Project Summary
Lung cancer (LC) with over 2 million cases/year worldwide also remains the leading cause of cancer-
related death in the US and Europe. Treating LC remains challenging due to ~60% of patients presenting with
Stage IV disease, the heterogeneity of tumors with respect to genetic and epigenetic mechanisms that alter
gene expression, and treatment-related resistance. Combining chemotherapy with immunotherapy as the first
treatment option for advanced LC has significantly improved response rates and survival; however, median
duration for progression free survival (PFS) was still 8.8 versus 4.9 months for Stage IV LC patients receiving
chemo/immune versus chemotherapy with 69% and 49% alive at one year, respectively. Second line drugs
after relapse provide minimal benefit. Epigenetic deregulation involves cytosine methylation in the promoter
region of hundreds of genes to impede transcription leading to loss of expression. Thus, a therapy that could
reverse methylation and awaken these genes could produce durable and sustained tumor regression. The
cytosine nucleoside analogs 5-azacytidine (5AZA) and 5-aza-2’-deoxycytidine (DAC) inhibit the enzyme
responsible for cytosine methylation resulting in re-expression of genes silenced through cytosine promoter
hypermethylation. These FDA approved drugs are serving as potent therapy for blood-borne cancers,
myelodysplasia and acute leukemia. Epigenetic therapy for solid tumors including LC has been impacted by
the poor stability in an aqueous solution of 5AZA and DAC and catabolism by cytidine deaminase in liver and
GI. Lovelace Biomedical working with Bend Research/Lonza have overcome these barriers by developing a
stable dry powder (DP) formulation of 5AZA (5AZA-DP). The novel dry powder nebulizer (DryNeb) developed
by Nob Hill Therapeutics generates optimal aerosol particle sizes for local lung delivery-activity and optimal
systemic absorption characteristics while facilitating patients’ “easy” tidal breathing inhalation with no forced
pulmonary function maneuvers. In studies in which 5AZA-DP was delivered to tidally breathing rats, superior
pharmacokinetics were achieved in the liver, and most impressively to the brain with a half-life of 4 hours when
compared with injected aqueous solutions of 5AZA. Using a rat lung tumor model developed from instilling
cells obtained from human lung tumors, tidally inhaled 5AZA-DP reduced tumor burden by 70–95% for the 4
different non-small cell lung tumors evaluated, far exceeding the 32% reduction seen with systemic injection of
5AZA. A proof-of-concept clinical study showed stable localized lung cancer in 3 of 8 Phase I patients treated
with nebulized aqueous 5AZA. This Phase II SBIR through three specific aims builds on these exciting data by
focusing on performing formulation scale up and stability optimization of 5AZA-DP, aerosol performance in the
DryNeb, and GLP toxicology studies. Completion of these aims will support filing an investigational drug
application (IND) to the FDA to allow evaluation of 5AZA-DP using DryNeb in a Phase I dose escalation safety
study followed by a Phase IB study in LC patients who have relapsed on standard-of-care therapy.