Abstract 1639: DP-9149, an investigational small molecule modulator of the Integrated Stress Response kinase GCN2, pre-clinically causes solid tumor growth inhibition as a single agent and regression in combination with standard of care agents

Background: The Integrated Stress Response (ISR) is one of the major adaptive stress response pathways in cancer and plays an important role in cell fate determination. Oncogene addicted solid tumors are under high stress levels, both extrinsic as well as intrinsic, and are dependent on a well-balanced ISR pathway activity to cope with the high demand for accelerated growth. The ISR is well known to be a double edge sword of survival and cell death and depending on context, the activation of the ISR kinase, GCN2, and downstream pathway can have either cytoprotective or cytotoxic effects. Given the context-dependent nature of the ISR pathway, the inhibition or stimulation of GCN2 in solid tumors can be pharmacologically leveraged to induce anti-tumoral effects.

Methods: Modulation of ISR kinases was characterized using enzymatic assays. Kinome selectivity profiling was determined using enzymatic and cellular assays. Cellular modulation of the ISR pathway (phospho-GCN2, ATF4, CHOP) or the apoptosis pathway (PARP and Caspase3/7) was assessed via Western blot or ELISA. In vivo upregulation of tumoral ATF4 was determined in a fibrosarcoma PK/PD xenograft model. In vivo inhibition of tumor growth was determined in solid tumor xenografts.

Results: Selective and potent modulators of GCN2 kinase with favorable drug-like properties were designed. These compounds were found to upregulate components of the ISR pathway (phospho-GCN2, ATF4, CHOP). The mechanism by which GCN2 modulator DP-9149 treatment induced the ISR pathway was found to be through the direct binding and activation of GCN2. Upregulation of the ISR pathway downstream of GCN2 led to induction of a programmed cell death pathway in oncogene-driven solid tumor cell lines in vitro. DP-9149-mediated activation of the ISR pathway led to cell growth arrest both as a single agent and in combination with standard-of-care (SOC) agents. Furthermore, oral dosing of DP-9149 in RAS mutant and other oncogene-driven xenograft models in vivo induced ATF4, and significantly inhibited tumor growth as a single agent and in combination with SOC agents. Additionally, therapeutic agents targeting the tumor microenvironment, including anti-angiogenic agents, synergized with DP-9149 to induce tumor regressions in vivo.

Conclusions: The ISR is a targetable vulnerability in oncogene addicted solid tumors. Upregulating the ISR by paradoxical activation of the ISR family member kinase, GCN2, by DP-9149 can be leveraged as a novel mechanism to cause anti-tumoral effects in solid tumors in vitro and in vivo, likely through the induction of an unresolved stress response. In particular, DP-9149 exhibited robust activity in RAS mutant cancers and in VHL-mutant renal cancers as a single agent and in combination with SOC agents in vivo.

Citation Format: Gada Al-Ani, Qi Groer, Kristin M. Elliott, Aaron J. Rudeen, Patrick C. Kearney, Jeffery D. Zwicker, Yu Mi Ahn, Stacie L. Bulfer, Cale L. Heiniger, Molly M. Hood, Salim Javid, Joshua W. Large, Max D. Petty, Kristen L. Stoltz, Bertrand Le Bourdonnec, Bryan D. Smith, Daniel L. Flynn. DP-9149, an investigational small molecule modulator of the Integrated Stress Response kinase GCN2, pre-clinically causes solid tumor growth inhibition as a single agent and regression in combination with standard of care agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1639.

Abstract 4045: DCC-3084, a RAF dimer inhibitor, broadly inhibits BRAF class I, II, III, BRAF fusions, and RAS-driven solid tumors leading to tumor regression in preclinical models

Background: Mutations in the RAS/MAPK pathway are a frequent driver of cancer, with oncogenic RAS or RAF mutations occurring in >30% of all cancers. First generation BRAF inhibitors are approved for use for tumors with Class I BRAF mutations (V600X). However, these drugs are not efficacious in RAF dimer mutant and RAS mutant cancers due to paradoxical activation of RAF dimers. Herein, we describe DCC-3084, a potent and selective investigational Switch Control inhibitor of BRAF and CRAF kinase dimers that targets Class I, II and III BRAF mutations, BRAF fusions, and BRAF/CRAF heterodimers. DCC-3084 combines with inhibitors of additional nodes in the MAPK pathway to potentially target a large unmet medical need in RAS and RAF mutant cancers.

Methods: Inhibition of RAF kinases, including off-rate analysis, was measured using recombinant enzymes. X-ray crystallography was used for structure-based drug design. Cellular proliferation was measured using resazurin to monitor cell viability. Synergy in cells was measured using BLISS scores and curve shift analysis. Inhibition of ERK or RSK phosphorylation was measured by AlphaLISA or ELISA. Pharmacokinetics (PK) in the plasma, brain and CSF compartments were measured following oral dosing in Wistar rats. RAF and RAS mutant mouse xenograft models were used to assess PK, pharmacodynamics (PD), and efficacy.

Results: DCC-3084 is a potent and selective Switch Control inhibitor of RAF dimers that was designed to target Class I, II, III BRAF mutants, BRAF fusions, and BRAF/CRAF heterodimers. DCC-3084 inhibits BRAF and CRAF, exhibiting slow off-rates (t1/2 >20 hr). Potent single-agent inhibition of MAPK pathway signaling and cellular proliferation was observed in a wide range of Class I, II, III BRAF and BRAF fusion altered cell lines. Synergy was observed in combination with inhibitors of other nodes in the RAS/MAPK pathway in RAS mutant cell lines. DCC-3084 was demonstrated to be CNS penetrable and exhibited dose dependent oral exposure with robust inhibition of the RAS/MAPK pathway in PK/PD models. DCC-3084 accumulated in tumor tissue relative to plasma, further demonstrating a favorable pharmaceutical profile. Oral treatment of DCC-3084 as a single agent resulted in tumor regression in BRAF mutant and KRAS Q61K mutant mouse xenograft models and tumor growth inhibition in KRAS G12C/D mutant models. Additionally, DCC-3084 in combination with a MEKi resulted in tumor regression in KRAS mutant models.

Conclusions: The Switch Control inhibitor DCC-3084 broadly inhibits Class I, II and III BRAF mutations, BRAF fusions, and BRAF/CRAF heterodimers leading to tumor regression in preclinical models. The overall preclinical profile of DCC-3084 supports IND-enabling activities towards clinical development in a key area of unmet medical need in RAS and RAF mutant cancers.

Citation Format: Stacie L. Bulfer, Bertrand Le Bourdonnec, Jeffery D. Zwicker, Yu Mi Ahn, Gada Al-Ani, Hikmat Al-Hashimi, Chase Crawley, Kristin M. Elliott, Saqib Faisal, Andrew M. Harned, Cale L. Heiniger, Molly M. Hood, Salim Javed, Michael Kennedy, Joshua W. Large, Cynthia B. Leary, Wei-Ping Lu, Kylie Luther, Max D. Petty, Hunter R. Picard, Justin T. Proto, Yeni K. Romero, Forrest A. Stanley, Kristen L. Stoltz, Daniel C. Tanner, Hanumaiah Telikepalli, Mary J. Timson, Lakshminarayana Vogeti, Subha Vogeti, Sihyung Yang, Lexy H. Zhong, Bryan D. Smith, Daniel L. Flynn. DCC-3084, a RAF dimer inhibitor, broadly inhibits BRAF class I, II, III, BRAF fusions, and RAS-driven solid tumors leading to tumor regression in preclinical models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4045.

Abstract 1640: DP-9024, an investigational small molecule modulator of the Integrated Stress Response kinase PERK, causes B-cell cancer growth inhibition as single agent and in combination with standard-of-care agents

Background: The Integrated Stress Response (ISR) is a major adaptive stress response pathway in cancer cell maintenance. The ISR kinase family member PERK controls one of the three arms of the Unfolded Protein Response (UPR). The UPR is considered an Achilles’ heel in B-cell cancers. Multiple myeloma (MM) and B-cell lymphomas are dependent on a well-balanced UPR pathway to cope with the high demand for protein folding and their secretory nature. Given the double-edge sword nature of the UPR, the activation of PERK and downstream pathway can have cytoprotective or cytotoxic effects. In B-cell cancers the UPR is at close to maximum cytoprotective capacity, such that further pharmacological stimulation of PERK can potentially be leveraged to cause a cancer cell cytotoxic response and induce antitumoral effects.

Methods: Modulation of ISR kinases was characterized using enzymatic assays. Kinome selectivity profiling was determined using enzymatic and cellular assays. Cellular assays of PERK activation assessed ATF4 by ELISA. Cellular assays of GCN2 modulation assessed phospho-GCN2 and ATF4 by Western blot or ELISA (under basal or low amino acid conditions). DP-9024-induced upregulation of components of the ISR/UPR pathway (ATF4, CHOP) or the apoptosis pathway (PARP and Caspase 3/7) was measured by Western blot or ELISA assays. Compound-mediated PERK activation was investigated mechanistically using a cellular nanoBRET dimerization assay. In vivo upregulation of tumoral ATF4 was determined in a MM PK/PD xenograft model. In vivo inhibition of tumor growth was determined in MM and B-cell lymphoma xenografts.

Results: DP-9024 was designed as a selective and potent modulator of PERK and GCN2. DP-9024 was found to upregulate the ISR/UPR pathway (ATF4, CHOP). The mechanism by which DP-9024 treatment induced the UPR pathway was found to be through the dimerization and activation of PERK. Upregulation of the UPR pathway downstream of PERK led to induction of apoptosis (PARP and Caspase 3/7) in MM and B-cell lymphoma lines in vitro. DP-9024 mediated activation of the UPR pathway in cell lines with high basal level of endoplasmic reticulum (ER) stress led to growth arrest in combination with FDA approved therapies. Oral dosing of DP-9024 in MM xenograft models induced ATF4, and combination efficacy was observed in MM and B-cell lymphoma xenografts in combination with FDA approved agents in vivo.

Conclusions: The ISR/UPR is a targetable vulnerability in cancers with high basal levels of ER stress. DP-9024 increases UPR signaling via activating PERK dimerization. This novel mechanism leads to antitumoral effects in B-cell cancers in vitro and in vivo likely through the induction of unresolved ER stress, which may potentially provide an alternative mechanism to current UPR targeting therapies.

Citation Format: Gada Al-Ani, Qi Groer, Aaron J. Rudeen, Kristin M. Elliott, Patrick C. Kearney, Jeffery D. Zwicker, Yu Mi Ahn, Stacie L. Bulfer, Cale L. Heiniger, Molly M. Hood, Salim Javed, Joshua W. Large, Max D. Petty, Kristen L. Stoltz, Bertrand Le Bourdonnec, Bryan D. Smith, Daniel L. Flynn. DP-9024, an investigational small molecule modulator of the Integrated Stress Response kinase PERK, causes B-cell cancer growth inhibition as single agent and in combination with standard-of-care agents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1640.

Abstract 1613: Dimerization-induced activation of the integrated stress response kinase PERK by an investigational small molecule modulator, DP-9024

Background: The Integrated Stress Response (ISR) is a major adaptive stress response pathway in cancers. The ISR kinase family member PERK controls one of the three arms of the Unfolded Protein Response (UPR). The UPR is considered an Achilles’ heel in B-cell cancers. Myelomas and B-cell lymphomas are dependent on a well-balanced UPR pathway to cope with the high demand for protein folding and their secretory nature. Given the double-edge sword nature of the UPR, the activation of PERK and downstream pathway can have cytoprotective or cytotoxic effects. In B-cell cancers the UPR is at close to maximum cytoprotective capacity, such that further pharmacological stimulation of PERK drives a cytotoxic outcome leveraged to induce antitumoral effects. Methods: Recombinant WT and mutant PERK constructs were assayed in the presence of DP-9024. Structures of compound-bound PERK were determined by X-ray crystallography. Kinome profiling was determined using enzymatic and cellular assays. Cellular modulation of the ISR/UPR pathway (phospho-GCN2, PERK, ATF4, CHOP) or the apoptosis pathway (cleaved-PARP, cleaved-Caspase 3/7) was measured by Western blot or ELISA. The level of DP-9024-induced PERK activation was determined using a cellular nanoBRET dimerization assay utilizing WT and mutant PERK constructs. Results: DP-9024 was designed as a selective and potent modulator of PERK and GCN2. DP-9024 was found to upregulate the ISR/UPR pathway (ATF4, CHOP). The mechanism by which DP-9024 induced the UPR pathway was found to be through dimerization-dependent activation of PERK. Utilizing recombinant biophysical and cellular assays of WT and mutant PERK constructs, we found that DP-9024 directly binds to a switch control site in the kinase domain of PERK that governs dimerization and that the binding of the compound to one monomer was sufficient to induce dimerization-mediated activation of the unoccupied monomer. This paradoxical stimulation of the unbound PERK monomer is reminiscent of the phenomenon observed with some BRAF inhibitors.1 X-ray crystallography studies revealed that PERK crystalizes as a dimer with both monomers bound to compound, due to the high concentration of compound used during crystallization. DP-9024-mediated PERK dimerization and transactivation led to the activation of downstream pathways (ATF4, CHOP), apoptotic pathway (Caspase 3/7, PARP1), and growth arrest in cell lines with high levels of endoplasmic reticulum (ER) stress such as multiple myeloma and B-cell lymphoma. Conclusions: Paradoxical stimulation of the ISR family member kinase PERK, through direct binding and dimerization by DP-9024, led to unresolved ER stress that can potentially be leveraged as a novel mechanism to induce growth arrest in UPR vulnerable cancers, including myelomas and B-cell lymphomas. References: 1. Poulikakos et al. 2010. Nature 464:427-30

Citation Format: Gada Al-Ani, Aaron J. Rudeen, Qi Groer, Kristin M. Elliott, Patrick C. Kearney, Jeffery D. Zwicker, Yu Mi Ahn, Stacie L. Bulfer, Cale L. Heiniger, Molly M. Hood, Salim Javid, Joshua W. Large, Max D. Petty, Kristen L. Stoltz, Bertrand Le Bourdonnec, Bryan D. Smith, Daniel L. Flynn. Dimerization-induced activation of the integrated stress response kinase PERK by an investigational small molecule modulator, DP-9024 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1613.

Effects of aromatase inhibitors and body mass index on steroid hormone levels in women with early and advanced breast cancer

BACKGROUND

Aromatase inhibitors (AIs) are central to the management of oestrogen receptor-positive breast cancer in the adjuvant and metastatic setting. Levels of circulating steroid hormones (SHs) were measured in patients established on AIs to investigate: the influence of body mass index (BMI) in both the adjuvant and metastatic setting; the class of AI utilized in the adjuvant setting (steroidal versus non-steroidal); and differences in SH levels between women treated adjuvantly and those receiving a second-line AI for locally advanced/metastatic disease.

METHODS

Plasma levels of androstenedione, 5-androstene-3β,17β-diol, dehydroepiandrosterone, oestradiol and testosterone were measured by radioimmunoassay in women with breast cancer who were receiving AIs in either an adjuvant or a metastatic setting. Differences between mean SH levels by class of AI, BMI, and second-line versus adjuvant therapy were assessed.

RESULTS

Sixty-four women were receiving AI therapy, 45 (70 per cent) in an adjuvant setting and 19 (30 per cent) were taking a second-line AI. There was no significant correlation between BMI and SH levels. However, BMI was significantly higher in the second-line AI cohort compared with the adjuvant cohort (29.8 versus 26.2 kg/m2 respectively; P = 0.026). In the adjuvant setting, patients receiving a steroidal AI had significantly higher levels of all five hormones (P < 0.050). In the second-line AI cohort, oestradiol levels were significantly higher than in the adjuvant cohort (4.5 versus 3.3 pg/ml respectively; P = 0.022). Multivariable analysis adjusted for BMI confirmed the higher residual oestradiol level in the second-line AI group (P = 0.063) and a significantly higher androstenedione level (P = 0.022).

CONCLUSION

Residual levels of SH were not significantly influenced by BMI. However, the significant differences in residual SH levels between the second-line and adjuvant AI cohort is of relevance in the context of resistance to AI therapy, and warrants further investigation.

Comparative study of analgesic efficacy and morphine-sparing effect of intramuscular dexketoprofen trometamol with ketoprofen or placebo after major orthopaedic surgery

AIMS

Multimodal analgesia is thought to produce balanced and effective postoperative pain control. A combined therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and opiates could result in synergistic analgesia by acting through different mechanisms. Currently there are very few parenterally administered NSAIDs suitable for the immediate postoperative period. Therefore, this study was undertaken to assess the analgesic efficacy, relative potency, and safety of parenteral dexketoprofen trometamol following major orthopaedic surgery.

METHODS

One hundred and seventy-two patients elected for prosthetic surgery, were randomized to receive two intramuscular injections (12 hourly) of either dexketoprofen 50 mg, ketoprofen 100 mg or placebo in a double-blind fashion. Postoperatively, the patient's pain was stabilized, then they were connected to a patient- controlled analgesia system (PCA) of morphine for 24 h (1 mg with 5 min lockout).

RESULTS

The mean cumulative amount of morphine (CAM) used was of 39 mg in the dexketoprofen group and 45 mg in the ketoprofen group vs 64 mg in the placebo group. (Reduction in morphine use was approximately one-third between the active compounds compared with placebo (adjusted mean difference of -25 mg between dexketoprofen and placebo and -23 mg between ketoprofen and placebo. These differences were statistically significant: P </= 0.0003; 95% CI -35, -14. Pain-intensity scores were consistently lower with the active compounds, the lowest corresponded to the dexketoprofen-treated patients. Regarding sedation, there were statistically significant differences between the two active compounds and placebo only at the 2nd and 13th hours. Wound bleeding was specifically measured with no statistically significant differences found between all the groups.

CONCLUSIONS

Intramuscular administration of dexketoprofen trometamol 50 mg has good analgesic efficacy both in terms of opioid-sparing effect and control of pain after major orthopaedic surgery.

Hospital patient satisfaction: correlates, dimensionality, and determinants

This paper investigates the correlates, dimensionality, and determinants of patient satisfaction in the hospital health care encounter. All of the individual hospital characteristics assessed were found to be significantly related to patient satisfaction. The findings suggest that patients evaluate hospital service quality along four distinct dimensions. The relative importance of these four factors in predicting overall satisfaction, in descending order, is: (1) physician/capabilities, (2) nurses/staff, (3) amenities, and (4) accessibility. In combination, these four factors explain 63 percent of overall patient satisfaction.

Service quality in the health care industry: how are hospitals evaluated by the general public?

This paper investigates the "expectations" aspect of service quality in the health care industry. Specifically, an examination is made of the importance of various hospital characteristics to consumers, the dimensionality of service quality, and the relative importance of these dimensions across demographic groups. The results suggest that the competency and the behavior of physicians are the most important characteristics in the minds of consumers. Moreover, it was found that hospitals are evaluated along: (1) interpersonal, (2) amenities, (3) capabilities, and (4) accessibility dimensions. These findings are consistent with previous research in this regard. Additionally, significant differences in the importance of these factors were found across respondent gender, age, income, and education.