RADVAN: a randomised phase 2 trial of WBRT plus vandetanib for melanoma brain metastases - results and lessons learnt

Systematic literature review and meta-analysis of clinical outcomes and prognostic factors for melanoma brain metastases

Background

More than 60% of all stage IV melanoma patients develop brain metastases, while melanoma brain metastases (MBM) is historically difficult to treat with poor prognosis.

Objectives

To summarize clinical outcomes and prognostic factors in MBM patients.

Methods

A systematic review with meta-analysis was conducted, and a literature search for relevant studies was performed on November 1, 2020. Weighted average of median overall survival (OS) was calculated by treatments. The random-effects model in conducting meta-analyses was applied.

Results

A total of 41 observational studies and 12 clinical trials with our clinical outcomes of interest, and 31 observational studies addressing prognostic factors were selected. The most common treatments for MBM were immunotherapy (IO), MAP kinase inhibitor (MAPKi), stereotactic radiosurgery (SRS), SRS+MAPKi, and SRS+IO, with median OS from treatment start of 7.2, 8.6, 7.3, 7.3, and 14.1 months, respectively. Improved OS was observed for IO and SRS with the addition of IO and/or MAPKi, compared to no IO and SRS alone, respectively. Several prognostic factors were found to be significantly associated with OS in MBM.

Conclusion

This study summarizes pertinent information regarding clinical outcomes and the association between patient characteristics and MBM prognosis.

Outcomes of stage IV melanoma in the era of immunotherapy: a National Cancer Database (NCDB) analysis from 2014 to 2016

BACKGROUND

To evaluate factors affecting the utilization of immunotherapy and to stratify results based on the approval of ipilimumab in 2011 and programmed death-1 inhibitors in 2014, an analysis of available data from the National Cancer Database (NCDB) was performed.

METHODS

The NCDB was analyzed to identify patients with stage IV melanoma from 2004 to 2016. Patients were categorized during the time periods 2004-2010, 2011-2014, and 2015-2016. Overall survival (OS) was analyzed by Kaplan-Meier, log-rank, and Cox proportional hazard models; IO status was analyzed using logistic regression.

RESULTS

24,544 patients were analyzed. Overall, 5238 patients (21.3%) who received IO had improved median OS compared with those who did not (20.2 months vs 7.4 months; p<0.0001). Between 2004 and 2010, 9.7% received immunotherapy; from 2011 to 2014, 21.9% received immunotherapy; and from 2015 to 2016, 43.5% received immunotherapy. Three-year OS significantly improved in patients treated with IO across treatment years: 31% (95% CI 29% to 34%) from 2004 to 2010, 35% (95% CI 33% to 37%) from 2011 to 2014, and 46% (95% CI 44% to 48%) from 2015 to 2016 (p<0.0001). Survival was worse in patients who did not receive IO during these treatment years: 16% (15%-17%), 21% (20%-22%), and 27% (25%-28%), respectively. In the overall cohort, age <65 years, female gender, private insurance, no comorbidities, residence in metropolitan area, and treatment at academic centers were associated with better OS (p<0.0001 for all). In the multivariate analysis, receipt of IO from 2015 to 2016 was associated with age <65 years (OR 1.27, 95% CI 1.08 to 1.50), African American race (OR 5.88, 95% CI 1.60 to 28.58), lack of comorbidities (OR 1.43, 95% CI 1.23 to 1.66), and treatment at academic centers (OR 1.44, 95% CI 1.26 to 1.65) (p<0.05 for all).

CONCLUSIONS

OS improved in patients with stage IV melanoma receiving IO, with the highest OS rate in 2015-2016. Our findings, which represent a real-world population, are slightly lower than recent trials, such as KEYNOTE-006 and CheckMate 067. Significant socioeconomic factors may impact receipt of IO and survival.

Radiation therapy for melanoma brain metastases: a systematic review

BACKGROUND

Radiation therapy (RT) for melanoma brain metastases, delivered either as whole brain radiation therapy (WBRT) or as stereotactic radiosurgery (SRS), is an established component of treatment for this condition. However, evidence allowing comparison of the outcomes, advantages and disadvantages of the two RT modalities is scant, with very few randomised controlled trials having been conducted. This has led to considerable uncertainty and inconsistent guideline recommendations. The present systematic review identified 112 studies reporting outcomes for patients with melanoma brain metastases treated with RT. Three were randomised controlled trials but only one was of sufficient size to be considered informative. Most of the evidence was from non-randomised studies, either specific treatment series or disease cohorts. Criteria for determining treatment choice were reported in only 32 studies and the quality of these studies was variable. From the time of diagnosis of brain metastasis, the median survival after WBRT alone was 3.5 months (IQR 2.4-4.0 months) and for SRS alone it was 7.5 months (IQR 6.7-9.0 months). Overall patient survival increased over time (pre-1989 to 2015) but this was not apparent within specific treatment groups.

CONCLUSIONS

These survival estimates provide a baseline for determining the incremental benefits of recently introduced systemic treatments using targeted therapy or immunotherapy for melanoma brain metastases.

State of affairs regarding targeted pharmacological therapy of cancers metastasized to the brain

In 1999 a visionary short article by The Wall Street Journal writers Robert Langreth and Michael Waldholz popularized the new term "personalized medicine," that is to say, the targeting of drugs to each unique genetic profile. From today's perspective, targeted approaches have clearly found the widest use in the antineoplastic domain. The current review was initiated to review the progress that has been made regarding the treatment of patients with advanced cancer and brain metastases. PubMed was searched for the terms brain metastasis, brain metastases, or metastatic brain in the Title/Abstract. Selection was limited to randomized controlled trial (RCT) and publication date January 2010 to February 2022. Following visual review, 51 papers on metastatic lung cancer, 12 on metastatic breast cancer, and 9 on malignant melanoma were retained and underwent full analysis. Information was extracted from the papers giving specific numbers for intracranial response rate and/or overall survival. Since most pharmacological trials on advanced cancers excluded patients with brain metastases and since hardly any information on adjuvant radiotherapy and radiosurgery is available from the pharmacological trials, precise assessment of the effect of targeted medication for the subgroups with brain metastases is difficult. Some quantitative information regarding the success of targeted pharmacological therapy is only available for patients with breast and lung cancer and melanoma. Overall, targeted approaches approximately doubled the lifespan in the subgroups of brain metastases from tumors with targetable surface receptors such as anaplastic lymphoma kinase (ALK) fusion receptor in non-small cell lung cancer or human epidermal growth factor receptor 2 (HER2)-positive breast cancer. For these types, overall survival in the situation of brain metastases is now more than a year. For receptor-negative lung cancer and melanoma, introduction of immune checkpoint blockers brought a substantial advance, although overall survival for melanoma metastasized to the brain appears to remain in the range of 6 to 9 months. The outlook for small cell lung cancer metastasized to the brain apparently remains poor. The introduction of targeted therapy roughly doubled survival times of advanced cancers including those metastasized to the brain, but so far, targeted therapy does not differ essentially from chemotherapy, therefore also facing tumors developing escape mechanisms. With the improved perspective of patients suffering from brain metastases, it becomes important to further optimize treatment of this specific patient group within the framework of randomized trials.

Treatment for Brain Metastases: ASCO-SNO-ASTRO Guideline

PURPOSE

To provide guidance to clinicians regarding therapy for patients with brain metastases from solid tumors.

METHODS

ASCO convened an Expert Panel and conducted a systematic review of the literature.

RESULTS

Thirty-two randomized trials published in 2008 or later met eligibility criteria and form the primary evidentiary base.

RECOMMENDATIONS

Surgery is a reasonable option for patients with brain metastases. Patients with large tumors with mass effect are more likely to benefit than those with multiple brain metastases and/or uncontrolled systemic disease. Patients with symptomatic brain metastases should receive local therapy regardless of the systemic therapy used. For patients with asymptomatic brain metastases, local therapy should not be deferred unless deferral is specifically recommended in this guideline. The decision to defer local therapy should be based on a multidisciplinary discussion of the potential benefits and harms that the patient may experience. Several regimens were recommended for non-small-cell lung cancer, breast cancer, and melanoma. For patients with asymptomatic brain metastases and no systemic therapy options, stereotactic radiosurgery (SRS) alone should be offered to patients with one to four unresected brain metastases, excluding small-cell lung carcinoma. SRS alone to the surgical cavity should be offered to patients with one to two resected brain metastases. SRS, whole brain radiation therapy, or their combination are reasonable options for other patients. Memantine and hippocampal avoidance should be offered to patients who receive whole brain radiation therapy and have no hippocampal lesions and 4 months or more expected survival. Patients with asymptomatic brain metastases with either Karnofsky Performance Status ≤ 50 or Karnofsky Performance Status < 70 with no systemic therapy options do not derive benefit from radiation therapy.Additional information is available at www.asco.org/neurooncology-guidelines.

Radiation Therapy for Brain Metastases: A Systematic Review

PURPOSE

This evidence report synthesizes the available evidence on radiation therapy for brain metastases.

METHODS AND MATERIALS

The literature search included PubMed, EMBASE, Web of Science, Scopus, CINAHL, clinicaltrials.gov, and published guidelines in July 2020; independently submitted data, expert consultation, and contacting authors. Included studies were randomized controlled trials (RCTs) and large observational studies (for safety assessments), evaluating whole brain radiation therapy (WBRT) and stereotactic radiosurgery (SRS) alone or in combination, as initial or postoperative treatment, with or without systemic therapy for adults with brain metastases due to lung cancer, breast cancer, or melanoma.

RESULTS

Ninety-seven studies reported in 189 publications were identified, but the number of analyses was limited owing to different intervention and comparator combinations as well as insufficient reporting of outcome data. Risk of bias varied, and 25 trials were terminated early, predominantly owing to poor accrual. The combination of SRS plus WBRT compared with SRS alone or WBRT alone showed no statistically significant difference in overall survival (hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.69%-1.73%; 4 RCTs) or death owing to brain metastases (relative risk [RR], 0.93; 95% CI, 0.48%-1.81%; 3 RCTs). Radiation therapy after surgery did not improve overall survival compared with surgery alone (HR, 0.98; 95% CI, 0.76%-1.26%; 5 RCTs). Data for quality of life, functional status, and cognitive effects were insufficient to determine effects of WBRT, SRS, or postsurgery interventions. We did not find systematic differences across interventions in serious adverse events, number of adverse events, radiation necrosis, fatigue, or seizures. WBRT plus systemic therapy (RR 1.44; 95% CI, 1.03%-2.00%; 14 studies) was associated with increased risks for vomiting compared with WBRT alone.

CONCLUSIONS

Despite the substantial research literature on radiation therapy, comparative effectiveness information is limited. There is a need for more data on patient-relevant outcomes such as quality of life, functional status, and cognitive effects.

Metabolic Rewiring in Radiation Oncology Toward Improving the Therapeutic Ratio

To meet the anabolic demands of the proliferative potential of tumor cells, malignant cells tend to rewire their metabolic pathways. Although different types of malignant cells share this phenomenon, there is a large intracellular variability how these metabolic patterns are altered. Fortunately, differences in metabolic patterns between normal tissue and malignant cells can be exploited to increase the therapeutic ratio. Modulation of cellular metabolism to improve treatment outcome is an emerging field proposing a variety of promising strategies in primary tumor and metastatic lesion treatment. These strategies, capable of either sensitizing or protecting tissues, target either tumor or normal tissue and are often focused on modulating of tissue oxygenation, hypoxia-inducible factor (HIF) stabilization, glucose metabolism, mitochondrial function and the redox balance. Several compounds or therapies are still in under (pre-)clinical development, while others are already used in clinical practice. Here, we describe different strategies from bench to bedside to optimize the therapeutic ratio through modulation of the cellular metabolism. This review gives an overview of the current state on development and the mechanism of action of modulators affecting cellular metabolism with the aim to improve the radiotherapy response on tumors or to protect the normal tissue and therefore contribute to an improved therapeutic ratio.

The impact of current treatment modalities on the outcomes of patients with melanoma brain metastases: A systematic review

Patients with melanoma brain metastases (MBM) still have a very poor prognosis. Several treatment modalities have been investigated in an attempt to improve the management of MBM. This review aimed to evaluate the impact of current treatments for MBM on patient‐ and tumor‐related outcomes, and to provide treatment recommendations for this patient population. A literature search in the databases PubMed, Embase, Web of Science and Cochrane was conducted up to January 8, 2019. Original articles published since 2010 describing patient‐ and tumor‐related outcomes of adult MBM patients treated with clearly defined systemic therapy were included. Information on basic trial demographics, treatment under investigation and outcomes (overall and progression‐free survival, local and distant control and toxicity) were extracted. We identified 96 eligible articles, comprising 95 studies. A large variety of treatment options for MBM were investigated, either used alone or as combined modality therapy. Combined modality therapy was investigated in 71% of the studies and resulted in increased survival and better distant/local control than monotherapy, especially with targeted therapy or immunotherapy. However, neurotoxic side‐effects also occurred more frequently. Timing appeared to be an important determinant, with the best results when radiotherapy was given before or during systemic therapy. Improved tumor control and prolonged survival can be achieved by combining radiotherapy with immunotherapy or targeted therapy. However, more randomized controlled trials or prospective studies are warranted to generate proper evidence that can be used to change the standard of care for patients with MBM.

Radiotherapy for Melanoma: More than DNA Damage

Despite its reputation as a radioresistant tumour, there is evidence to support a role for radiotherapy in patients with melanoma and we summarise current clinical practice. Melanoma is a highly immunogenic tumour and in this era of immunotherapy, there is renewed interest in the potential of irradiation, not only as an adjuvant and palliative treatment, but also as an immune stimulant. It has long been known that radiation causes not only DNA strand breaks, apoptosis, and necrosis, but also immunogenic modulation and cell death through the induction of dendritic cells, cell adhesion molecules, death receptors, and tumour-associated antigens, effectively transforming the tumour into an individualised vaccine. This immune response can be enhanced by the application of clinical hyperthermia as evidenced by randomised trial data in patients with melanoma. The large fraction sizes used in cranial radiosurgery and stereotactic body radiotherapy are more immunogenic than conventional fractionation, which provides additional radiobiological justification for these techniques in this disease entity. Given the immune priming effect of radiotherapy, there is a strong but complex biological rationale and an increasing body of evidence for synergy in combination with immune checkpoint inhibitors, which are now first-line therapy in patients with recurrent or metastatic melanoma. There is great potential to increase local control and abscopal effects by combining radiotherapy with both immunotherapy and hyperthermia, and a combination of all three modalities is suggested as the next important trial in this refractory disease.

Protein Tyrosine Signaling and its Potential Therapeutic Implications in Carcinogenesis

Protein tyrosine phosphorylation is a crucial signaling mechanism that plays a role in epithelial carcinogenesis. Protein tyrosine kinases (PTKs) control various cellular processes including growth, differentiation, metabolism, and motility by activating major signaling pathways including STAT3, AKT, and MAPK. Genetic mutation of PTKs and/or prolonged activation of PTKs and their downstream pathways can lead to the development of epithelial cancer. Therefore, PTKs became an attractive target for cancer prevention. PTK inhibitors are continuously being developed, and they are currently used for the treatment of cancers that show a high expression of PTKs. Protein tyrosine phosphatases (PTPs), the homeostatic counterpart of PTKs, negatively regulate the rate and duration of phosphotyrosine signaling. PTPs initially were considered to be only housekeeping enzymes with low specificity. However, recent studies have demonstrated that PTPs can function as either tumor suppressors or tumor promoters, depending on their target substrates. Together, both PTK and PTP signal transduction pathways are potential therapeutic targets for cancer prevention and treatment.

Risk of gastrointestinal events with newly approved (after 2011) vascular endothelial growth factor receptor tyrosine kinase inhibitors in cancer patients: a meta-analysis of randomized controlled trials

PURPOSE

We performed a meta-analysis to systematically review the gastrointestinal (GI) events (diarrhea, nausea, vomiting, anorexia) of five newly approved (after 2011) VEGFR-TKIs in cancer patients.

METHODS

The relevant studies of the randomized controlled trials (RCTs) in cancer patients treated with cabozantinib, vandetanib, lenvatinib, regorafenib, and axitinib were retrieved and the systematic evaluation was conducted.

RESULTS

Forty-one randomized controlled trials and 10,860 patients were included. Current analysis suggested that the use of these agents increased the risk of all-grade and high-grade GI events, and the diarrhea was the most common GI events. The risk of all-grade and high-grade GI events varies significantly within drug types, tumor types, and VEGFR-TKIs-based regimens.

CONCLUSION

The available data suggested that the use of the five newly approved VEGFR-TKIs may increase risk of GI events in cancer patients. Physicians and patients should be aware of these risks and frequent monitoring and careful management should be emphasized when managing these VEGFR-TKIs.