Should "on-demand" treatments for Parkinson's disease OFF episodes be used earlier?

We discuss a shift in the treatment paradigm for OFF episode management in patients with Parkinson's disease, based on clinical experience in the United States (US). Three "on-demand" treatments are currently available in the US as follows: subcutaneous apomorphine, levodopa inhalation powder, and sublingual apomorphine. We empirically propose that "on-demand" treatments can be utilized as a complementary treatment when OFF episodes emerge and can be utilized when needed rather than reserving these treatments only until other treatment approaches (adjustment of baseline treatment and/or addition of adjunctive treatment with "ON-extenders") have failed. Current treatment approaches combine "ON-extenders" with increasing levodopa dosing and/or frequency to treat OFF episodes. Yet, OFF episodes often persist, with a substantial amount of daily OFF time. OFF episode treatment is hindered by variable gastrointestinal (GI) absorption of oral levodopa, reflecting GI dysmotility and protein competition. Novel "on-demand" treatments bypass the gut and can improve OFF symptoms more rapidly and reliably than oral levodopa. With the emergence of novel "on-demand" treatments, we conclude that a shift in treatment paradigm to the earlier, complementary use of these medications be considered.

Indirect comparison of apomorphine sublingual film and levodopa inhalation powder for Parkinson's disease 'OFF' episodes.

Aim: To compare efficacy of apomorphine sublingual film (APL) and levodopa inhalation powder (CVT-301) for 'on-demand' treatment of Parkinson's disease 'OFF' episodes. Patients & methods: Patient-level data from an APL pivotal study were re-weighted to match average baseline characteristics from a CVT-301 study (SPAN-PD). Placebo-adjusted treatments were compared at week 12. Results: Improvements in predose Unified Parkinson's Disease Rating Scale Part III scores were significantly larger for APL versus CVT-301 at 60 min postdose (least squares mean difference-in-difference: -8.82; p = 0.002); difference at 30 min favored APL but was not statistically significant (-4.46; p = 0.103). Total daily 'OFF' time reductions were significantly larger for APL versus CVT-301 (-1.31 h; p = 0.013). Conclusion: Results suggest APL treatment may lead to improved efficacy versus CVT-301.

Cost-Effectiveness of Apomorphine Sublingual Film as an "On-Demand" Treatment for "OFF" Episodes in Patients with Parkinson's Disease.

Background: "On-demand" treatments approved in the United States (US) for "OFF" episodes in Parkinson's disease (PD) include apomorphine hydrochloride injection (SC-APO), apomorphine sublingual film (APL), and levodopa inhalation powder (CVT-301). APL received US approval in 2020, and its cost-effectiveness has not been compared with SC-APO and CVT-301. Objective: To develop a cost-effectiveness analysis model comparing APL versus SC-APO and CVT-301 for treatment of patients with PD experiencing "OFF" episodes from a US payer perspective. Methods: The model estimated total costs and effectiveness for each comparator arm, informed from the treatments' pivotal studies or literature, over a 10-year horizon. Total and incremental patient costs (in 2020 US dollars), total time spent without "OFF" episode symptoms, and quality-adjusted life years (QALY) gained were summarized and compared. Incremental cost-effectiveness ratios for APL versus SC-APO and CVT-301 were estimated and expressed as incremental patient costs per patient QALY gained and incremental cost per "OFF" hour avoided. Scenario analyses varying inputs and including caregiver costs were also conducted. Results: In the base case, APL had the lowest total "on-demand" treatment costs ($42,095) compared with SC-APO ($276,320; difference: -$234,225) and CVT-301 ($69,577; difference: -$27,482) over the 10-year horizon. APL was also associated with the highest utility, with incremental QALYs of 0.019 versus SC-APO and 0.235 versus CVT-301. APL was dominant over CVT-301 in terms of incremental cost per "OFF" hour, and dominant over both CVT-301 and SC-APO in terms of incremental cost per QALY gained. In all scenario analyses, APL was dominant against both SC-APO and CVT-301, confirming the robustness of the base-case results. Discussion: APL was dominant compared with both comparator arms, being less costly and more effective on average than SC-APO and CVT-301 in terms of QALYs. For SC-APO, cost-effectiveness of APL was driven by lower "on-demand" treatment costs and adverse event-related disutilities. For CVT-301, cost-effectiveness of APL was driven by lower "on-demand" treatment costs and substantially higher efficacy. Conclusions: From a US payer perspective, APL represents a cost-effective option compared with SC-APO and CVT-301 for treatment of "OFF" episodes in patients with PD.