Stem Cell Research: Amyotrophic Lateral Sclerosis

Cell Type Used

• MSC-NTF Therapy: Uses Mesenchymal Stem Cells Secreting Neurotrophic Factors (MSC-NTF), trademarked as NurOwn.
• Cell Source: Derived from the patient’s own bone marrow.
• What They Are: The patient’s bone marrow cells are “super-charged” in the lab to produce and release large amounts of neurotrophic factors that protect and heal nerve cells.
• The Goal: Deliver protective proteins directly to damaged nerve cells in the spinal cord.

Delivery Method

• Intrathecal Injection: The cells are injected into the spinal fluid using a standard lumbar puncture (spinal tap).
• The Placebo: A nutrient solution that looks identical to the treatment but contains no active cells.

Cell Dosage

• Total number of cells per injection is not specified in current documents.
• Schedule: Both active treatment and placebo are administered every 8 weeks for three injections in the initial controlled phase (Part A).

Follow-up Schedule

• The trial runs for 48 weeks, split into two parts:
• Part A (24 Weeks): Randomized, double-blind, placebo-controlled phase. Participants receive either NurOwn or placebo every 8 weeks.
• Part B (24 Weeks): Open-Label Extension. All eligible participants who finish Part A receive the active NurOwn treatment every 8 weeks.

Primary Outcomes (What They Are Measuring)

• Effectiveness: Change in ALSFRS-R total score from baseline to Week 24.
• Safety: Tracking frequency and severity of Adverse Events throughout 48 weeks.

Other Outcomes

• Breathing Function: Changes in Slow Vital Capacity.
• Muscle Strength: Upper limb muscle strength measured with Hand-Held Dynamometry (HHD).
• Neurodegeneration: Levels of the nerve damage marker Neurofilament Light (NfL).
• Quality of Life: Patient self-reported ALSAQ-40 questionnaire results.
• Caregiver Burden: Zarit Caregiver Burden Interview (ZBI) to assess impact on caregivers.

Cell Type Used (iPSC-MNP)

• iPSC-MNP: Induced Pluripotent Stem Cells – Motor Neuron Precursors.
• What They Are: Adult stem cells guided to develop into the motor neurons that ALS destroys. These can originate from the patient or a donor.
• The Goal: Replace damaged motor neurons and protect existing ones by releasing growth factors and reducing inflammation.

Delivery Method

• Surgical Procedure: Multi-dose delivery directly into the brain.
• Surgical Implant: Under general anesthesia, patients have a Sofia drug pouch installed under the skin.
• Intraventricular Injection: Cells are injected through this pouch directly into the fluid-filled brain spaces.

Cell Dosage

• Dose per Injection: 50 million cells in a 2 mL solution.
• Schedule: Four total injections, administered every two weeks through the implanted pouch.

Follow-up Schedule

• Total treatment and observation period: approximately 7.5 months from the first cell injection.
• Safety and efficacy follow-ups at 1, 3, and 6 months after the final transplant.
• New subjects can only enroll after the prior subject completes 6 months of observation without serious side effects.

What They Are Measuring

• Primary Goal (Safety): Track any Adverse or Serious Adverse Events.
• Safety monitored via MRIs of the head and spine, blood tests, and vital sign checks.

Other Outcomes

• Functional Assessment: Changes in ALSFRS-R scores (functional ability scale).
• Cognitive & Mood Testing: Depression (HAMD 17), anxiety (HAMA), and cognition (MMSE, MoCA).
• Biomarkers: Spinal fluid tests for neurotrophic factors to confirm cell activity.

Cell Type Used: Allogeneic iPSC-MNP

• Therapy Type: Allogeneic iPSC-Derived Motor Neuron Progenitor Cells (XS228CN).
• What They Are: These cells come from a universal, healthy donor rather than the patient. Adult cells are reprogrammed into Induced Pluripotent Stem Cells and then guided to become Motor Neuron Progenitor Cells.
• The Goal: Introduce healthy nerve-precursor cells into the spinal fluid to replace lost motor neurons and improve nervous system function.

Delivery Method

• Intrathecal Injection: Cells are injected directly into the spinal fluid via lumbar puncture (spinal tap).
• No Placebo: This is an open-label trial, meaning all participants receive the active stem cell treatment.

Cell Dosage

• The trial tests four dose and schedule combinations to find the safest dose.
• Low Dose (50 million cells):
• Group 1: Single injection of 50 million cells.
• Group 2: Four injections of 50 million cells (every two weeks).
• High Dose (100 million cells):
• Group 3: Single injection of 100 million cells.
• Group 4: Four injections of 100 million cells (every two weeks).

Follow-up Schedule

• Main Safety Period: Safety monitored for 28 days after the final injection.
• Study Duration: Estimated to continue through late 2028.

What They Are Measuring

• The main objective is safetyrecording all treatment-related Adverse Events and Serious Adverse Events.

Other Outcomes

• Preliminary Efficacy: Collect early data on potential benefits of the therapy.
• Functional Assessment: Though not formally listed, ALS functional rating scales are typically used to track patient changes.

Cell Type Used: Bone Marrow Derived Autologous MSC

• Therapy Type: Autologous Bone-Marrow-Derived Mesenchymal Stem Cells (STR04).
• What They Are: The patient’s own MSCs collected from bone marrow, then multiplied and prepared (“manufactured”) before re-injection.
• The Goal: MSCs are used for their potential to repair tissue, reduce inflammation, and secrete protective factors that support damaged nerve cells.

Delivery Method

• Intravenous (IV) Injection: The STR04 cells are delivered via IV infusion.
• No Placebo: This is an open-label study (no masking); all participants receive the active STR04 treatment.

Cell Dosage

• Cell Dose: The exact number of cells per injection is not specified.
• Schedule: Participants receive 4 doses of STR04, one every 12 weeks.

Follow-up Schedule

• Treatment Period: 4 doses given over 36 weeks (9 months).
• Final Assessment: The total study duration, including the final assessment, is 69 weeks.

What They Are Measuring

• Main Goals: Evaluate both effectiveness and safety.
• Effectiveness: Change in ALS Functional Rating Scale (ALSFRS-R) score at 25 weeks.
• Safety: Track treatment-related Adverse Events.

Other Outcomes

• Functional Decline: Change in ALSFRS-R score over the study period.
• Breathing: Monitor Percent-predicted Forced Vital Capacity (FVC).
• Muscle Strength: Measure using the Manual Muscle Test (MMT).
• Quality of Life: Track using the ALS Assessment Questionnaire (ALSAQ-40).
• Biomarker: Monitor changes in plasma neurofilament light (NfL), a marker of nerve damage.

Cell Type Used (Allogeneic Neural Stem Cells)

• Therapy Type: Allogeneic Human Neural Stem Cells (hNSC).
• What They Are: Factory-produced stem cells, not from the patient, created under strict GMP standards. These are the source cells for all nerve cells in the brain and spinal cord.
• The Goal: Replace lost neurons and release protective factors directly into damaged areas of the brain.

Delivery Method

• Intracerebroventricular Transplantation: Cells are delivered directly into the brain’s fluid spaces (lateral ventricle).
• Surgical Reservoir: Delivered through an Ommaya reservoir implanted beneath the scalp for precise, direct injections.
• Controlled vs. Placebo: Randomized, placebo-controlled, triple-blind trial — some patients receive the active cells, others receive saline (placebo).

Cell Dosage

• Phase A (Safety/Dose-Finding): Six patients initially test two dose levels for safety.
• Phase B (Main Trial): Patients randomized into three groups:
• Low Dose: 20 million hNSCs.
• High Dose: 40 million hNSCs.

Follow-up Schedule

• Study Duration: Main study phase (Phase B) lasts approximately 24 months.
• Long-Term Monitoring: All patients will undergo lifelong safety monitoring due to the advanced nature of the therapy.
• Crossover Design: Patients receiving placebo will later be re-randomized to an active cell dose after three months, ensuring all eventually receive treatment.

What They Are Measuring

• Main Goal: Safety — track treatment-emergent and serious Adverse Events over the first 12 months.

Other Outcomes

• Biomarker Levels: Measuring biomarkers in spinal fluid and blood, including inflammatory markers.
• Cell Modeling: Creating patient-specific cell models (from blood and skin) to produce iPSCs and NSCs for studying treatment mechanisms.

Delivery Method

• Each participant received three injections intrathecally into the spinal fluid.
• The injections were performed using a standard lumbar puncture and were spaced eight weeks apart.

Cell Type & Source

• Autologous Mesenchymal Stem Cells induced to secrete Neurotrophic Factors (MSC-NTF).
• Source: The patient’s own bone marrow.

Cell Preparation

• Mesenchymal stem cells were collected from the patient’s bone marrow.
• The cells were treated in a lab under “proprietary conditions” that reprogrammed them to produce and secrete high levels of neurotrophic factors.

Dosage

• The study does not specify the exact number of cells contained in each injection.

Safety

• The treatment was safe and well-tolerated.
• Most side effects were mild to moderate, temporary, and related to the lumbar puncture procedure itself.
• There were no deaths related to the treatment.

Clinical Improvements (Primary Outcome)

• The study failed to meet its primary endpoint.
• There was no statistically significant difference in response between the stem cell group (33%) and the placebo group (28%).

Other Key Findings (Biomarkers & Subgroup)

• Improved Biomarkers: The therapy led to large and statistically significant improvements in key biomarkers in the spinal fluid.
• Neuroprotection: Levels of VEGF, a protective factor for motor neurons, increased significantly.
• Reduced Inflammation & Degeneration: Levels of MCP-1 and NfL were significantly reduced.
• Subgroup Analysis: In patients with less severe disease (ALSFRS-R score ≥ 35), response was 35% vs. 16% for placebo (not statistically significant).

How the Cells Worked

• The therapy was designed to support the nervous system, not to replace or rebuild it.
• The modified cells secrete high levels of neurotrophic factors directly into the spinal fluid.
• These proteins help damaged neurons survive, reduce inflammation, and protect the nervous system.
• Researchers found strong biomarker evidence confirming these effects in the spinal fluid.

• This was a large Phase 3 trial of MSC-NTF therapy in ALS.
• While it did not meet its primary clinical goal, it demonstrated that the treatment is safe and biologically active.
• Patients with less severe disease showed promising signals of benefit.
• Further studies are needed to confirm clinical efficacy and refine patient selection.

Delivery Method

• Each participant received a single treatment session consisting of ten injections directly into the lumbar spinal cord.

Cell Type & Source

• Human Neural Progenitor Cells, a specific type of stem cell.
• All cells came from a single, donated human fetal tissue sample, grown and expanded in a lab to ensure a large, pure, consistent supply.

Cell Preparation

• Cells were genetically modified via transduction to constantly produce the protective protein GDNF.
• Genetic modification occurred at passage 27, and the final cells were collected at passage 29.

Dosage

• Low-Dose Group: 2 million cells total.
• High-Dose Group: 5 million cells total.

Safety

• The therapy was safe; no serious adverse events were caused by the cell product itself.
• Half of the participants experienced long-term neuropathic pain.
• Post-mortem analysis revealed small, benign neuromas near injection sites.

Clinical Improvements

• The study did not meet its secondary goal of slowing disease progression.
• No statistically significant difference in muscle strength loss between treated and untreated legs.

Other Key Findings (Post-Mortem)

• Long-Term Cell Survival: transplanted cells survived up to 42 months post-injection.
• Sustained Protein Production: surviving cells actively produced GDNF years after injection.
• Confirmed Mechanism: cells acted as a permanent, living source of GDNF protein in the spinal cord.

What We Don’t Know

• Surgical injections were not perfectly accurate; many cells ended up away from the motor neurons they were meant to target.
• Formation of neuromas is a serious finding needing further study before future trials.

Conclusion

• First-of-its-kind trial for ALS; primary goal of demonstrating safety was met.
• Provided long-term evidence that engineered cell therapy can survive and function for years in the human nervous system.
• This foundational knowledge is crucial for designing better, more accurate trials in the future.

Delivery Method

• Each participant received a single intrathecal injection of AstroRx cells via a standard lumbar puncture (spinal tap).

Cell Type & Source

• The treatment used a product called AstroRx, which is a pure population of human astrocytes.
• These astrocytes are derived from a clinical-grade human embryonic stem cell line.

Cell Preparation

• The cells were differentiated, not reprogrammed. They’re guided through natural development in the lab to become astrocytes.
• The final AstroRx product was freshly prepared, formulated in a 5 ml solution and transported to the hospital for injection within 24 hours.

Dosage

• Low-Dose Group: 100 million AstroRx cells.
• High-Dose Group: 250 million AstroRx cells.

Safety

• The therapy met its primary goal and was found to be safe and well-tolerated.
• No adverse events were related to the AstroRx cells themselves.
• The most common side effect was a temporary post-lumbar puncture headache.
• MRI scans 6 months after treatment showed no tumor formation.

Clinical Improvements

• The study showed a statistically significant and clinically meaningful slowing of disease progression for the first 3 months after treatment (ALSFRS-R score).
• Low-Dose Group: 66% slowing of decline.
• High-Dose Group: 45% slowing of decline.
• By 6 months, the rate of decline returned to pre-treatment levels.
• No statistically significant improvements in muscle strength or respiratory function.

How the Cells Worked

• The therapy provided functional support to the nervous system, not tissue replacement.
• Healthy transplanted astrocytes compensated for malfunctioning astrocytes in ALS patients.
• AstroRx cells helped clear excess glutamate, reduced oxidative stress, secreted protective proteins & regulated immune response.

What We Don’t Know

• The study did not investigate how long transplanted cells survived, so it’s unclear why the effect was temporary.
• Because the trial was small and lacked a placebo group, the results are preliminary.

Conclusion

• This was a first-in-human trial of AstroRx, an astrocyte therapy derived from embryonic stem cells.
• The study succeeded in its primary goal of demonstrating safety.
• Showed a temporary but significant slowing of ALS progression for three months.
• Researchers recommend larger, controlled trials testing repeated doses every three months to sustain the effect.
• A Phase II trial has been cleared by the FDA and is expected to begin in 2025.

Delivery Method

• Each participant received six IV infusions of the CL2020 cells.
• The infusions were given once a month for six months.

Cell Type & Source

• The treatment used Muse cells, a specific type of pluripotent stem cell within MSCs.
• The CL2020 product was manufactured from allogeneic human mesenchymal stem cells.
• Muse cells are identified by markers SSEA-3 and CD105.

Cell Preparation

• CL2020 was manufactured under GMP conditions and frozen until use.
• Before infusion, the cells were thawed and diluted in Ringer’s acetic acid solution.

Dosage

• Each of the six infusions contained 15 million cells.

Safety

• The therapy met its primary goal and was safe and well-tolerated.
• No serious side effects were related to the CL2020 product.
• Most common side effects: headache and fatigue.

Clinical Improvements

• Main efficacy goal of slowing ALSFRS-R decline was not met.
• Positive trend: 3 of 5 patients showed slower progression after 12 months.
• 1 patient worsened, 1 showed no change.

Other Key Findings (Biomarkers)

• Markers of inflammation (IL-6, TNF-α) and nerve damage (CHIT-1, NfL) tended to increase after treatment.
• S1P, a compound Muse cells respond to, decreased continuously over 12 months.

How the Cells Worked

• Muse cells travel to damaged areas and provide reparative effects.
• They can differentiate into tissue-specific cells for repair and functional recovery.
• Muse cells have immunomodulatory capacity, regulating immune and inflammatory functions.

What We Don’t Know

• The study was small (5 patients) with no placebo group, limiting conclusions about efficacy.
• Biomarker results were unexpected. Inflammation markers did not decrease as anticipated, and nerve damage markers continued to rise.

Conclusion

• This early-phase trial tested the safety of multiple intravenous doses of Muse cells in ALS.
• Primary goal (safety) was met successfully.
• Positive trend in slowing disease for 3 of 5 patients suggests potential benefit.
• A larger, double-blind study is needed to properly evaluate CL2020’s effectiveness in ALS.

Cell Type & Source

• The treatment, Lenzumestrocel (Neuronata-R), uses Mesenchymal Stem Cells harvested from the patient’s own bone marrow.

Delivery Method

• Delivered through an intrathecal injection (spinal tap).
• Stem cells were slowly injected into the spinal canal to reach the fluid around the brain and spinal cord.
• After injection, patients remained head-down with a gentle hip vibrator for 2 hours to help distribute the cells.

Dosage

• Dose customized to patient weight: 1 million cells per kilogram.
• Two treatment schedules were tested over 12 months:
• Group 1 (Single Cycle): 2 injections given 26 days apart.
• Group 2 (Booster): 5 injections total. 2 initial doses (26 days apart) followed by boosters at 4, 7, and 10 months.

Safety

• Confirmed Safe: Therapy repeatedly proven safe and well-tolerated.
• No Serious Complications: No serious adverse events linked to Lenzumestrocel across all participants.

Clinical Improvements

• Overall Population: No statistically significant benefit over placebo in the total patient group.
• Slow-Progressor Subgroup: Significant, lasting benefits in slower-progressing patients:
• Better function (higher ALSFRS-R scores at 12 months).
• Improved breathing. Significant advantage in respiratory function at 8–9 months.
• Dose effect: 5-dose booster group outperformed the 2-dose group, suggesting multiple injections sustain benefits.

How the Cells Worked

• Biomarker Evidence: Blood markers like NfL showed reduced nerve damage, confirming neuroprotective action.
• Mechanism: Reduced inflammation, protected motor neurons, and released proteins to support healthy nerve environments.

What This Means

• Multiple injections of a patient’s own stem cells are safe and feasible.
• While not effective for all, clear benefits were seen in slow-progressing ALS patients.
• These results highlight the potential for personalized, targeted treatment in ALS.

The Next Step

• The company is seeking accelerated FDA approval focused on the slow-progressing subgroup.
• Key improvements in breathing and function are central to improving quality of life and extending survival.

Main Goals of the Review:

• Assess the safety and efficacy of MSCs, NSCs, and iPSCs in ALS treatment.
• Determine which stem cell type is most promising and key differences in sourcing and mechanisms of action.
• Evaluate actual results and safety issues seen in human trials for MSCs and NSCs.
• Identify major roadblocks preventing these therapies from becoming standard ALS treatments.

1. Clinical Evidence: Does It Work?

• MSCs: Most extensively studied in ALS clinical trials. Some trials showed potential to slow progression and improve survival with multiple injections. Results inconsistent; many trials small and non-randomized.
• NSCs: Early-phase human trials showed safety of spinal cord injections. Some patients had temporary functional improvements. No conclusive efficacy evidence.
• iPSCs: Research limited to animal models. Promising results improving motor function and neuron protection. No human trials yet.

2. How They Work

• MSCs: Do not replace lost cells. Regulate immune system, reduce inflammation, release supportive proteins and growth factors.
• NSCs: Release neurotrophic factors to protect neurons; can differentiate into neurons/glial cells to replace lost support cells.
• iPSCs: Can become any cell type; potential to replace lost motor neurons, create supportive cells, or deliver protective factors using patient’s own cells.

3. Stem Cell Sources

• MSCs: Bone marrow, fat tissue, umbilical cord.
• NSCs: Donated human fetal brain or spinal cord tissue; ethical and supply limitations.
• iPSCs: Reprogrammed adult cells (skin, blood) in lab; avoids fetal tissue ethical issues.

4. Delivery Methods

• Intrathecal Injection: into spinal fluid via lumbar puncture.
• Intraspinal Injection: directly into spinal cord tissue.
• Intravenous Infusion: into bloodstream.

5. Safety and Limitations

• MSCs: Inconsistent results; optimal source and dosage unclear.
• NSCs: Ethical concerns and invasive delivery; limited long-term survival and migration.
• iPSCs: Expensive, complex, risk of genetic instability or tumor formation.

Conclusions:

• Each stem cell type offers unique potential for ALS treatment, but none are ready as standard therapies.
• MSCs are most clinically advanced but results are inconsistent; larger Phase 3 trials needed.
• NSCs are safe to inject, but ethical/practical challenges limit potential.
• iPSCs offer personalized medicine potential but face major technical and safety hurdles; still preclinical.
• Future work requires standardized research methods and larger controlled trials to identify which approaches could become effective ALS therapies.

• Gather information on ALS: Discuss the disease and current lack of a definitive cure.
• Evaluate MSC’s role: Study MSCs in laboratory and human trials for ALS treatment or management.
• Find new strategies: Highlight promising approaches to potentially increase patient lifespan.
• Examine mechanisms: Summarize how MSCs work, including immune regulation, inflammation reduction, and potential neuron protection or replacement.

• 1. Effectiveness (Clinical Studies)
• Some trials reported slowing of decline in FVC and ALS-FRS scores in subsets of patients.
• Increased life expectancy observed in some patients receiving autologous Bone Marrow-MSCs.
• Recent study: ALS-FRS and FVC improved 3 months after simultaneous IV and intrathecal injections.
• 2. Mechanism of Action (How the Cells Work)
• Protective Role: Secrete beneficial factors, remove toxic molecules, improve nerve environment.
• Immune-Regulating Action: Immunoregulatory and anti-inflammatory; increases T-regulatory cells.
• Repairing Damage: Help repair dendrites and axons; may differentiate into nerve-like cells.
• 3. Stem Cell Sources
• Bone Marrow (BM-MSCs): Most common source.
• Adipose Tissue (Fat Tissue).
• Umbilical Cord.
• 4. Dosage and Delivery
• Delivery Methods: Intrathecal (spinal canal) and intravenous (IV).
• Dosages ranged from 10 million to 100 million cells per injection.
• 5. Safety
• Generally safe and well-tolerated.
• No serious adverse events such as tumors or abnormal spinal cord changes, even long-term.
• 6. Limitations in Reviewed Studies
• Small sample sizes.
• Lack of control group in early studies.
• High variability in ALS progression.
• Short follow-up periods in some trials.

• MSCs are a promising therapeutic approach due to their beneficial features.
• Promising results observed in ALS management, but further research is needed.
• Future directions:
• Repeated administration of MSCs.
• Larger, controlled clinical trials to fully evaluate effectiveness, safety, and long-term outcomes.
• Clarify mechanisms of action and optimize dosage and delivery routes.