The Effect of RNS60 on ALS Biomarkers

ALS is a rare neurodegenerative disease that affects motor neurons in the spinal cord, brainstem and motor cortex. The only drug showing to improve survival in patients with ALS is riluzole. However, the benefits of riluzole only consist in a three-month delay of death while disability and other outcome measures are virtually unaffected. This highlights the need to test novel approaches with documented activity on markers of disease mechanisms and, at the same time, able to slow the progression of the disease.

The major determinants of motor neuron death in ALS remain to be established. Emerging evidence points to an involvement of the adaptive immune response in disease progression. RNS60 is a novel agent with immunomodulatory properties. Adding to previous reports of anti-inflammatory and neuroprotective activities of RNS601,2,3,4, our group showed a protective effect of RNS60 on motor neurons in both in vitro and in vivo models of familial ALS carrying the SOD1G93A mutation (unpublished data). Therefore, RNS60 presents itself as a promising candidate for the treatment of ALS patients. Its exceptional safety profile, demonstrated both in preclinical toxicology studies and FDA-approved clinical phase I studies upon inhaled and IV administration, supports testing of RNS60 in clinical phase II studies in ALS.

The investigators have identified six candidate pharmacodynamic markers of RNS60 that have previously been associated with ALS: 1. T-reg (measured via FOXP3 and CD25 mRNA); 2. Cyp-A; 3. 3-NT; 4. Actin-NT; 5. MCP-1; 6. IL-17.

The investigators have measured and reported the effects on T-reg and IL172 in experimental allergic encephalitis. The investigators also have preliminary unpublished data on MCP1 in allergic asthma.

This background provides the sound rationale for a phase II, biomarker-driven, placebo-controlled, randomized clinical trial.

Primary Objective:

1. To measure the effect of RNS60 treatment on selected pharmacodynamic biomarkers in ALS patients concurrently treated with riluzole. Candidate markers include 1. T-reg (measured via FOXP3 and CD25 mRNA); 2. Cyp-A; 3. 3-NT; 4. Actin-NT; 5. MCP-1; 6. IL-17.

Secondary Objectives:

1. The preliminary efficacy of RNS60 on functional disability, as measured by the ALSFRS-R scale;

2. The preliminary efficacy of RNS60 in prolonging survival (or time to tracheostomy, whichever comes first);

3. The preliminary efficacy of RNS60 in slowing the decline of forced vital capacity (FVC) from baseline;

4. The tolerability and safety of RNS60 through the identification of unexpected adverse events;

5. The impact of RNS60 on quality of life as measured by ALSAQ-40 scale.

RNS60 has been tested in three Phase I safety studies in the USA (NCT01264783, NCT01057498, and NCT01511302), and a recently completed Phase IIa (NCT02422121) study in UK. Two additional investigator initiated Phase IIa trials are currently ongoing, one at Mass General Hospital (NCT02525471), and one at the University of Zurich (with University of Innsbruck as a second site). The choice of measuring both biological and clinical markers of disease in the same study reflects the attempt to accurately capture the complete clinical impact of RNS60 treatment. If both the biomarker results and clinical measures of the study support the purported efficacy of the drug, a follow-up study (or studies) will be designed to confirm the efficacy of RNS60 in a larger patient population. It is also possible that this study may result in promising biomarker findings but null clinical findings. If this were the case, more dose-finding work would be necessary before ruling out a possible clinical effect. Conversely, positive clinical findings accompanied by negative biomarker findings may necessitate the identification of new biomarkers of target engagement to further guide the drug development process.