Checkpoint Inhibitors Immunotherapy in Metastatic Melanoma: When to Stop Treatment?

Background: Immune checkpoint inhibition (ICI) has significantly improved the survival of metastatic melanoma (MM) with a significant proportion of patients obtaining long-lasting responses. However, ICI also exposes patients to new, heavy, and sometimes irreversible toxicities. Thus, identifying the minimal amount of treatment time is extremely urgent. Methods: We researched English peer-reviewed literature from electronic databases (MEDLINE and PubMed) until July 2022 with the aim of evaluating the clinical outcomes after the cessation of ICI therapy due to elective study plans, clinician–patient sharing, and adverse events. Results: Although most of the data are from retrospective studies, considering that most patients with major responses maintain it after treatment cessation, it is proposed that for complete response (CR)/near CR, a further six months of therapy after best response may be considered enough. For partial response (PR) or stable disease (SD), treatment must be continued for at least 2 years and, in some cases, indefinitely, based on residual disease, the patient’s will, and the toxic profile. Of note, in spite of the best response, 25–30% of patients relapsed, and, when retreated, responded far less than in front-line treatment. Conclusions: Most of the data being from retrospective and heterogeneous experiences, their grade of evidence is limited and no consensus has been reached on the optimal treatment duration. Controlled prospective studies are needed.

Early discontinuation of PD-1 blockade upon achieving a complete or partial response in patients with advanced melanoma: the multicentre prospective Safe Stop trial

Background

The introduction of programmed cell death protein 1 (PD-1) blockers (i.e. nivolumab and pembrolizumab) has significantly improved the prognosis of patients with advanced melanoma. However, the long treatment duration (i.e. two years or longer) has a high impact on patients and healthcare systems in terms of (severe) toxicity, health-related quality of life (HRQoL), resource use, and healthcare costs. While durable tumour responses have been observed and PD-1 blockade is discontinued on an individual basis, no consensus has been reached on the optimal treatment duration. The objective of the Safe Stop trial is to evaluate whether early discontinuation of first-line PD-1 blockade is safe in patients with advanced and metastatic melanoma who achieve a radiological response.

Methods

The Safe Stop trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 200 patients with advanced and metastatic cutaneous melanoma and a confirmed complete response (CR) or partial response (PR) according to response evaluation criteria in solid tumours (RECIST) v1.1 will be included to early discontinue first-line monotherapy with nivolumab or pembrolizumab. The primary objective is the rate of ongoing responses at 24 months after discontinuation of PD-1 blockade. Secondary objectives include best overall and duration of response, need and outcome of rechallenge with PD-1 blockade, and changes in (serious) adverse events and HRQoL. The impact of treatment discontinuation on healthcare resource use, productivity losses, and hours of informal care will also be assessed. Results will be compared to those from patients with CR or PR who completed 24 months of treatment with PD-1 blockade and had an ongoing response at treatment discontinuation. It is hypothesised that it is safe to early stop first-line nivolumab or pembrolizumab at confirmed tumour response while improving HRQoL and reducing costs.

Discussion

From a patient, healthcare, and economic perspective, shorter treatment duration is preferred and overtreatment should be prevented. If early discontinuation of first-line PD-1 blockade appears to be safe, early discontinuation of PD-1 blockade may be implemented as the standard of care in a selected group of patients.

Trial registration

The Safe Stop trial has been registered in the Netherlands Trial Register (NTR), Trial NL7293 (old NTR ID: 7502), https://www.trialregister.nl/trial/7293. Date of registration September 30, 2018.

Sequential treatment approaches in the management of BRAF wild-type advanced melanoma: a cost–effectiveness analysis

Aim: To evaluate the cost–effectiveness of treatment sequences with checkpoint inhibitors in patients with BRAF wild-type melanoma. Materials & methods: Using a discrete event simulation model, cost and health outcomes were estimated. Pooled data from CheckMate 067/069 trials were used to calculate survival outcomes including treatment-free interval extrapolated over a patient's lifetime. Costs accounted for treatment, administration, toxicity, and disease management. Results: First-line anti-PD-1 + anti-CTLA-4 initiating sequences had the highest estimated mean survival gain (7.6–7.7 years), driven by a longer estimated mean treatment-free interval (5.3 years). Incremental costs per incremental quality-adjusted life year gained for anti-PD-1 + anti-CTLA-4 followed by chemotherapy were US$30,955 versus anti-PD-1 initiating sequences, within the willingness-to-pay threshold. Conclusion: Anti-PD-1 + anti-CTLA-4 initiating sequences for BRAF wild-type melanoma are cost-effective versus anti-PD-1.