P-056 - (Poster #56) Evaluating the Impact of Ongoing Treatment with the High-Concentration Capsaicin Topical System (HCCTS) on Pain, Sleep, Quality of Life (QOL), and Affective Distress in Patients with Painful Diabetic Peripheral Neuropathy (DPN) of the Hands: Findings from the Real-World CASPAR Study

Chronic pain develops in 30% to 50% of people with DPN.^1-3 Pain, depression, anxiety, and sleep disturbance reduce QOL for patients with painful DPN.⁴ The prevalence of affective distress, including depression, anxiety, and stress, in this patient population is 51.4%.⁵ It is unclear whether affective distress is impacted by analgesic treatment.⁶ Compared with feet, painful DPN of the hands occurs later on in the disease course and is understudied.^7,8

Purpose/Objectives: The purpose of this study was to evaluate the real-world efficacy and tolerability of ongoing HCCTS applications for the treatment of painful DPN of the hands in a clinic rather than in a controlled trial setting.

Methods: CASPAR, a non-interventional, retrospective, cohort study, used data from the German Pain e-Registry (283 pain centers) to assess 24-hour average pain intensity (API), sleep, QOL, and affective distress in a real-world cohort of patients with painful DPN of the hands after ≥1 HCCTS treatments (~3-month intervals) over a 12-month period. API was measured using a visual analogue scale (VAS); affective distress was evaluated using the Depression, Anxiety and Stress Scale (DASS) subscale scores; QOL was assessed using the Veteran’s Research and Development (RAND-12) health survey physical and mental component scores; sleep was assessed using the modified pain disability index (mPDI) sleep item; and suicidal ideation was assessed by self-administered questionnaire. Concomitant medication use was also evaluated during the 12-month period.

Results:

A total of 191 patients with painful DPN of the hands received one (n=52), two (n=48), three (n=37), or four (n=54) HCCTS treatments. Significant reductions in 24-hour API were seen by Month 3 following one treatment (55.0 [95% CI: 48.7, 61.3] at baseline vs 38.6 [95% CI: 34.3, 42.9], P< 0.001 vs baseline) and improved with time and ongoing treatment (57.8 [95% CI: 52.2, 63.4] at baseline vs 10.1 [95% CI: 7.2, 13.0] at 12 months for those receiving four treatments, P< 0.001). Similar improvements in sleep were also seen by Month 3 following one treatment (62.4 [95% CI: 55.6, 69.2] at baseline vs 44.4 [95% CI: 39.2, 49.6] at 3 months, P< 0.001) and improved with time and ongoing treatment (67.6 [95%CI: 60.2, 75.0] at baseline vs 11.5 [95% CI:8.7, 14.3] at 12 months for those receiving four treatments, P< 0.001). Over 12 months, both RAND-12 physical and mental components and DASS subscale scores for depression, anxiety, and stress improved with repeat HCCTS applications. API, effects on sleep, QOL impairment, and affective distress began to worsen when treatments were discontinued. The percentage of patients reporting suicidal ideation that occurred frequently or sometimes decreased significantly from 24.1% at baseline to 8.4%, 0.5%, 0%, and 0% after a first, second, third, and fourth treatment, respectively. Use of concomitant pain medication for neuropathic pain decreased as treatment continued, with 26% of patients who received four treatments being able to stop all comedication for painful DPN of the hands 12 months after initial treatment. HCCTS tolerability was consistent with its known profile and primarily involved application-site reactions.

Conclusions/Implications for future research and/or clinical care:

Results from the CASPAR real-world clinical study highlight the effectiveness of repeat HCCTS treatments in patients with painful DPN of the hands, demonstrating significant reductions in API and improved sleep, QOL, and affective distress over 12 months, with the biggest improvements observed in patients who received four treatments. The results of this subanalysis are consistent with those from an analysis of CASPAR data for patients treated with painful DPN of the feet.