Berzosertib Plus Topotecan vs Topotecan Alone in Patients With Relapsed Small Cell Lung Cancer: A Randomized Clinical Trial

Importance

Patients with relapsed small cell lung cancer (SCLC), a high replication stress tumor, have poor prognoses and few therapeutic options. A phase 2 study showed antitumor activity with the addition of the ataxia telangiectasia and Rad3-related kinase inhibitor berzosertib to topotecan.

Objective

To investigate whether the addition of berzosertib to topotecan improves clinical outcomes for patients with relapsed SCLC.

Design, Setting, and Participants

Between December 1, 2019, and December 31, 2022, this open-label phase 2 randomized clinical trial recruited 60 patients with SCLC and relapse after 1 or more prior therapies from 16 US cancer centers. Patients previously treated with topotecan were not eligible.

Interventions

Eligible patients were randomly assigned to receive topotecan alone (group 1), 1.25 mg/m2 intravenously on days 1 through 5, or with berzosertib (group 2), 210 mg/m2 intravenously on days 2 and 5, in 21-day cycles. Randomization was stratified by tumor sensitivity to first-line platinum-based chemotherapy.

Main Outcomes and Measures

The primary end point was progression-free survival (PFS) in the intention-to-treat population. Secondary end points included overall survival (OS) in the overall population and among patients with platinum-sensitive or platinum-resistant tumors. The PFS and OS for each treatment group were estimated using the Kaplan-Meier method. The log-rank test was used to compare PFS and OS between the 2 groups, and Cox proportional hazards models were used to estimate the treatment hazard ratios (HRs) and the corresponding 2-sided 95% CI.

Results

Of 60 patients (median [range] age, 59 [34-79] years; 33 [55%] male) included in this study, 20 were randomly assigned to receive topotecan alone and 40 to receive a combination of topotecan with berzosertib. After a median (IQR) follow-up of 21.3 (18.1-28.3) months, there was no difference in PFS between the 2 groups (median, 3.0 [95% CI, 1.2-5.1] months for group 1 vs 3.9 [95% CI, 2.8-4.6] months for group 2; HR, 0.80 [95% CI, 0.46-1.41]; P = .44). Overall survival was significantly longer with the combination therapy (5.4 [95% CI, 3.2-6.8] months vs 8.9 [95% CI, 4.8-11.4] months; HR, 0.53 [95% CI, 0.29-0.96], P = .03). Adverse event profiles were similar between the 2 groups (eg, grade 3 or 4 thrombocytopenia, 11 of 20 [55%] vs 20 of 40 [50%], and any grade nausea, 9 of 20 [45%] vs 14 of 40 [35%]).

Conclusions and Relevance

In this randomized clinical trial, treatment with berzosertib plus topotecan did not improve PFS compared with topotecan therapy alone among patients with relapsed SCLC. However, the combination treatment significantly improved OS.

Trial Registration

ClinicalTrials.gov Identifier: NCT03896503.

Targeting Replication Stress and Chemotherapy Resistance with a Combination of Sacituzumab Govitecan and Berzosertib: A Phase I Clinical Trial

PURPOSE

Despite promising preclinical studies, toxicities have precluded combinations of chemotherapy and DNA damage response (DDR) inhibitors. We hypothesized that tumor-targeted chemotherapy delivery might enable clinical translation of such combinations.

PATIENTS AND METHODS

In a phase I trial, we combined sacituzumab govitecan, antibody-drug conjugate (ADC) that delivers topoisomerase-1 inhibitor SN-38 to tumors expressing Trop-2, with ataxia telangiectasia and Rad3-related (ATR) inhibitor berzosertib. Twelve patients were enrolled across three dose levels.

RESULTS

Treatment was well tolerated, with improved safety over conventional chemotherapy-based combinations, allowing escalation to the highest dose. No dose-limiting toxicities or clinically relevant ≥grade 4 adverse events occurred. Tumor regressions were observed in 2 patients with neuroendocrine prostate cancer, and a patient with small cell lung cancer transformed from EGFR-mutant non-small cell lung cancer.

CONCLUSIONS

ADC-based delivery of cytotoxic payloads represents a new paradigm to increase efficacy of DDR inhibitors. See related commentary by Berg and Choudhury, p. 3557.

Extrachromosomal DNA Amplification Contributes to Small Cell Lung Cancer Heterogeneity and Is Associated with Worse Outcomes

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine lung cancer. Oncogenic MYC amplifications drive SCLC heterogeneity, but the genetic mechanisms of MYC amplification and phenotypic plasticity, characterized by neuroendocrine and nonneuroendocrine cell states, are not known. Here, we integrate whole-genome sequencing, long-range optical mapping, single-cell DNA sequencing, and fluorescence in situ hybridization to find extrachromosomal DNA (ecDNA) as a primary source of SCLC oncogene amplifications and driver fusions. ecDNAs bring to proximity enhancer elements and oncogenes, creating SCLC transcription-amplifying units, driving exceptionally high MYC gene dosage. We demonstrate that cell-free nucleosome profiling can noninvasively detect ecDNA amplifications in plasma, facilitating its genome-wide interrogation in SCLC and other cancers. Altogether, our work provides the first comprehensive map of SCLC ecDNA and describes a new mechanism that governs MYC-driven SCLC heterogeneity. ecDNA-enabled transcriptional flexibility may explain the significantly worse survival outcomes of SCLC harboring complex ecDNA amplifications.

SIGNIFICANCE

MYC drives SCLC progression, but the genetic basis of MYC-driven SCLC evolution is unknown. Using SCLC as a paradigm, we report how ecDNA amplifications function as MYC-amplifying units, fostering tumor plasticity and a high degree of tumor heterogeneity. This article is highlighted in the In This Issue feature, p. 799.

Detection of Putative Novel Mutation in Zp1 Gene Causing Empty Follicle Syndrome

Introduction/Objective

Mutations in the zona pellucida glycoprotein genes have been reported to be associated with empty follicle syndrome (EFS) and abnormal zona pellucida (ZP). At our clinic, in a cohort of infertile patients, we found three cases with empty follicle syndrome as a root cause of infertility. Further, we designed a study to identify the disease-causing gene mutations in these patients. At present, there are no citations or functional evidence in ClinVar for NM_207341.3:c.1168del variant indicating the involvement of this variant in empty follicle syndrome. But it has been interpreted to be Likely pathogenic causing female infertility due to zona pellucida defect.

Methods/Case Report

In this prospective study conducted at Al Ain Fertility Center (AAFC), U.A.E, we performed genetic analysis on three patients (first-degree sisters) having a mean age of 31.7 (2.52) years. Patient indications were primary female infertility and IVF failures due to no eggs present in the follicles when egg retrieval was attempted. We characterized these three patients as suffering from empty follicle syndrome. Along with the patient's sample, we also included their common parent's sample for Whole Exome Sequencing and Sanger sequencing, to rule out the inheritance pattern in the family. The effects of this mutation were further characterized through mRNA and protein studies.

Results (if a Case Study enter NA)

N/A.

Conclusion

To our knowledge, this is the first study in the U.A.E. showing the familial novel variant in the ZP1 gene associated with empty follicle syndrome. We identified a novel mutation in these patients (NM_207341.3:c.1168del) in the ZP1 gene in the homozygous state and the same variant in the heterozygous state in the parents. Our findings add to the existing mutational spectrum of the ZP1 gene associated with empty follicle syndrome and abnormal oocytes and provide new support for the genetic diagnosis of female infertility.

Clinical correlation and assessment of olfactory dysfunction with n-butanol in COVID-19 patients: our experience

Background: Studies showed olfactory disturbances in COVID patients. This has attracted focus of clinicians as an easy clinical screening tool in suspected population. Material and methods: 70 mild and moderate category COVID-19 RT-PCR positive patients, more than 10 years of age were tested on day of admission for olfaction with serial dilution of n-butanol and asked to grade severity of their olfactory dysfunction according to visual analogue score from 1-10. Results: Fatigue 42 (93.33%), sore throat 37 (82.22%), fever 36 (80%) and dyspnea 23 (51.11%) were the most common symptoms in moderate patients. Diabetes, hypertension and allergy were the three prominent risk factors. At time of admission, n-butanol diagnosed 20 patients having olfactory dysfunction compared to 11 by VAS. Patients tend to grade their dysfunction higher on VAS whereas the n-butanol test classified their olfactory dysfunction lower. Viral load and high CRP were not found to be significantly related with olfactory dysfunction. d-Dimer and LDH levels were found statistically associated with higher grading of olfactory dysfunction detected by n-butanol. Conclusion: The majority of cases developed hyposmia before they were admitted to hospital even before they realized that they were having hyposmia as revealed by n-butanol testing. We should go for objective tests of olfaction.

InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards

Increased use and improved methodology of carbonate clumped isotope thermometry has greatly enhanced our ability to interrogate a suite of Earth-system processes. However, interlaboratory discrepancies in quantifying carbonate clumped isotope (Δ47) measurements persist, and their specific sources remain unclear. To address interlaboratory differences, we first provide consensus values from the clumped isotope community for four carbonate standards relative to heated and equilibrated gases with 1,819 individual analyses from 10 laboratories. Then we analyzed the four carbonate standards along with three additional standards, spanning a broad range of δ47 and Δ47 values, for a total of 5,329 analyses on 25 individual mass spectrometers from 22 different laboratories. Treating three of the materials as known standards and the other four as unknowns, we find that the use of carbonate reference materials is a robust method for standardization that yields interlaboratory discrepancies entirely consistent with intralaboratory analytical uncertainties. Carbonate reference materials, along with measurement and data processing practices described herein, provide the carbonate clumped isotope community with a robust approach to achieve interlaboratory agreement as we continue to use and improve this powerful geochemical tool. We propose that carbonate clumped isotope data normalized to the carbonate reference materials described in this publication should be reported as Δ47 (I-CDES) values for Intercarb-Carbon Dioxide Equilibrium Scale.

DFT and MD simulation supplemented experiments for isotopic fractionation of zinc compounds using a macrocyclic crown ether appended polymeric resin

Isotope effect is a quantum mechanical phenomenon and thus poses a challenge for the separation of isotopes of an element of interest, especially for heavy elements. Isotopic fractionation of zinc is also quite difficult and challenging but is necessitated due to various applications of its isotopes ranging from nuclear medicine to nuclear power reactors. Here, we developed the dibenzo-18-crown-6 (DB18C6) ether-functionalized poly(methacrylic acid) (PMA) resin by exploiting the ion and isotope recognition ability of the crown ether using DFT/MD simulations followed by experiments for isotopic fractionation of zinc. The PMADB18C6 adsorbent was prepared and suitably characterized. Both computational and experimental findings demonstrate that the adsorption and isotope separation of zinc with PMADB18C6 are due to the molecular recognition effect of the "O" dipole of the crown ether. Furthermore, both MD simulations and experiments suggest Langmuir type adsorption isotherms. The adsorption of Zn2+ ions on the PMA resin is predicted to be endothermic, whereas it is exothermic on the PMADB18C6 resin, as revealed from the experimentally observed enthalpy change. A small scale fixed bed column study was demonstrated to test the scale-up application. The values of the experimental separation factors: 1.0013 for 66/64 and 1.0027 for 68/64 confirm the computationally predicted results of 1.00088 and 1.0010, respectively, thus establishing the combined strength of the theory and experiments for the identification of efficient fractionating agents for a complex quantum isotope effect which eventually helps in planning further experiments in view of medicinal and technological applications of zinc isotopes.

Factors affecting survivability of local Rohilkhand goats under organized farm

AIM

To study the pattern of mortality as affected by age, season and various diseases in local goats of Rohilkhand region maintained at the Indian Veterinary Research Institute, Bareilly.

MATERIALS AND METHODS

Post-mortem records of 12 years (2000-01 to 2011-12) were used, and total 243 mortality data were collected and analyzed. The causes of mortality were classified into seven major classes viz. digestive disorders, respiratory disorders, cardiovascular disorders, musculoskeletal disorder, parasitic disorders, mixed disorders (combination of digestive, respiratory, parasitic, and cardiovascular disorders) and miscellaneous disorders (cold, hypoglycemia, emaciation, endometritis, traumatic injury, etc.).

RESULTS

The average mortality was 10.93%. The overall mortality was more during rainy season followed by winter and summer season. The mortality in 4-6 months of age was high (2.52%) followed by 0-1 month (2.34%) and 2-3 months (1.35%). The average mortality among adult age groups (>12 months) was 3.42%. The mortality showed declining trend with the advancement of age up to 3 months and then again increased in 4-6 months age group. The digestive diseases (3.51%) followed by respiratory diseases (1.89%) and parasitic diseases (1.48%) contributed major share to the total mortality occurred and the remaining disorders were of lesser significance in causing death in goats. There is significant (p<0.01; χ(2)=55.62) association between year with season and age with the season (p<0.05, χ(2)=16.083) found in the present study.

CONCLUSION

This study confirms that overall mortality rate averaged 10.93% (ranged between 1.10% and 25.56%) over 12 years under semi-intensive farm condition. It was generally higher in rainy season. The mortality remains higher in kids particularly under 1 month of age. The digestive diseases contributed major share to overall mortality.

Air pollution induces enhanced mitochondrial oxidative stress in cystic fibrosis airway epithelium

We studied the effects of airborne particulate matters (PM) on cystic fibrosis (CF) epithelium. We noted that PM enhanced human CF bronchial epithelial apoptosis, activated caspase-9 and PARP-1; and reduced mitochondrial membrane potential. Mitochondrial inhibitors (4,4-diisothiocyanatostilbene-2,2'disulfonic acid, rotenone and thenoyltrifluoroacetone) blocked PM-induced generation of reactive oxygen species and apoptosis. PM upregulated pro-apoptotic Bad, Bax, p53 and p21; and enhanced mitochondrial localization of Bax. The anti-apoptotic Bcl-2, Bcl-xl, Mcl-1 and Xiap remained unchanged; however, overexpression of Bcl-xl blocked PM-induced apoptosis. Accordingly, we provide the evidence that PM enhances oxidative stress and mitochondrial signaling mediated apoptosis via the modulation of Bcl family proteins in CF.

Bim mediates mitochondria-regulated particulate matter-induced apoptosis in alveolar epithelial cells

We studied the role of Bim, a pro-apoptotic BCL-2 family member in Airborne particulate matter (PM 2.5 microm)-induced apoptosis in alveolar epithelial cells (AEC). PM induced AEC apoptosis by causing significant reduction of mitochondrial membrane potential and increase in caspase-9, caspase-3 and PARP-1 activation. PM upregulated pro-apoptotic protein Bim and enhanced translocation of Bim to the mitochondria. ShRNABim blocked PM-induced apoptosis by preventing activation of the mitochondrial death pathway suggesting a role of Bim in the regulation of mitochondrial pathway in AEC. Accordingly, we provide the evidence that Bim mediates PM-induced apoptosis via mitochondrial pathway.

Fibroblast growth factor-10 prevents H2O2-induced cell cycle arrest by regulation of G1 cyclins and cyclin dependent kinases

We studied the effects of fibroblast growth factor (FGF-10) on H2O2-induced alveolar epithelial cell (AEC) G1 arrest and the role of G1 cyclins. FGF-10 prevented H2O2-induced AEC G1 arrest. FGF-10 induced 2-4-fold increase in cyclin E, cyclin A and CDKs (2,4) alone and in AEC treated with H2O2. H2O2 downregulated cyclin D1; FGF-10 blocked these effects. FGF-10 prevented H2O2-induced upregulation of CDK inhibitor, p21. SiRNAp21 blocked H2O2-induced downregulation of cyclins, CDKs and AEC G1 arrest. Accordingly, we provide first evidence that FGF-10 regulates G1 cyclins and CDKs, and prevents H2O2-induced AEC G1 arrest.

Fibroblast growth factor-10 upregulates Na,K-ATPase via the MAPK pathway

We studied the effects of fibroblast growth factor (FGF-10) on alveolar epithelial cell (AEC) Na,K-ATPase regulation. Within 30 min FGF-10 increased Na,K-ATPase activity and alpha1 protein abundance by 2.5-fold at the AEC plasma membrane. Pretreatment of AEC with the mitogen-activated protein kinase (MAPK) inhibitor U0126, a Grb2-SOS inhibitor (SH3-b-p peptide), or a Ras inhibitor (farnesyl transferase inhibitor (FTI 277)), as well as N17-AEC that express a Ras dominant negative protein each prevented FGF-10-mediated Na,K-ATPase recruitment to the AEC plasma membrane. Accordingly, we provide first evidence that FGF-10 upregulates (short-term) the Na,K-ATPase activity in AEC via the Grb2-SOS/Ras/MAPK pathway.