Company: APM
Filing Date: 2025-12-05
Form Type: 424B5
Source: 0001213900-25-118752
Chunk: 216

Company: Aptorum Group Ltd
Filing Date: 2025-12-05
Form: 424B5
Chunk 216
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 responsible for the characteristic golden color. This pigment has proven to be an important factor in promoting
bacterial invasion as well as rendering the bacteria resistant to attack from reactive oxygen species (ROS) and neutrophils. In other
words, pigmented bacteria have increased resistance to the host’s immune defenses. ALS-4 may have particular value if it can be
shown to be an effective therapy in situations where a Staphylococcus aureus infection is resistant to available antibiotics (i.e., where
the pathogen is MRSA).

In a study by the inventor, Prof. Richard Kao, ALS-4 demonstrates potent
activity against Staphylococcus aureus pigment formation in vitro, as indicated in Figure 1, with an IC50 (IC50 is defined as the concentration
of a drug which inhibits half of the maximal response of a biochemical process. In this case, inhibition of the formation of the golden
pigment is the response) equal to 20 nM.

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Figure 1

Figure 1: In vitro pigment inhibition by compound ALS-4: Inhibition
of staphyloxathin (the golden pigment in S. Aureus) in the presence of increasing concentrations of ALS-4

A study conducted by a third-party contract research organization,
assessed ALS-4’s effect in the healing of open wounds infected with MRSA in a mouse model. The study utilized 5 mice per treatment
group to evaluate therapeutic efficacy. Compared with topical dosing of 2% Mupirocin and oral dosing of Linezolid at 100mg/kg twice a day,
oral dosing of ALS-4 at 30mg/kg twice a day showed statistically significant improvement in wound healing. Specifically, at the end
of the study on Day 7, ALS-4 exhibited 63.8% of wound closure compared with 48.4% for oral Linezolid and 43.2% for topical Mupirocin 2%.
The results are further illustrated in the graph below. (Figure 2)

During the study period, body weight monitoring was conducted as a
safety parameter. No significant adverse effects or safety concerns were observed in the ALS-4 treatment group. This study was designed
as a proof-of-concept efficacy evaluation, with comprehensive toxicology assessments subsequently completed during the IND-enabling studies
phase.

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Figure 2

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