Long Term Results and Prognostic Biomarkers for Anti-PD1 Immunotherapy Used after BRAFi/MEKi Combination in Advanced Cutaneous Melanoma Patients

(1) Background: BRAFi/MEKi are usually offered as a first line treatment for patients requiring rapid response; with elevated lactate dehydrogenase (LDH) activity, large tumor burden, and with brain metastases. The efficacy of second line therapies after BRAFi/MEKI failure is now well defined. (2) Methods: Patients treated with first line target BRAFi/MEKi therapy (vemurafenib plus cobimetinib, dabrafenib plus trametinib or encorafenib plus binimetinib); and for the second line treatment immunotherapy with programmed cell death 1 (PD-1) checkpoint inhibitors (nivolumab or pembrolizumab) with at least one cycle of second line were analyzed for survival and prognostic biomarkers. (3) Results: There were no statistically significant differences in ORR between the treatment groups with nivolumab and pembrolizumab, as well as median progression free-survival (PSF) and overall survival (OS) since the initiation of second line therapy; on nivolumab OS was 6.6 months, and on pembrolizumab 5.0 months. The greatest clinical benefit with second line immunotherapy was observed in patients with LDH ≤ ULN and <3 organ sites with metastasis at baseline. Longer OS was also noted in patients with time to PD  >6 months in first line (slow progression). (4) Conclusions: Second line anti-PD1 immunotherapy is effective in BRAF-mutated melanoma patients after BRAFi/MEKi therapy failure.

Dramatic Therapeutic Response to Dabrafenib Plus Trametinib in BRAF V600E Mutated Papillary Craniopharyngiomas: A Case Report and Literature Review

Background

Craniopharyngioma is a rare intracranial tumor, with a high morbidity rate due to its common refractiveness to conventional treatments. BRAF V600E mutation has recently been identified as the principal oncogenic molecular driver of papillary craniopharyngiomas (PCP), one of the two main variants of craniopharyngioma.

Case Presentation

A 49-year-old man with recurrent craniopharyngioma, harboring BRAF V600E mutation, has been treated with targeted therapy based on a combination of a BRAF-inhibitor, dabrafenib (150 mg, orally two times daily), and a MEK-inhibitor, trametinib (2 mg, orally two times daily). Before starting treatment, the patient was symptomatic: he lamented confusion, dysphasia, and intense fatigue, that did not allow him to work normally. After just one cycle of treatment, the patient showed an important clinical improvement, reporting a progressive regression of the basal symptoms, hinting at a rapid and dramatic response, which was confirmed at the first radiological assessment. Thus, treatment was continued and at the time of writing, the treatment is still ongoing (total duration of treatment: 14 months) and it is well tolerated, with very good quality of life: the patient has no limitations in daily activities and he has even been able to restart to work.

Conclusion

The use of targeted therapies—as a clinical practice or in clinical trials—represents an important therapeutic alternative and a great evolution for patients' prognosis vs. the standard of care, historically represented by unselected chemotherapies. The discovery of the BRAF V600E mutation in patients with PCP is very rare, resulting in a lack of data on the efficacy of the combination of dabrafenib and trametinib.

Combining BRAF/MEK Inhibitors with Immunotherapy in the Treatment of Metastatic Melanoma

The management and prognosis of BRAF-mutant metastatic melanoma have changed drastically following the introduction of immune checkpoint inhibitors and molecularly targeted agents. These treatment options present different mechanisms of action and toxicities but also totally distinct kinetics of their response, including a "relatively" short-lasting benefit in subsets of patients treated with BRAF/MEK inhibitors and a lower response rate in patients treated with immune checkpoint inhibitors. BRAF/MEK inhibitors, when administered prior to or concurrently with immune checkpoint inhibitors, at least transiently alter some immunosuppressive parameters of the tumor microenvironment and theoretically improve sensitivity to immunotherapy. Preclinical data from mouse models with oncogene-addicted melanoma confirmed this beneficial immune/targeted synergy and supported the clinical testing of combinations of BRAF/MEK inhibitors and immune checkpoint inhibitors to improve the activity of upfront anti-melanoma therapies. The first positive phase III results were published in 2020, and triggered the discussion about the benefits, the limitations, as well as the possible implications of combining or sequencing targeted therapies with immune checkpoint inhibitors in everyday practice. Beginning from the interplay of immune/targeted agents within the melanoma microenvironment, this review outlines available information from the retrospective experience up to the late-stage randomized evidence on combinatorial treatments. Many clinical trials are currently underway exploring open questions about optimal timing, new immune biomarkers, and eligible patient subsets for these immune/targeted regimens. Awaiting these results, decision making in the first-line setting for BRAF-mutant melanoma is still guided by the patients' characteristics and the biological aspects of melanoma.