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Example Milestones for NINDS Cooperative Program in Translational Research


Milestones are not either-this-direction /or-that-direction decision points; instead they are used to determine whether a study continues or stops. The adequacy of the proposed project milestones, and the feasibility of achieving them, is considered by peer reviewers in determining the scientific merit and score for the application. Thus, it is very important that applicants convey the rationale underlying milestone design.

Each milestone should be constructed to include: (a) the goals and timeline for completion (setting milestones at the end of each funding year), (b) the criteria for success, and (c) the rationale for the choices of in vitro or in vivo models, parameters tested, and quantitative values for the go/no go's. Note that not all of your activities generate milestones. The rationale section should be used to clearly state the logic behind your choices and make it clear why each is a go/no go milestone. If consensus guidelines have been established for therapeutic testing within a research field, citing these guidelines is helpful in establishing the rationale behind your milestones.

Disclaimer : The stepwise approaches and in vitro and in vivo models, parameters, and quantitative values for the go/no go milestones shown below are for illustrative purposes only. NINDS is not endorsing particular development plans or models, parameters, or cut-off values for a disease. Investigators should make these selections based upon the stage of their therapy development project and the appropriateness of testing paradigms and quantitative cut-off values for each therapeutic development effort.


Example A . Hypothetical small molecule drug development program for an inherited demyelinating neuropathy.

Year 1

Goals and timeline: Optimize chemical scaffolds for potency and toxicity. 12 months.
Criteria for success: Two lead scaffolds selected based upon the following traits: (a) EC50 in the Pmp22 gene in vitro reporter assay of < 10 nm, (b) activity on the Pmp22 gene promoter in a human Schwann cell line, defined as a minimum of 50% increase in luciferease fluorescence, and (c) cytotoxicity in the HEK-293 cell line at no less than 5-fold above EC50.
Rationale: The Pmp22 reporter assay used here has been validated as having predictive value for human clinical trials of NeuroRegeneration Pharma's NewMyelin drug. Based upon discussions with our clinical collaborators of patient dosing requirements, we established a threshold potency (EC50 < 10nm) suitable for this stage of therapeutic development with anticipation that further optimization will improve potency to the necessary clinically feasible level. A therapeutic window of 5-fold above presumptive clinical dose provides sufficient safety for the targeted patient population. An increase of 50% or more in the Pmp22 promoter activity has been published by the Myelin Study Group as appropriate for medium-throughput screening efforts in drug development for demyelinating neuropathies.

Year 2

Goals and timeline: Synthesize analogs for each lead scaffold and select lead compounds for each of the two scaffolds based upon in vivo target modulation in the myelinless mouse. 12 months.
Criteria for success: Lead compounds for each of the two scaffolds meet minimum acceptable standard of (a) 50% increase in Pmp22 protein expression at a dose of < 100 nm, as measured by immunoblot in the myelinless mouse model, (b) 2-fold increase in the number of axonal profiles in skin biopsies from forepaw, and (c) a minimum of 2.5-fold increase in tibial nerve conduction velocity.
Rationale: The myelinless mouse is a widely accepted model of demyelinating neuropathy. Although its predictive value has yet to be established in human studies, measurements of conduction velocity and nerve ending density in skin biopsies of myelinless mice have been shown to be responsive to both pharmaceutical and gene therapy agents. Measurement of protein levels by immunoblot will confirm the targeting of the promoter by the lead compounds; a 50% improvement in protein levels has been shown to correlate with improved nerve function.
Goals and timeline: Demonstrate synthetic scale-up potential for the selected lead compound. 12 months.
Criteria for success: Show scale-up of production the lead compound up to a 10-gram scale.
Rationale: The go/no go value was selected for lead compound synthesis based upon the required dosage and cohort size to be used for the subsequent in vivo efficacy testing.

Year 3

Goals and timeline: Identify a development candidate compound from one of the scaffolds to undergo IND-enabling testing for clinical development. 12 months.
Criteria for success: The development candidate has the following characteristics: (a) oral availability in rodent as measured by favorable pharmacokinetic properties, t1/2 > 6 hours after oral administration in rodent, (b) therapeutic index of 10-fold in rodent, and (c) demonstrated efficacy in the myelinless mouse as demonstrated by a 25% improvement in rotorod performance.
Rationale: For the targeted patient population, oral dosing is essential. Milestone parameters were selected to achieve availability and pharmacokinetic properties in support of twice daily dosing. As we optimize lead compounds, a higher stringency is being applied for therapeutic index-this will increase our flexibility in dosing in the subsequent clinical trial and may allow use of the therapeutic in more severe neuropathies. A 25% improvement in rotorod performance has been accepted as adequate efficacy to move a candidate forward by the Myelin Study Group.
Goals and timeline: Pre-IND meeting. 12 months.
Criteria for success: Hold pre-IND meeting with FDA.
Rationale: Meeting necessary to define acceptable parameters for the IND-enabling toxicology and biodistribution testing.
Goals and timeline: Demonstrate synthetic scale-up potential for the development candidate. 12 months.
Criteria for success: Show scale-up production for development candidate to scale sufficient to comply with FDA response to plans for IND-enabling non-clinical studies.

Year 4

Goals and timeline: Completion of GLP safety and toxicology testing of development candidate in two species according to plan acceptable to the Division of Drug Evaluation and Research, FDA. 12 months.
Criteria for success: No toxicity that would preclude FDA approval for the clinical trial.
Rationale: Only studies required for IND submission to be performed; success criteria set by FDA.
Goals and timeline: Submission of IND. 12 months.
Criteria for success: Submission of an IND application to the FDA.

 


Example B . Hypothetical gene therapy development program for progressive thalamic neurodegenerative disorder.

Year 1

Goals and timeline: Produce rAAV8.CMV.GDGF vector for intracranial delivery to the thalamic ventroposteriolateral nucleus (VPL) of the allodynic mouse. 12 months.
Criteria for success: rAAV8.CMV.GDGF vector produced at a yield of 5 x l012 vg.
Rationale: 5 x l012 vg provides sufficient vector for completion of mouse efficacy studies, with cohort size based upon power analysis and our prior use of the allodynic mouse model.
Goals and timeline: Determine transfection efficiency and efficacy in the allodynic mouse model of rAAV8.CMV.GDGF delivered through an intracranial catheter. 12 months.
Criteria for success: > 35% transfection of VPL neurons as measured by cell counts of sections stained with GDGF antibody and 30% improvement in tactile allodynia in the allodynic mouse model as determined by the Warburg light touch/pressure sensitivity test applied to the hindpaw, as compared to allodynic mice treated with saline control.
Rationale: Mouse testing is designed to work out the vector delivery parameters as well as to develop better information on efficacy potential for this therapeutic strategy. The Warburg light touch/pressure sensitivity test has been shown to activate identical neurophysiologic pathways in mouse and human and thus is considered by the field to be an appropriate efficacy measure for VPL function. 30% improvement in the value obtained with this test has been associated with reduced hindlimb ulceration and thus is a valid marker of somatosensory function and quality of life in mice.

Year 2

Goals and timeline: Produce rAAV8.CMV.eGFP for intracranial delivery to the VPL of the rhesus macaque monkey. 12 months.
Criteria for success: rAAV8.CMV.eGFP vector produced at a yield of 2 x l014 vg.
Rationale: 2 x l014 vg provides sufficient vector for scale-up of evaluation of transfection efficiency testing in a non-human primate. Such testing is viewed by the FDA as essential non-clinical information before progressing to the clinical trial.
Goals and timeline: Demonstrate transfection of the VPL of the rhesus macaque with rAAV8.CMV.eGFP following intracranial delivery. 12 months.
Criteria for success: Treated monkeys show an average transfection, via eGFP fluorescence, of at least 35% of neurons within the cytoarchitectural boundaries of the VPL.
Rationale: Monkey testing is viewed as essential proof of concept for the scale up of the vector delivery system to a large mammalian brain. Delivery of eGFP in the initial monkey studies is viewed as essential to optimizing the delivery parameters prior to testing the vector construct intended for therapeutic use. The 35% threshold for transfection efficiency is derived from the allodynic mouse studies cited above.

Year 3

Goals and timeline: Demonstrate persistence of expression of GDGF protein in the VPL of rhesus macaques treated with a transient immunosuppression regimen. 12 months.
Criteria for success: Treated monkey VPL nuclei show 40% of neurons expressing GDGF protein, as measured by immunocytochemistry at 6 months following intracranial injections.
Rationale: Based upon preclinical efforts in other neurodegenerative diseases, immunoresponse to the vector capsid has been a rate-limiting factor in the efficiency of gene therapy. The approach used here is to ensure persistence of therapeutically significant level of GDGF at a time point when the transient response to vector capsid is no longer operative.
Goals and timeline: Pre-IND meeting. 12 months.
Criteria for success: Hold pre-IND meeting with FDA.
Rationale: Meeting necessary to define acceptable parameters for the IND-enabling toxicology and biodistribution testing.

Year 4

Goals and timeline: Completion of GLP safety and toxicology testing according to plan acceptable to the Center of Biologics Evaluation and Research, FDA. 12 months.
Criteria for success: No toxicity that would preclude FDA approval for the clinical trial.
Rationale: Only studies required for IND submission to be performed; success criteria set by FDA.
Goals and timeline: Submission of IND. 12 months.
Criteria for success: Submission of an IND application to the FDA.



Last updated April 16, 2014