A CIRM Disease Team to Develop Allopregnanolone for Prevention and Treatment of Alzheimer's Disease
Alzheimer’s disease (AD) is now a nation-wide epidemic and California is at the epicenter of the epidemic. One-tenth of all people in the United States diagnosed with AD live in California. In the US, 5.4 million people have AD and another American develops AD every 69 seconds. No therapeutic strategies exist to prevent or treat AD. And the situation is worse than expected. Results of a recent two year clinical study show that the currently available medications for managing AD symptoms are ineffective in patients with mild cognitive impairment or mild AD.
We seek to develop a small molecule therapeutic, allopregnanolone (APα) to prevent and treat AD. APα promotes the ability of brain to regenerate itself by increasing the number and survival of newly generated neurons. The APα-induced increase in newly generated neurons was associated with a reversal of cognitive deficits and restored learning and memory function to normal in a preclinical mouse model of AD. Further, APα reduced the amount of AD pathology in the brain. Importantly, when given peripherally either by injection under the skin or applied topically to the skin, APα was able to enter the brain to increase the generation of new neurons. The unique mechanism of APα action reduces the risk that APα would cause proliferation of other cells in the body. Because APα was efficacious in both pre-pathology and post-pathology stages of AD progression, APα has the potential to be effective for both the prevention of and early stage treatment of Alzheimer’s disease. Further, APα induced neurogenesis and restoration of cognitive function in normal aged mice suggesting that APα could be efficacious to sustain cognitive function and prevent development of AD in a normal aged population. In other clinical studies, APα has been proven safe in animals and humans and in both men and women. Together, these findings provide a strong foundation on which to plan a clinical trial of APα in persons with prodromal and diagnosed Alzheimer’s disease.
To plan for a Phase I-IIa clinical trial to determine safety, dosing and clinical efficacy, we have assembled an interdisciplinary team of clinicians, scientists, therapeutic development, regulatory, data management and statistical analysis experts. The objectives of this proposal are to: a) develop allopregnanolone as a therapeutic for Alzheimer’s disease; to plan an early clinical development program for its use as a neurogenesis agent; b) file a complete and well-supported IND with the Food and Drug Administration (FDA); c) complete phase I/IIa clinical studies to evaluate safety, biological activity, and early efficacy in humans; and (d) complete a phase II clinical trial that will evaluate efficacy and lead to larger multisite clinical studies of efficacy.
California is at the epicenter of the epidemic of Alzheimer’s disease (AD). Nationwide there are 5.4 million persons living with AD. Ten percent or over half a million Californians have AD. Among California’s baby boomers aged 55 and over, one in eight will develop AD. It is estimated that one in six Californians will develop a form of dementia. By 2030 the number of Californians living with AD will double to over 1.1 million. While all races and ethnic groups and regions of the state will be affected, not all regions within California will be equally affected. Los Angeles County has the greatest population in the state and thus will be the true epicenter of the Alzheimer’s epidemic in California.
Alzheimer’s is a disease that affects an entire family, community and health care system. Nation-wide there are nearly 15 million Alzheimer and dementia care givers providing 17 billion hours of unpaid care per year. Total costs for caring for people with AD, totals $183 billion per year. California shouldered $18.3 billion of those costs and most of those costs were born by persons and health care services in Los Angeles County. Because of the psychological and physical toll of caring for people with Alzheimer’s, caregivers had $7.9 billion in additional health care costs. Proportionally that translates into $790 million of health care costs for Californians. In total, California spent over $19 billion per year for costs associated with Alzheimer’s disease. Multiple analyses indicate that a delay of just 5 years can reduce the number of persons diagnosed with Alzheimer’s by 50% and dramatically reduce the associated costs.
We seek to develop a small molecule therapeutic, allopregnanolone (APα) to prevent and treat AD. APα promotes the innate regenerative capacity of the brain to increase the pool of neural progenitor cells. The APα-induced increase in neurogenesis was associated with a reversal of cognitive deficits and restored learning and memory function to normal in a preclinical mouse model of AD. Further, APα reduced the development of AD pathology. APα crosses the blood brain barrier and acts through a mechanism unique to neural progenitor cells and thus is unlikely to exert proliferative effects in other organs. Because APα was efficacious in both pre-pathology and post-pathology stages of AD progression, APα has the potential to be effective for both the prevention of and early stage treatment .
As a result of the planning grant award, the Allopregnanolone (APα) team accomplished the following that enabled submission of the CIRM Disease Team Therapy Development Research Awards Proposal:
1) Created a team of experts in regeneration, neurology and Alzheimer's disease drug development to generate strategy and overall development plan. Through the team’s efforts we developed preclinical and clinical studies, determined correct dosing parameters for clinical studies, identified an optimal route of administration, developed chemistry, manufacturing and controls, and submitted our Pre-IND documents to the FDA.
2) Filed a Pre-IND document with the FDA and held a Pre-IND meeting with the FDA and obtained feedback from the FDA on our program. FDA provided guidance on requirements for the preclinical plan along with input on the design of our two Phase 2 clinical studies. We also obtained agreement that we may cross-reference the existing IND of our academic partner, Michael Rogawski at UC Davis and utilize product manufactured at UC Davis.
3) We developed an integrated CMC plan to manufacture allopregnanolone (clinical API) and established compliant processes to ensure material requirements are met for the preclinical and clinical studies. Manufacture of clinical API will be conducted at the UC Davis CIRM GMP facility.
4) FDA required preclinical IND-enabling research strategy was developed. Teams at USC and a California-based CRO, were identified to conduct three studies: 1) Bridging Study: subcutaneous to IV dosing and administration to bridge from previous subcutaneous preclinical analyses to clinical studies using IV APα administration to determine a) optimal IV dose to promote neurogenesis and b) optimal infusion rate to achieve required peak of APα and area under the curve. 2) Cerebral Microhemorrhage: The FDA advised a safety test for the occurrence of cerebral microhemorrhages localized to the cerebral vasculature in areas of cerebral amyloid angiopathy with various anti-Aβ immunotherapies. 3) Chronic GLP Toxicity Analyses: Based on FDA guidance, safety studies will be required for chronic exposure of Alzheimer’s patients to APα. To initiate the chronic exposure Phase 2a Proof of Concept trial, chronic preclinical toxicology is required. We have designed 6-month and 9-month IV dose GLP toxicity studies in rat and dog, respectively. The studies include systemic toxicology and toxicokinetic evaluation.
5) In support of developing ideal dosing parameters for the Phase 2 clinical studies, the California CRO, Simulations Plus was utilized. ADMET Predictor™ was used to estimate the biopharmaceutical properties of APα. Predictive modeling of optimal dosing regimen and expected human exposure in Alzheimer’s patients was performed.
6) Designed two Phase 2 clinical trials, a Multiple Ascending Dose (MAD) and a Proof of Concept. A California-based CRO, Worldwide Clinical Trials and Alzheimer's clinical trials expert were identified to partner with USC to design and conduct our clinical trials. Phase 2 MAD study primary objectives are to evaluate safety, tolerability and pharmacokinetics. MAD exploratory objectives are to evaluate effect of allopregnanolone on MRI biomarker outcomes and cognition. Proposed MRI biomarkers include hippocampal volume, white matter integrity, and functional connectivity. Phase 2 Proof of Concept trial primary objectives are to evaluate safety and tolerability with long-term exposure. Therapeutic efficacy of allopregnanolone will be determined by outcomes on cognition and biomarkers of regeneration in brain.
7) A Steering Committee and Advisory Board were established. Both advisory groups are composed of internationally recognized researchers, translational scientists, regulatory experts and therapeutic development experts. The charge of the Steering Committee is to provide oversight that CIRM allopregnanolone team progress is on track to meet milestones, ensure that processes and strategies are aligned. The Advisory Board is comprised of internationally recognized experts in Alzheimer’s disease and experts in stem cell biology. Advisory Board members will provide an objective evaluation of CIRM allopregnanolone project progress. The functions of Advisory Board are: 1) Advise CIRM allopregnanolone project leadership on identifying key milestones; 2) Review progress on meeting milestones and hitting development targets; 3) Provide strategic and tactical counsel to the Leadership team and Steering Committee.
8) Generated viable commercial potential through partnership with SAGE Therapeutics. Ensured patent progression and prosecution through USC. Engaged key opinion leaders in the field and educated these experts regarding therapeutic potential of allopregnanolone as a first in class drug for neuroregeneration in Alzheimer's disease.