Upfront combination therapy: does the AMBITION study herald a new era in the treatment of pulmonary arterial hypertension?

Assessment of the REPLACE study composite endpoint in riociguat-treated patients in the PATENT study

The goal of treatment in patients with pulmonary arterial hypertension is to achieve a low risk status, indicating a favorable long-term outcome. The REPLACE study investigated the efficacy of switching to riociguat in patients with pulmonary arterial hypertension and an insufficient response to phosphodiesterase-5 inhibitors. In this post hoc analysis, we applied the REPLACE composite endpoint of clinical improvement to the placebo-controlled PATENT-1 study of riociguat in pulmonary arterial hypertension and its long-term extension, PATENT-2. Clinical improvement was defined as ≥2 of the following in patients who completed the study without clinical worsening: ≥10% or ≥30 m improvement in 6-minute walking distance; World Health Organization functional class I or II; ≥30% decrease in N-terminal prohormone of brain natriuretic peptide. At PATENT-1 Week 12, patients treated with riociguat were more likely to achieve the composite endpoint vs. placebo (P < 0.0001), with similar results in pretreated (P = 0.0189) and treatment-naïve (P < 0.0001) patients. Achievement of the composite endpoint at Week 12 was associated with a 45% reduction in relative risk of death and a 19% reduction in relative risk of clinical worsening in PATENT-2. Overall, these data suggest that use of the REPLACE composite endpoint in patients with pulmonary arterial hypertension is a valid assessment of response to treatment.

Novel composite clinical endpoints and risk scores used in clinical trials in pulmonary arterial hypertension

This manuscript on endpoints incorporates the broad experience of members of Pulmonary Vascular Research Institute’s Innovative Drug Development Initiative as an open debate platform for academia, the pharmaceutical industry and regulatory experts surrounding the future design of clinical trials in pulmonary hypertension. It reviews our current understanding of endpoints used in phase 2 and 3 trials for pulmonary hypertension and discusses in detail the value of newer approaches. These include the roles of composite endpoints and how these can be developed and validated. The newer concept of risk analysis is also discussed, including how such risk scores might be utilised as endpoints in clinical trials.

Emerging application of genomics-guided therapeutics in personalized lung cancer treatment

In lung cancer, genomics-driven comprehensive molecular profiling has identified novel chemically and immunologically addressable vulnerabilities, resulting in an increasing application of precision medicine by targeted inactivation of tumor oncogenes and immunogenic activation of host anti-tumor surveillance as modes of treatment. However, initially profound response of these targeted therapies is followed by relapse due to therapy-resistant residual disease states. Although distinct mechanisms and frameworks for therapy resistance have been proposed, accounting for and upfront prediction of resistance trajectories has been challenging. In this review, we discuss in both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), the current standing, and challenges associated with genomics-guided strategies for personalized therapy against both oncogenic alterations as well as post-therapy resistance mechanisms. In NSCLC, we catalog the targeted therapy approaches against most notable oncogenic alterations such as epidermal growth factor receptor (EGFR), serine/threonine-protein kinase b-raf (BRAF), Kirsten rat sarcoma viral proto-oncogene (KRAS), anaplastic lymphoma kinase (ALK), ROS1 proto-oncogene receptor tyrosine kinase (ROS1). For SCLC, currently highly recalcitrant to targeted therapy, we enumerate a range of exciting and maturing precision medicine approaches. Furthermore, we discuss a number of immunotherapy approaches, in combination or alone, that are being actively pursued clinically in lung cancer. This review not only highlights common mechanistic themes underpinning different classes of resistance and discusses tumor heterogeneity as a source of residual disease, but also discusses potential ways to overcome these barriers. We emphasize how an extensive understanding of these themes can predict and improve therapeutic strategies, such as through poly-therapy approaches, to forestall tumor evolution upfront.

A Contemporary Approach to Pulmonary Arterial Hypertension

In recent years, there have been major changes in the landscape of pulmonary arterial hypertension therapy with the introduction of novel agents and innovative treatment strategies for this progressive disease. The aim of this review is to discuss the evolution in trial design in this field and highlight the salient features of recently published studies. We also summarize our approach to therapy selection in this chronic disease and identify areas for future exploration. The therapeutic armamentarium now includes 13 approved therapies. While most of these agents have been studied in small, short-term trials using the 6-min walk distance as a primary endpoint, there has been a shift in recent years toward larger, long-term, event-driven trials that utilize combined morbidity and mortality endpoints. The SERAPHIN and GRIPHON trials were two such studies, which led to the approval of the dual endothelin-receptor antagonist macitentan and the selective prostacyclin receptor antagonist selexipag, respectively. Other event-driven trials, like AMBITION and COMPASS-2, have provided valuable insight into the use of combined oral therapies in symptomatic patients. In conclusion, despite being a more manageable disease in the modern treatment era, pulmonary hypertension is still associated with considerable morbidity and much more work remains to be done in this field. Important questions remain about the most optimal way to manage patients and conduct trials going forward.

Efficacy and Safety of Pulmonary Arterial Hypertension-specific Therapy in Pulmonary Arterial Hypertension: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Previous meta-analyses of pulmonary arterial hypertension (PAH)-specific therapy for PAH pooled PAH-specific combination therapy and monotherapy. This flaw may threaten the authenticity of their findings.

METHODS

PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials that evaluated any PAH-specific medications in the treatment of PAH. We calculated ORs with 95% CIs for dichotomous data and standardized mean differences for continuous data.

RESULTS

In total, 35 randomized controlled trials involving 6,702 patients were included. In monotherapy vs placebo/conventional therapy, significance was obtained in mortality reduction (OR, 0.50 [95% CI, 0.33 to 0.76]; P = .001), 6-min walk test (mean difference, 31.10 m [95% CI, 25.40 to 36.80]; P < .00001), New York Heart Association/World Health Organization functional class (OR, 2.48 [95% CI, 1.51 to 4.07]; P = .0003), and hemodynamic status based on mean pulmonary artery pressure, pulmonary vascular resistance, cardiac index, and incidence of withdrawal due to adverse effects. In combination therapy vs monotherapy, significance was reached for the 6-min walk test (mean difference, 19.96 m [95% CI, 15.35 to 24.57]; P < .00001), functional class (OR, 1.65 [95% CI, 1.20 to 2.28]; P = .002), hemodynamic status, and incidence of withdrawal due to adverse effects (OR, 2.01 [95% CI, 1.54 to 2.61]; P < .00001) but not for mortality reduction (OR, 0.98 [95% CI, 0.57 to 1.68]; P = .94).

CONCLUSIONS

Our meta-analysis revealed that PAH-specific monotherapy could improve mortality, exercise capacity, functional class, and hemodynamic status compared with placebo or conventional therapy. However, combination therapy could further improve exercise capacity, functional class, and hemodynamic status compared with monotherapy, but it had no proven effect on mortality. Combination therapy had a much higher incidence of withdrawal due to adverse effects than monotherapy.