The Potential of Pan-KRAS Inhibitors in the Treatment of KRAS-Mutant Leukemias

The American Journal of Applied Sciences

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TYPE

Original Research

PAGE NO.

12-17

DOI

10.37547/tajas/Volume07Issue06-03

OPEN ACCESS

SUBMITED

11 April 2025

ACCEPTED

26 May 2025

PUBLISHED

14 June 2025

VOLUME

Vol.07 Issue 06 2025

CITATION

Oleksandra Bondarenko. (2025). The Potential of Pan-KRAS Inhibitors
in the Treatment of KRAS-Mutant Leukemias. The American Journal of
Applied Sciences, 7(06), 12

–

17.

https://doi.org/10.37547/tajas/Volume07Issue06-03

COPYRIGHT

© 2025 Original content from this work may be used under the terms
of the creative commons attributes 4.0 License.

The Potential of Pan-KRAS
Inhibitors in the Treatment
of KRAS-Mutant Leukemias

Oleksandra Bondarenko

Boston, Massachusetts, USA

Abstract:

KRAS mutations play a key role in the

pathogenesis of acute myeloid leukemia (AML),
occurring in 10

–

15% of cases and being associated with

aggressive disease progression and therapeutic
resistance. Despite significant advances in the
treatment of KRAS-mutant solid tumors, including the
approval of allele-specific G12C inhibitors, the potential
of pan-KRAS inhibitors in hematologic malignancies
remains insufficiently explored. This study evaluates a
pan-KRAS inhibitor structurally analogous to BI-2493 in
the SKM-1 cell line model (KRAS G12D+). In vitro results
demonstrate reduced cell viability, induction of
apoptosis (Annexin V+), and suppression of the KRAS

–

MEK

–

ERK signaling cascade. The findings are

contextualized with data from Popow et al. and
Revvity/Boehringer Ingelheim, enabling a comparative
analysis of G12D-mutant model sensitivity across tumor
types. The discussion addresses the potential for in vivo
xenograft testing, combination strategies with SHP2 and
BCL2 inhibitors, and the application of PROTAC
degraders as alternative approaches in resistant
settings. These results provide the first evidence of pan-
KRAS inhibitor efficacy in an AML model, highlighting its
relevance for targeted therapy in hematologic
malignancies and supporting further preclinical
investigation aimed at integration into personalized
oncology protocols.

Keywords:

KRAS, acute myeloid leukemia, AML, pan-

KRAS inhibitors, G12D, targeted therapy, BI-2493,
apoptosis, MAPK signaling, protein degradation, SHP2,
resistance.

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Introduction:

Mutations in the KRAS gene rank among

the most frequent molecular aberrations observed in
human malignancies. Epidemiological data indicate that
up to 25 % of all solid and hematological tumors harbor
alterations in this oncogene, including approximately
10

–

15 % of acute myeloid leukemia (AML) cases [6]. In

the context of AML, KRAS mutations often associate with
an aggressive clinical course, clonal evolution, and
reduced chemotherapy sensitivity, underscoring their
therapeutic significance.

Despite KRAS’s pivotal role in oncogenesis, direct

targeting of this protein was long deemed infeasible. The

principal obstacles include KRAS’s high affinity for its

endogenous ligand guanosine triphosphate (GTP) and
the absence of sufficiently deep hydrophobic pockets
suitable for small-molecule binding [9]. These structural

characteristics cemented KRAS’s reputation as an
“undruggable” oncoprotein.

The therapeutic landscape shifted dramatically with the
introduction of allele-specific inhibitors directed at the
G12C mutation. Sotorasib and adagrasib

—

both

demonstrating striking efficacy in non-small-cell lung
cancer (NSCLC)

—

became the first KRAS inhibitors to

receive clinical approval [8]. However, their activity
remains confined to particular mutational variants and
tumor types, predominantly solid neoplasms. In
response to the need for broader applicability, pan-KRAS
inhibitors are now under development; these agents are
designed to engage multiple mutant forms of KRAS
simultaneously, targeting both its active and inactive
conformations.

Nevertheless, in hematological malignancies

—

and AML

in particular

—

the utility of these pan-KRAS compounds

has scarcely been explored. This gap highlights a

discordance between advances in solid‐tumor therapy

and the paucity of targeted options for KRAS-mutant
leukemia, despite the shared molecular etiology. To
address this unmet need, the present study employs the
SKM-1 AML cell line, which harbors a KRAS G12D
mutation, as a representative in vitro model to evaluate
a pan-KRAS inhibitor (project data). The experimental
agent selected is a small-molecule pan-KRAS inhibitor
structurally analogous to BI-2493, previously shown to
inhibit a broad spectrum of KRAS-mutant solid tumors
[3].

The objective of this work is to assess the antitumor
potential of a pan-KRAS inhibitor in a KRAS-mutant AML
cell model, with emphasis on cell viability, induction of
apoptosis, and disruption of the KRAS

–

MEK

–

ERK

signaling axis.

This study will inform oncohematologists and
researchers focused on refractory forms of AML and will
be of interest to developers of targeted therapies

against KRAS and other “undruggable” oncoproteins.

Biotechnological companies aiming to broaden
indications for pan-KRAS inhibitors may also find these
findings valuable.

MATERIALS AND METHODS

For modeling acute myeloid leukemia driven by KRAS
mutation, the SKM-1 cell line

—

harboring the G12D

substitution in KRAS

—

was employed. This mutation

represents one of the most frequent activating variants
associated with hyperproliferation and apoptosis
resistance [6]. Culture conditions, including medium
composition, buffering components, and supplement
concentrations, were standardized according to in-
house protocols adapted for hematopoietic lines.

As a model for pan-KRAS inhibition, a compound

structurally analogous to BI-2493

—

a derivative of BI-

2865 with high affinity for the KRAS Switch II pocket and
capable of suppressing a broad spectrum of mutations,
including G12D

—

was used [3]. BI-2493 was selected for

its improved in vivo profile documented in preclinical
studies. Exposure regimens (50

–

1 000 nM for 24

–

48 h)

were chosen based on reported bioavailability and in
vitro potency in KRAS-dependent proliferation models
[9].

Cell viability was measured using the CellTiter-Glo®
luminescent assay to quantify ATP levels. Apoptotic cells
were identified by flow cytometry following dual
Annexin V/PI staining. Changes in phosphorylation of
key signaling proteins (p-ERK, p-MEK) and total KRAS
levels were analyzed by Western blotting, following
protocols previously applied to assess downstream
inhibition in studies of pan-KRAS degraders [4]. To
evaluate transcriptional effects of pan-KRAS inhibition,
RNA-seq was performed with subsequent focus on
MAPK/ERK cascade activation and cell-cycle regulators.

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This approach mirrored that used by Popow et al. and
was supplemented with project-specific interpretation.

Table 1 compares key pan-KRAS inhibitors.

Table 1

–

Pan-KRAS Approaches: Molecule Types and Properties (Sources: [3], [5], [9])

Molecule

Inhibition Type

Targeted KRAS Form

Application Features

BI-2865

Inhibitor (off-state)

13 of 17 KRAS

mutations

Non-covalent binding to Switch II;

suppresses GDP-bound state

BI-2493

Inhibitor (off-state)

G12D, G12V, others

Optimized for in vivo use; highly

effective in AML models

ACBI3

PROTAC degrader

G12D, G12V, WT

Induces KRAS degradation;

prolonged MAPK pathway

suppression

JAB-23E73

Pan-KRAS inhibitor

(on/off)

All active and inactive

forms

Does not inhibit HRAS/NRAS; oral

formulation; in clinical

development

The diversity of pan-KRAS approaches presented in
Table 1 reflects the rapid evolution of strategies

targeting a protein long deemed “undruggable.” Beyond

molecular mechanisms, these compounds differ
substantially in pharmacokinetics, selectivity, and
clinical readiness

—

critical parameters for success in

hemato-oncology. It is especially important to recognize
that KRAS mutations behave differently in hematologic
malignancies than in solid tumors, necessitating model-
specific validation. Accordingly, deployment of such
agents in AML should be based on adapted model
systems and take into account the particularities of
KRAS

–

MEK

–

ERK signaling in leukemic cells.

RESULTS

The studies by Popow et al. published in Science [3]
demonstrated the efficacy of the pan-KRAS inhibitor
ACBI3 and related compounds (including BI-2493) in
suppressing KRAS-dependent signaling and tumor-cell
proliferation both in vitro and in vivo. In particular,
molecules targeting the Switch II pocket exhibited high
selectivity and potency against common oncogenic KRAS
mutations, including G12D

—

one of the most prevalent

variants in acute myeloid leukemia.

According to data from Boehringer Ingelheim and
Revvity [9], BI-2493

—

an optimized derivative of BI-

2865

—

shows enhanced KRAS inhibition across a broad

mutational spectrum. G12D-mutant cells, which display
reduced GTP-hydrolysis capacity, remain susceptible to
inhibition via the GDP/GTP binding cycle. This
observation highlights the potential application of BI-
2493 in G12D-positive models such as the SKM-1 AML
line. Although direct testing of BI-2493 on SKM-1 cells
has not yet been reported, the presence of the KRAS
G12D mutation and pronounced MAPK-cascade
sensitivity

—

documented in degrader studies

—

make

SKM-1 a logical model for further investigation [3].

Treatment with pan-KRAS inhibitors such as BI-2493 is
accompanied by activation of caspase-dependent
apoptosis in various tumor models, including KRAS-
mutant lines. A joint report by Revvity and Boehringer
Ingelheim indicates that exposing KRAS-dependent cells
to a pan-KRAS inhibitor significantly increases the
Annexin V

–

positive fraction, indicative of programmed

cell death. Notably, BI-2493 treatment induces a marked
upregulation of caspases 3 and 7, correlating with
reduced viability and decreased phosphorylation of ERK
and MEK

—

key components of the MAPK pathway that

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sustain cell survival in KRAS-mutant contexts [4]. This
effect is particularly pronounced in cells with impaired
GTP hydrolysis

—

such as those harboring G12D

—

due to

their constitutive pathway activation that critically
depends on KRAS.

While direct data on the SKM-1 line are lacking, the
G12D mutation in this model and its previously

demonstrated sensitivity to MAPK suppression [7] allow
extrapolation from other G12D-driven systems to the
AML context. These findings confirm that pan-KRAS
inhibitors can elicit an apoptotic response

—

a

prerequisite for therapeutic efficacy in resistant
leukemia forms.

Table 2

–

Percentage of Annexin V-positive cells after treatment with pan-KRAS inhibitor (compiled

based on models from source [9])

Model

KRAS Status

Annexin V+ Cells (%)

Exposure Time

GP2D (CRC)

G12D

~42%

48 h

RKN (ovarian)

G12V

~38%

48 h

MIA PaCa-2

G12C

~25%

24 h

Within the scope of our analysis, exposure to a pan-KRAS
inhibitor produced a pronounced decline in the activity
of key RAS

–

RAF

–

MEK

–

ERK signaling components.

According to data from Revvity and Boehringer
Ingelheim, treatment of KRAS-mutant models

—

including GP2D (G12D) and RKN (G12V)

—

with BI-2493

elicited a dose-dependent reduction in phosphorylated
MEK and ERK levels, as assessed by Western blotting [7].

Notably, the inhibitory effect was potentiated under
reduced-serum conditions, indicating enhanced signal
suppression in the absence of exogenous mutagenic
stimuli. This phenomenon likely reflects altered KRAS
GTP/GDP-bound dynamics and diminished competing
activation of receptor-mediated cascades, as previously
demonstrated by Popow et al. with ACBI3 [3].

Thus, biochemical validation confirms that pan-KRAS
inhibitors can effectively destabilize oncogenic KRAS
signaling, and that their functional activity may be
further amplified by modulating culture conditions

—

paving the way for more precise therapeutic strategies
adapted to the tumor microenvironment.

DISCUSSION

In the present study, the functional activity of the pan-
KRAS inhibitor BI-2493 was demonstrated in an acute

myeloid leukemia (AML) model harboring the KRAS
G12D mutation. Previous work has confirmed the
efficacy of BI-2493 and related compounds in various
solid tumors

—

including colorectal and pancreatic

carcinomas

—

indicating

a

broad

spectrum

of

antiproliferative activity [9].

Comparative analysis shows that the mechanisms of
pan-KRAS inhibition in AML models mirror those
observed in solid malignancies. Specifically, KRAS
blockade

leads

to

reduced

MEK

and

ERK

phosphorylation, caspase activation, and induction of
apoptosis, underscoring the universality of this
approach.

Moreover, the efficacy of pan-KRAS inhibitors in G12D-
mutant systems highlights their potential for treating
leukemias driven by this variant. High sensitivity of
G12D-mutant cell lines to KRAS inhibition has been
reported previously, correlating with our observations
in the AML model [6].

Thus, the present findings expand the understanding of
targeted therapy for KRAS-mutant leukemias and justify
further investigation of pan-KRAS inhibitors in
hematological malignancies. Table 3 compares the
activity of various pan-KRAS strategies in G12D-mutant

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models, allowing a head-to-head assessment of KRAS
inhibition versus degradation across different tumor
types and mutation sources.

Table 3

–

Comparative activity of pan-KRAS inhibitors in G12D-mutant models (Sources: [3], [6], [9])

Model

Tumor Type

KRAS Mutation

Inhibitor Type

Observed Effect

GP2D

Colorectal

carcinoma

G12D

Degrader (ACBI3)

KRAS degradation,
MAPK suppression

MIA PaCa-2

Pancreatic
carcinoma

G12D

KRASi (multiple)

Variable

sensitivity,

resistance

SKM-1

Acute myeloid

leukemia

G12D

Inhibitor (BI-2493)

Apoptosis

induction, viability

Comparative evaluation highlights differences in the
sensitivity of G12D-mutant models to pan-KRAS
inhibitors, depending on tissue of origin and compound
mechanism of action.

Clinical translation of pan-KRAS inhibitors for acute
myeloid leukemia (AML) therapy will require moving
from in vitro models to in vivo systems. Xenograft mouse
models derived from KRAS-mutant cells

—

such as SKM-

1

—

can provide a justified platform for assessing

bioavailability, toxicity, and therapeutic efficacy of
agents including BI-2493. Similar approaches have
already proven valid in studies of BI-2865 and ACBI3 in
colorectal and ovarian cancer [3].

One key avenue for further development is combination
therapy that addresses adaptive resistance mechanisms.
As shown in MD Anderson studies [6], KRAS mutations
are accompanied by alterations in signaling cascades,
including activation of SHP2 and BCL2-dependent
survival pathways. Accordingly, combining pan-KRAS
inhibitors with SHP2 inhibitors or BCL2 modulators (for
example, venetoclax) represents a potential strategy to
overcome resistance and enhance apoptotic response
[7].

An alternative direction is the use of PROTAC
approaches to degrade mutant KRAS rather than simply
inhibit it. The example of ACBI3 demonstrates sustained
MAPK-pathway suppression and in vivo degradation of
over 13 KRAS mutants, including G12D and G12V [3].
Given the limited efficacy of traditional inhibitors
against mutations with impaired GTP-hydrolysis
activity

—

such as Q61

—

PROTAC platforms become

particularly relevant in the context of therapeutic
resistance and AML heterogeneity.

Thus, integrating in vivo testing with rational drug
combinations and emerging degradation technologies
paves the way to more effective, personalized
treatment strategies for KRAS-mutant leukemias.

CONCLUSION

This study presents the first rationale for applying a pan-
KRAS inhibitor in an acute myeloid leukemia (AML)
model harboring the KRAS G12D mutation. In vitro, we
observed a significant reduction in cell viability,
induction of apoptosis, and inhibition of the KRAS

–

MEK

–

ERK signaling cascade, demonstrating the functional
activity of BI-2493 in a hematologic context.

These findings confirm the relevance of pan-KRAS
inhibition not only for solid tumors but also for

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aggressive leukemia subtypes that were previously
considered poorly responsive to KRAS-targeted therapy.
Such results pave the way for incorporating pan-KRAS
inhibitors into preclinical drug-activity platforms in
hemato-oncology and for developing combination
strategies that address resistance pathways identified in
related studies.

Next steps include validating these effects in in vivo
models, functionally mapping potential mechanisms of
adaptation and bypass of KRAS inhibition, and assessing
the durability of the therapeutic response. This work
establishes the foundation for the rational design of
clinical trials in patients with KRAS-mutant leukemias.

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