A Single-Arm, Prospective Study of Papaverine for the Treatment of Refractory Peripheral Neuropathy Induced by Taxane-Based Chemotherapy

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and often long-lasting side effect of cancer treatment. Patients may experience numbness, tingling, pain, burning sensations, weakness, or difficulty with walking and daily activities. Paclitaxel-related CIPN is especially common, and current treatment options are limited. For patients whose symptoms do not improve with standard therapies such as duloxetine, pregabalin, or gabapentin, there is an important unmet clinical need. Papaverine is a vasodilator and smooth muscle relaxant that may improve blood flow in the small vessels supplying nerves. Based on the hypothesis that impaired microcirculation and ischemia may contribute to CIPN, papaverine may help relieve symptoms and support nerve recovery. Preliminary clinical observations by the investigators suggested that papaverine injection may rapidly improve numbness and weakness in some patients with refractory paclitaxel-induced CIPN.This is a prospective, single-center, single-arm, open-label phase II study designed to evaluate the preliminary efficacy and safety of papaverine injection in patients with refractory paclitaxel-induced peripheral neuropathy. Eligible participants are adults aged 18 to 75 years with histologically or cytologically confirmed malignancy, prior treatment with a paclitaxel-containing regimen, persistent clinically significant neuropathy of grade 2 or higher, and failure of at least one standard treatment for CIPN. Participants will receive papaverine hydrochloride 120 mg diluted in 100 mL normal saline by intravenous infusion once daily, given as 1 treatment day followed by 6 rest days, with 7 days defined as one cycle. Up to 3 cycles of treatment may be given if patients benefit and tolerate therapy well.The main goal of the study is to assess improvement in patient-reported sensory neuropathy symptoms using the EORTC QLQ-CIPN20 sensory subscale. Secondary objectives include changes in overall neuropathy symptoms, physician-assessed neuropathy grade, quality of life, and safety. Exploratory assessments include nerve conduction findings and inflammatory biomarkers. The study aims to enroll approximately 43 patients and will provide early evidence on whether papaverine may be a useful treatment option for patients with refractory paclitaxel-induced CIPN.

Study Overview

• Status: Not yet recruiting
• Conditions: Chemotherapy-Induced Peripheral Neuropathy; Paclitaxel-Induced Peripheral Neuropathy; Refractory Chemotherapy-Induced Peripheral Neuropathy
• Intervention / Treatment: Drug: Papaverine hydrochloride injection

• Study Type: Interventional
• Enrollment (Estimated): 43
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yinuo Tan; Phone Number: +86 13805753262; Email: tan0yi0nuo@zju.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age 18 to 75 years.
• Histologically or cytologically confirmed malignancy.
• Prior treatment with a taxane-containing chemotherapy regimen, including but not limited to paclitaxel, docetaxel, or nab-paclitaxel, with completion of chemotherapy at least 4 weeks before enrollment.
• Persistent, clinically significant peripheral neuropathy mainly attributed to taxane-based chemotherapy, with NCI-CTCAE v5.0 sensory neuropathy grade ≥ 2.
• Failure of at least one standard treatment for chemotherapy-induced peripheral neuropathy, such as duloxetine ≥ 60 mg/day, pregabalin ≥ 150 mg/day, or gabapentin ≥ 900 mg/day, for at least 4 weeks, defined as lack of symptom improvement or intolerance to treatment.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
• Adequate organ function, including hematologic, hepatic, and renal function within acceptable ranges.
• Willingness to participate and ability to provide written informed consent.

Exclusion Criteria:

• Peripheral neuropathy due to causes other than chemotherapy, such as uncontrolled diabetes mellitus (HbA1c > 7.0%), severe renal insufficiency, vitamin B12 deficiency, thyroid dysfunction, or history of alcohol abuse.
• Known hypersensitivity to papaverine or any of its components.
• Contraindications to papaverine, such as complete atrioventricular block.
• Current use of other investigational drugs that may affect neurological function.
• Pregnant or breastfeeding women.
• Severe hepatic or renal dysfunction, defined as ALT or AST > 3 × upper limit of normal or serum creatinine > 2 × upper limit of normal.
• Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation in the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Papaverine Treatment

Drug: Papaverine hydrochloride injection; Intervention Description: Papaverine hydrochloride injection will be administered at a dose of 120 mg diluted in 100 mL of 0.9% sodium chloride solution by intravenous infusion once daily. Treatment consists of 1 day of administration followed by 6 days of rest, with 7 days defined as one cycle. Patients who demonstrate clinical benefit and tolerate treatment may receive up to 3 cycles. Concomitant use of stable-dose neurotrophic agents is allowed, while initiation of new treatments that may affect neuropathy is prohibited.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change from baseline in EORTC QLQ-CIPN20 sensory scale score	From baseline to Day 15 (end of treatment)

Collaborators and Investigators

• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: April 21, 2026
• First Submitted That Met QC Criteria: May 5, 2026
• First Posted (Actual): May 7, 2026

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Alkaloids; Opiate Alkaloids; Isoquinolines; Benzylisoquinolines; Papaverine
• Other Study ID Numbers: 2026-Lunshenyan-0272

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No