KRASG12C Inhibitor Research Articles

KROCUS: A phase II study investigating the efficacy and safety of fulzerasib (GFH925) in combination with cetuximab in patients with previously untreated advanced KRAS G12C mutated NSCLC.

LBA8511 Background: Fulzerasib (GFH925), a KRAS G12C inhibitor, showed substantial efficacy in previously treated NSCLC patients (pts) as monotherapy. Activation of epidermal growth factor receptor (EGFR) is identified to be one of the dominant mechanisms for KRAS inhibition resistance. Preclinical evidence showed synergistic activity in KRAS G12C mutant NSCLC modeling using fulzerasib in combination with cetuximab. Here we report the first results for a KRAS G12C inhibitor combined with an anti-EGFR antibody in NSCLC pts as front-line treatment. Methods: KROCUS (NCT05756153) was an open-label, single-arm, multi-center, Phase II study with the primary objective to evaluate the efficacy of fulzerasib in combination with cetuximab in pts with previously untreated advanced NSCLC harboring KRAS G12C mutation. Secondary objectives included safety/tolerability, pharmacokinetics and biomarkers. Pts were enrolled to receive fulzerasib (oral, 600 mg BID) and cetuximab (intravenous, 500 mg/m2, every two weeks [Q2W]) combination treatment in a 28-day cycle. Results: As of Jan. 30, 2024, a total of 27 pts (median age: 68 yrs old; 55.6% female) were treated, 11 (40.7%) with baseline brain metastases. Of 20 pts who had at least one post-treatment tumor assessment, ORR was 80.0% (95% CI: 56.3, 94.3, including one CR), of whom eight pts had ≥ 50% tumor shrinkages in the target lesions. Disease control rate (DCR) was 100% (95% CI: 83.2, 100.0). Five out of seven pts (71.4%) with brain metastases achieved PRs. Nine pts with baseline PD-L1 expression tested (six TPS≥1% and three TPS <1%) all achieved PRs. The overall safety profile of the combination was favorable. Treatment-related adverse events (TRAEs) of any grade occurred in 21 (77.8%) pts. 5 pts (18.5%) experienced G3 TRAEs and no G4 or 5 TRAEs. Three pts (11.1%) had dose reduction/interruption with fulzerasib due to TRAEs but no pts discontinued treatment while one pt (3.7%) had dose reduction/interruption and three (11.1%) discontinued cetuximab due to TRAEs. Table 1 shows the most common TRAEs or G3 TRAEs. Conclusions: The preliminary data from ongoing KROCUS study has demonstrated very promising efficacy and favorable safety profile of fulzerasib + cetuximab in the first line setting of KRAS G12C mutated NSCLC. More data will be generated to provide clinical evidence supporting this combination as a potential frontline therapy. Clinical trial information: NCT05756153 . [Table: see text]

KRYSTAL-12: Phase 3 study of adagrasib versus docetaxel in patients with previously treated advanced/metastatic non-small cell lung cancer (NSCLC) harboring a KRASG12C mutation.

LBA8509 Background: Adagrasib (ADA) is a potent covalent inhibitor of KRASG12C with favorable properties such as long half-life (23 h), dose-dependent pharmacokinetics, and brain penetrance. In the phase 1/2 KRYSTAL-1 trial, ADA demonstrated deep and durable responses with promising PFS and OS in patients (pts) with previously treated KRASG12C-mutated NSCLC. Here, we report the primary analysis from KRYSTAL-12 (NCT04685135), a randomized, open-label phase 3 trial of ADA compared with docetaxel (DOCE) in pts with KRASG12C-mutated locally advanced or metastatic NSCLC who had previously received a platinum-based chemotherapy, concurrently or sequentially with anti-PD-(L)1 therapy. Methods: Pts with KRASG12C-mutated locally advanced or metastatic NSCLC, previously treated with platinum-based chemotherapy and anti-PD-(L)1 therapy, were randomized 2:1 (stratified by region [non-Asia Pacific vs Asia Pacific] and sequential vs concurrent chemoimmunotherapy) to receive ADA (600 mg BID orally; tablet formulation) or DOCE (75 mg/m2 Q3W IV), with the ability to crossover to ADA upon disease progression (assessed by real-time blinded independent central review [BICR]). No washout period was required between prior anti-PD-(L)1 therapy and study treatment. Primary endpoint was PFS assessed per BICR according to RECIST v1.1. Secondary endpoints included ORR by BICR, duration of response (DOR), OS, 1-year OS rate, and safety. Results: In total, 301 pts were randomized to ADA and 152 to DOCE. Baseline characteristics were generally similar between treatment arms. With a median follow-up of 9.4 mo (data cutoff 31 Dec, 2023), the primary endpoint of PFS was significantly improved with ADA over DOCE (HR 0.58 [95% CI, 0.45–0.76]; P < 0.0001; median PFS 5.49 vs 3.84 mo). ORR by BICR was also significantly higher with ADA compared with DOCE (31.9% [95% CI, 26.7–37.5] vs 9.2% [95% CI, 5.1–15.0]; odds ratio 4.68 [95% CI, 2.56–8.56]; P < 0.0001); median DOR was 8.31 (95% CI, 6.05–10.35) vs 5.36 (95% CI, 2.86–8.54) mo, respectively. Treatment-related adverse events (TRAEs) were reported in 94.0% of pts treated with ADA and 86.4% with DOCE; grade ≥3 TRAEs occurred in 47.0% and 45.7% of pts, respectively. TRAEs led to discontinuation of ADA in 7.7% of pts and DOCE in 14.3%. Additional efficacy and safety analyses, including subgroup analyses, will be presented. Conclusions: In the phase 3 KRYSTAL-12 trial, ADA demonstrated a statistically significant and clinically meaningful improvement in PFS and ORR over DOCE in pts with previously treated KRASG12C-mutated NSCLC. Safety profile of ADA was consistent with previous reports and with no new safety signals. These results further support ADA as an efficacious treatment option for pts with previously treated KRASG12C-mutated locally advanced or metastatic NSCLC. Funding: Mirati, a Bristol Myers Squibb Company. Acknowledgements: KRYSTAL-12 was sponsored by Mirati, a Bristol Myers Squibb Company. Third-party medical writing support, under the direction of the authors, was provided by Flaminia Fenoaltea, MSc, of Ashfield MedComms, an Inizio company, and was funded by Mirati, a Bristol Myers Squibb Company. Clinical trial information: NCT04685135 .

Phase 1/2 trial of the XPO1 inhibitor selinexor in combination with docetaxel in previously treated, advanced KRAS mutant non-small cell lung cancer (NSCLC).

8597 Background: KRAS mutant NSCLC remains a therapeutic challenge. Although KRAS G12C inhibitors are now approved for cases harboring that specific mutation, their efficacy is modest and the G12C variant accounts for only 40% of KRAS mutations in NSCLC. To date, there are no approved targeted therapies for non-G12C KRAS mutant NSCLC. Selective inhibitors of nuclear export (SINE) modulate cancer cell biology by retaining certain proteins—such as tumor suppressors—within the nucleus, where they remain physiologically active. The XPO1 inhibitor selinexor demonstrated efficacyinpreclinicalNSCLC models harboring various KRAS mutations. Methods: In this 3 + 3 dose-escalation phase 1/2 trial, patients with previously treated advanced KRAS mutant NSCLC received selinexor (dosed orally weekly) plus docetaxel 75 mg/m2 IV every three weeks (NCT03095612). Prior treatment with KRAS G12C inhibitors was permitted. Results: Among 40 enrolled patients, median age was 66 years, 22 (55%) were female, and 34 (85%) were white. KRAS mutation types included G12C (28%), G12V (23%), G12D (20%), G12A (13%), G12R (5%), G13C (5%), and one case each of G12S, G13D, Q61L, and K117N. Patients had received a median of 2 prior lines of therapy (range 1-4). The maximum tolerated dose of selinexor was 60 mg PO weekly combined with docetaxel. The most common adverse events (AE) were nausea (73%, Gr ≥3 8%), fatigue (70%, Gr ≥3 5%), neutropenia (65%, Gr ≥3 60%), diarrhea (58%, Gr ≥3 10%), anorexia (50%, Gr ≥3 0%), and vomiting (45%, Gr ≥3 5%). Of 32 patients evaluable for efficacy, 7 (22%) had partial response (PR) and 18 (56%) had stable disease (SD) as best response. Median progression-free survival (PFS) was 4.1 months (95% CI, 2.9-5 months); median overall survival (OS) was 7.1 months (95% CI, 4.5-13.7 months). Clinical outcomes did not differ significantly among KRAS mutation types. However, TP53co-mutations (48%) were associated with significantly worse outcomes: disease control rate (PR + SD) 27% vs 92% ( P=0.006); median PFS 1.8 vs 7.4 months ( P<0.001); median OS 5.8 vs 17 months ( P=0.006). Additional biomarker studies are ongoing. Conclusions: Selinexor plus docetaxel is tolerated with multi-agent supportive care. The combination shows moderate efficacy across KRAS mutation types, with promising activity in TP53 wild type cases. Clinical trial information: NCT03095612 .

Safety and efficacy of ifebemtinib (IN10018) combined with D-1553 in non-small-cell lung cancer (NSCLC) with KRAS G12C mutation: Results from a phase Ib/II study.

8605 Background: KRAS G12C mutation is present in about 12-14% of NSCLC population. Ifebemtinib (IN10018) is a highly potent and selective oral inhibitor of focal adhesion kinase (FAK). D-1553 (garsorasib) is a novel oral and potent KRAS G12C inhibitor. Preclinical data showed that ifebemtinib in combination with KRAS G12C inhibitors had synergistic anti-cancer effect in multiple KRAS G12C mutant cancer models. This study is to evaluate the safety and antitumor activity of ifebemtinib combined with D-1553 in solid tumors with KRAS G12C mutation. Here we report the preliminary data from phase II part of front-line NSCLCs with KRAS G12C mutation. Methods: Locally advanced or metastatic NSCLC subjects without prior systemic anti-cancer therapy were enrolled. Subjects were required to have KRAS G12C mutation in tumor tissues. All subjects were assigned to the recommended phase II dose (RP2D) of ifebemtinib (100mg qd) + D-1553 (600mg bid). Results: As of 31 January 2024, 33 front-line NSCLC subjects with KRAS G12C mutation were enrolled and received the combination therapy. Median age was 65yrs (range 58, 83), 93.9% were male, and 81.8% had stage IV metastatic disease. Median study follow-up (FU) was 2.2 months (range 1.1, 9.2). The safety profile of the combination therapy is comparable to each single agent without additive toxicities. No ifebemtinib- or D-1553-related death was reported. Four subjects (12.1%) had ifebemtinib-related SAEs (diarrhea, enteritis, oedema peripheral and proteinuria) as assessed by investigators, and all SAEs were also considered D-1553 related. Six subjects (18.1%) had ≥ Grade 3 ifebemtinib-related AEs as assessed by investigators, and all were also D-1553 related AEs. The majority of ifebemtinib-related AEs were CTCAE Grade 1 or 2. There was no event leading to study treatment discontinuation. We have observed continuing tumor shrinkage in almost all subjects who had at least 2 tumor assessments. Among 16 subjects with ≥ 3 months FU, preliminary efficacy found that 14 had best overall response of partial response (PR) including 12 confirmed PRs and 2 unconfirmed but still in treatment, 1 had stable disease (SD), and 1 had progressive disease (PD). The overall response rate (ORR) was 87.5% (95%CI: 56.6, 96.2), and disease control rate (DCR) was 93.8% (95%CI: 63.6, 98.5). The median duration of response (DOR), median progression-free survival (PFS) and overall survival (OS) have not been reached. Conclusions: The combination of ifebemtinib and D-1553, as a dual-oral regimen, showed promising antitumor activity and manageable safety profile in KRAS G12C mutant front-line NSCLC population. Long term follow-up is needed to assess the potential of such novel combo. Clinical trial information: NCT06166836 ; NCT05379946 .

Characterization of BTX-10908, a first-in-class, orally bioavailable SOS1 bifunctional degrader for the treatment of KRAS- and RTK-driven cancers.

e15192 Background: Despite early clinical responses of targeted therapeutics against specific nodes in the RTK-RAS-MAPK pathway, limitations in the depth and duration of efficacy occur due to the emergence of adaptive and acquired resistance mechanisms. Resistance can result from the removal of feedback inhibition to reactivate RTKs, on-target amplification and new mutations. The efficacy of these oncogene-targeted agents in the clinic could be improved by co-treatment with additional therapies that address either type of resistance mechanism. The RAS guanine nucleotide exchange factor, Son of Sevenless 1 (SOS1), represents an ideal target to enhance clinical potency of other pathway inhibitors for two reasons. In addition to mitigating inputs from upstream RTKs to downstream RAS proteins, SOS1’s activity is also regulated by ERK- and RSK-mediated negative feedback inhibition with upstream and downstream inhibitors alleviating this inhibition to reengage pathway activation. Methods: To address this need, we utilized our PRODEGY platform to generate orally bioavailable, Cereblon (CRBN)-based SOS1 bifunctional degrader, BTX-10908, for the treatment of KRAS- and RTK-driven tumors. Results: BTX-10908 demonstrated rapid and potent SOS1 degradation with <10nM DC50 and maximum degradation > 90%. Consistent with BTX-10908’s mechanism of action, SOS1 degradation required CRBN and the proteasome. Not only did it reduce active RAS levels, but BTX-10908 also inhibited downstream signaling proteins (pERK, pRSK, pS6) and lowered ERK-mediated transcripts in KRAS- and EGFR-mutant as well as MET amplified cell lines under anchorage-independent (3D) conditions. Additionally, drug washout experiments demonstrated prolonged suppression of pERK and ERK-regulated transcripts with SOS1 degradation whereas rebound occurred quicker with SOS1 inhibitors. BTX-10908 displayed CRBN- and SOS1-dependent antiproliferative activity with IC50 values ranging from 0.5-20nM. Notably, BTX-10908 was significantly more potent than the clinical SOS1 inhibitor at reducing pERK levels and cell viability in multiple KRAS- and RTK-driven cell lines. Oral administration of BTX-10908 resulted in dose-dependent SOS1 degradation and tumor growth inhibition in H358 (KRAS G12C) and H441 (KRAS G12V) xenografts. The combination of BTX-10908 with KRAS G12C inhibitors (Sotorasib, Adagrasib) and various RTK inhibitors (EGFR, Met, BCR-ABL, and FLT3) prevented pathway reactivation driven by these inhibitors resulting in synergistic effects in in vitro proliferation assays and enhanced tumor growth inhibition in KRAS-mutant xenograft models. Conclusions: Our developmental candidate, BTX-10908, displayed robust in vitro and in vivo activity supporting its further development for monotherapy and combination therapies of KRAS and RTK-driven cancers.

Updated safety and efficacy data of combined KRAS G12C inhibitor (glecirasib, JAB-21822) and SHP2 inhibitor (JAB-3312) in patients with KRAS p.G12C mutated solid tumors.

3008 Background: Resistance to KRAS G12C inhibitor in non-small cell lung cancer (NSCLC) can be overcome by SHP2 blockade. This concept was tested in Phase I study of glecirasib combined with JAB-3312 in patients (pts) with KRAS p.G12C mutated tumors. Promising preliminary data of safety and response were reported at the 2023 ESMO (653O). Here, we present the updated safety and efficacy data with treatment response and progression-free survival (PFS) of the combination therapy in front-line NSCLC. Methods: The phase 1/2a study [NCT05288205] evaluated glecirasib plus JAB-3312 in patients with KRAS p.G12C mutated solid tumors. The primary objective of the dose-escalation phase was to assess the safety and tolerability of the combination therapy, and the primary objective of the dose-expansion phase was to assess efficacy. Efficacy endpoints included objective response rate (ORR), disease control rate (DCR), duration of response (DoR), PFS by investigator per RECIST1.1 and overall survival. Glecirasib 400 mg or 800 mg daily was combined with various JAB-3312 doses and schedules. Results: As of December 1st, 2023, 179 pts were enrolled, including 157 with NSCLC, 17 with colorectal cancer, and five with other tumor types. Treatment-related adverse events (TRAE) ≥ grade 3 occurred in 41.9% of all pts. There were no treatment-related deaths. Discontinuation of either glecirasib or JAB-3312 due to TRAE occurred in 7.8% of all pts. The AE profile was unchanged from the last ESMO report. The most common ( > 20%) TRAEs included anemia, ALT/AST increased, hypertriglyceridemia, bilirubin increased, neutropenia/leukopenia, creatine kinase increased, and edema. No overlapped toxicity was observed for this combination therapy. Amongst all pts enrolled, 88 had NSCLC and received the combination therapy as front-line treatment in seven dosing groups. The median follow-up duration was 6.1 (range:0.5-16.7) months. Eighty pts had at least once post-treatment efficacy assessment. The ORR was 72.5% (58/80) and DCR was 96.3% (77/80). In the group of glecirasib 800mg QD + JAB-3312 2mg one week on/one week off, the ORR was 77.8% (21/27) and DCR was 92.6% (25/27). The median PFS was not mature by the data cut-off date. The 6-month and 12-month PFS rate were 67.3% and 53.7%, respectively. Additional safety and efficacy data will be presented at the meeting. Conclusions: Glecirasib plus JAB-3312 has a manageable safety profile and a promising ORR and PFS as a front-line treatment for patients with KRAS p.G12C NSCLC. This combination will be further evaluated in a randomized phase III trial in NSCLC. Clinical trial information: NCT05288205 .

Impact of trial eligibility criteria on enrollment to KRASG12C inhibitor trials in patients with non-small cell lung cancer.

11012 Background: Clinical trials of novel therapies should enroll a population that reflects patients (pts) who might receive the drug upon FDA approval. In 2017 ASCO proposed modifications to common eligibility criteria (EC) to increase the generalizability of trial findings. Despite this, barriers to trial enrollment in the recent era of molecularly-targeted therapies are not well-characterized. We examined a cohort of non-small cell lung cancer (NSCLC) pts with KRAS G12C mutations to determine whether EC for trials of KRAS G12C inhibitors allowed enrollment of patients seen as part of routine care at an academic medical center. Methods: We extracted EC for Phase I-III trials among six KRAS G12C inhibitors: sotorasib, adagrasib, LY3537982 , divarasib, JDQ443 and RMC-6291. We retrospectively reviewed pts with NSCLC and G12C mutations detected on universal, NGS-based testing of NSCLCs at Columbia University Irving Medical Center (CUIMC) from 2020 to 2023. We defined dates of disease progression and evaluated pts for clinical trial eligibility for each line of treatment. Pts were deemed trial-eligible if they met all EC, borderline if they had 1 laboratory value < 20% from cutoff, or ineligible. The association between baseline factors including self-reported race, sex, and age with rates of eligibility were evaluated with chi-squared tests. Results: EC criteria for 14 trials were characterized. EC were similar across trials regardless of agent or phase and did not substantially change over time; 1 Phase III trial had expanded EC from the Phase I/II trials. Of 1172 patients with NSCLC, we identified 185 pts with G12C mutations (15%), including 69 pts with advanced or metastatic disease. Of these, 19% (13/69) would have been eligible for any G12C trial, 15% (10/69) were borderline, and 67% (46/69) were ineligible. 9% (6) would have qualified for only 1 of the trials. The most common reasons for ineligibility were poor performance status (54% [30/56]), excluded comorbidities (25% [14/56]), and renal dysfunction (27% [15/56]). Among patients who received therapy after FDA accelerated approval (N = 22), only 23% (5) would have been eligible for the related Phase III trial. Conclusions: Our findings suggest that most patients with KRAS G12C mutations would not have been eligible for relevant trials, including > 75% of patients who received KRAS G12C inhibitors off-trial after accelerated FDA approval. EC did not expand after early phase trials demonstrated evidence of safety. These data should guide sponsor and FDA considerations in the development of trial protocols for targeted therapies, as fewer barriers to trial participation would enable trials to be completed more quickly and would improve the generalizability of trial results.

Candidate molecular alterations associated with potential resistance in KRAS G12D gastrointestinal cancers.

3519 Background: KRAS G12D commonly occurs in pancreatic (PDAC) and colorectal (CRC) cancers. Though developing KRAS G12D inhibitors is pertinent, it is expected that primary and acquired resistance will limit efficacy, similar to those seen with KRAS G12C inhibitors. Here, we assessed the prevalence and outcomes of candidate mutations co-occurring with KRAS G12D in PDAC and CRC using liquid biopsy data. Methods: Patients with advanced CRC and PDAC tested with Guardant360 genomic profiling from 2020 to 2023 (~2500 & 3500 samples) were included. Candidate resistance mutations were determined based on mutations reported following KRAS G12C inhibition. Patients with advanced CRC and PDAC tested with Guardant360 at Mayo Clinic (2016-2023) (1158 & 904 samples) were assessed for overall survival (OS). Patients were divided into three groups: KRAS G12D alone, KRAS G12D with candidate resistance alterations, and KRAS G12D not detected (ND). OS was estimated using Kaplan-Meier method. Cox regression was used for multivariable survival analyses. Results: The Guardant360 database reported KRAS G12D in 16.5% of CRC and 40.2% of PDAC samples. The Table below summarizes the most frequent candidate resistance alterations co-occurring with KRAS G12Dincluding point mutations of KRASand PIK3CAand amplifications of EGFR, KRAS, BRAFand MYC. In the Mayo cohort, 8.9% of CRC and 23.5% of PDAC patients had KRAS G12D. In CRC, those with KRAS G12Dand ≥1 candidate resistance alteration had a significantly lower OS (mOS 18.7m) than KRAS G12D alone (30.9m), and ND (37.3m) ( p=0.004). The presence of concurrent candidate resistance alterations with KRAS G12D remained a poor prognostic factor with HR 2.1 (95% CI: 1.3 – 3.2, p=0.001) after adjusting for age and other patient characteristics. Similarly, in PDAC, those with KRAS G12D and ≥1 resistance mutation had significantly lower OS (mOS 8.1m) than KRAS G12D alone (10.5m) and ND (16.1m) (p<0.0001). In multivariable analyses, both KRAS G12D with candidate resistance alterations (HR 2.1, 95% CI: 1.4-3.3, p<0.001) and G12Dalone (HR 1.6; 1.3–2.0, p<0.001) were poor prognostic factors. Among patients with serial Guardant360, treatment response trended with KRAS G12D variant allele frequency. Conclusions: Circulating tumor DNA testing is a useful tool to reveal candidate molecular alterations linked to potential resistance to KRAS G12D targeting in patients with KRAS G12D gastrointestinal cancers. KRAS G12D with these concurrent molecular alterations is a poor prognostic factor in both PDAC and CRC. [Table: see text]

TTF-1 negativity as a biomarker of outcomes to immunotherapy, chemoimmunotherapy, and KRAS G12C inhibitors in lung adenocarcinoma.

8608 Background: Thyroid transcription factor 1 (TTF-1) expression is routinely assessed in lung adenocarcinomas (LUAD) and is negative (TTF-1Neg) in 15-20% of cases. Whether these tumors differ from LUAD expressing TTF-1 (TTF-1Pos) in terms of biologic features and outcomes is unclear. Methods: Patients (pts) with LUAD and available TTF-1 expression by IHC at five institutions were included. Clinicopathologic, genomic, and outcomes data were compared according to TTF-1 expression. Results: Among 3,315 pts with LUAD, TTF-1 was negative in 15% (N=499). Compared to TTF-1Pos (N=2,816), pts with TTF-1Neg LUAD were more likely male (44% vs 38%, P=0.01), smokers (82% vs 74%, P<0.001), with stage IV disease at diagnosis (76% vs 71%, P<0.001), and lower median PD-L1 tumor proportion score (TPS, 1% vs 10%, P<0.001). At stage IV diagnosis, TTF-1Neg cases less commonly had brain metastasis than TTF-1Pos cases (35% vs 44%, P=0.04), but more frequently had bone metastasis (53% vs 45%, P=0.03). TTF-1Neg LUAD was enriched for KRAS, STK11, KEAP1, SMARCA4, and CDKN2A mutations (q<0.05), while TTF-1Pos LUAD was enriched for EGFR and MET mutations (q<0.05). Compared to TTF-1Pos LUAD, TTF-1Neg LUAD had higher prevalence of KRAS G12D (12% vs 4%, P<0.001) and G12V mutations (11% vs 7%, P=0.001), but similar frequency of G12C mutations (14% vs 15%, P=0.82). The association between TTF-1 and treatment outcomes was next investigated. Pts with stage III unresectable TTF-1Neg LUAD who received durvalumab after chemo-radiation (N=20), compared to TTF-1Pos cases (N=174), had shorter median progression-free survival (mPFS, 7.6 vs 24.7 months, P=0.01) and overall survival (mOS, 22.7 months vs not reached, P=0.01). Among pts with stage IV LUAD, TTF-1Neg cases treated with immune checkpoint inhibitors (N=237), compared to TTF-1Pos (N=1,161), had worse objective response rate (ORR, 17% vs 28%, P<0.001), mPFS (2.5 vs 4.7 months, P<0.001) and mOS (9.8 vs 20.9 months, P<0.001). Similarly, pts with TTF-1Neg LUAD (N=297) treated with chemoimmunotherapy, compared to TTF-1Pos cases (N=920), had worse ORR (27% vs 42%, P<0.001), mPFS (4.6 vs 8.1 months, P<0.001) and mOS (11.2 vs 23.4 months, P<0.001). TTF-1 negativity retained its association with worse outcomes after adjusting for treatment line, ECOG performance status, smoking status, PD-L1 TPS, STK11/ KEAP1 mutation status in multivariable cox regression models. Lastly, pts with KRAS G12C mutated TTF-1Neg LUAD treated with KRAS inhibitors (N=25), compared to TTF-1Pos (N=138), had worse ORR (12% vs 35%, P=0.03), mPFS (2.7 vs 5.9 months, P<0.001), and mOS (4.4 vs 12.1 months, P<0.001). After excluding mucinous LUAD cases, which are more commonly TTF-1Neg, similar results were observed. Conclusions: TTF-1 negativity identifies a unique clinicopathologic and genomic subset of LUAD with worse outcomes to diverse systemic therapies.

A unique model: Partnership between community oncology and pharma for clinical trial enrichment.

1535 Background: Clinical trials are the foundation of oncologic drug development. Historically, only 23% of oncology trials are conducted in the community despite >70% of patients being treated this setting, leading to a disconnect between the therapy being tested and target population. Also, patients are hesitant to enroll in trials- in 2020, only 49% were willing, down from 85% in 2019. One way to improve this is participation by community oncologists, allowing patients to stay close to home. Targeted therapies are increasingly being approved by the FDA, with 89 small molecule drugs approved by 2020. Given the above landscape, Precision Health Informatics (PHI) collaborated with Mirati Therapeutics to pilot a clinical trial enrichment program focused on increasing enrollment of patients in the community related to efficacy and outcomes of adagrasib (KRAS G12C inhibitor) for NSCLC and CRC. Methods: This pilot was launched in 2021, with a prescreening study (DetECT) to find eligible patients with KRASG12C mutations. The pilot was then expanded across Mirati ‘Krystal’ studies in 2022 and to “1719” studies in 2023. These studies were available to all investigators throughout Texas Oncology (TxO) via STAR model (clinical trial access to all TxO investigators/sites through a regulated but rapid approval process). Eligible patients were identified from PHI’s proprietary molecular data warehouse (that stores molecular results for >400,000 patients treated at TxO). A data analyst identified patients with KRAS G12C mutation from the warehouse, and then cross-referenced patient-centric data in EMR to assess eligibility. The treating physician was then alerted of their patient’s eligibility. Patient demographic information was also collected from the EMR. Results: This collaboration resulted in accrual of 118 patients, engagement of 40 different PIs, across 8 different trials. 6 studies remain open across the practice. 21 patients were enrolled on Krystal-001, 7 on Krystal-007, 10 on Krystal-010 and 56 on DetECT. Enrollment was inclusive of patients from urban areas of DFW as well as rural populations in NE Texas, South and West Texas. In DetECT, TxO provided 84% of the total US enrollment, with a diverse population – 54% white, 23% Hispanic, 12% black, 9% Asian. Texas Oncology is the 2nd highest screening and enrolling site on Krystal studies. Conclusions: This pilot successfully demonstrates that community oncology can lead the way in clinical trial enrollment, even in early phase targeted therapy studies. Community physicians can be engaged so patients can benefit from research participation close to home. This model shows that a diverse population was accrued and may serve as a blueprint to help Pharma satisfy the diversity requirements for clinical trials. PHI, with its molecular database, may partner with Pharma to identify targetable mutations and drive rapid trial enrollment for targeted therapies.

Survival and mutational differences based on ESR1 and ESR2 expression in non-small cell lung cancer (NSCLC).

8526 Background: Estrogen receptor (ER) can activate MAPK signaling but the contribution of the two classical receptors—ER-alpha ( ESR1) and ER-beta ( ESR2) is unclear. Past trials targeting ER and EGFR in NSCLC lacked efficacy. We evaluated the association of ESR1& 2 expression with the genomic landscape and overall survival (OS) in NSCLC. Methods: NSCLC tumors (N = 21603) were tested at Caris Life Sciences (Phoenix, AZ) with NextGen Sequencing of DNA (592-gene or whole exome) and RNA (whole transcriptome). Mutation prevalence (-Mt) was calculated for pathogenic SNVs/indels. ESR1& 2 expression was split into quartiles (transcripts per million, top (-H) and bottom (-L) quartiles were compared). A transcriptomic signature associated with MAPK activation (MPAS, arbitrary units: AU) was applied. The X2 test was applied, p-value was adjusted for multiple comparisons ( p < .05). Real-world OS was obtained from insurance claims and Kaplan-Meier estimates were calculated. Results: There was a greater proportion of females in ESR1-H (53%) versus (v) -L (45%, p < .05) but not in ESR2-H v -L (50% v 50%). There was a greater proportion of adenocarcinoma (AD) in ESR1-H (65%) v -L (44%) and a greater proportion of squamous (SCC) tumors in ESR2-H (27%) v -L (15%) ( p < .001 all). The prevalence of EGFR-Mt and KRAS-Mt was greater in ESR1-H v -L and smaller in ESR2-H v -L. (Table) Of all KRAS-Mt, there was a greater percent of KRAS G12C-Mt in ESR1-H (44%) v -L (39%, p = .001). In EGFR-Mt, ESR1-H/ ESR2-H had a higher MPAS (1.4 AU) than ESR1-H/ ESR2-L (.52), ESR1-L/ ESR2-H (.59) or ESR1-L/ ESR2-L (-1.6, p < .05). In KRAS-Mt, ESR1-H/ ESR2-H (1.7 AU) and ESR1-L/ ESR2-H (1.8) had a higher MPAS than ESR1-H/ ESR2-L (.7) or ESR1-L/ ESR2-L (-.7, p < .001). ESR1-H had longer median OS v -L (22 months (m) v 16 m, p < .001) as did ESR2-H v -L (23 m v 15 m p< .001). ESR1-H/ ESR2-H had the longest OS (25 m) followed by ESR1-H/ ESR2-L (18 m), ESR1-L/ ESR2-H (16 m) and ESR1-L/ ESR2-L (14 m, p < .001). In EGFR-Mt, a significant difference in survival since treatment (SST) with osimertinib was seen for ESR1-L/ ESR2-H (40 m, N = 13), ESR1-H/ ESR2-L (36 m, N = 62), ESR1-H/ ESR2-H (34 m, N = 161) and ESR1-L/ ESR2-L (30 m, N = 138, p = .03). In KRAS G12C-Mt, a significant difference in SST was seen with sotorasib; ESR1-H/ ESR2-H had the longest SST (median not reached, N = 17), followed by ESR1-H/ ESR2-L (17 m, N = 17), ESR1-L/ ESR2-L (13 m, N = 34) and ESR1-L/ ESR2-H (1 m, N = 1, p = .002). Conclusions: ESR1-H had a higher percentage of females, AD, and EGFR/ KRAS-mt v ESR1-L while ESR2-H had no sex difference, more SCC, and fewer EGFR/ KRAS-mt v ESR2-L. ESR1-H/ ESR2-H tumors had the highest MPAS and longest OS and there were SST differences with EGFR and KRAS G12C inhibition. ESR1& 2 may play key roles in activating the MAPK pathway and future trials could consider targeted therapy combined with ER inhibition based on ESR1&2 expression. [Table: see text]

Effect of targeting FAK by ifebemtinib and immunogenic cell death of Kras G12C/G12D inhibition on the efficacy of PD1 blockade.

e15102 Background: Focal adhesion kinase (FAK) is one major component of focal adhesion complex and is important in regulating cancer cell survival. Previously, we found that a clinical-stage FAK inhibitor, ifebemtinib (aka IN10018) can overcome drug resistance of Kras G12C inhibitors by down regulating the FAK-YAP signaling. Combination of Kras G12Ci and FAKi has demonstrated encouraging efficacy in NSCLC. Here, we reported that targeting Kras G12D by selective Kras G12Di can also be enhanced by ifebemtinib. Further, Kras G12C inhibition plus PD1 blockade has demonstrated clinical benefits in PD-L1 high expression patient population, but ≈30% of patients experienced early disease progression; this might be attributed to loss-of-function of LKB1 and others. Immunogenic cell death (ICD) of Kras inhibition is enhanced by ifebemtinib, ICD reportedly enhances anti-PD1 activity. Thus, Kras inhibition and PD1 blockade plus ifebemtinib may be an ideal combination for patients with Kras G12D. Methods: Cell killing and apoptosis assays were performed to test the combination of Kras G12D inhibition and ifebemtinib. FACs analysis evaluated exposure levels vs. ICD biomarkers. The mice inoculated with CRC GP2D and PDAC PC-07-0013 were used for evaluating the combinational effects of Kras G12Di and ifebemtinib. The tumor bearing mice with Kras G12D mutant/LKB1 loss, NSCLC KPL, and CRC CT26 with knock-in Kras G12C were used for testing the effects of Kras inhibition, ifebemtinib, and PD1 blockade. Results: Ifebemtinib enhances the drug effects of Kras G12D inhibition in vitro and in vivo. The dual regimen of ifebemtinib and Kras inhibition outperformed either monotherapy with significant ICD induction in vitro (calreticulin/GRP94 exposure). The triple regimen of Kras inhibition, FAK inhibition and PD1 blockade exhibited stronger anti-cancer effects compared to the other related therapies, especially in a Kras G12D mutant, LKB1 loss animal model which is intrinsically resistant to PD1 blockade/Kras G12D inhibition. Conclusions: We discovered that targeting FAK by ifebemtinib enhances the anti-cancer effects of Kras G12D inhibition. It promotes ICD by targeting Kras G12D or G12C, further primes the dual regimen of Kras inhibition and ifebemtinib towards a response to anti PD1 therapy. The preclinical results warrant a further evaluation in the clinic.

Therapeutic activity of a new KRASG12C inhibitor JMKX001899 in brain metastases: Preclinical models of KRASG12C-mutant non-small cell lung cancer.

8630 Background: Development of therapies targeting KRAS have transformed KRAS from undruggable to druggable. However, patients with KRASG12C-mutant non-small cell lung cancer (NSCLC) with brain metastasis (BM) have a poor prognosis. JMKX001899, a new potent oral small-molecule KRASG12C inhibitor, irreversibly and selectively binds KRASG12C, locking it in its inactive state. Its antitumor activity in the intracranial is unclear. Methods: In order to verify the activity of new KRASG12C inhibitor JMKX001899 in KRASG12C-mutant NSCLC with BM, murine models were employed for investigating the efficacy. 5-6 weeks old female Balb/c nude mice were implanted intracranially with H358-Luc and H23-Luc cells. Baseline bioluminescent imaging (BLI) was used to monitor the tumor burden and total flux was calculated by Living Image. Ten days after implantation, oral once-daily dosing of vehicle, sotorasib (AMG510) at 100 mg/kg, 30 mg/kg and JMKX001899 at 100 mg/kg, 30 mg/kg, 10 mg/kg was started and continued for 21 days. The tumor burden was monitored by BLI weekly. The mice were weighed per 3 days. Results: At the 30mg/kg and 100mg/kg dose level, the mean cerebrospinal fluid (CSF)-to-unbound plasma ratios (Kp,uu) was 0.18-0.50, which determined JMKX001899 CSF exposure was sufficient to mediate regression tumors in experimental BM models. In mice bearing intracranial xenografts of H358-Luc and H23-Luc, oral JMKX001899 100mg/kg once daily treatment for 21 days resulted in significant inhibition of brain tumor growth revealed by BLI, compared with vehicle and AMG510. H358-Luc xenografts responded particularly well to the JMKX001899 treatment, showed by the ratio of 14 days and 0 days total bioluminescence flux (vehicle vs. AMG510 100mg/kg vs. JMKX001899 100mg/kg, 0.85 vs. 0.89 vs. 0.01, p < 0.05). In addition, JMKX001899 at 100mg/kg once daily demonstrated an increase in over survival. JMKX001899 100 mg/kg once daily treatment was well tolerated with minimal sign of overt toxicity or animal weight loss. Conclusions: The preclinical models in vivo suggest the new KRASG12C inhibitor JMKX001899 penetrates the central nervous system and show great inhibition of KRASG12C-mutant NSCLC with BM, which demonstrates therapeutic activity of JMKX001899 in BM. These data support further development of JMKX001899 in patients with KRASG12C-mutant NSCLC with BM.

Gene expression correlates of adagrasib response in KRASG12C mutated non-small cell lung cancer (NSCLC).

8529 Background: KRASG12C inhibitors such as adagrasib and sotorasib have shown clinical promise in targeting KRASG12C-mutated lung cancers; however, most patients develop primary or secondary resistance. A biomarker of response to KRASG12C inhibitor is needed for better patient stratification and to understand the resistance mechanism. Methods: We analyzed transcriptional correlates of adagrasib treatment outcome in 68 patients in the KRYSTAL-1 trial, a phase 1/2 clinical trial of adagrasib monotherapy in the second line and beyond treatment for NSCLC. We also treated KRAS-mutated lung cancer mouse models and organoids with a KRAS inhibitor for the long term and characterized the resistant tumors’ transcriptional profile to identify resistance mechanisms. We also performed serial gene expression analysis of KrasG12D mutated lung organoids undergoing squamous transformation to identify transcription factor involved in the resistance process. Results: In patients with lung adenocarcinoma with KRASG12C and STK11/ LKB1 co-mutations, we find an enrichment of the squamous cell carcinoma gene signature in pre-treatment biopsies correlates with a poor response to adagrasib. Studies of Lkb1-deficient KRASG12C and KrasG12D lung cancer mouse models and organoids, treated with KRAS inhibitors adagrasib and MRTX1133, respectively, reveal that tumors invoke a lineage plasticity program, adeno-to-squamous transition (AST), that enables resistance to KRAS inhibition. We identify TP63 to be a transcription factor whose expression correlated with squamous transformation. The analysis of lineage plasticity program, adagrasib resistant tumors, and p63 regulon revealed KRT6A to be a common biomarker whose expression correlated with overall survival in the KRYSTAL-1 cohort. Conclusions: KRASG12C mutated lung adenocarcinoma patients with a higher expression of squamous cell carcinoma gene expression signature respond poorly to adagrasib treatment. Expression of the AST plasticity signature and KRT6A at baseline correlates with poor adagrasib responses. These data indicate the role of AST in KRAS inhibitor resistance and provide predictive biomarkers for KRAS-targeted therapies in lung cancer.

Efficacy and safety of olomorasib (LY3537982), a second-generation KRAS G12C inhibitor (G12Ci), in combination with pembrolizumab in patients with KRAS G12C-mutant advanced NSCLC.

8510 Background: While immunotherapy (IO) is established as the cornerstone of first-line treatment for KRAS-mutant NSCLC, outcomes remain suboptimal. Further progress may be achieved with the addition of targeted therapy to IO, an established first-line paradigm in some other cancer types (RCC), but historically challenging in NSCLC. Here, we study pembrolizumab plus olomorasib, a potent and highly selective second-generation inhibitor of GDP-bound KRAS G12C, in NSCLC patients treated on LOXO-RAS-20001, a phase 1/2 study of olomorasib in KRAS G12C-mutant solid tumors (NCT04956640). Methods: Patients (pts) with advanced KRAS G12C mutant NSCLC (tissue or plasma) in any treatment line, including prior KRAS G12Ci and/or prior IO were eligible. Dose escalation of olomorasib plus pembrolizumab followed a mTPI-2 method. Safety was evaluated across all pts dosed with the combination. Antitumor activity per RECIST v1.1 was studied in all pts who had ≥1 post-baseline response assessment (PBRA) or had discontinued before the first PBRA. Results: As of 30 October 2023, 50 pts with advanced NSCLC received 50-150 mg BID PO olomorasib plus 200 mg Q3W pembrolizumab. Median age was 66 yrs (range, 42-83), median number of prior systemic therapies was 2 (range, 0-8), and 34% had received a prior KRAS G12Ci. During escalation, 2 of 6 ptstreated at 150 mg BID developed grade ≥3 LFTs, precluding further evaluation of this dose. In 44 pts treated at 50 or 100 mg BID, TRAEs ≥10% (related to olomorasib and/or pembrolizumab) were diarrhea (30%), ALT increased (20%), AST increased (18%), fatigue (14%), nausea (14%) and pruritus (11%); grade 3 TRAEs in ≥10% of pts were diarrhea (16%); pneumonitis was seen in 3 pts (grades 2/3/4). TRAEs led to olomorasib dose reduction in 14% of pts, olomorasib dose hold in 27%, and pembrolizumab dose hold in 18%. Due to TRAEs, 9% of pts discontinued olomorasib or pembrolizumab and 9% discontinued both. 27 pts remain on treatment, and 17 discontinued treatment (10 due to PD, 4 due to AE). Among the 30 efficacy evaluable KRAS G12Ci-naïve pts (60% IO pre-treated, 60% chemotherapy pre-treated), at a median follow-up of 6 months (95% CI, 4-7) ORR was 63% (15 PR, 4 unconfirmed PR pending/ongoing; 95% CI, 44-80) and DCR was 93% (28/30; 95% CI, 78-99); the median PFS was not estimable (95% CI, 5-NE); ORR was 75% (9/12) in PD-L1 ≥50%, 56% (10/18) in PD-L1 < 50%/unknown (3 pts PD-L1 unavailable). In 9 first-line pts, ORR was 78% (6 PR, 1 unconfirmed PR pending/ongoing; 95% CI, 40-97) and DCR was 100%. Conclusions: Olomorasib (50 or 100 mg BID) in combination with pembrolizumab demonstrated favorable safety and antitumor activity in pts with KRAS G12C-mutant advanced NSCLC, supporting further development in first-line NSCLC. A global, registrational study investigating this combination in first-line NSCLC is currently enrolling (SUNRAY-01, NCT06119581). Clinical trial information: NCT04956640 .

Pan-tumor activity of olomorasib (LY3537982), a second-generation KRAS G12C inhibitor (G12Ci), in patients with KRAS G12C-mutant advanced solid tumors.

3007 Background: Olomorasib is a potent and highly selective second-generation inhibitor of GDP-bound KRAS G12C, which preclinically delivers >90% sustained target occupancy. Here, we report updated results from LOXO-RAS-20001, a phase 1/2 study of olomorasib in patients with KRAS G12C-mutant advanced solid tumors (NCT04956640). Methods: Patients (pts) with advanced solid tumors positive for KRAS G12C (tissue or plasma) were eligible. Dose escalation used a mTPI-2 method, followed by expansion cohorts in NSCLC (with/without prior G12Ci), CRC, and other solid tumors. Safety was evaluated across all pts dosed. Antitumor activity per RECIST v1.1 was studied in all pts who had ≥1 post-baseline response assessment (PBRA) or had discontinued before the first PBRA. Serial ctDNA analysis was performed using FoundationOne Liquid CDx. Results: As of 30 October 2023, 157 pts (58 NSCLC, 32 CRC, 24 PANC, 43 other solid tumors) received single agent olomorasib (50-200 mg BID PO); 29 pts with NSCLC had received a prior KRAS G12Ci. Median age was 65 yrs (range, 36-85), median number of prior systemic therapies was 3 (range, 0-11). Any grade TRAEs were 62%; TRAEs ≥10% were diarrhea (24%), fatigue (10%), and nausea (10%); grade ≥3 TRAEs were 5%. TRAEs led to dose hold in 10% of pts, dose reduction in 3%, and discontinuation in 2%. Among 10 pts treated after discontinuing prior G12Ci due to toxicity (5/10 due to LFT increase), 1 pt (10%) required olomorasib dose reduction and none discontinued due to toxicity. 68 pts are ongoing and 89 discontinued treatment. 146 pts were efficacy evaluable (120 G12Ci-naïve; 26 with prior G12Ci) with a median follow-up of 10 months (95% CI, 7-13). As anticipated, ORR was lower in 32 pts with CRC (9%, 3 PR; DCR 84%)1 and higher in 88 pts with non-CRC tumors (40%, 30 PR and 5 uPR pending/ongoing in 13 unique tumor types; DCR 90%). mPFS ranged across tumor types from 4 months (CRC, 95% CI, 3-7) to 9 months (NSCLC, 95% CI, 3-NE). In the 26 efficacy evaluable NSCLC pts with prior KRAS G12Ci treatment (16 discontinued due to PD, 9 due to AE), the ORR was 39% (9 PR, 1 uPR pending/ongoing; DCR 73%); mPFS was 6 months (95% CI, 3-NE). In 37 pts with ctDNA results at baseline and ongoing, ctDNA response (>50% KRAS G12C VAF reduction) was seen in pts with PR (11/11), SD (17/22), and PD (1/4). Conclusions: Olomorasib demonstrates efficacy across a range of KRAS G12C-mutant solid tumors with a favorable safety profile including in pts with prior G12Ci intolerance. Activity of the second-generation G12Ci olomorasib after prior exposure to G12Ci demonstrates the increased potency and target coverage these agents can deliver compared to first generation inhibitors. Phase 2 expansion is currently enrolling pts with PANC, and a global registrational study investigating olomorasib in combination with pembrolizumab in first-line NSCLC is ongoing (NCT06119581). 1. Hollebecque A. et al. ASCO-GI 2024. Clinical trial information: NCT04956640 .

SUNRAY-01, a pivotal, global study of olomorasib (LY3537982) in combination with pembrolizumab with or without chemotherapy for 1L treatment in KRAS G12C-mutant advanced NSCLC.

TPS8649 Background: Mutations in KRAS are among the most frequent oncogenic drivers with the G12C variant found in ~13% of NSCLC. Outcomes for KRAS G12C-mutant NSCLC may be improved by combining KRAS G12C inhibitors with current 1L standard of care (SOC). Olomorasib is a potent and highly selective second-generation inhibitor of KRAS G12C, which delivers >90% sustained target occupancy in preclinical models. In the LOXO-RAS-20001 phase 1/2 study, olomorasib in combination with pembrolizumab demonstrated preliminary efficacy and a favorable safety profile.1 Methods: SUNRAY-01 (NCT06119581) is a pivotal, global, phase 3 study in 1L advanced KRAS G12C-mutated NSCLC designed to seamlessly 1) optimize the dosing of olomorasib in combination with 1L SOC, and then 2) compare efficacy and safety of olomorasib plus SOC with placebo plus SOC. In the open-label randomized dose optimization (pembrolizumab plus olomorasib 50 mg vs 100 mg BID) and single arm safety lead-in (olomorasib plus pembrolizumab, pemetrexed, platinum), the optimal dose of olomorasib for combination therapy will be determined before the phase 3 study (parts A and B) is opened for enrollment. In part A, 384 participants with PD-L1 expression ≥50% are randomized (1:1) to pembrolizumab plus olomorasib or placebo. In part B, 552 participants are randomized (1:1) to pembrolizumab, pemetrexed, platinum plus olomorasib or placebo regardless of PD-L1 expression. Allocation of participants with PD-L1 expression ≥50% to either part A or part B will be at the discretion of the investigator. The primary objective is to compare efficacy based on PFS per RECIST v1.1 by blinded independent central review. Secondary endpoints include OS, ORR, DOR, DCR, TTR, PFS2, safety and tolerability, and patient-reported outcomes. Eligible participants (≥18 years) must have a KRAS G12C mutation in tumor or blood and known PD-L1 expression (0-100%), stage IIIB, IIIC, or IV NSCLC not suitable for curative intent radical surgery or radiation therapy, measurable disease per RECIST v1.1, and an ECOG PS 0-1. Participants can be enrolled based on local KRAS and PD-L1 testing results. Participants should not have received prior systemic therapy for advanced or metastatic NSCLC, however 1 cycle of SOC treatment prior to enrollment is allowed if immediate treatment is clinically indicated. Participants with asymptomatic (lesions ≤1.5 cm) or previously treated radiographically stable brain metastases are eligible. Key exclusion criteria include history of pneumonitis/interstitial lung disease and clinically significant active cardiovascular disease or malabsorption syndrome. The study opened for enrollment in December 2023. 1Murciano-Goroff et al. 2023 Cancer Res 83 (8 Suppl): CT028. Clinical trial information: NCT06119581 .

Krascendo-170 Lung: A phase Ib/II study of divarasib + pembrolizumab ± platinum-based chemotherapy and pemetrexed in untreated KRAS G12C+advanced non-small cell lung cancer (NSCLC).

TPS8651 Background: The KRAS G12C mutation, present in ~12% of NSCLC patients, drives oncogenic signaling and cancer formation and is associated with poor prognosis. The current first-line treatment for advanced KRAS G12C+ NSCLC is checkpoint inhibitor (CPI) ± chemotherapy (CT). Novel combinations using a more targeted, biomarker-directed approach are supported by pre-clinical evidence and may further improve outcomes. Divarasib is an oral KRAS G12C inhibitor with potent pre-clinical and clinical anti-tumor activity. We hypothesize that divarasib + CPI ± CT may improve outcomes for patients with KRAS G12C+ NSCLC. Methods: Krascendo-170 Lung (NCT05789082) is a phase Ib/II, open-label study evaluating the safety and activity of divarasib + pembrolizumab in patients with PD-L1 tumor cell expression ≥1% (Cohort A) and of divarasib + pembrolizumab with platinum-based CT and pemetrexed in patients with any PD-L1 tumor cell expression level (Cohort B). Patients must be ≥18 years old with untreated unresectable/metastatic non-squamous NSCLC (measurable per RECIST v1.1), a confirmed KRASG12C mutation, and an Eastern Cooperative Oncology Group performance status 0/1. Each cohort will have two stages: divarasib combination dose finding and dose expansion, with two planned dose levels of divarasib (Table). Tumor assessments will be performed at baseline and every 6 weeks for 48 weeks, then every 9 weeks thereafter. Plasma samples will be taken at various timepoints before and after divarasib and pembrolizumab dosing to characterize pharmacokinetics. Patients will be treated until disease progression per RECIST v1.1 or unacceptable toxicity. The co-primary endpoints are adverse events and change from baseline in targeted safety parameters. Key secondary endpoints include objective response rate, progression-free survival and duration of response (all investigator assessed per RECIST v1.1). Enrollment into the combination dose finding stage of Cohort A has been completed without dose-limiting toxicities and enrollment into the dose expansion stage is continuing. Clinical trial information: NCT05789082 . [Table: see text]

A potent and selective pan-RAS inhibitor, ADT-1004, targeting complex KRAS mutations for pancreatic cancer.

e15085 Background: Pancreatic ductal adenocarcinoma (PDAC) is a challenging cancer with a 5-year survival rate of under 12%. More than 90% of PDAC cases involve KRAS mutations. KRASG12C inhibitors recently developed have limited use because only 3% of PDAC express this mutation, highlighting the urgent need for pan-RAS inhibitors to address the complex mutation landscape in PDAC while avoiding resistance mechanisms. We synthesized and evaluated a novel pan-RAS inhibitor, ADT-1004, in mouse tumor models transplanted with mouse PDAC cell lines or patient-derived xenografts. ADT-1004 is an orally bioavailable prodrug of ADT-007, a highly potent and selective pan-RAS inhibitor (doi.org/10.1101/2023.05.17.541233). Methods: Human and mouse PDAC cell lines were utilized to evaluate in vitro growth inhibitory potency and selectivity of ADT-007. For in vivo experiments, KPC-Luc (1 × 105) and 2838C3-Luc (1.5 × 105) PDAC cells harboring the KRASG12D mutation were injected into the pancreas of C57BL/6J mice. After one week, the mice were randomly divided into treatment groups (n = 7 per group) and received oral ADT-1004 at a dose of 40mg/kg body weight five times a week for 4 weeks. Tumor burden was assessed weekly by monitoring bioluminescence signals using the IVIS Xenogen imaging system. Four patient-derived xenografts from PDAC patients with KRASG12C, KRASG12D, KRASG12V, KRASG13Q mutations were subcutaneously implanted in NSG mice by a small incision in the right flank. A week later, when the tumors reached a size of 100mm3 mice were randomized (n = 7 per group) and treated orally with 40mg/kg of ADT-1004 five times a week for 6 weeks. Body weight and tumor size were measured twice weekly. Results: ADT-007 potently and selectively inhibited the growth of human and mouse PDAC cell lines. For example, the IC50 value of ADT-007 for KRASG12C MIA PaCA-2 PDAC cells was as low as 2 nM compared to 2500 nM for RASWT BxPC3 PDAC cells. Growth inhibition was dependent on activated RAS and associated with reduced GTP-RAS levels and MAPK/AKT signaling. ADT-1004 was well tolerated in mice at a dose up to 175 mg/kg bid orally with sustained plasma levels of ADT-007 far exceeding growth IC50 values. When administered orally at 40 mg/kg body weight, ADT-1004 displayed robust antitumor activity in mouse tumor models using patient or mouse derived PDAC cell lines with G12D, G12V, G12C, or G13Q KRAS mutations, causing significant inhibitory effects on ERK phosphorylation. Conclusions: ADT-1004 inhibited tumor growth of KRAS mutant PDA tumors by targeting activated RAS to disrupt downstream MAPK/AKT signaling. The results highlight the promise of ADT-1004 as a novel pan-RAS inhibitor and open new strategies for addressing the complex genetic landscape of PDAC and other RAS driven cancers.

Discovery of novel coumarin-based KRAS-G12C inhibitors from virtual screening and Rational structural optimization

KRAS-G12C inhibitors has been made significant progress in the treatment of KRAS-G12C mutant cancers, but their clinical application is limited due to the adaptive resistance, motivating development of novel structural inhibitors. Herein, series of coumarin derivatives as KRAS-G12C inhibitors were found through virtual screening and rational structural optimization. Especially, K45 exhibited strong antiproliferative potency on NCI-H23 and NCI-H358 cancer cells harboring KRAS-G12C with the IC50 values of 0.77 μM and 1.50 μM, which was 15 and 11 times as potent as positive drug ARS1620, respectively. Furthermore, K45 reduced the phosphorylation of KRAS downstream effectors ERK and AKT by reducing the active form of KRAS (KRAS GTP) in NCI-H23 cells. In addition, K45 induced cell apoptosis by increasing the expression of anti-apoptotic protein BAD and BAX in NCI-H23 cells. Docking studies displayed that the 3-naphthylmethoxy moiety of K45 extended into the cryptic pocket formed by the residues Gln99 and Val9, which enhanced the interaction with the KRAS-G12C protein. These results indicated that K45 was a potent KRAS-G12C inhibitor worthy of further study.