Oral delivery of systemic monoclonal antibodies, peptides and small molecules using gastric auto-injectors

Abstract

Oral administration provides a simple and non-invasive approach for drug delivery. However, due to poor absorption and swift enzymatic degradation in the gastrointestinal tract, a wide range of molecules must be parenterally injected to attain required doses and pharmacokinetics. Here we present an orally dosed liquid auto-injector capable of delivering up to 4-mg doses of a bioavailable drug with the rapid pharmacokinetics of an injection, reaching an absolute bioavailability of up to 80% and a maximum plasma drug concentration within 30 min after dosing. This approach improves dosing efficiencies and pharmacokinetics an order of magnitude over our previously designed injector capsules and up to two orders of magnitude over clinically available and preclinical chemical permeation enhancement technologies. We administered the capsules to swine for delivery of clinically relevant doses of four commonly injected medications, including adalimumab, a GLP-1 analog, recombinant human insulin and epinephrine. These multi-day dosing experiments and oral administration in awake animal models support the translational potential of the system.

Extended Data Fig. 1:. Liquid Formulation Stability.

Human Insulin (HI) concentrated to 12.5 mg/mL and a semaglutide (Sema) exploratory formulation concentrated to 50 mg/mL were placed inside of either an L-SOMA or a glass vial and were subjected to a 40°C and 75% relative humidity environment for two weeks. (a) Purity loss and (b) high molecular weight protein (HMWP) formation were then measured. (Mean ± SD, n=3 device replicates; Unpaired t test).

Extended Data Fig. 2:. L-SOMA needle injection images.

(a) High speed photography of an initial prototype L-SOMA device with a 21 G needle actuating into 0.3% agarose gel demonstrated that all of the liquid exits through the needle tip and none of the liquid exits through the bottom membrane. (Images are from one of n=3 technical replicates). (b) No drug is delivered if the needle lacks a side channel (Images are from one of n=3 technical replicates). Prototypes used during future ex vivo and in vivo studies employed a 32 G needle rather than a 21 G needle. (n=3 technical replicates). (c) Hole on top of the L-SOMA device allows access to the (d) dissolving pellet, which actuates the needle injection. (e-g) Sequential MicroCT images of a non-retracting L-SOMA delivering contrast dye into ex vivo swine tissue. (Images are from one of n=8 technical replicates). Scales Bars = 5 mm.

Extended Data Fig. 3:. Injection test mechanism setup and ex vivo injection force calculations.

(a) (Top) Computer aided design of the custom actuation mechanism used to insert a needle a controlled distance and inject an exact amount of fluid. (Bottom) Experimental setup of controlled injection studies. The texture analyzer pushes down on the plunger which causes the liquid to inject into the swine stomach tissue below. (b-c) The force required to inject a depot into ex vivo swine stomach tissue at a given needle insertion depth. (Mean ± SD; 4 mm: n=11; 4.5 mm: n=9; 5 mm: n=18). (d-e) The force required to inject a depot into ex vivo swine stomach tissue using a needle with a 10° backgrind and a backgrind of >50°. (Mean ± SD; 10°: n=20; >50°: n=5; Unpaired t test).

Extended Data Fig. 4:. Dog ex vivo histology from L-SOMA injection.

Histology of ex vivo dog stomach after an L-SOMA insulin injection using a (a) hematoxylin and eosin stain, (b) an immunohistochemistry stain against insulin, (c) or an immunohistochemistry stain against smooth muscle actin. These are example images from one of 3 replicates. Scale bar = 1 mm.

Extended Data Fig. 5:. L-SOMA needle retraction mechanism design.

The device first actuates after the hub pellet (red) dissolves and allows the latching mechanism at the top of the pill to release. The retraction spring, located axially around the needle shaft, compresses after the first stage of actuation due to the inherent movement of the needle during injection. The dissolution of the second pellet, which is exposed only after the first pellet dissolves, frees the spring to expand and draw the needle back into the capsule.

Extended Data Fig. 6:. Blood glucose change in swine after 0.24 mg epinephrine injection.

Colored lines represent individual swine profiles and black lines represent the mean values.

Extended Data Fig. 7:. In vivo swine histology after L-SOMA epinephrine injection.

Hematoxylin and eosin stain histology of swine stomach hours after L-SOMA injection. L-SOMA devices were injected in the fundus or body of the stomachs. An increase in cellularity is seen between the control and the experimental tissues, but this variability is expected in tissue locations with rapidly dividing cells. Moreover, the regular injection of epinephrine in the stomach during endoscopy supports the safety of intermittent administration of this drug in this location. The control histology is of swine stomach tissue not dosed with any device. These are example images from one of three animal replicates.

Extended Data Fig. 8:. Pharmacokinetics of gavage dosed epinephrine and adalimumab.

Dissolved (a) adalimumab (4 mg) or (b) epinephrine (0.24 mg) were dosed through an endoscope into the lumen of swine stomachs (n=3 animal replicates).

Extended Data Fig. 9:. Histology taken from swine dosed multiple times with L-SOMAs over three days.

(a-c) Three samples were collected according to standard histopathological procedures representing the (a) cardia, the (b) fundic, and the (c) pyloric region. No treatment related findings were observed in these standard samples in any of the three swine. (d) Histology from a minimal focal lesion from the fundic region of one of the three swine. The image shows an acute minimal erosion with sloughing of epithelial cells and peripheral acute hemorrhage. This injury is most likely a mechanical trauma caused by the endoscope when dosing the animal and is not a direct effect of the intended L-SOMA dosing. (e) Zoomed in image of “d”. (a-c: Scale Bar = 500 μm; d: Scale Bar = 1 mm.; e: Scale Bar = 250 μm).

Extended Data Fig. 10:. SOMA actuation in dog stomach after oral dosing in an awake dog.

A radiograph of the SOMA device (a) before and (b) after actuating in the gastric cavity. Note the extension of the spring in the right panel. Scale Bar = 5 mm.

Figure 1:. An oral pill for liquid drug injections into the gastric submucosa.

(a) Device timeline. (b) Molecular weight of drugs delivered using L-SOMA. (c) CAD design, (d) Micro-CT scan, and (e) photo of non-retracting device before actuation. (f) In vivo actuation of L-SOMA and (g) close-up of needle injection site. (h-l) Representative images of contrast dye which remained in ex vivo swine stomach tissue after 170 μL injection. (m) Top and (n) side view of an 80 μL depot of contrast dye injected by an L-SOMA capsule with a needle insertion length of 4.5 mm. (o) Microtome image of fixed swine stomach tissue before and (p) after an injection with the L-SOMA. (q) Percent of contrast dye which remained in tissue after injection. The value was calculated using 3D reconstructions of Micro-CT images (Mean ± SD. Ordinary one-way ANOVA with Tukey’s multiple comparisons test). (r-u) Micro-CT images of an L-SOMA (s) actuating into ex vivo swine stomach tissue, (t) injecting contrast dye, and (u) retracting its needle. Images are clipped from Supplementary video S1. (b, c, h-l, o-p: Scale Bar = 1 mm; d, f, g, m, n, r-u: Scale Bar = 5 mm) (n=X technical replicates [3 mm: n=6, 4 mm: n=12; 4.5 mm: n=12; 5 mm n=12; 6 mm: n=4; L-SOMA: n=8]).

Figure 2:. Histology after L-SOMA capsule administration.

(a-c) Histology of ex vivo swine stomach after an LSOMA insulin injection using (a) a hematoxylin and eosin stain, (b) an immunohistochemistry stain against alpha smooth muscle actin, or (c) an immunohistochemistry stain against insulin. (d-e) Histology of in vivo swine stomach immediately following L-SOMA administration of green dye using (d) a hematoxylin and eosin stain or (e) an immunohistochemistry stain against alpha smooth muscle actin. (f) Histology sample from an injection site of a swine dosed with multiple L-SOMA injections over three days. Image shows a minimal acute superficial hemorrhage with intact epithelial lining. This area was likely the location of the injection that occurred six hours prior to euthanasia. No other macroscopic abnormalities were found in the stomach from devices fired more than one day before euthanasia. (g-l) Zoomed histology images respectively corresponding to the boxed section of the images a-e. SM=Submucosa. Musc= Outer Muscle Layer. (a-f: Scale Bar = 1 mm. g-l: Scale bar = 250 μm). Example images are from one of three animal replicates.

Figure 3:. Single and multiday oral delivery of monoclonal antibodies, peptides, and small molecule drugs in swine.

(a) Blood plasma human insulin and (b) glucose levels after dosing an L-SOMA capsule containing 4 International Units (IU) (0.14 mg) of recombinant human insulin (n=7, black line=mean). The negative control for plasma glucose is the L-SOMA delivery of 4 mg inactivated GLP-1 analog (n=4 animal replicates). (c-d) Blood plasma levels of inactivated GLP-1 analog after dosing an L-SOMA containing 4 mg of inactivated GLP-1 analog. (n=9). Swine receiving anesthesia only during L-SOMA administration (0.25h) and swine receiving anesthesia for two hours after administration are noted on the graphs. (e) Blood plasma human insulin and (f) glucose levels after subcutaneously dosing 4 IU of recombinant human insulin (n=3). (g-h) Blood plasma levels of inactivated GLP-1 analog after subcutaneously dosing 4 mg of inactivated GLP-1 analog. (n=3). (i) Blood serum levels of adalimumab after dosing an L-SOMA capsule containing 4 mg of adalimumab (n=3). (j) Blood plasma levels of epinephrine and (k) associated heart rate change after dosing an L-SOMA capsule containing 0.24 mg epinephrine (n=3, black line=mean). The negative control for heart rate change is an endoscopic gavage dosing containing 0.24 mg epinephrine (n=3). (l) Blood serum adalimumab levels after subcutaneous dosing of 4 mg adalimumab (n=3). (m) Blood plasma epinephrine levels and (n) associated heart rate change after intramuscular dosing of 0.24 mg of epinephrine (n=3, black line=mean). For the heart rate change data, time 0 corresponds to the time of device actuation or injection. For all other data, time 0 corresponds to the time of device administration. (o) Sequential multiday administration of recombinant human insulin to three swine using the L-SOMA demonstrates consistent systemic drug exposures and (p) plasma glucose lowering responses. On day 1, a device did not actuate in swine 3, and on day 2, a device actuated in swine 1 but did not systemically deliver drug. Solid black lines represent the average for a given administration group. All other lines represent the dosing of a different animal or the same animal dosed at least three weeks apart.