(T1430-12-68) Inhaled Ponatinib-Cyclodextrin Complex for Anticancer Effects on Non-Small Cell Lung Cancer

Purpose: Non-Small cell lung cancer (NSCLC), a leading cause of morbidity and cancer deaths in the United States as well as throughout the world, remains an inevitable health burden worldwide. Drug resistance to existing chemotherapy demands for extensive research to discover new, safe, and effective chemotherapeutic agents for the management of NSCLC. In this study, we intend to target the overexpressed tyrosine kinases on the surface of the cancer cells. Several tyrosine kinases (i.e., EGFR, FGFR, PDGFR, VEGFR), are aberrantly activated in NSCLC. Ponatinib, an orally active multi-tyrosine kinase inhibitor (TKIs) is currently approved by the US Food and Drug Administration for treating chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia. In some preclinical studies (1), it demonstrated potent anti-tumorigenic properties in various cancers, including lung cancers. However, ponatinib (PTB) has limited therapeutic applications because of its low water solubility. To address the limitation, we intend to increase the solubility by complexation with cyclodextrins. Cyclodextrins are cyclic oligosaccharides consisting of α-1,4-linked glucopyranose units with a hydrophilic outer surface and a hydrophobic central cavity (2). Therefore, cyclodextrins are of particular interest for poorly water-soluble drugs such as PTB as a carrier for inhalation delivery (3). The ponatinib/sulfobutylether-β-cyclodextrin inclusion complex (PTB-CD) formulation can be administered by inhalation for a localized therapy. Which improves aerosolization for an effective pulmonary deposition. In this project, a PTB-CD was prepared to significantly increase the water solubility of ponatinib, and to increase therapeutic efficacy and targeting of lung cancer tissue by inhalation delivery.

Methods: The inclusion complex was prepared by examining different concentrations of SBECD (Cyclolab, (0–200 mM)) with an equal amount of PTB (1 mg). Briefly, different amounts of CD were dissolved in water to create various % CD concentrations; and excess PTB (1 mg) was added. Mixtures were stirred for 48h at room temperature. The next day, insolubilized PTB was separated by centrifugation, followed by filtration through a 0.2-μm syringe filter. The amount of PTB solubilized was quantified using ultra-performance liquid chromatography (UPLC). In addition, % concentrations of SBECD to the amount of PTB was translated into millimolar ratios. Finally, 100mM of SBE-β-CD (1% w/v solution) was chosen as an ideal concentration to complex with 1 mg of PTB. The complex formed was evaluated for % entrapment efficiency along with physical characterization studies including TEM, DSC, XRD was performed. In-vitro aerosolization behavior of the microparticles was characterized using Next Generation Impactor (NGI).

Results: The phase solubility study shown in Fig. 1 indicated a linear relationship between PTB solubility with increasing SBECD concentration at the highest SBECD concentration i.e., 200mM the solubility is 800μg/ml. However, to avoid high SBECD concentration, 100mM concentration was chosen for further study of PTB-CD complex. The % complexation between PTB and SBECD was measured at 320μg/ml, which is a significant increase from inherent aqueous solubility of ponatinib at 0.09 μg/ml (»35-fold increase). TEM images of PTB-CD complex as shown in Fig. 2a, suggest spherical particles with particle size ~500nm. DSC thermograms of PTB, SBECD, PTB and SBECD physical mixture and PTB-CD complex are shown in Fig. 2b. The crystalline state of PTB showed endotherm at 145°C and 200°C showing two polymorph forms of PTB. SBECD showed its characteristic endotherm centered at 111.8°C. DSC for PTB and SBECD physical mixture showed similar endotherm to SBECD and PTB. However, in samples containing PTB-CD complex, this endotherm disappeared indicating successful inclusion of PTB in the SBECD cavity. XRD studies further confirm the amorphous nature of PTB in PTB-CD complex. As depicted in Fig. 2c, PTB is a crystalline drug showing sharp diffractions in the 2θ range of 5–60°. SBECD showed a broad peak in the 2θ range of 15–25°. However, no obvious diffractions peaks were observed in the PTB-CD complex suggesting amorphized PTB. The NGI studies suggest appropriate mass median aerodynamic diameter of 3.6 ± 0.02μm( < 5μm) and good aerosolization performance with fine particle fraction of 85.05 ± 3.0%. The particle deposition (%) of PTB-CD complex on each stage of the NGI is plotted in Fig. 3.

Conclusion: Taken together, the study suggested that encapsulation of cyclodextrin complexed ponatinib (PTB-CD) can be proposed to be an ideal way to deliver ponatinib for NSCLC treatment. Inhalation delivery of the complex formulation can achieve a localized treatment of PTB in lung tissue effectively. Further in vitro/in vivo studies will be conducted to perceive the full scope of this approach’s potential to treat NSCLC with local targeting for lung cancer tissue.

References: 1. Tan FH, Putoczki TL, Stylli SS, Luwor RB. Ponatinib: a novel multi-tyrosine kinase inhibitor against human malignancies. OncoTargets Ther. 2019;12:635–45.
2. Stella VJ, Rajewski RA. Sulfobutylether-β-cyclodextrin. Int J Pharm. 2020 Jun 15;583:119396.
3. Evrard B, Bertholet P, Gueders M, Flament MP, Piel G, Delattre L, et al. Cyclodextrins as a potential carrier in drug nebulization. J Control Release Off J Control Release Soc. 2004 May 18;96(3):403–10.
4. Wang X, Parvathaneni V, Shukla SK, Kanabar DD, Muth A, Gupta V. Cyclodextrin Complexation for Enhanced Stability and Non-invasive Pulmonary Delivery of Resveratrol-Applications in Non-small Cell Lung Cancer Treatment. AAPS PharmSciTech. 2020 Jul 6;21(5):183.


Fig. 1: Phase solubility of PTB to SBECD concentrations.


Fig. 2: a: Representative TEM image of PTB-CD inclusion complex; b: Overlay of DSC thermograms; c: Overlay of XRD patterns of PTB, SBECD, PTB-CD-Physical Mix, and PTB-CD-Complex


Fig. 3: In vitro aerodynamic deposition of PTB-CD in Next-Gen Impactor™(NGI).