Citations

How the KRAS oncogene drives cancer growth remains poorly understood. Therefore, we established a systemwide portrait of KRAS- and extracellular signal–regulated kinase (ERK)–dependent gene transcription in KRAS-mutant cancer to delineate the molecular mechanisms of growth and of inhibitor resistance. Unexpectedly, our KRAS-dependent gene signature diverges substantially from the frequently cited Hallmark KRAS signaling gene signature, is driven predominantly through the ERK mitogen-activated protein kinase (MAPK) cascade, and accurately reflects KRAS- and ERK-regulated gene transcription in KRAS-mutant cancer patients. Integration with our ERK-regulated phospho- and total proteome highlights ERK deregulation of the anaphase promoting complex/cyclosome (APC/C) and other components of the cell cycle machinery as key processes that drive pancreatic ductal adenocarcinoma (PDAC) growth. Our findings elucidate mechanistically the critical role of ERK in driving KRAS-mutant tumor growth and in resistance to KRAS-ERK MAPK targeted therapies.

e13156 Background: Breast Cancer (BC) patients are classified as HER2-positive (IHC3+ or IHC2+/ISH+) or HER2-negative (IHC0, IHC1+ and 2+/ISH-). Within the HER2-negative category, patients who meet HER2-low (IHC1+ or IHC2+/ISH-) criteria can benefit from HER2 targeted therapy like trastuzumab deruxtecan. Patients who meet IHC0 criteria with incomplete and faint membrane staining in >0 but ≤10% of tumor cells — defined as “HER2 Ultra-low”, may also benefit from HER2 targeted therapy. This study aimed to assess the prevalence of “HER2 Ultra-Low” expression based on re-scored HER2 IHC biopsy slides. Methods: This study utilized EHR data from all three US Mayo Clinic campuses. A total of 300 patients with advanced BC (stages III-IV), and clinically documented HER2 IHC0 status between Jan 2017 and Jan 2023, were identified. One biopsy slide per patient (IHC assay: VENTANA Pathway anti-HER2/neu (4B5) rabbit monoclonal primary antibody) was digitized and scanned at 40x magnification. Two Mayo Clinic pathologists independently scored and reported HER2 status according to 2023 ASCO-CAP guidelines and included tumor stain percentage for each slide. Patients were considered “HER2 Ultra-Low” if their slide was scored as IHC0 with >0% but ≤10% staining. Cohen’s κ was used to quantify agreement between pathologists. Results: The re-scored patients (n=300) had a mean age of 57.8 years (SD=13.5), with ~97% having IHC0 documentation within 30 days of the reviewed biopsy slide. A total of 285 (95%) patients remained classified as IHC0 by at least one pathologist. Of these, 60% (n=171) were determined as “HER2 Ultra-low” by at least one pathologist. The rate of “HER2 Ultra-Low” per pathologist ranged from 43% (n=121) to 45% (n=104). The overall inter-pathologist concordance was 57%; patients with no observable HER2 IHC staining accounted for majority of the concordant patients (Table). Conclusions: About 3 in 5 advanced BC patients originally classified as HER2 IHC0 met the “HER2 Ultra-Low” criteria by at least one pathologist, implying that significant number of additional patients may benefit from HER2 targeted therapy. The relatively low concordance between HER2 expert pathologists in identifying lower levels of HER2 expression suggests the need for increased precision enabled by digital tools, leveraging AI, training for community practice pathologists, and continuing to follow best practice recommendations in determining HER2 IHC status. [Table: see text]

PURPOSE We investigated time to pregnancy, efficacy and safety of fertility preservation, and assisted reproductive technologies (ARTs) in women with early hormone receptor–positive breast cancer (BC) desiring future pregnancy. PATIENTS AND METHODS POSITIVE is an international, single-arm, prospective trial, in which 518 women temporarily interrupted adjuvant endocrine therapy to attempt pregnancy. We evaluated menstruation recovery and factors associated with time to pregnancy and investigated if ART use was associated with achieving pregnancy. The cumulative incidence of BC-free interval (BCFI) events was estimated according to the use of ovarian stimulation at diagnosis. The median follow-up was 41 months. RESULTS Two hundred seventy-three patients (53%) reported amenorrhea at enrollment, of whom 94% resumed menses within 12 months. Among 497 patients evaluable for pregnancy, 368 (74%) reported at least one pregnancy. Young age was the main factor associated with shorter time to pregnancy with cumulative incidences of pregnancy by 1 year of 63.5%, 54.3%, and 37.7% for patients age <35, 35-39, and 40-42 years, respectively. One hundred and seventy-nine patients (36%) had embryo/oocyte cryopreservation at diagnosis, of whom 68 reported embryo transfer after enrollment. Cryopreserved embryo transfer was the only ART associated with higher chance of pregnancy (odds ratio, 2.41 [95% CI, 1.75 to 4.95]). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis, 9.7% (95% CI, 6.0 to 15.4), compared with those who did not, 8.7% (95% CI, 6.0 to 12.5). CONCLUSION In POSITIVE, fertility preservation using ovarian stimulation was not associated with short-term detrimental impact on cancer prognosis. Pregnancy rates were highest among those who underwent embryo/oocyte cryopreservation followed by embryo transfer.

PURPOSE To report the results of OPAL (ClinicalTrials.gov identifier: NCT03574779 ) cohort A, a single-arm substudy of niraparib plus dostarlimab and bevacizumab for the treatment of advanced, platinum-resistant ovarian cancer (PROC). METHODS Participants with PROC who received 1-2 previous lines of therapy were treated with niraparib (200 or 300 mg once daily), dostarlimab (500 mg once every 3 weeks for four 21-day cycles, followed by 1,000 mg once every 6 weeks), and bevacizumab (15 mg/kg once every 3 weeks). The primary end point was investigator-assessed objective response rate (ORR) per RECIST v1.1. Safety was also assessed. Exploratory biomarker end points included evaluation of changes in the tumor molecular profile and microenvironment using baseline and on-treatment tumor samples. RESULTS Of 41 enrolled participants (median age, 66.0 years [range, 37-83 years]), 9.8% had tumors that were BRCA-mutated, 19.5% were homologous recombination (HR)–deficient, and 17.1% were HR repair (HRR)–mutated. As of the cutoff date, all participants discontinued treatment. The ORR was 17.1% (80% CI, 9.8 to 27.0), including one complete response (2.4%); the disease control rate was 73.2% (80% CI, 62.3 to 82.2). Two participants withdrew before first postbaseline scan because of adverse events (AEs). Grade ≥3 treatment-emergent AEs were reported in 92.7% of participants, with the most common being hypertension (26.8%). Response was not correlated with BRCA, HRR, HR deficiency (HRD), or PD-L1 status. Changes suggesting immune activation were observed in on-treatment samples after triplet therapy. CONCLUSION Results demonstrated modest activity of niraparib, dostarlimab, and bevacizumab in participants with PROC, many of whom had prognostic factors for poor treatment response. Most participants with response were bevacizumab-naïve. No association was found with HRD, BRCA, or PD-L1 status. AEs were consistent with previous monotherapy reports, except that hypertension was reported more frequently.

ABSTRACT Phage therapy has not been established in the clinical routine, in part due to uncertainties concerning efficacy and immunogenicity. Here, three rabbits were immunized against staphylococcal phage K to assess viral potency in the presence of immunized serum. Three rabbits received weekly intramuscular injections of ~10 10±1 pfu/mL phage K. Phage K-specific IgG formation was measured by an enzyme-linked immunosorbent assay (ELISA); phage inactivation was assessed by calculating K-rates. Using transmission electron microscopy (TEM) and immunogold labeling, antibody binding to phage K was visualized. This was numerically assessed by objective imaging analysis comparing the relative distances of each gold particle to the nearest phage head and tail structure. Immunization led to a strong IgG response, plateauing 7 days after the last phage injection. There was no significant correlation between K-rate and antibody titer over time. TEM showed IgG binding to the head structure of phage K. Image analysis showed a significant reduction in relative distances between antibodies and phage head structures when comparing samples from day 0 and day 28 ( P < 0.0001). These results suggest that while individual serum analysis for antibodies against therapeutic phage bears consideration prior to and with prolonged therapy, during phage application, the formation of specific antibodies against phage may only partially explain decreased phage potency in the presence of immunized serum. Instead, other factors may contribute to an individual’s “humoral receptiveness” to phage therapy. Future investigations should be directed toward the identification of the humoral factors that have the most significant predictive value on phage potency in vivo .

Abstract Background: The POSITIVE trial recently demonstrated that temporary interruption of ET to attempt pregnancy does not increase the short-term risk of recurrence in pts with hormone receptor-positive (HR+) BC. Yet, uncertainty exists regarding the safety of ovarian stimulation for embryo/oocyte cryopreservation to preserve fertility in these pts. In addition, very limited data exist regarding safety and efficiency of ART to achieve pregnancy after ET interruption. Methods: POSITIVE is an international, single-arm, prospective trial that enrolled pts ≤ 42 years with stage I-III HR+ BC who had already received 18-30 months of ET prior to enrollment. The use of ART was a predefined 2ry endpoint. We evaluated factors associated with time to pregnancy in a Fine and Gray competing risks model, which included chemotherapy (chemo) ± GnRH analogue (GnRHa), age, prior ET, prior birth, and menstrual status at enrollment. The cumulative incidence of pregnancy at 12 months from enrollment by age was estimated controlling for competing risks. We performed a logistic regression model to evaluate whether ART use was associated with achieving pregnancy, adjusting for age, receipt of chemo ± GnRHa. The cumulative incidence of BCFI events was estimated according to whether or not ovarian stimulation for cryopreservation was performed at diagnosis and prior to enrollment. BC-free interval (BCFI) was defined as the time from enrollment until the first BC event (invasive local, regional, or distant recurrence or contralateral disease). A 24-month landmark analysis was performed to investigate the safety of ART use after enrollment. Median follow-up was 41 months. Results: 497 out of 516 included pts (96%) were followed for at least 6 months and were evaluable for pregnancy status. 368 out of 497 evaluable pts (74%) reported at least one pregnancy. In a multivariable model, young age was the only factor associated with shorter time to pregnancy. The cumulative incidence of pregnancy at 12 months was 64%, 54% and 38% for pts aged &lt; 35, 35-39 and 40-42 years, respectively. 179 pts (36.0%) had undergone ovarian stimulation for embryo/oocyte cryopreservation at diagnosis and prior to enrollment, of whom 68 (37.9%) reported cryopreserved embryo transfer after enrollment. 215 pts (43.3%) reported using any ART after enrollment, of whom 80 (37.2%) underwent ovarian stimulation for in-vitro fertilization (FIVET) or intracytoplasmic sperm injection (ICSI). Other ART used included clomiphene (n=19), intrauterine insemination (n=37) and egg donation (n=17). Pregnancy rates were 82.4% and 67.5% for women who underwent cryopreserved embryo transfer and FIVET/ICSI, respectively. In a multivariate model, cryopreserved embryo transfer was the only ART independently associated with a higher chance of pregnancy (OR:2.41, 95% CI: 1.75-4.95). The cumulative incidence of BCFI events at 3 years was similar for women who underwent ovarian stimulation for cryopreservation at diagnosis and before enrollment, 9.7% (95% CI: 6.0-15.4%), and those who did not, 8.7% (95% CI: 6.0-12.5%). A 24-month landmark analysis showed no impact of ovarian stimulation for FIVET/ICSI after enrollment on BCFI. Conclusions: This is the largest prospective study to investigate fertility preservation and ART in pts with HR+ BC. Young age was the main factor associated with shorter time to pregnancy. Embryo/oocyte cryopreservation at BC diagnosis followed by embryo transfer after ET interruption was the only approach associated with an increased chance of pregnancy. Ovarian stimulation either at BC diagnosis for embryo/oocyte cryopreservation or after enrollment to POSITIVE for FIVET/ICSI did not appear to impact prognosis in the short term. These data are of paramount importance for oncofertility counselling of young BC pts. Citation Format: Hatem Azim, Samuel Niman, Ann Partridge, Isabelle Demeestere, Monica Ruggeri, Marco Colleoni, Cristina Saura, Chikako Shimizu, Anna Saetersdal, Judith Kroep, Audrey Mailliez, Ellen Warner, Virginia Borges, Frédéric Amant, Andrea Gombos, Akemi Kataoka, Christine Rousset-Jablonski, Simona Borstnar, Junko Takei, Jeong Eon Lee, Janice Walshe, Manuel Ruíz - Borrego, Halle Moore, Christobel Saunders, Vesna Bjelic-Radisic, Snezana Susnjar, Fatima Cardoso, Natalie Klar, Tanya Spanic, Kathryn Ruddy, Martine Piccart, Larissa Korde, Aron Goldhirsch, Richard Gelber, Olivia Pagani, Fedro Alessandro Peccatori. Fertility preservation and assisted reproductive technologies (ART) in breast cancer (BC) patients (pts) interrupting endocrine therapy (ET) to attempt pregnancy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS02-11.

Importance Effects of antiamyloid agents, targeting either fibrillar or soluble monomeric amyloid peptides, on downstream biomarkers in cerebrospinal fluid (CSF) and plasma are largely unknown in dominantly inherited Alzheimer disease (DIAD). Objective To investigate longitudinal biomarker changes of synaptic dysfunction, neuroinflammation, and neurodegeneration in individuals with DIAD who are receiving antiamyloid treatment. Design, Setting, and Participants From 2012 to 2019, the Dominantly Inherited Alzheimer Network Trial Unit (DIAN-TU-001) study, a double-blind, placebo-controlled, randomized clinical trial, investigated gantenerumab and solanezumab in DIAD. Carriers of gene variants were assigned 3:1 to either drug or placebo. The present analysis was conducted from April to June 2023. DIAN-TU-001 spans 25 study sites in 7 countries. Biofluids and neuroimaging from carriers of DIAD gene variants in the gantenerumab, solanezumab, and placebo groups were analyzed. Interventions In 2016, initial dosing of gantenerumab, 225 mg (subcutaneously every 4 weeks) was increased every 8 weeks up to 1200 mg. In 2017, initial dosing of solanezumab, 400 mg (intravenously every 4 weeks) was increased up to 1600 mg every 4 weeks. Main Outcomes and Measures Longitudinal changes in CSF levels of neurogranin, soluble triggering receptor expressed on myeloid cells 2 (sTREM2), chitinase 3–like 1 protein (YKL-40), glial fibrillary acidic protein (GFAP), neurofilament light protein (NfL), and plasma levels of GFAP and NfL. Results Of 236 eligible participants screened, 43 were excluded. A total of 142 participants (mean [SD] age, 44 [10] years; 72 female [51%]) were included in the study (gantenerumab, 52 [37%]; solanezumab, 50 [35%]; placebo, 40 [28%]). Relative to placebo, gantenerumab significantly reduced CSF neurogranin level at year 4 (mean [SD] β = −242.43 [48.04] pg/mL; P &amp;lt; .001); reduced plasma GFAP level at year 1 (mean [SD] β = −0.02 [0.01] ng/mL; P = .02), year 2 (mean [SD] β = −0.03 [0.01] ng/mL; P = .002), and year 4 (mean [SD] β = −0.06 [0.02] ng/mL; P &amp;lt; .001); and increased CSF sTREM2 level at year 2 (mean [SD] β = 1.12 [0.43] ng/mL; P = .01) and year 4 (mean [SD] β = 1.06 [0.52] ng/mL; P = .04). Solanezumab significantly increased CSF NfL (log) at year 4 (mean [SD] β = 0.14 [0.06]; P = .02). Correlation analysis for rates of change found stronger correlations between CSF markers and fluid markers with Pittsburgh compound B positron emission tomography for solanezumab and placebo. Conclusions and Relevance This randomized clinical trial supports the importance of fibrillar amyloid reduction in multiple AD-related processes of neuroinflammation and neurodegeneration in CSF and plasma in DIAD. Additional studies of antiaggregated amyloid therapies in sporadic AD and DIAD are needed to determine the utility of nonamyloid biomarkers in determining disease modification. Trial Registration ClinicalTrials.gov Identifier: NCT04623242

AbstractINTRODUCTIONAmyloid beta and tau pathology are the hallmarks of sporadic Alzheimer's disease (AD) and autosomal dominant AD (ADAD). However, Lewy body pathology (LBP) is found in ≈ 50% of AD and ADAD brains.METHODSUsing an α‐synuclein seed amplification assay (SAA) in cerebrospinal fluid (CSF) from asymptomatic (n = 26) and symptomatic (n = 27) ADAD mutation carriers, including 12 with known neuropathology, we investigated the timing of occurrence and prevalence of SAA positive reactivity in ADAD in vivo.RESULTSNo asymptomatic participant and only 11% (3/27) of the symptomatic patients tested SAA positive. Neuropathology revealed LBP in 10/12 cases, primarily affecting the amygdala or the olfactory areas. In the latter group, only the individual with diffuse LBP reaching the neocortex showed α‐synuclein seeding activity in CSF in vivo.DISCUSSIONResults suggest that in ADAD LBP occurs later than AD pathology and often as amygdala‐ or olfactory‐predominant LBP, for which CSF α‐synuclein SAA has low sensitivity.Highlights Cerebrospinal fluid (CSF) real‐time quaking‐induced conversion (RT‐QuIC) detects misfolded α‐synuclein in ≈ 10% of symptomatic autosomal dominant Alzheimer's disease (ADAD) patients. CSF RT‐QuIC does not detect α‐synuclein seeding activity in asymptomatic mutation carriers. Lewy body pathology (LBP) in ADAD mainly occurs as olfactory only or amygdala‐predominant variants. LBP develops late in the disease course in ADAD. CSF α‐synuclein RT‐QuIC has low sensitivity for focal, low‐burden LBP.