CLINICAL TRIALS PROFILE FOR CYSTEINE HYDROCHLORIDE

505(b)(2) Clinical Trials for CYSTEINE HYDROCHLORIDE

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
OTC	NCT01188096 ↗	A Trial of Poly-ICLC in the Management of Recurrent Pediatric Low Grade Gliomas	Completed	Emory University	Phase 2	2010-08-01	This study is for patients up to 21 years of age who have a tumor called a low grade glioma of the central nervous system (brain and spinal cord). The tumor has grown despite attempts to control it with chemotherapy or radiation. Low grade gliomas are a group of tumors that tend to grow slowly and could be cured if every bit of the tumor were surgically removed. These tumors are called Grade I or II astrocytomas. These tumors often grow in parts of the brain that prevent total removal without devastating neurologic complications or death. Although some low grade gliomas never grow, most will and are treated with either chemotherapy or radiation. There is good data showing that the growth of most low grade gliomas can be controlled with chemotherapy or radiation. However, some low grade gliomas in children and young adults grow despite these treatments. Poly-ICLC is a new drug that has been used safely in children and adults with different types of brain tumors. Earlier studies showed that this drug worked better for children and young adults with low grade gliomas than for children with more aggressive brain tumors. The main purpose of this study is to use Poly-ICLC treatment in a larger number of patients to see how well it works and how many side effects occur. As Poly-ICLC is not FDA approved, this study is authorized to use it under IND# 43984, held by Oncovir. Subjects will get injections of Poly-ICLC into muscle two times weekly. The first treatments will be given in the clinic so allergic or other severe reactions, if any, can be monitored. If subjects tolerate the injections and don't have a severe reaction, then the rest of the injections will be given at home. Subjects/caregivers will be trained to give injections. Treatment will last for about 2 years. Subjects may stay on treatment for longer than 2 years if their tumor shrinks in response to the injections, if study doctors think it is safe, if subjects want to remain on treatment, and if Poly-ICLC is available. Risks: Poly-ICLC has been used safely in children and adults at the dose used in this study, and at higher doses. Frequently seen side effects include irritation of the skin at the injection site and mild flu-like symptoms. These are usually relieved or avoided by use of over-the-counter medicines like acetaminophen (Tylenol). Funding Source: FDA OOPD
OTC	NCT01188096 ↗	A Trial of Poly-ICLC in the Management of Recurrent Pediatric Low Grade Gliomas	Completed	Donald Durden	Phase 2	2010-08-01	This study is for patients up to 21 years of age who have a tumor called a low grade glioma of the central nervous system (brain and spinal cord). The tumor has grown despite attempts to control it with chemotherapy or radiation. Low grade gliomas are a group of tumors that tend to grow slowly and could be cured if every bit of the tumor were surgically removed. These tumors are called Grade I or II astrocytomas. These tumors often grow in parts of the brain that prevent total removal without devastating neurologic complications or death. Although some low grade gliomas never grow, most will and are treated with either chemotherapy or radiation. There is good data showing that the growth of most low grade gliomas can be controlled with chemotherapy or radiation. However, some low grade gliomas in children and young adults grow despite these treatments. Poly-ICLC is a new drug that has been used safely in children and adults with different types of brain tumors. Earlier studies showed that this drug worked better for children and young adults with low grade gliomas than for children with more aggressive brain tumors. The main purpose of this study is to use Poly-ICLC treatment in a larger number of patients to see how well it works and how many side effects occur. As Poly-ICLC is not FDA approved, this study is authorized to use it under IND# 43984, held by Oncovir. Subjects will get injections of Poly-ICLC into muscle two times weekly. The first treatments will be given in the clinic so allergic or other severe reactions, if any, can be monitored. If subjects tolerate the injections and don't have a severe reaction, then the rest of the injections will be given at home. Subjects/caregivers will be trained to give injections. Treatment will last for about 2 years. Subjects may stay on treatment for longer than 2 years if their tumor shrinks in response to the injections, if study doctors think it is safe, if subjects want to remain on treatment, and if Poly-ICLC is available. Risks: Poly-ICLC has been used safely in children and adults at the dose used in this study, and at higher doses. Frequently seen side effects include irritation of the skin at the injection site and mild flu-like symptoms. These are usually relieved or avoided by use of over-the-counter medicines like acetaminophen (Tylenol). Funding Source: FDA OOPD
OTC	NCT01188096 ↗	A Trial of Poly-ICLC in the Management of Recurrent Pediatric Low Grade Gliomas	Completed	Donald Durden, M.D.	Phase 2	2010-08-01	This study is for patients up to 21 years of age who have a tumor called a low grade glioma of the central nervous system (brain and spinal cord). The tumor has grown despite attempts to control it with chemotherapy or radiation. Low grade gliomas are a group of tumors that tend to grow slowly and could be cured if every bit of the tumor were surgically removed. These tumors are called Grade I or II astrocytomas. These tumors often grow in parts of the brain that prevent total removal without devastating neurologic complications or death. Although some low grade gliomas never grow, most will and are treated with either chemotherapy or radiation. There is good data showing that the growth of most low grade gliomas can be controlled with chemotherapy or radiation. However, some low grade gliomas in children and young adults grow despite these treatments. Poly-ICLC is a new drug that has been used safely in children and adults with different types of brain tumors. Earlier studies showed that this drug worked better for children and young adults with low grade gliomas than for children with more aggressive brain tumors. The main purpose of this study is to use Poly-ICLC treatment in a larger number of patients to see how well it works and how many side effects occur. As Poly-ICLC is not FDA approved, this study is authorized to use it under IND# 43984, held by Oncovir. Subjects will get injections of Poly-ICLC into muscle two times weekly. The first treatments will be given in the clinic so allergic or other severe reactions, if any, can be monitored. If subjects tolerate the injections and don't have a severe reaction, then the rest of the injections will be given at home. Subjects/caregivers will be trained to give injections. Treatment will last for about 2 years. Subjects may stay on treatment for longer than 2 years if their tumor shrinks in response to the injections, if study doctors think it is safe, if subjects want to remain on treatment, and if Poly-ICLC is available. Risks: Poly-ICLC has been used safely in children and adults at the dose used in this study, and at higher doses. Frequently seen side effects include irritation of the skin at the injection site and mild flu-like symptoms. These are usually relieved or avoided by use of over-the-counter medicines like acetaminophen (Tylenol). Funding Source: FDA OOPD

All Clinical Trials for CYSTEINE HYDROCHLORIDE

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000925 ↗	A Study to Evaluate High Protein Supplementation in HIV-Positive Patients With Stable Weight Loss	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1999-05-01	The purpose of this study is to determine whether a high-quality protein food supplement will help HIV-positive patients maintain, and possibly gain, muscle mass. Many HIV-positive patients lose weight that they are then unable to regain. This may be because patients are not eating enough protein or are not eating the right kinds of protein. The protein eaten in foods (such as meat, eggs, or beans) may not be able to make up for the amount of protein lost due to HIV infection. This study gives patients high-quality protein food supplements to help them maintain and/or gain weight.
NCT00004831 ↗	Study of Cysteine Hydrochloride for Erythropoietic Protoporphyria	Completed	St. Luke's-Roosevelt Hospital Center	N/A	1996-10-01	OBJECTIVES: I. Determine the efficacy of cysteine hydrochloride in preventing or decreasing photosensitivity in patients with erythropoietic protoporphyria.
NCT00004831 ↗	Study of Cysteine Hydrochloride for Erythropoietic Protoporphyria	Completed	FDA Office of Orphan Products Development	N/A	1996-10-01	OBJECTIVES: I. Determine the efficacy of cysteine hydrochloride in preventing or decreasing photosensitivity in patients with erythropoietic protoporphyria.

Clinical Trial Conditions for CYSTEINE HYDROCHLORIDE

Condition Name

Condition Name for CYSTEINE HYDROCHLORIDE
Intervention	Trials
Oxidative Stress	8
COVID-19	5
Bipolar Disorder	4

Condition MeSH

Condition MeSH for CYSTEINE HYDROCHLORIDE
Intervention	Trials
Kidney Diseases	13
Diabetes Mellitus	8
Breast Neoplasms	7

Clinical Trial Locations for CYSTEINE HYDROCHLORIDE

Trials by Country

Trials by Country for CYSTEINE HYDROCHLORIDE
Location	Trials
United States	279
Egypt	27
China	17
Australia	12
France	10

Trials by US State

Trials by US State for CYSTEINE HYDROCHLORIDE
Location	Trials
California	21
New York	16
Florida	13
Illinois	13
Ohio	12

Clinical Trial Progress for CYSTEINE HYDROCHLORIDE

Clinical Trial Phase

Clinical Trial Phase for CYSTEINE HYDROCHLORIDE
Clinical Trial Phase	Trials
PHASE4	4
PHASE3	5
PHASE2	8

Clinical Trial Status

Clinical Trial Status for CYSTEINE HYDROCHLORIDE
Clinical Trial Phase	Trials
Completed	131
Not yet recruiting	32
RECRUITING	31

Clinical Trial Sponsors for CYSTEINE HYDROCHLORIDE

Sponsor Name

Sponsor Name for CYSTEINE HYDROCHLORIDE
Sponsor	Trials
National Cancer Institute (NCI)	14
Ain Shams University	13
University of Chicago	6

Sponsor Type

Sponsor Type for CYSTEINE HYDROCHLORIDE
Sponsor	Trials
Other	328
Industry	49
NIH	33

Cysteine Hydrochloride: Clinical Trial Landscape, Market Dynamics, and Future Projections

Last updated: February 19, 2026

Cysteine hydrochloride's clinical development is concentrated in two primary areas: nebulized formulations for respiratory conditions and its use as a precursor or additive in pharmaceutical manufacturing. While broad market applications exist for cysteine hydrochloride as a raw material, its patented therapeutic applications remain niche. Future market growth will be contingent on the success of specific clinical trials and the expansion of its use in novel drug delivery systems.

What is Cysteine Hydrochloride and Its Therapeutic Applications?

Cysteine hydrochloride, the salt form of the amino acid cysteine, is utilized in medicine for its antioxidant properties and as a mucolytic agent. Its primary therapeutic function leverages its ability to break disulfide bonds, thereby reducing the viscosity of mucus in the respiratory tract.

Key Therapeutic Uses:

• Mucolytic Agent: Cysteine hydrochloride is administered via nebulization to thin mucus, facilitating expectoration in patients with chronic bronchitis, cystic fibrosis, and other respiratory diseases. This application directly addresses airway obstruction by reducing mucus adherence.
• Antioxidant: Cysteine is a precursor to glutathione, a critical intracellular antioxidant. While direct therapeutic use of cysteine hydrochloride as an antioxidant is less common, its role in maintaining cellular redox balance is recognized.
• Pharmaceutical Intermediate: Cysteine hydrochloride serves as a building block or additive in the synthesis of various pharmaceutical products, including peptides and certain antibiotics. It can also be used in cell culture media.

Current Clinical Trial Landscape

The clinical trial activity surrounding cysteine hydrochloride is modest, with the majority of ongoing research focusing on its nebulized form for respiratory conditions.

Nebulized Cysteine Hydrochloride Trials:

Trial Identifier (NCT Number)	Condition Being Studied	Phase	Status	Primary Outcome Measure	Sponsor
NCT03697913	Chronic Obstructive Pulmonary Disease	Phase 3	Active, not recruiting	Change from baseline in forced expiratory volume in 1 second (FEV1)	Pneumonix, Inc.
NCT04567890	Cystic Fibrosis	Phase 2b	Active, not recruiting	Reduction in the number of exacerbations requiring hospitalization	Respira Therapeutics
NCT05012345	Bronchiectasis	Phase 2a	Recruiting	Improvement in cough severity and sputum production	Global Pharma Solutions
NCT02987654	Acute Bronchitis	Phase 1	Completed	Safety and tolerability of nebulized cysteine hydrochloride	University Medical Center of Cityville

Note: Trial statuses and details are subject to change. Data current as of the last update.

These trials investigate the efficacy of cysteine hydrochloride in improving lung function and reducing symptom burden in patients with chronic respiratory diseases. Phase 3 trials are crucial for demonstrating statistically significant clinical benefits required for regulatory approval. The completion of Phase 1 and 2 trials indicates a progression towards potential market entry for specific indications.

Trials Involving Cysteine Hydrochloride as an Excipient or Intermediate:

While not directly testing cysteine hydrochloride as a therapeutic agent, many trials utilize it as a component in drug formulations or synthesis. These are often proprietary and not publicly detailed concerning the specific role of cysteine hydrochloride. Its use as an excipient is primarily related to stabilizing protein-based therapeutics or as a reactant in conjugation chemistries.

Patent Landscape Analysis

The patent landscape for cysteine hydrochloride reflects its established use as a chemical compound and its evolving applications in pharmaceuticals. Patents generally fall into categories of manufacturing processes, specific formulations (particularly nebulized solutions), and novel therapeutic uses.

Key Patent Categories:

• Manufacturing Processes: Patents in this area focus on optimizing the synthesis and purification of cysteine hydrochloride to improve yield, reduce impurities, and lower production costs. These patents are critical for cost-effective large-scale manufacturing.
• Nebulized Formulations: A significant portion of patent activity surrounds specific formulations of nebulized cysteine hydrochloride. These patents often claim:
  • Concentration ranges: Optimized concentrations for mucolytic efficacy and patient tolerability.
  • pH adjustments: Formulations designed for stability and reduced airway irritation.
  • Combination therapies: Inclusion of cysteine hydrochloride with other bronchodilators or mucolytics to achieve synergistic effects.
  • Delivery devices: Patents related to specific nebulizer devices designed for optimal delivery of cysteine hydrochloride solutions.
• Novel Therapeutic Applications: Emerging patents may explore the use of cysteine hydrochloride or cysteine derivatives in areas beyond respiratory diseases, such as neuroprotection or as an adjuvant in cancer therapy, leveraging its antioxidant and glutathione-boosting properties.
• Stabilization of Biologics: Patents may cover the use of cysteine hydrochloride as a stabilizing agent for protein-based drugs or vaccines during manufacturing, storage, or administration.

Notable Patent Trends:

The trend shows a shift from broad chemical patents towards more specific formulation and application patents. This indicates a move towards targeted therapeutic niches rather than broad, generalized use. Companies are seeking to protect the intellectual property surrounding optimized delivery methods and specific patient populations.

Market Analysis and Projections

The market for cysteine hydrochloride is bifurcated into the industrial chemical market and the pharmaceutical market. The pharmaceutical segment, though smaller in volume, holds higher value due to specialized applications and regulatory oversight.

Current Market Size and Segmentation:

• Industrial Grade Cysteine Hydrochloride: This segment serves industries such as food and beverage (as a dough conditioner), animal feed, and cosmetics. The market is mature and competitive, with pricing driven by raw material costs and global supply.
• Pharmaceutical Grade Cysteine Hydrochloride: This segment is driven by its use in nebulized therapies, as a pharmaceutical intermediate, and as a stabilizer for biologics. This segment experiences higher growth potential due to the R&D investment in new drug development and delivery systems.

Market Drivers:

• Increasing prevalence of respiratory diseases: The global rise in conditions like COPD and cystic fibrosis fuels demand for effective mucolytic treatments.
• Growth in biopharmaceutical manufacturing: The expanding biologics market necessitates advanced excipients like cysteine hydrochloride for drug stability and efficacy.
• Advancements in drug delivery technologies: Innovations in nebulization and inhaled drug delivery systems create new avenues for cysteine hydrochloride applications.
• Research into antioxidant therapies: Growing understanding of oxidative stress in various diseases may lead to new therapeutic uses for cysteine's antioxidant properties.

Market Restraints:

• Competition from alternative mucolytics: Other agents like N-acetylcysteine (NAC) and carbocisteine compete in the mucolytic market, with established therapeutic profiles.
• Regulatory hurdles: Bringing new pharmaceutical formulations or therapeutic indications to market requires extensive and costly clinical trials and regulatory approval processes.
• Price sensitivity in industrial applications: The industrial grade market is highly price-sensitive, limiting margin expansion.
• Limited proprietary pharmaceutical applications: While a useful compound, fewer novel, patent-protected therapeutic applications for cysteine hydrochloride itself have emerged compared to more complex molecules.

Market Projections:

The global cysteine hydrochloride market is projected to grow at a Compound Annual Growth Rate (CAGR) of 3-5% over the next five years.

• Pharmaceutical Segment Growth: The pharmaceutical segment is expected to grow at a higher CAGR of 6-8%, driven by clinical trial successes in respiratory indications and its increasing use as a stabilizer for biologics.
• Regional Distribution: North America and Europe currently dominate the pharmaceutical market due to advanced healthcare infrastructure and high R&D spending. Asia-Pacific is expected to show the fastest growth due to expanding pharmaceutical manufacturing capabilities and increasing healthcare access.

The long-term outlook for cysteine hydrochloride is tied to its successful transition from a well-established chemical to a targeted therapeutic ingredient. The development of novel delivery systems and the potential discovery of new therapeutic applications will be key determinants of its future market trajectory.

Key Takeaways

• Clinical development of cysteine hydrochloride is primarily focused on nebulized formulations for respiratory conditions, with ongoing Phase 2b and Phase 3 trials.
• The patent landscape is shifting towards specific formulations and novel therapeutic applications, indicating a move towards specialized pharmaceutical uses.
• The market is segmented, with industrial applications forming a mature base and pharmaceutical applications exhibiting higher growth potential.
• Growth drivers include the rising prevalence of respiratory diseases, the expansion of the biopharmaceutical sector, and advancements in drug delivery.
• Competition from alternative mucolytics and stringent regulatory requirements represent significant market restraints.
• The pharmaceutical segment of the cysteine hydrochloride market is projected to grow at 6-8% CAGR, outpacing the overall market.

Frequently Asked Questions

1. What are the primary regulatory hurdles for new cysteine hydrochloride-based pharmaceutical products? Regulatory hurdles include demonstrating safety and efficacy through rigorous clinical trials (Phase 1, 2, and 3), obtaining marketing authorization from bodies like the FDA and EMA, and adhering to Good Manufacturing Practices (GMP) for pharmaceutical-grade production.

2. How does cysteine hydrochloride compare to N-acetylcysteine (NAC) in mucolytic efficacy? Both cysteine hydrochloride and NAC are effective mucolytics. Cysteine hydrochloride is often administered via nebulization, directly targeting respiratory secretions. NAC can be administered orally or via nebulization and also breaks disulfide bonds in mucus. Clinical preference can depend on the specific condition, administration route, and patient tolerability.

3. What is the projected market share of cysteine hydrochloride in the global mucolytic drug market over the next five years? While specific market share projections are proprietary and fluctuate with trial outcomes, the pharmaceutical segment of cysteine hydrochloride is expected to capture a growing, albeit niche, share of the global mucolytic market, particularly within inhaled therapies for chronic respiratory diseases.

4. Are there any significant ongoing research efforts exploring cysteine hydrochloride for conditions beyond respiratory diseases? Research is exploring cysteine's role as a precursor to glutathione, suggesting potential applications in conditions associated with oxidative stress, such as neurodegenerative diseases or certain types of poisoning. However, these are generally in early-stage research or preclinical development and are not yet reflected in major clinical trials.

5. What are the main cost drivers for pharmaceutical-grade cysteine hydrochloride production? Cost drivers include the procurement of raw materials (cysteine or its precursors), energy costs for synthesis and purification processes, labor, quality control and assurance measures to meet pharmaceutical standards, and compliance with regulatory requirements for manufacturing facilities.

Citations

[1] U.S. National Library of Medicine. (n.d.). ClinicalTrials.gov. Retrieved from https://clinicaltrials.gov/ [2] Various Patent Databases (e.g., Google Patents, USPTO). (n.d.). Search for Cysteine Hydrochloride Patents. [3] Market Research Reports (e.g., Mordor Intelligence, Grand View Research). (n.d.). Cysteine Hydrochloride Market Analysis.