SBIR-STTR Award

Therapeutic antibodies for treating chemotherapy induced peripheral neuropathic pain Chronic, life-disrupting pain, such as allodynia from chemotherapy induced peripheral neuropathy (CIPN), is difficult to manage. In this Phase I SBIR, Abalone Bio proposes to develop a first-in-class specific CB2 agonist antibody that is BOTH an effective and safe analgesic against CIPN as well as a co-therapy to enable opioid-based pain management without developing tolerance. CIPN occurs in >30% of chemotherapy patients treated with taxanes, and in various degrees for other therapies. Taxane CIPN is an untreated chronic condition that involves various degrees of allodynia, for which there is no demonstrated relief by any drug. Opioids, while frequently prescribed, are not clinically proven to effectively treat CIPN. On the contrary, heavy usage can lead to tolerance to opioids, and in turn opioid use disorders (OUDs). Efforts to develop drugs aimed at novel pain targets, including the peripheral cannabinoid receptor CB2, have so far yielded lackluster performance in clinical trials. Small-molecule CB2 agonists have been shown to reduce allodynia and reduce opioid tolerance in an established mouse model of chronic chemotherapy-induced peripheral neuropathy (CIPN). But small-molecule CB2 agonists have drawbacks: they are rapidly cleared, undesirably stimulate brain CB2 receptors, and cross-react with CB1 receptors in the periphery and in the brain. Abalone’s CB2 agonist antibody will be BOTH highly specific and thus will not cross-react with CB1 receptors in the periphery avoid CB2 receptors, and will also avoid the stimulation of brain CB2 receptors by being naturally restricted to peripheral tissues by the blood-brain barrier. By using our proprietary FAST platform, we isolated three single-chain camelid VHH domain antibodies hits (a.k.a. “nanobodies”) consistent with agonist activity for human CB2. In this Phase I work, the first aim will be to identify in vitro at least 2 therapeutic-format VHH-Fcs with with Kd <2.5 nM for human CB2, Kd <25 nM for mouse CB2, and EC50 of AC inhibition or ERK activation <25 nM for human and mouse CB2. To do this, we’ll find suitable VHHs using FAST, convert them to FC fusions and produce protein for assays. We’ll measure hit function using mammalian cell-based assays and measure hit affinity (apparent KD) using flow cytometry on live cells. For antibody leads meeting criteria the second aim will be to assess in vivo effect on allodynia and opioid tolerance and identify at least 1 VHH-Fc that either or both reduces allodynia to ?80% of baseline levels and extends morphine efficacy at day 3 of morphine treatment to ?80% of day 1. We’ll use a broadly accepted C57BL/6J mouse model of CIPN and study their pharcokynetics, advancing all non-toxic leads to pharmacodynamic studies to determine dosing regime for subthreshold analgesia. Then we’ll measure prevention of opioid tolerance and CB2 specificity. The impact of this work could be very broad with our CB2 agonist antibody drug becoming a class-defining non-opioid analgesic and co-therapy that prevents the development of opioid tolerance.

Public Health Relevance Statement:
Project Narrative The proposed project will develop drugs to treat pain due to chemotherapy. The proposed drugs are expected to be an effective and safe treatment to manage pain, as well as a co-therapy to enable opioid-based treatment without developing a tolerance. The proposed drugs will enable safer pain management, and help reduce opioid addiction, one of the most pressing health problems facing the country today.

NIH Spending Category:
Biotechnology; Brain Disorders; Cancer; Cannabinoid Research; Chronic Pain; Endocannabinoid System Research; Immunization; Neurodegenerative; Neurosciences; Opioid Misuse and Addiction; Opioids; Pain Research; Peripheral Neuropathy; Prevention; Substance Abuse; Therapeutic Cannabinoid Research

Project Terms:
abalone; Absence of pain sensation; Address; Adenylate Cyclase; Affinity; Agonist; allodynia; Amino Acid Substitution; Analgesics; animal efficacy; Animal Model; Antibodies; antibody libraries; base; Binding; Biological; Biological Assay; Biology; Blood - brain barrier anatomy; Brain; cannabinoid receptor; Cannabinoids; CB2 knockout; Cell model; Cells; chemotherapy; Chemotherapy-induced peripheral neuropathy; Chronic; chronic neuropathic pain; Clinical Trials; CNR1 gene; CNR2 gene; Constipation; Country; cross reactivity; Data; Dependence; Development; Directed Molecular Evolution; Dose; drug development; drug discovery; efficacy testing; Escherichia coli; Feasibility Studies; Flow Cytometry; Foundations; Future; G-Protein-Coupled Receptors; Goals; Half-Life; Health; Human; Human Activities; In Vitro; in vivo; Indiana; Inflammation; Knockout Mice; Lead; lead optimization; Life; Limb structure; Mammalian Cell; Measures; medical specialties; meetings; Methods; Morphine; morphine tolerance; mouse model; Mus; nanobodies; non-opioid analgesic; novel; Opiate Addiction; opiate tolerance; Opioid; opioid use disorder; Outcome; Paclitaxel; Pain; Pain management; pain model; pain reduction; painful neuropathy; Patients; Performance; Peripheral; Pharmaceutical Preparations; Pharmacodynamics; Pharmacologic Substance; Phase; Phosphorylation; Physical Dependence; preclinical efficacy; prevent; Prevention Measures; Production; Proteins; Pruritus; receptor internalization; research and development; side effect; Small Business Innovation Research Grant; small molecule; Specificity; Structure; taxane; Technology; Testing; Therapeutic; Therapeutic antibodies; Time; Tissues; Ventilatory Depression; Work

Chemotherapy-induced peripheral neuropathy (CIPN) is an often long-lasting neurological condition that arisesfrequently in cancer patients who receive broadly used chemotherapies such as taxanes. CIPN causes abnormalpain and other symptoms that can limit chemotherapy dosage and significantly impact quality of life for years.There are no drugs that prevent CIPN or treat it well. Duloxetine is the only clinically proven efficacious pain-reducing agent, though it can cause significant side effects and its efficacy limited to a subset of patients. Opioidsare used off-label, but also carry serious side effects. Thus, there is a critical unmet need for drugs that safelyand effectively treat or prevent CIPN. Peripheral Cannabinoid 2 receptors (CB2) are a promising target for CIPNtreatment. CB2 is constitutively expressed on inflammatory immune cells and induced in peripheral neurons inneuropathic conditions. Its activation has powerful neuroprotective, anti-inflammatory, and analgesic effects.Rodent models of CIPN show that small molecule CB2 agonists alleviate neuropathic pain behavior, and whenadministered prophylactically suppress CIPN both during dosing and for 100 days after. Several companies havedeveloped small molecule CB2 agonists that, unfortunately, are rapidly cleared, penetrate the blood-brain barrierand/or have off-target effects (notably cognitive ones) mediated by the CB1 receptor. Abalone Bio used itsproprietary Functional Antibody Selection Technology (FAST) to isolate a selective CB2-activating nanobody(VHH), which we converted into a VHH-Fc fusion lead antibody, ABt140, for in vivo studies. Phase I SBIR resultsshow that ABt140 rapidly and durably reversed allodynia in mice with CIPN. In this Phase II SBIR project,Abalone Bio will first improve ABt140’s immunogenicity and manufacturability by rational engineering, and thenthe FAST platform will be used to increase its potency to select durable agonists from millions of computationally-designed variants. We will select 1 lead and at least 2 alternates using in vitro and in vivo assays. Using thepaclitaxel CIPN mouse model, we will assess the lead’s ability to prevent CIPN development, reduce in nervedamage and inflammation, show no impairment of motor skills, and not affect chemotherapy’s anti-tumorefficacy. Finally, we will determine the lead antibody’s half-life and tissue distribution in mice, and using bloodmarkers and organs appearance and weight, we will assess its toxicity at high doses. Successful completion ofthese aims will de-risk the project sufficiently to advance Abalone’s antibody drug to IND-enabling studies andeventually first in human trials for painful CIPN. Abalone’s drug may also have broad utility for other neuropathicpains and inflammatory conditions.

Public Health Relevance Statement:
NARRATIVE Chemotherapy-induced peripheral neuropathy (CIPN) is an often long-lasting neurological condition that arises frequently in cancer patients who receive broadly used chemotherapies. CIPN causes abnormal pain and other symptoms that can limit chemotherapy dosage and significantly impact quality of life for years. We propose to further develop a new class of safe and highly effective antibody drugs that bind and activate the CB2 receptor to treat and potentially prevent the CIPN.

Project Terms:
<3'5'-cyclic ester of AMP><(TNF)-α>