of drug. Combining them with ionizing radiation therapy (IR), which is commonly used for treatment of head and neck tumors, could improve tumor control, but could also increase negative side effects on surrounding normal tissue. (2) The effect of KI of the DDR (ATMi: AZD0156; ATRi: VE-822, dual DNA-PKi/mTORi: CC-115) in combination with IR on HPV-positive and HPV-negative HNSCC and healthy skin cells was analyzed. Cell death and cell cycle arrest were determined using flow cytometry. Additionally, clonogenic survival and migration were analyzed. (3) Studied HNSCC cell lines reacted differently to DDRi. An increase in cell death for all of the malignant cells could be observed when combining IR and KI. Healthy fibroblasts were not affected by simultaneous treatment. Migration was partially impaired. Influence on the cell cycle varied between the cell lines and inhibitors; (4) In conclusion, a combination of DDRi with IR could be feasible for patients with HNSCC. Side effects on healthy cells are expected to be limited to normal radiation-induced response. Formation of metastases could be decreased because cell migration is impaired partially. The treatment outcome for HPV-negative tumors tends to be improved by combined treatment.

Safety assessment of anticancer drugs in association with radiotherapy in metastatic malignant melanoma: a real-life report : Radiation/systemic drug combo in metastatic melanoma

PURPOSE

To assess the safety of the association of radiotherapy (RT) and systemic treatments for patients with metastatic malignant melanoma (mMM).

METHODS

A retrospective analysis included consecutive patients treated with palliative RT, and at least one line of systemic therapy for mMM between 2001 and 2016. Treatments were defined as sequential or concomitant when RT and the systemic drug were administered, respectively, at more or less than five half-lives from each other.

RESULTS

92 patients were included. They had 110 palliative RT treatments. RT was delivered with a "conventional" chemotherapy (mainly fotemustine and/or dacarbazine) and a "modern" systemic therapy (BRAF inhibitors, association of BRAF and MEK inhibitors, immunotherapy), respectively, in 88 (80%) and 22 (20%) cases. Systemic treatments and RT were mainly concurrently performed (n = 61, 55.5%). Regarding acute grade ≥ 3 toxicity, no difference was reported between sequential and concomitant groups either in the whole cohort (p = 1) or in the subgroup of patients receiving "modern" systemic therapies (p = 1). Acute and late grade ≥ 3 toxicities only occurred with vemurafenib. BRAF inhibitors and RT produced more severe infield adverse events than other associations (p = 0.001) with two deaths.

CONCLUSION

In our series, compared to sequential administration, concomitant association of systemic anticancer drugs and palliative RT did not increase toxicity in mMM patients. BRAF inhibitors and RT produced severe infield toxicities. Prospective studies are needed to better characterize the toxicity of each association.

Impact of radiation, systemic therapy and treatment sequencing on survival of patients with melanoma brain metastases

BACKGROUND

Combining stereotactic radiosurgery (SRS) and active systemic therapies (STs) achieved favourable survival outcomes in patients with melanoma brain metastases (MBMs) in retrospective analyses. However, several aspects of this treatment strategy remain poorly understood. We report on the overall survival (OS) of patients with MBM treated with a combination of radiotherapy (RT) and ST as well as the impact of the v-Raf murine sarcoma viral oncogene homolog B (BRAF)-V600 mutation (BRAFmut) status, types of RT and ST and their sequence.

PATIENTS AND METHODS

Data of 208 patients treated with SRS or whole brain radiation therapy (WBRT) and either immunotherapy (IT) or targeted therapy (TT) within a 6-week interval to RT were analysed retrospectively. OS was calculated from RT to death or last follow-up. Univariate and multivariate Cox proportional hazard analyses were performed to determine prognostic features associated with OS.

RESULTS

The median follow-up was 7.3 months. 139 patients received IT, 67 received TT and 2 received IT and TT within 6 weeks to RT (WBRT 45%; SRS 55%). One-year Kaplan-Meier OS rates were 69%, 65%, 33% and 18% (P < .001) for SRS with IT, SRS with TT, WBRT with IT and WBRT with TT, respectively. Patients with a BRAFmut receiving IT combined with RT experienced higher OS rates (88%, 65%, 50% and 18%). TT following RT or started before and continued thereafter was associated with improved median OS compared with TT solely before RT (12.2 [95% confidence interval {CI} 9.3-15.1]; 9.8 [95% CI 6.9-12.6] versus 5.1 [95% CI 2.7-7.5]; P = .03).

CONCLUSION

SRS and IT achieved the highest OS rates. A BRAFmut appears to be a favourable prognostic factor for OS. For the combination of RT and TT, the sequence appears to be crucial. Combinations of WBRT and ST achieved unprecedentedly high OS rates and warrant further studies.

Combination of novel systemic agents and radiotherapy for solid tumors - Part II: An AIRO (Italian association of radiotherapy and clinical oncology) overview focused on treatment toxicity

Clinical development and use of novel systemic agents in combination with radiotherapy (RT) is at nowadays most advanced in the field of treatment of solid tumors. Although for many of these substances preclinical studies provide sufficient evidences on their principal capability to enhance radiation effects, the majority of them have not been investigated in even phase I clinical trials for safety in the context of RT. In clinical practice, unexpected acute and late side effects may emerge especially in combination with RT. As a matter of fact, despite combined modality treatment holds potential for enhancing the therapeutic ratio, some concerns are raised from the lack of high-quality clinical data to guide the care of patients who are treated with novel compounds in conjunction with RT. The aim of this review is to provide, from a radio-oncological point of view, an overview of the most advanced combined treatment concepts for solid tumors focusing on treatment toxicity.

Cutaneous toxicities of new treatments for melanoma

New drugs against advanced melanoma have emerged during last decade. Target therapy and immunotherapy have changed the management of patients with metastatic disease. Along with its generalized use, drug toxicities have appeared and the skin is the target organ of a significant part of them. This revision summarizes the most common side effects and consensus management to improve the compliance of therapies and patients' quality of life. Among the BRAF inhibitors, main cutaneous side effects are photosensitivity, plantar hyperkeratosis, and the appearance of verrucal keratosis or squamous cell carcinoma. Special attention must be paid to the development of new primary melanomas or changes on nevi during BRAF inhibitor therapy. The most common cutaneous side effects of immunotherapy are rash, pruritus, and vitiligo. It remains controversial the possible role of these toxicities as markers of response to therapy.

Combined irradiation and targeted therapy or immune checkpoint blockade in brain metastases: toxicities and efficacy

Background

Targeted therapies (TT) and immune checkpoint inhibitors (ICI) are currently modifying the landscape of metastatic cancer management and are increasingly used over the course of many cancers treatment. They allow long-term survival with controlled extra-cerebral disease, contributing to the increasing incidence of brain metastases (BMs). Radiation therapy remains the cornerstone of BMs treatment (either whole brain irradiation or stereotactic radiosurgery), and investigating the safety profile of radiation therapy combined with TT or ICI is of high interest. Discontinuing an efficient systemic therapy, when BMs irradiation is considered, might allow systemic disease progression and, on the other hand, the mechanisms of action of these two therapeutic modalities might lead to unexpected toxicities and/or greater efficacy, when combined.

Patients and methods

We carried out a systematic literature review focusing on the safety profile and the efficacy of BMs radiation therapy combined with targeted agents or ICI, emphasizing on the role (if any) of the sequence of combination scheme (drug given before, during, and/or after radiation therapy).

Results

Whereas no relevant toxicity has been noticed with most of these drugs, the concomitant use of some other drugs with brain irradiation requires caution.

Conclusion

Most of available studies appear to advocate for TT or ICI combination with radiation therapy, without altering the clinical safety profiles, allowing the maintenance of systemic treatments when stereotactic radiation therapy is considered. Cognitive functions, health-related quality of life and radiation necrosis risk remain to be assessed. The results of prospective studies are awaited in order to complete and validate the above discussed retrospective data.

The safety and efficacy of dabrafenib and trametinib for the treatment of melanoma

INTRODUCTION

The introduction of BRAF and MEK inhibitors into clinical practice improved the prognosis of metastatic melanoma patients. The combination of BRAF inhibitor dabrafenib with MEK inhibitor trametinib has shown its superiority to single agent therapy and is characterized by a tolerable spectrum of adverse events which shows a decrease in incidence over time on treatment. Areas covered: The current scientific literature on safety and adverse events (AEs) related to BRAF and MEK-inhibition has been investigated with special focus on the large phase 3 studies (COMBI-v, COMBI-d and CoBRIM) as well as recent updates presented at oncology and melanoma meetings. Additionally, published case series/case reports were screened for information on AEs. Expert opinion: Even though almost every patient (98%) under combination therapy with dabrafenib and trametinib experiences at least one adverse event, these are generally mild to moderate, reversible and can be managed with dose reductions or interruptions. However, due to an increased life expectancy, there is a substantial need to prevent and treat also mild adverse events, as they play a central role for the quality of life of patients. Ongoing clinical trials will have to demonstrate the efficacy as well as safety of triple combination with anti-PD-1/anti-PD-L1 antibodies.

Radiosensibilisierung durch BRAF Inhibitoren

HINTERGRUND

In der letzten Zeit wurden in der Literatur vermehrt erhöhte Hauttoxizitäten während einer Kombinationstherapie mit BRAF Inhibitoren und Radiotherapie beschrieben.

MATERIAL UND METHODIK

Wir berichten über sieben Melanompatienten in einem nicht resezierbaren Stadium III oder IV, die eine kombinierte Behandlung aus Bestrahlung und BRAF-Inhibitor erhielten.

ERGEBNISSE

Bei allen Patienten konnte durch die Kombinationstherapie ein gutes lokales Ansprechen erreicht werden. Nur bei zwei Patienten wurde eine schwere Radiodermatitis (CTCAE Grad 3 bzw. 4) beobachtet. Bei diesen Patienten, die beide Vemurafenib erhielten, trat die Radiodermatitis nach ein bzw. zwei Wochen auf und resultierte in einer Unterbrechung der BRAF-Inhibitor Behandlung.. Die kumulative Dosis bis zum Zeitpunkt der Strahlendermatitis betrug 10 Gy bzw. 35 Gy. Bei allen anderen Vemurafenibpatienten konnten nur milde Reaktionen im Sinne einer Radiodermatitis CTCAE Grad 2, beim Dabrafenibpatienten CTCAE Grade 1 diagnostiziert werden. Bei einem Patienten wurde eine Recalldermatitis nach 14 Tagen einer beendeten Strahlentherapie mit einer kumulativen Dosis von 30 Gy diagnostiziert.

SCHLUSSFOLGERUNGEN

Schwere Toxizitätsreaktionen der Haut unter einer BRAF-Inhibitionen treten nicht häufig auf und sind meistens gut therapierbar. Deshalb sollte die Kombinationstherapie bei aggressiv wachsenden Melanomen eine Therapieoption bleiben. Obwohl ein erhöhtes Risiko der Hauttoxizität unter einer Kombinationstherapie von Radiatio und BRAF-Inhibitoren besteht, wird diese von den meisten Patienten gut toleriert. Sequenzielle Therapie anstelle von gleichzeitiger Behandlung scheint die Toxizitätreaktionen nicht zu verhindern.

Radiosensitization by BRAF inhibitors

BACKGROUND

Increased skin toxicity during combination therapy with a BRAF inhibitor and radiation therapy has recently been reported.

MATERIAL AND METHODS

We present seven melanoma patients with non-resectable stage III or IV disease and concomitant treatment with a BRAF inhibitor and radiation therapy.

RESULTS

In all patients, combination therapy yielded a good local response. Only two patients, both on vemurafenib, showed severe radiation dermatitis (CTCAE grade 3/4) after one and two weeks, respectively, resulting in interruption of BRAF inhibitor treatment. The respective cumulative radiation dose was 10 Gy and 35 Gy. The remaining vemurafenib patients displayed only mild radiation dermatitis CTCAE grade 2; the only dabrafenib patient CTCAE grade 1. In one patient, recall dermatitis was diagnosed 14 days after completion of radiation therapy with a cumulative dose of 30 Gy.

CONCLUSIONS

Severe skin toxicity caused by BRAF inhibitor-induced radiosensitization is not common and usually amenable to treatment. Thus, combination treatment should remain a therapeutic option, especially in melanoma patients characterized by aggressive tumor growth. Although there is an increased risk of skin toxicity during combination therapy, it is usually well tolerated by most patients. Sequential - instead of simultaneous - treatment does not seem to prevent such toxicity reactions.

Chronic radiation-induced dermatitis: challenges and solutions

Chronic radiation dermatitis is a late side effect of skin irradiation, which may deteriorate patients’ quality of life. There is a lack of precise data about its incidence; however, several risk factors may predispose to the development of this condition. It includes radiotherapy dose, fractionation, technique, concurrent systemic therapy, comorbidities, and personal and genetic factors. Chronic radiation dermatitis is mostly caused by the imbalance of proinflammatory and profibrotic cytokines. Clinical manifestation includes changes in skin appearance, wounds, ulcerations, necrosis, fibrosis, and secondary cancers. The most severe complication of irradiation is extensive radiation-induced fibrosis (RIF). RIF can manifest in many ways, such as skin induration and retraction, lymphedema or restriction of joint motion. Diagnosis of chronic radiation dermatitis is usually made by clinical examination. In case of unclear clinical manifestation, a biopsy and histopathological examination are recommended to exclude secondary malignancy. The most effective prophylaxis of chronic radiation dermatitis is the use of proper radiation therapy techniques to avoid unnecessary irradiation of healthy skin. Treatment of chronic radiation dermatitis is demanding. The majority of the interventions are based only on clinical practice. Telangiectasia may be treated with pulse dye laser therapy. Chronic postirradiation wounds need special dressings. In case of necrosis or severe ulceration, surgical intervention may be considered. Management of RIF should be complex. Available methods are rehabilitative care, pharmacotherapy, hyperbaric oxygen therapy, and laser therapy. Future challenges include the assessment of late skin toxicity in modern irradiation techniques. Special attention should be paid on genomics and radiomics that allow scientists and clinicians to select patients who are at risk of the development of chronic radiation dermatitis. Novel treatment methods and clinical trials are strongly needed to provide more efficacious therapies.

Therapeutic approach to treating patients with BRAF-mutant lung cancer: latest evidence and clinical implications

Lung adenocarcinoma is known for its high rate of somatic mutations and genomic rearrangements. The identification of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements that sensitize tumors to specific drugs has changed the therapeutic approach and prognosis in these molecularly-defined subgroups. Several other key genetic alterations have been identified, of which BRAF mutations are found in 4% of non-small cell lung cancer (NSCLC) cases. Targeted drugs against BRAF and downstream MEK were recently approved for the treatment of BRAF-positive melanoma and have entered clinical evaluation in NSCLC. In this review we discuss the latest evidence on the treatment of BRAF-mutated NSCLC, including tumor biology, targeted treatment with BRAF and MEK inhibitors, therapeutic resistance and strategies to overcome resistance.

The evolution of combined molecular targeted therapies to advance the therapeutic efficacy in melanoma: a highlight of vemurafenib and cobimetinib

Metastatic melanoma is an aggressive, rapidly progressive disease which historically had very few effective treatment options. However, since 2011, the therapeutic landscape of melanoma has undergone a dramatic transformation with two distinct approaches and has catalyzed the successful advancement in the clinical field of immuno-oncology. In addition, the recognition of a key oncogenic driver mutation in melanoma, BRAF, stimulated the development of multiple potent kinase inhibitors which has also influenced the expansion and use of targeted agents in the practice of oncology. Vemurafenib, the initial BRAF inhibitor approved for the treatment of melanoma, was the first agent to demonstrate rapid clinical responses and significantly improved survival which was a clinical breakthrough in the treatment of melanoma. Although exciting and practice changing, the unparalleled responses with vemurafenib are usually not sustained. Further investigations delineated several mechanisms of acquired resistance which are most often mediated by the upregulation of the MAPK pathway. MEK inhibitors, another class of small-molecule inhibitors, were developed as an alternative agent to suppress the MAPK pathway downstream, independent from BRAF activation. Multiple studies have demonstrated the improvement in antitumor activity when MEK inhibitors are used in combination with BRAF inhibitors in the treatment of metastatic melanoma. This is a review of the investigations that led to the US Food and Drug Administration approval in 2015 of the combination of vemurafenib and cobimetinib, adding to the quickly growing armament for the treatment of advanced or metastatic melanoma with a BRAF V600 mutation.

Avoiding Severe Toxicity From Combined BRAF Inhibitor and Radiation Treatment: Consensus Guidelines from the Eastern Cooperative Oncology Group (ECOG)

BRAF kinase gene V600 point mutations drive approximately 40% to 50% of all melanomas, and BRAF inhibitors (BRAFi) have been found to significantly improve survival outcomes. Although radiation therapy (RT) provides effective symptom palliation, there is a lack of toxicity and efficacy data when RT is combined with BRAFi, including vemurafenib and dabrafenib. This literature review provides a detailed analysis of potential increased dermatologic, pulmonary, neurologic, hepatic, esophageal, and bowel toxicity from the combination of BRAFi and RT for melanoma patients described in 27 publications. Despite 7 publications noting potential intracranial neurotoxicity, the rates of radionecrosis and hemorrhage from whole brain RT (WBRT), stereotactic radiosurgery (SRS), or both do not appear increased with concurrent or sequential administration of BRAFis. Almost all grade 3 dermatitis reactions occurred when RT and BRAFi were administered concurrently. Painful, disfiguring nondermatitis cutaneous reactions have been described from concurrent or sequential RT and BRAFi administration, which improved with topical steroids and time. Visceral toxicity has been reported with RT and BRAFi, with deaths possibly related to bowel perforation and liver hemorrhage. Increased severity of radiation pneumonitis with BRAFi is rare, but more concerning was a potentially related fatal pulmonary hemorrhage. Conversely, encouraging reports have described patients with leptomeningeal spread and unresectable lymphadenopathy rendered disease free from combined RT and BRAFi. Based on our review, the authors recommend holding BRAFi and/or MEK inhibitors ≥3 days before and after fractionated RT and ≥1 day before and after SRS. No fatal reactions have been described with a dose <4 Gy per fraction, and time off systemic treatment should be minimized. Future prospective data will serve to refine these recommendations.

Combination of Radiotherapy and Targeted Agents in Brain Metastasis: An Update

OPINION STATEMENT

The combination of radiation therapy and targeted agents (molecular inhibitors or immunotherapy) represents an opportunity to improve the outcomes of patients with brain metastases. The combination of whole-brain radiation therapy (WBRT) with targeted agents takes advantage of radiosensitization, while the combination with stereotactic radiosurgery (SRS) may allow one to substitute an effective systemic agent for adjuvant WBRT, the historical standard of care. This strategy may in turn allow the promotion of secondary prevention paradigms with possibly less cognitive toxicity. At present, the combination of targeted therapy with SRS rather than with WBRT is the more viable option although both avenues will likely have a role in the future management of brain metastases. Patients should be encouraged to enter clinical trials since the off-study use of these combinations will delay the advancement of the field. Caution is advised in the combination of radiation and targeted agents as unexpected toxicities can occur. Clinicians should avail themselves of clinical trials in order to offer patients these promising options and to move the field forward. In the absence of a clinical trial, we recommend the combination of SRS with targeted agents and deferred WBRT. Small, asymptomatic brain metastases may be best managed with single-modality targeted agents with deferred radiation therapy, preferably on a clinical trial. Advances in targeted therapies combined with radiation therapy will most likely improve local control and hopefully the quality of life and survival of patients with brain metastasis.

Combination of dabrafenib and radiotherapy: could skin toxicity be affected by different irradiation techniques?

The prognosis of patients with metastatic melanoma is changing owing to the introduction of selective BRAF inhibitors combined with MEK inhibitors. Management of these patients continues to be a challenge, especially when systemic therapy has to be combined with concomitant radiotherapy, particularly owing to skin toxicity. Here we report a case of a patient who underwent concomitant treatment for two vertebral sites using two different radiotherapy techniques. An unexpected acute skin toxicity was reported at one of the treated sites. This finding might be owing to the different absorbed dose to the subcutaneous tissues linked with the technique of irradiation.

Comprehensive molecular tumor profiling in radiation oncology: How it could be used for precision medicine

New technologies enabling the analysis of various molecules, including DNA, RNA, proteins and small metabolites, can aid in understanding the complex molecular processes in cancer cells. In particular, for the use of novel targeted therapeutics, elucidation of the mechanisms leading to cell death or survival is crucial to eliminate tumor resistance and optimize therapeutic efficacy. While some techniques, such as genomic analysis for identifying specific gene mutations or epigenetic testing of promoter methylation, are already in clinical use, other "omics-based" assays are still evolving. Here, we provide an overview of the current status of molecular profiling methods, including promising research strategies, as well as possible challenges, and their emerging role in radiation oncology.

Role of radiation therapy in melanomas: Systematic review and best practice in 2016

Radiotherapy has been used for skin cancers since early after the discovery of X-rays. The introduction of sophisticated surgery techniques and information of the general population on potential late radiation-induced toxicity and carcinogenesis have led to limiting indications in the dermatologist community. However, radiotherapy (RT) has undergone considerable developments, essentially including technological advances, to sculpt radiation delivery, with demonstration of the benefit either alone or after adding concomitant cytotoxic agents or targeted therapies. Although side effects due to high doses and/or the use of old RT techniques have been significantly decreased, the risk of atrophic scars, ulcerations or secondary cancers persist. In this systematic review, we aim to discuss indications for RT in melanomas with focus on new advances that may lead to rehabilitating this treatment option according to the tumor radiosensitivity and clinical benefit/risk ratio. Melanomas have been considered as radioresistant tumors for many years.

Targeted Therapy in Brain Metastases: Ready for Primetime?

Brain metastasis is a serious complication of cancer that causes significant morbidity for patients. Over the last decade, numerous new driver somatic mutations have been recognized and targeted therapies are changing the landscape of treatment in lung cancer, breast cancer, and melanoma, which are also the three most common cancers that result in brain metastases. The common actionable mutations include the EGFR mutation and anaplastic lymphoma kinase (ALK) translocations in non-small cell lung cancer, the HER2 mutation in breast cancer, and the BRAF mutation in melanoma. However, most of the early trials with targeted agents excluded patients with brain metastases. With a better understanding of the biology, several recent trials of targeted therapy that focus on brain metastases have been reported and others are ongoing. Novel agents with better penetration across the blood-brain barrier are currently being investigated for patients with brain metastases. In this review, we discuss the current state of use and future directions of targeted therapies in brain metastases.

Radiotherapy with BRAF inhibitor therapy for melanoma: progress and possibilities

The introduction of small molecule BRAFV600 kinase inhibitors represents a milestone in the targeted therapy of patients with metastatic melanoma by a significant increase in therapeutic efficacy in terms of overall and progression-free survival compared with conventional chemotherapy. Beside BRAFV600 inhibitor treatment, radiotherapy is a further mainstay for the therapy of metastatic melanoma and thus a concomitant or sequential application of BRAFV600 inhibitors and radiotherapy is inevitable. Recent reports show a significant radiosensitization of the irradiated healthy tissue in patients with melanoma after the combination of radiotherapy and BRAFV600 inhibitors, evoking concern in clinical practice. We review interactions of BRAFV600 inhibitors and radiation with regard to antitumor effects and an increased radiotoxicity in the healthy tissue.

Novel Drugs and Combination Therapies for the Treatment of Metastatic Melanoma

Metastatic melanoma (MM) still remains as one of the most worrisome cancer known to mankind. In last two decades, treatment of melanoma took a dramatic turn with the discovery of targeted therapy which targets the mutations in mitogen-activated protein kinase (MAPK) pathway and immune checkpoint inhibitors. These new findings have led to emergence of many novel drugs that have been approved by FDA. Targeted therapy drugs such as vemurafenib, trametinib and dabrafenib target the MAPK pathway whereas immunotherapies such as ipilimumab, nivolumab and pembrolizumab block immune checkpoint receptors on T lymphocytes. All these drugs have shown to improve the overall survival in MM. Despite these recent discoveries, treatment of MM remains challenging because of rapid development of resistance to targeted therapy. This review will discuss recently approved drugs and their adverse effects and also shed light on combination therapy in treatment of melanoma.

Radiosensitization by BRAF inhibitor therapy-mechanism and frequency of toxicity in melanoma patients

BACKGROUND

Recent evidence suggests that ionizing radiation may be associated with unexpected side-effects in melanoma patients treated with concomitant BRAF inhibitors. A large multicenter analysis was carried out to generate reliable safety data and elucidate the mechanism.

METHODS

A total of 161 melanoma patients from 11 European skin cancer centers were evaluated for acute and late toxicity, of whom 70 consecutive patients received 86 series of radiotherapy with concomitant BRAF inhibitor therapy. To further characterize and quantify a possible radiosensitization by BRAF inhibitors, blood samples of 35 melanoma patients were used for individual radiosensitivity testing by fluorescence in situ hybridization of chromosomal breaks after ex vivo irradiation.

RESULTS

With radiotherapy and concomitant BRAF inhibitor therapy the rate of acute radiodermatitis ≥2° was 36% and follicular cystic proliferation was seen in 13% of all radiotherapies. Non-skin toxicities included hearing disorders (4%) and dysphagia (2%). Following whole-brain radiotherapy, rates of radiodermatitis ≥2° were 44% and 8% (P < 0.001) for patients with and without BRAF inhibitor therapy, respectively. Concomitant treatment with vemurafenib induced acute radiodermatitis ≥2° more frequently than treatment with dabrafenib (40% versus 26%, P = 0.07). In line with these findings, analysis of chromosomal breaks ex vivo indicated significantly increased radiosensitivity for patients under vemurafenib (P = 0.004) and for patients switched from vemurafenib to dabrafenib (P = 0.002), but not for patients on dabrafenib only. No toxicities were reported after stereotactic treatment.

CONCLUSION

Radiotherapy with concomitant BRAF inhibitor therapy is feasible with an acceptable increase in toxicity. Vemurafenib is a more potent radiosensitizer than dabrafenib.

Radiation recall dermatitis and radiation pneumonitis during treatment with vemurafenib

The basis of radiation recall reactions (RRR) is a subclinical radiation damage that is uncovered later by treatment with anticancer agents. Several drugs have been associated with RRR, in particular taxanes and anthracyclines. Recently, a few cases were reported concerning radiation recall dermatitis caused by vemurafenib. Up to now, there have been no reports of RRR in the lung induced by vemurafenib. We describe the occurrence of RRR in three melanoma patients who had undergone radiotherapy for metastases followed by systemic treatment with the BRAF inhibitor vemurafenib. Two patients developed radiation recall pneumonitis (RRP) and one patient developed radiation recall dermatitis (RRD) 5-7 weeks after the radiation treatment was finished and 2-4 weeks after vemurafenib was started. The early application of systemic (RRP) and topical corticosteroids (RRD) enabled us to continue the treatment with vemurafenib without dose reduction. Caution is needed when vemurafenib is planned for patients who have undergone previous radiotherapy, and RRR of the skin and the lung have to be taken into account.

[Cutaneous side effects of anti-tumor therapy with BRAF and MEK inhibitors]

BACKGROUND

BRAF and MEK inhibitors are new targeted therapies which are used in the treatment of malignancies, in particular of malignant melanoma.

SIDE EFFECTS

Cutaneous side effects are common during the treatment with both types of inhibitors. These side effects include inflammatory reactions such as maculopapular and papulopustular exanthema, hand-foot syndrome, panniculitis, paronychia, photo- and radio-sensitization. As a class effect, BRAF-inhibitors induce proliferative disorders of keratinocytes and melanocytes, such as palmoplantar hyperkeratosis (as part of the hand-foot syndrome), verruciform and acanthoma-like lesions, follicular and Grover disease-like hyperkeratoses, keratoacanthomas, squamous cell carcinomas and atypical melanocytic nevi with transition to secondary melanomas. Furthermore, hair alterations and xerosis are possible.

CONCLUSIONS

Treatment with BRAF and MEK inhibitors requires close dermatologic monitoring of the patient. This manuscript summarizes the most frequent cutaneous side effects and their management.

Local control after stereotactic radiosurgery for brain metastases in patients with melanoma with and without BRAF mutation and treatment

OBJECT

BRAF inhibitors improve progression-free and overall survival in patients with metastatic melanoma. Brain metastases are common, and stereotactic radiosurgery (SRS) has been used, resulting in excellent local control. Because BRAF inhibitors are associated with intracranial responses, the authors hypothesized that BRAF inhibitors would improve local control in patients with melanoma who are receiving SRS for brain metastases.

METHODS

The authors retrospectively identified patients with metastatic melanoma who had been tested for BRAF mutation and treated with SRS for brain metastases. Patients with previous resection, multiple brain metastases, or multiple courses of SRS were eligible. SRS was delivered in a single fraction to a median dose of 2000 cGy. Patients with a BRAF mutation were treated with a BRAF inhibitor on the basis of physician preference.

RESULTS

The authors identified 52 patients who were treated in 82 treatment sessions for 185 brain metastases and 13 tumor beds. At a median follow-up of 10.5 months, the 1-year local control rate was 69.2%. At 1 year, the local control rate for brain metastases in patients with BRAF mutation with BRAF treatment was 85.0%, and the local control rate for brain metastases in those without BRAF treatment was 51.5% (p = 0.0077). The rates of distant brain failure, freedom from whole-brain radiation, and overall survival were not different on the basis of BRAF mutation status or inhibitor therapy. The number of new intratumoral hemorrhages after SRS was increased significantly in patients with BRAF treatment.

CONCLUSIONS

Treatment with BRAF inhibitors was associated with improved local control after SRS in patients with melanoma and brain metastases. An increased number of intratumoral hemorrhages was associated with BRAF inhibitor therapy.

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.

A primary melanoma and its asynchronous metastasis highlight the role of BRAF, CDKN2A, and TERT

BACKGROUND

Alterations in pathways including BRAF, CDKN2A, and TERT contribute to the development of melanoma, but the sequence in which the genetic alterations occur and their prognostic significance remains unclear. To clarify the role of these pathways, we analyzed a primary melanoma and its metastasis.

METHODS

Immunohistochemistry for BRAF-V600E, Sanger sequencing of BRAF and the TERT promoter, fluorescence in-situ hybridization, and telomere analyses were performed on a primary melanoma and its asynchronous cerebellar metastasis. Using the log-rank test and Cox-proportional model, the cancer genome atlas (TCGA) cohort of melanomas was analyzed for the effect of BRAF mutation and CDKN2A loss on survival.

RESULTS

The primary melanoma expressed mutant BRAF-V600E and possessed a homozygous deletion of CDKN2A. In addition to these early defects, the metastatic lesion also possessed evidence of aneuploidy and an activating mutation of the TERT promoter. In the TCGA melanoma cohort, there was a non-significant trend toward poor prognosis in early stage cutaneous melanoma patients with concomitant BRAF mutation and CDKN2A loss.

CONCLUSION

BRAF mutation and CDKN2A loss occurred early and TERT promoter mutation later in a case of lethal metastatic melanoma. The effects of these pathways on survival warrant further investigation in early stage cutaneous melanoma patients.

A single-centre experience of patients with metastatic melanoma enrolled in a dabrafenib named patient programme

We studied the efficacy, tolerability and clinical courses of dabrafenib in patients with metastatic melanoma who were ineligible for enrolment into a clinical trial. Between July 2011 and May 2013, patients with unresectable stage III or stage IV, V600-mutated metastatic melanoma who were not eligible for inclusion into clinical trials were offered treatment with dabrafenib through a named patient programme. Routine efficacy and toxicity data were collected throughout treatment and studied retrospectively. The endpoints were progression-free survival (PFS), overall survival and best overall response. Thirty-one patients commenced dabrafenib therapy including six individuals who had progressed on a prior BRAF-inhibitor treatment. The majority of patients had cerebral metastases (n=17) and/or a poor performance status [Eastern Cooperative Oncology Group (ECOG)≥2, n=11]. Median overall survival was 5.6 months (range 0.1-22 months). Median PFS was 3.3 months (range 0.1-21) and was similar despite performance status. One patient had a complete response and eight showed partial responses to treatment. Patients with cerebral metastases (n=17) had a median PFS of 4.6 months. Five patients (16%) had dose-limiting toxicities. Despite several poor prognostic features, dabrafenib is a safe and effective treatment in the community setting, with occasional impressive outcomes.

Radiation necrosis mimicking rapid intracranial progression of melanoma metastasis in two patients treated with vemurafenib

Optimal treatment of metastases to the central nervous system (CNS) in patients with malignant melanoma remains a clinical challenge. In particular, for patients with BRAF-mutant melanoma and CNS metastases, much remains unknown about the safety and efficacy of the novel BRAF-targeted agents when administered in close sequence with radiation. We report two cases of rapid development of CNS radiation necrosis in patients with metastatic melanoma treated with the BRAF inhibitor, vemurafenib, closely sequenced with stereotactic radiosurgery or fractionated stereotactic radiation therapy. In the absence of prospective safety data from clinical trials, we advise vigilance in monitoring patients with BRAF-mutant melanoma whose treatment plan includes CNS radiation and vemurafenib and caution when assessing treatment response within the CNS in these patients.

BRAF inhibitors: experience in thyroid cancer and general review of toxicity

The US Food and Drug Administration-approved BRAF inhibitors, vemurafenib and dabrafenib, have demonstrated superior efficacy in patients with BRAF-mutant melanomas but have limited efficacy in BRAF-mutant colorectal cancer. Little is known at this time regarding BRAF inhibitors in thyroid cancer. Initial reports in patients with progressive, radioactive iodine-refractory BRAF-mutant papillary thyroid cancer suggest response rates of approximately 30-40%. In this review, we discuss BRAF inhibitors in the context of thyroid cancer, the toxicities associated with BRAF inhibitors, and the suggested management of those toxicities. The management of vemurafenib and dabrafenib toxicities is applicable across all tumor types and may serve as a practical guide to their use.

Interaction of radiation therapy with molecular targeted agents

The development of molecular targeted therapeutics in oncology builds on many years of scientific investigation into the cellular mechanics of malignant transformation and progression. The past two decades have brought an accelerating pace to the clinical investigation of new molecular targeted agents, particularly in the setting of metastatic disease. The integration of molecular targeted agents into phase III clinical trial design has lagged in the curative treatment setting, particularly in combination with established therapeutic modalities such as radiation. In this review, we discuss the interaction of radiation and molecular targeted therapeutics. The dynamics of cellular and tumor response to radiation offer unique opportunities for beneficial interplay with molecular targeted agents that may go unrecognized with conventional screening and monotherapy clinical testing of novel agents. By using epidermal growth factor receptor (EGFR) as a primary example, we discuss recent clinical studies that illustrate the potential synergy of molecular targeted agents with radiation and highlight the clinical value of such interactions. For various molecular targeted agents, their greatest clinical impact may rest in combination with radiation, and efforts to facilitate systematic investigation of this approach appear highly warranted.

Localized Epidermal Cysts as a Radiation Recall Phenomenon in a Melanoma Patient Treated with Radiotherapy and the BRAF Inhibitor Vemurafenib

BRAF inhibitors are broadly used for metastatic melanoma with BRAF mutations. Their use results in various cutaneous side effects, such as the development of keratoacanthomas and squamous cell carcinomas. We report a patient with metastatic melanoma treated with vemurafenib who developed dozens of histologically confirmed epidermal cysts within 2 months after initiation of vemurafenib administration. The cystic lesions were observed only in the localized area where a large exophytic melanoma tumor mass had been previously irradiated. Localized epidermal cysts may constitute an unusual radiation recall reaction in patients treated with BRAF inhibitors.

Dabrafenib for the treatment of BRAF V600-positive melanoma: a safety evaluation

INTRODUCTION

V-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors are emerging as the standard of care for treating advanced melanomas harboring the BRAF V600 oncogenic mutation. Dabrafenib is the second approved selective BRAF inhibitor (after vemurafenib) for the treatment of unresectable or metastatic BRAF V600-positive melanoma.

AREAS COVERED

This review covers the current data on the efficacy and safety of the selective BRAF inhibitor dabrafenib in patients with metastatic BRAF V600 positive melanoma. The pharmacological, safety and efficacy data are discussed from Phase I, II, and III studies of dabrafenib monotherapy as well as in combination with the MEK inhibitor trametinib.

EXPERT OPINION

Dabrafenib has demonstrated comparable efficacy to vemurafenib in BRAF V600E mutant melanoma patients. Dabrafenib is well tolerated in patients with metastatic melanoma, including patients with brain metastases. Nevertheless side effects are common, but usually manageable. In the Phase III study testing dabrafenib, 53% of patients reported grade 2 or higher adverse events (AEs). Toxicities were similar to those seen in the early-phase trials, with the most common being cutaneous manifestations (hyperkeratosis, papillomas, palmar-plantar erythrodysesthesia), pyrexia, fatigue, headache, and arthralgia. Combining a BRAF inhibitor with a MEK inhibitor, which may block paradoxical MAPK activation in BRAF wild type (skin) cells, may lower the incidence of squamoproliferative eruptions.

Managing the skin toxicities from new melanoma drugs

Patients treated with ipilimumab or targeted inhibitors of the RAF-MEK-ERK pathway (vemurafenib, dabrafenib, and trametinib) for advanced cutaneous melanoma often experience drug-related skin toxicities denoted as dermatologic adverse events (DAEs). Although rarely life-threatening, DAEs may emerge dramatically and potentially compromise oncologic therapy if not managed in a timely and effective manner. Early recognition of DAEs is critical to providing optimal skin care and prompt consultation with a dermatologist should be obtained when a diagnosis is unclear. The expanding utilization of new melanoma drugs compels physicians to maintain a watchful eye for both known and novel DAEs and to adopt a low threshold to biopsy worrisome skin findings. Numerous therapeutic options are available to manage DAEs including topical and systemic agents as well as surgical and destructive modalities. Applying such methods improves overall patient care and optimizes the effectiveness of new therapies for advanced cutaneous melanoma.