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Posts Tagged ‘checkpoint inhibitors’


Durable responses with checkpoint inhibitor

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Immunotherapy Active in ‘Universally Lethal’ Glioblastoma

ACTIVATE CME    by Kristin Jenkins 

  • Contributing Writer, MedPage Today

http://www.medpagetoday.com/HematologyOncology/BrainCancer/57641

 

Two pediatric siblings with recurrent multifocal glioblastoma multiforme (GBM) refractory to current standard therapies exhibited “remarkable and durable” responses to immune checkpoint inhibition with single-agent nivolumab (Opdivo), researchers said.

Following pre-clinical testing in 37 biallelic mismatch repair deficiency (bMMRD) cancers, a regimen of 3 mg/kg nivolumab every 2 weeks resulted in clinically significant responses and a profound radiologic response, Uri Tabori, MD, of The Hospital for Sick Children, Toronto, Ontario, Canada, and colleagues reported in the Journal of Clinical Oncology.

The 6-year-old white female patient and her 3.5-year-old brother resumed normal schooling and daily activities after 9 and 5 months of therapy, respectively, the researchers said.

“This observation is especially encouraging because these children are still clinically stable, whereas most relapsed pediatric GBMs will progress within 1 to 2 months despite salvage treatment, and survival is usually 3 to 6 months post-recurrence. It also highlights the utility of germline predisposition in guiding novel treatment options — in this case, immunotherapy — for cancer treatment.”

Findings from this lab study and small case series report may have implications for GBM as well as for other hypermutant cancers arising from primary (genetic predisposition) or secondary MMRD, the researchers said. “Given the increasing availability of commercial sequencing platforms, analysis of mutation burden and neoantigens can play a role in transforming treatment of these patients.”

Still, they added that these results, while encouraging, need to be validated in multinational prospective clinical trials of these “universally lethal” bMMRD-driven hypermutant cancers.

“Sometimes very small studies can yield meaningful results,” Robert Fenstermaker, MD, of Roswell Park Cancer Institute in Buffalo, N.Y., told MedPage Today via email. “Although anecdotal, the results of this study are quite encouraging because they tend to confirm current theory about immunotherapy for glioblastoma.”

Although these kinds of clinical responses to single-agent drug therapy in GBM are uncommon and the results may not be broadly applicable to all glioblastoma patients, this paper “is of much greater importance than just these few cases,” Fenstermaker emphasized. “The excellent responses in these particular cases suggest that an immune checkpoint inhibitor (nivolumab) may have enabled the immune system to respond fully.”

This “very small case series” report of a “compelling clinical experience” is a “fascinating and beautiful example of how mechanistic insight can be linked to rationally designed clinical applications — in turn, stimulating new downstream ideas,” Stephanie Weiss, MD, a radiation oncologist at Fox Chase Cancer Center in Philadelphia, commented in an email.

“This series also tests ‘proof of principle,’ that bMMRD tumors are hypermutated and associated with a high neoantigen load, and therefore may respond much like other immune checkpoint inhibitor-sensitive tumors. In this sense, the results reveal a tantalizing glimpse into the disease process of at least a subset of GBMs and can guide high-quality study of novel treatment for GBM.”

For the study, Tabori and colleagues performed exome sequencing and neoantigen prediction on 37 bMMRD-associated tumors, including 21 GBMs, and compared them with childhood and adult brain neoplasms.

The bMMRD GBMs were found to be hypermutant and to have an extremely strong neoantigen load — up to 16 times higher than the signature commonly seen in known immune checkpoint inhibitors (P<.001).

The female patient, diagnosed with a left parietal GBM, underwent near-total resection and focal irradiation over 6.5 weeks. After a clinical remission lasting 3 months, surveillance MRI revealed recurrence in the initial tumor bed and a second lesion in the left temporal lobe.

Six months earlier, the index patient’s brother had been diagnosed with a right frontoparietal GBM and treated with surgery, focal irradiation, and temozolomide (Temodal). Ten months after diagnosis, surveillance MRI revealed an asymptomatic diffuse multinodular GBM recurrence.

When given nivolumab as a last-resort therapeutic agent, both children initially experienced serious symptoms that on imaging mimicked tutor progression. After symptomatic management and observation, both stabilized, and follow-up imaging demonstrated significant improvement in tumor-related abnormalities.

Fenstermaker said that important next steps lie ahead, such as combining immune checkpoint inhibitors with specific cancer vaccines designed to immunize patients with glioblastomas other than this rare hypermutated type. “There are a number of prospective vaccines currently in the glioblastoma drug pipeline that would be candidates for this kind of approach,” he told MedPage Today. Examples include SurVaxM, NeoVax, HSPPC-96, and various dendritic cell vaccines.

In addition, newer genomic techniques are being developed that could make it possible to create a personalized profile of the mutant proteins in a given patient’s tumor, he noted. “One can imagine combining such a personalized vaccine against these mutant proteins together with an immune checkpoint inhibitor. Such a combination might result in many more responses like the ones seen in this small study.”

 

PD-1 Blockade in Tumors with Mismatch-Repair Deficiency

Dung T. Le, Jennifer N. Uram, Hao Wang, Bjarne R. Bartlett, Holly Kemberling, Aleksandra D. Eyring, et al.
http://www.nejm.org/doi/full/10.1056/NEJMoa1500596

BACKGROUND

Somatic mutations have the potential to encode “non-self” immunogenic antigens. We hypothesized that tumors with a large number of somatic mutations due to mismatch-repair defects may be susceptible to immune checkpoint blockade.

METHODS

We conducted a phase 2 study to evaluate the clinical activity of pembrolizumab, an anti–programmed death 1 immune checkpoint inhibitor, in 41 patients with progressive metastatic carcinoma with or without mismatch-repair deficiency. Pembrolizumab was administered intravenously at a dose of 10 mg per kilogram of body weight every 14 days in patients with mismatch repair–deficient colorectal cancers, patients with mismatch repair–proficient colorectal cancers, and patients with mismatch repair–deficient cancers that were not colorectal. The coprimary end points were the immune-related objective response rate and the 20-week immune-related progression-free survival rate.

RESULTS

The immune-related objective response rate and immune-related progression-free survival rate were 40% (4 of 10 patients) and 78% (7 of 9 patients), respectively, for mismatch repair–deficient colorectal cancers and 0% (0 of 18 patients) and 11% (2 of 18 patients) for mismatch repair–proficient colorectal cancers. The median progression-free survival and overall survival were not reached in the cohort with mismatch repair–deficient colorectal cancer but were 2.2 and 5.0 months, respectively, in the cohort with mismatch repair–proficient colorectal cancer (hazard ratio for disease progression or death, 0.10 [P<0.001], and hazard ratio for death, 0.22 [P=0.05]). Patients with mismatch repair–deficient noncolorectal cancer had responses similar to those of patients with mismatch repair–deficient colorectal cancer (immune-related objective response rate, 71% [5 of 7 patients]; immune-related progression-free survival rate, 67% [4 of 6 patients]). Whole-exome sequencing revealed a mean of 1782 somatic mutations per tumor in mismatch repair–deficient tumors, as compared with 73 in mismatch repair–proficient tumors (P=0.007), and high somatic mutation loads were associated with prolonged progression-free survival (P=0.02).

CONCLUSIONS

This study showed that mismatch-repair status predicted clinical benefit of immune checkpoint blockade with pembrolizumab. (Funded by Johns Hopkins University and others; ClinicalTrials.gov number, NCT01876511.)

Eric BouffetValérie LaroucheBrittany B. CampbellDaniele MericoRichard de Borja, et al.

Purpose Recurrent glioblastoma multiforme (GBM) is incurable with current therapies. Biallelic mismatch repair deficiency (bMMRD) is a highly penetrant childhood cancer syndrome often resulting in GBM characterized by a high mutational burden. Evidence suggests that high mutation and neoantigen loads are associated with response to immune checkpoint inhibition.

Patients and Methods We performed exome sequencing and neoantigen prediction on 37 bMMRD cancers and compared them with childhood and adult brain neoplasms. Neoantigen prediction bMMRD GBM was compared with responsive adult cancers from multiple tissues. Two siblings with recurrent multifocal bMMRD GBM were treated with the immune checkpoint inhibitor nivolumab.

Results All malignant tumors (n = 32) were hypermutant. Although bMMRD brain tumors had the highest mutational load because of secondary polymerase mutations (mean, 17,740 ± standard deviation, 7,703), all other high-grade tumors were hypermutant (mean, 1,589 ± standard deviation, 1,043), similar to other cancers that responded favorably to immune checkpoint inhibitors. bMMRD GBM had a significantly higher mutational load than sporadic pediatric and adult gliomas and all other brain tumors (P < .001). bMMRD GBM harbored mean neoantigen loads seven to 16 times higher than those in immunoresponsive melanomas, lung cancers, or microsatellite-unstable GI cancers (P < .001). On the basis of these preclinical data, we treated two bMMRD siblings with recurrent multifocal GBM with the anti–programmed death-1 inhibitor nivolumab, which resulted in clinically significant responses and a profound radiologic response.

Conclusion This report of initial and durable responses of recurrent GBM to immune checkpoint inhibition may have implications for GBM in general and other hypermutant cancers arising from primary (genetic predisposition) or secondary MMRD.

Glioblastoma multiforme (GBM) is a highly malignant brain tumor and the most common cause of death among children with CNS neoplasms.1 Despite primary management, which consists of surgical resection followed by radiation therapy and chemotherapy, most GBMs will recur, resulting in rapid death. Patients with recurrent disease have a particularly poor prognosis, with a median survival of fewer than 6 months; no effective therapies currently exist.

In contrast to adult CNS malignancies, a significant proportion of childhood brain tumors occur in the context of cancer predisposition syndromes.2 Pediatric GBMs are associated with germline mutations in TP53 (Li-Fraumeni syndrome)1 and the mismatch repair (MMR) genes (biallelic MMR deficiency syndrome [bMMRD]).3 Patients with bMMRD are unique in both the molecular events that lead to GBM formation and opportunities for innovative management of these tumors to possibly improve survival.

bMMRD is caused by homozygous germline mutations in one of the four MMR genes (PMS2, MLH1, MSH2, and MSH6) and is arguably the most penetrant cancer predisposition syndrome, with 100% of biallelic mutation carriers developing cancers in the first two decades of life. These are most commonly malignant gliomas, hematologic malignancies, and GI cancers.3,4 Understanding the relationship between the bMMRD somatic mutational landscape and tumor biology can lead to development of novel therapies and improved patient outcomes.

bMMRD GBMs harbor the highest mutation load among human cancers.5 Combined germline mutations in the MMR genes and somatic mutations in DNA polymerase result in complete ablation of proofreading during DNA replication and underpin this phenomenon. bMMRD GBMs, in contrast to other childhood cancers and adult MMR-proficient gliomas, exhibit a molecular signature characterized by single-nucleotide changes present in exponentially higher numbers. An important characteristic of non-bMMRD cancers exhibiting high mutation loads—subsets of malignant melanomas and lung, bladder, and microsatellite-unstable GI cancers—is responsiveness to immune checkpoint inhibitors.69

Checkpoint inhibitors target the immunomodulatory effect of CTLA-4 (cytotoxic T lymphocyte–associated protein 4) and programmed death-1 (PD-1)/programmed death-ligand 1, restoring effector T-cell function and antitumor activity. Recent reports have shown that patients whose tumors bear a high mutation load and/or definedtumor-associated antigen (neoantigen) signatures derive enhanced clinical benefit from checkpoint inhibitor therapy.10

Nivolumab is an anti–PD-1–directed immune checkpoint inhibitor approved for use in the treatment of non–small-cell lung cancer11and melanoma and under clinical investigation in multiple adult and pediatric tumors.12,13 However, this response is currently unknown in bMMRD-associated cancers and the uniformly lethal GBM.

 

Fig 1.

Fig 1.   Clinical and molecular features of the biallelic mismatch repair (MMR) deficiency (bMMRD) family. (A) Pedigree of the family with both bMMRD-affected children (solid square and circle). Both siblings presented with glioblastoma multiforme (GBM), whereas parents remained unaffected, as observed in other bMMRD families. (B) Immunohistochemistry staining of the index patient’s GBM for the four MMR genes: MSH2, MSH6,MLH1, and PMS2. A PMS2-negative stain in both tumor and normal cells prompted subsequent genetic testing that confirmed the diagnosis of bMMRD. NF1, neurofibromatosis type 1.   http://jco.ascopubs.org/content/early/2016/03/17/JCO.2016.66.6552/F1.small.gif

 

To examine whether immune checkpoint inhibitors would be applicable for bMMRD cancers, we surveyed the extent of hypermutation across bMMRD tumors form various tissues. Exome sequencing of 37 cancers collected from the bMMRD consortium revealed that all malignant tumors (n = 32) were hypermutant. Although bMMRD brain tumors had the highest mutational load resulting from secondary polymerase mutations (mean, 17,740 ± standard deviation [SD], 7,703), all other high-grade tumors were hypermutant, harboring more than 100 exonic mutations (mean, 1,589 ± SD, 1,043; Fig 2A). Lower-grade bMMRD tumors (n = 5) did not exhibit hypermutation (mean, 40 ± SD, 18). Importantly, bMMRD GBMs had a significantly higher mutational load than sporadic pediatric and adult gliomas and all other brain tumors (P < .001; Fig 2A). To test the extent to which hypermutation translates to a strong neoantigen signature, a current predictor of response to immune checkpoint inhibition, we performed genome-wide somatic neoepitope analysis using similar algorithms previously used for melanoma, lung, and colon cancers.9,14,15 For each study, we compared our cohort of tumors with other tumors that were reported to respond to immune checkpoint inhibitors (Fig 2B). Strikingly, bMMRD GBMs had a significantly higher number of predicted neoantigens, whereas other tumors responded with a fraction of the neoantigens found in our patients (P < .001; Fig 2B). The mean neoantigen load was seven to 16 times higher than those of immunoresponsive melanomas, lung cancers, and microsatellite-unstable GI cancers.

 

Fig 2.

Fig 2.  Tumor mutation and neoantigen analysis. (A) Boxplot comparing the number of mutations per tumor exome in several biallelic mismatch repair deficiency (bMMRD) cancer types with pediatric and adult brain tumors. (B) Ratio of the number of neoantigens found in immunoresponsive tumors from melanoma (n = 27), lung cancer (n = 14), and colon cancer (n = 7) data sets compared with median number of neoantigens in bMMRD glioblastoma multiforme (GBM; n = 13). ATRT, atypical teratoid rhabdoid tumor; DIPG, diffuse intrinsic pontine glioma; L/L, leukemia/lymphoma; LGG, low-grade glioma; MB, medulloblastoma; PA, pilocytic astrocytoma; PNET, primitive neuroectodermal tumor.

 

We describe two pediatric patients with recurrent multifocal GBM refractory to current standard therapies who exhibited remarkable and durable responses to immune checkpoint inhibition with single-agent nivolumab. This observation is especially encouraging because these children are still clinically stable, whereas most relapsed pediatric GBMs will progress within 1 to 2 months19 despite salvage treatment, and survival is usually 3 to 6 months postrecurrence.20 Furthermore, bMMRD GBMs have outcomes similar to those of sporadic childhood GBMs,21 and data gathered from the consortium reveal a mean time from relapse to death of 2.6 months in bMMRD GBM. To our knowledge, this is the first report of such a response in childhood or adult GBM. It also highlights the utility of germline predisposition in guiding novel treatment options—in this case, immunotherapy—for cancer treatment. ….

sjwilliamspa

Not sure if the link between PD-L1 response and MMR status is causal in this ase. there are many tumors with MMR and especially all tumors had high degree of MMR. Perhaps they need to look at tumors that have a more stable genome like certain hepatocarcinomas.

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AstraZeneca’s WEE1 protein inhibitor AZD1775 Shows Success Against Tumors with a SETD2 mutation

Stephen J. Williams, Ph.D., Curator

There have been multiple trials investigating the utility of cyclin inhibitors as anti-tumoral agents (see post) with the idea of blocking mitotic entry however another potential antitumoral mechanism has been to drive the cell into mitosis in the presence of DNA damage or a defective DNA damage repair capacity. A recent trial investigating an inhibitor or the cell cycle checkpoint inhibitor Wee1 showed positive results in select cohorts of patients with mutations in DNA repair, indicating the therapeutic advantage of hijacking the cell’s own DNA damage response, much like how PARP inhibitor Olaparib works in BRCA1 mutation positive ovarian cancer patients.

John Carroll at FierceBiotech reported that an Oxford team spotlights promise of AstraZeneca drug in targeting cancers.

According to his report,

Investigators at Oxford University say that one of AstraZeneca’s ($AZN) pipeline drugs proved particularly effective in killing cancer cells with a particular genetic mutation.

The ex-Merck ($MRK) drug is AstraZeneca’s WEE1 protein inhibitor AZD1775, which proved particularly lethal to genes with a SETD2 mutation, which the researchers see as a potential ‘Achilles heel’ often found in kidney cancer and childhood brain tumors.

“When WEE1 was inhibited in cells with a SETD2 mutation, the levels of deoxynucleotides, the components that make DNA, dropped below the critical level needed for replication,” noted Oxford’s Andy Ryan. “Starved of these building blocks, the cells die. Importantly, normal cells in the body do not have SETD2 mutations, so these effects of WEE1 inhibition are potentially very selective to cancer cells.”

AstraZeneca landed rights to the drug back in 2013, when incoming Merck R&D chief Roger Perlmutter opted to spin it out while focusing an immense effort around the development of its PD-1 checkpoint inhibitor KEYTRUDA® (pembrolizumab)‎. Since then, AstraZeneca has made it available to academic investigators through their open innovation program.

Since picking up the drug, AstraZeneca has posted positive mid-stage data for p53 mutated ovarian cancer at the last big ASCO meeting, (and see associated abstract on Multicenter randomized Phase II study of AZD1775 plus chemotherapy versus chemotherapy alone in patients with platinum-resistant TP53-mutated epithelial ovarian, fallopian tube, or primary peritoneal cancer) noting its qualification as a first-in-class player in their pipeline.

Wee1, DNA damage checkpoint and cell cycle regulation

 

In fission yeast, Wee1 delays entry into mitosis by inhibiting the activity of Cdk1, the cyclin-dependent kinase that promotes entry into mitosis (Cdk1 is encoded by the cdc2+ gene in fission yeast and the CDC28 gene in budding yeast) (Russell and Nurse, 1987a). Wee1 inhibits Cdk1 by phosphorylating a highly conserved tyrosine residue at the N-terminus (Featherstone and Russell, 1991; Gould and Nurse, 1989; Lundgren et al., 1991; Parker et al., 1992; Parker and Piwnica-Worms, 1992). The phosphatase Cdc25 promotes entry into mitosis by removing the inhibitory phosphorylation (Dunphy and Kumagai, 1991; Gautier et al., 1991; Kumagai and Dunphy, 1991; Millar et al., 1991; Russell and Nurse, 1986; Strausfeld et al., 1991). Loss of Wee1 activity causes cells to enter mitosis before sufficient growth has occurred and cytokinesis therefore produces two abnormally small daughter cells (Fig. 1A) (Nurse, 1975). Conversely, increasing the gene dosage of wee1 causes delayed entry into mitosis and an increase in cell size, indicating that the levels of Wee1 activity determine the timing of entry into mitosis and can have strong effects on cell size (Russell and Nurse, 1987a). Similarly, cdc25 mutants undergo delayed entry into mitosis, producing abnormally large cells, and an increase in the gene dosage of cdc25 causes premature entry into mitosis and decreased cell size (Russell and Nurse, 1986). Despite these difficulties, early work in fission yeast suggested that the Wee1 kinase plays an important role in a checkpoint that coordinates cell growth and cell division at the G2/M transition (Fantes and Nurse, 1978; Nurse, 1975; Thuriaux et al., 1978). WEE1 is an evolutionarily conserved nuclear tyrosine kinase (Table 2) that is markedly active during the S/G2 phase of the cell cycle [24, 25]. It was first discovered 25 years ago as a cell division cycle (cdc) mutant-wee1– in the fission yeast, Schizosaccharomyces pombe [26]. Fission yeast lacking WEE1 are characterized by a smaller cell size, and this phenotype has been attributed to the ability of WEE1 to negatively regulate the activity of cyclin dependent kinase, Cdc2 (Cdc28 in budding yeast and CDK1 in human), in the Cdc2/CyclinB complex [27]. Recently, WEE1 was shown to directly phosphorylate the mammalian core histone H2B at tyrosine 37 in a cell cycle dependent manner. Inhibition of WEE1 kinase activity either by a specific inhibitor (MK-1775) or suppression of its expression by RNA interference abrogated H2B Y37-phosphorylation with a concurrent increase in histone transcription [17].

 

As shown in the Below figure Wee1 is a CDK cyclin kinase which results in an inactivating phosphorylation event on CDK/Cyclin complexes

CellCycleFig3Wee1Chk1

Figure 1. Schematic representation of the effects of Chk1 and Wee1 inhibition on CDK-CYCLIN complex regulation, that gets more activated being unphosphorylated from Cell cycle, checkpoints and cancer by Laura Carrassa.

CellCycleWee1

Figure 2. Schematic representation of the role of Chk1 and Wee1 in regulation of the CDK-cyclin complexes involved in S phase and M phase entry from Cell cycle, checkpoints and cancer by Laura Carrassa.

The following articles discuss how Wee1 can be a target and synergize with current chemotherapy

Wee1 kinase as a target for cancer therapy

 

Combined inhibition of the cell cycle related proteins Wee1 and Chk1/2 induces synergistic anti-cancer effect in melanoma.

Magnussen GI, Emilsen E, Giller Fleten K, Engesæter B, Nähse-Kumpf V, Fjær R, Slipicevic A, Flørenes VA.

BMC Cancer. 2015 Jun 10;15:462. doi: 10.1186/s12885-015-1474-8.

A functional screen identifies miRNAs that inhibit DNA repair and sensitize prostate cancer cells to ionizing radiation.

Hatano K, Kumar B, Zhang Y, Coulter JB, Hedayati M, Mears B, Ni X, Kudrolli TA, Chowdhury WH, Rodriguez R, DeWeese TL, Lupold SE.

Nucleic Acids Res. 2015 Apr 30;43(8):4075-86. doi: 10.1093/nar/gkv273. Epub 2015 Apr 6.

 

 

 

p53 mutation Frequency in Ovarian Cancer and contribution to chemo-resistance

The following is from the curated database TCGA and cBioPortal TCGA Data Viewer for mutations found in ovarian cancer sequencing studies in the literature

http://www.cbioportal.org/study.do?cancer_study_id=ov_tcga_pub

According to TCGA researchers have:

  • Confirmed that mutations in gene TP53 are present in more than 96 percent of ovarian cases (>57% mutation frequency) while SETD2 mutations are present in only 1% of cases (1.1% mutation frequency).

In general, ovarian cancers with TP53 are considered to have increased resistance to commonly used cytotoxic agents used for this neoplasm, for example cisplatin and taxol, as TP53 is a major tumor suppressor/transcription factor involved in cell cycle, DNA damage response, and other chemosensitivity mechanisms. One subtype of TP53 mutations, widely termed gain-of-function (GOF) mutations, surprisingly converts this protein from a tumor suppressor to an oncogene. We term the resulting change an oncomorphism. In this review, we discuss particular TP53 mutations, including known oncomorphic properties of the resulting mutant p53 proteins. For example, several different oncomorphic mutations have been reported, but each mutation acts in a distinct manner and has a different effect on tumor progression and chemoresistance.

p53mutonco

Figure 1. The spectrum of protection against cancer provided by WT p53. As copies of WT p53 (TP53+/+) are lost, cancer protection decreases. When oncomorphic mutations are acquired, cancer susceptibility is increased.

Oncomorphic p53 proteins were first identified over two decades ago, when different TP53 mutants were introduced into cells devoid of endogenous p53 [38,39]. Among all cancers, the most common oncomorphic mutations are at positions R248, R273, and R175, and in ovarian cancers the most common oncomorphic TP53 mutations are at positions R273, R248, R175, and Y220 at frequencies of 8.13%, 6.02%, 5.53%, and 3.74%, respectively [33,34]. In in vitro studies, cells with oncomorphic p53 demonstrate increased invasion, migration, angiogenesis, survival, and proliferation as well as resistance to chemotherapy [35,37,40,41].

hotspotsforp53mutations

Figure 2. Hotspots for TP53 mutations. Mutations that occur at a frequency greater than 3% are highlighted. Certain p53 mutants have oncomorphic activity (denoted by *), functioning through novel protein interactions as well as novel transcriptional targets to promote cell survival and potentially chemoresistance. Codons in the “other” category include those that produce non-functional p53 or have not been characterized to date.

Wee-1 kinase inhibition overcomes cisplatin resistance associated with high-risk TP53 mutations in head and neck cancer through mitotic arrest followed by senescence.

Osman AA, Monroe MM, Ortega Alves MV, Patel AA, Katsonis P, Fitzgerald AL, Neskey DM, Frederick MJ, Woo SH, Caulin C, Hsu TK, McDonald TO, Kimmel M, Meyn RE, Lichtarge O, Myers JN.

Mol Cancer Ther. 2015 Feb;14(2):608-19. doi: 10.1158/1535-7163.MCT-14-0735-T. Epub 2014 Dec 10.

Mol Cancer Ther. 2015 Jan;14(1):90-100. doi: 10.1158/1535-7163.MCT-14-0496. Epub 2014 Nov 5.

Mol Cancer Ther. 2013 Aug;12(8):1442-52. doi: 10.1158/1535-7163.MCT-13-0025. Epub 2013 May 22.

Preclinical evaluation of the WEE1 inhibitor MK-1775 as single-agent anticancer therapy.

Guertin AD1, Li J, Liu Y, Hurd MS, Schuller AG, Long B, Hirsch HA, Feldman I, Benita Y, Toniatti C, Zawel L, Fawell SE, Gilliland DG, Shumway SD.

The protein phosphatase 2A inhibitor LB100 sensitizes ovarian carcinoma cells to cisplatin-mediated cytotoxicity.

Chang KE1, Wei BR2, Madigan JP1, Hall MD1, Simpson RM2, Zhuang Z3, Gottesman MM4.

Author information

  • 1Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland.
  • 2Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland.
  • 3Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland.
  • 4Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland. mgottesman@nih.gov.

Abstract

Despite early positive response to platinum-based chemotherapy, the majority of ovarian carcinomas develop resistance and progress to fatal disease. Protein phosphatase 2A (PP2A) is a ubiquitous phosphatase involved in the regulation of DNA-damage response (DDR) and cell-cycle checkpoint pathways. Recent studies have shown that LB100, a small-molecule inhibitor of PP2A, sensitizes cancer cells to radiation-mediated DNA damage. We hypothesized that LB100 could sensitize ovarian cancer cells to cisplatin treatment. We performed in vitro studies in SKOV-3, OVCAR-8, and PEO1, -4, and -6 ovarian cancer lines to assess cytotoxicity potentiation, cell-death mechanism(s), cell-cycle regulation, and DDR signaling. In vivo studies were conducted in an intraperitoneal metastatic mouse model using SKOV-3/f-Luc cells. LB100 sensitized ovarian carcinoma lines to cisplatin-mediated cell death. Sensitization via LB100 was mediated by abrogation of cell-cycle arrest induced by cisplatin. Loss of the cisplatin-induced checkpoint correlated with decreased Wee1 expression, increased cdc2 activation, and increased mitotic entry (p-histone H3). LB100 also induced constitutive hyperphosphorylation of DDR proteins (BRCA1, Chk2, and γH2AX), altered the chronology and persistence of JNK activation, and modulated the expression of 14-3-3 binding sites. In vivo, cisplatin sensitization via LB100 significantly enhanced tumor growth inhibition and prevented disease progression after treatment cessation. Our results suggest that LB100 sensitizes ovarian cancer cells to cisplatin in vitro and in vivo by modulation of the DDR pathway and cell-cycle checkpoint abrogation.

 

So Why SETD2 Mutations?

SETD2 is a histone methyltransferase that is specific for lysine-36 of histone H3, and methylation of this residue is associated with active chromatin and chromatin remodeling.

Evidences for mutations in the histone modifying gene SETD2 as critical drivers in leukemia development. Wang Q, et al. Sci China Life Sci, 2014 Sep. PMID 25077743

SETD2 loss-of-function promotes renal cancer branched evolution through replication stress and impaired DNA repair.

Kanu N, Grönroos E, Martinez P, Burrell RA, Yi Goh X, Bartkova J, Maya-Mendoza A, Mistrík M, Rowan AJ, Patel H, Rabinowitz A, East P, Wilson G, Santos CR, McGranahan N, Gulati S, Gerlinger M, Birkbak NJ, Joshi T, Alexandrov LB, Stratton MR, Powles T, Matthews N, Bates PA, Stewart A, Szallasi Z, Larkin J, Bartek J, Swanton C.

Oncogene. 2015 Mar 2. doi: 10.1038/onc.2015.24. [Epub ahead of print]

PMID:

 

Microsatellite instability: an update.

Yamamoto H, Imai K.

Arch Toxicol. 2015 Jun;89(6):899-921. doi: 10.1007/s00204-015-1474-0. Epub 2015 Feb 22.

PMID:

25701956

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Select item 255282163.

Loss of MLH1 confers resistance to PI3Kβ inhibitors in renal clear cell carcinoma with SETD2 mutation.

Feng C, Ding G, Jiang H, Ding Q, Wen H.

Tumour Biol. 2015 May;36(5):3457-64. doi: 10.1007/s13277-014-2981-y. Epub 2014 Dec 21.

PMID:

25528216

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Select item 249316104.

SETD2-dependent histone H3K36 trimethylation is required for homologous recombination repair and genome stability.

Pfister SX, Ahrabi S, Zalmas LP, Sarkar S, Aymard F, Bachrati CZ, Helleday T, Legube G, La Thangue NB, Porter AC, Humphrey TC.

Cell Rep. 2014 Jun 26;7(6):2006-18. doi: 10.1016/j.celrep.2014.05.026. Epub 2014 Jun 12.

PMID:

24931610

Free PMC Article

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Select item 248430025.

SETD2 is required for DNA double-strand break repair and activation of the p53-mediated checkpoint.

Carvalho S, Vítor AC, Sridhara SC, Martins FB, Raposo AC, Desterro JM, Ferreira J, de Almeida SF.

Elife. 2014 May 6;3:e02482. doi: 10.7554/eLife.02482.

PMID:

24843002

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Select item 245764046.

Identification of somatic mutations in EGFR/KRAS/ALK-negative lung adenocarcinoma in never-smokers. (NOTE did this as post before)

Ahn JW, Kim HS, Yoon JK, Jang H, Han SM, Eun S, Shim HS, Kim HJ, Kim DJ, Lee JG, Lee CY, Bae MK, Chung KY, Jung JY, Kim EY, Kim SK, Chang J, Kim HR, Kim JH, Lee MG, Cho BC, Lee JH, Bang D.

Genome Med. 2014 Feb 27;6(2):18. doi: 10.1186/gm535. eCollection 2014.

PMID:

24576404

 

The histone mark H3K36me3 regulates human DNA mismatch repair through its interaction with MutSα.

Li F, Mao G, Tong D, Huang J, Gu L, Yang W, Li GM.

Cell. 2013 Apr 25;153(3):590-600. doi: 10.1016/j.cell.2013.03.025.

PMID:

23622243

Free PMC Article

 

Active NCI Clinical Trials of MK-1775 for Solid Tumors

 

NOTE Four Clinical Trials Investigating Mk-1775 and TP53 Status

1 Recruiting A Study of AZD1775 + Chemotherapy Versus Chemotherapy in Patients to Treat Ovarian, Fallopian Tube, Peritoneal Cancer.

Condition: Ovarian, Fallopian Tube, Peritoneal Cancer,

P53 Mutation

Intervention: Drug: AZD1775
2 Recruiting Gemcitabine Hydrochloride With or Without WEE1 Inhibitor MK-1775 in Treating Patients With Recurrent Ovarian, Primary Peritoneal, or Fallopian Tube Cancer

Conditions: Malignant Ovarian Mixed Epithelial Tumor;   Ovarian Brenner Tumor;   Ovarian Carcinosarcoma;   Ovarian Clear Cell Cystadenocarcinoma;   Ovarian Endometrioid Adenocarcinoma;   Ovarian Mucinous Cystadenocarcinoma;   Ovarian Serous Cystadenocarcinoma;   Ovarian Serous Surface Papillary Adenocarcinoma;   Recurrent Fallopian Tube Carcinoma;   Recurrent Ovarian Carcinoma;   Recurrent Primary Peritoneal Carcinoma;   Undifferentiated Ovarian Carcinoma
Interventions: Drug: Gemcitabine Hydrochloride;   Other: Laboratory Biomarker Analysis;   Other: Pharmacological Study;   Other: Placebo;   Drug: WEE1 Inhibitor AZD1775
3 Active, not recruiting A Study of MK-1775 in Combination With Paclitaxel and Carboplatin Versus Paclitaxel and Carboplatin Alone for Participants With Platinum-Sensitive Ovarian Tumors With the P53 Gene Mutation (MK-1775-004)

Condition: Ovarian Cancer
Interventions: Drug: MK1775;   Drug: Placebo;   Drug: paclitaxel;

Drug: carboplatin

4 Not yet recruiting Phase II, Single-arm Study of AZD1775 Monotherapy in Relapsed Small Cell Lung Cancer Patients

Condition: Small Cell Lung Cancer
Intervention: Drug: AZD1775

 

#2. Gemcitabine Hydrochloride With or Without WEE1 Inhibitor MK-1775 in Treating Patients With Recurrent Ovarian, Primary Peritoneal, or Fallopian Tube Cancer

This study is currently recruiting participants. (see Contacts and Locations)

ClinicalTrials.gov Identifier: NCT02101775

Purpose

This randomized phase II clinical trial studies how well gemcitabine hydrochloride and WEE1 inhibitor MK-1775 work compared to gemcitabine hydrochloride alone in treating patients with ovarian, primary peritoneal, or fallopian tube cancer that has come back after a period of time. Gemcitabine hydrochloride may prevent tumor cells from multiplying by damaging their deoxyribonucleic acid (DNA, molecules that contain instructions for the proper development and functioning of cells), which in turn stops the tumor from growing. The protein WEE1 may help to repair the damaged tumor cells, so the tumor continues to grow. WEE1 inhibitor MK-1775 may block the WEE1 protein activity and may increase the effectiveness of gemcitabine hydrochloride by preventing the WEE1 protein from repairing damaged tumor cells without causing harm to normal cells. It is not yet known whether gemcitabine hydrochloride with or without WEE1 inhibitor MK-1775 may be an effective treatment for recurrent ovarian, primary peritoneal, or fallopian tube cancer.

Primary Outcome Measures:

  • PFS evaluated using RECIST version 1.1 [ Time Frame: Time from start of treatment to time to progression or death, whichever occurs first, assessed up to 1 year ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

  • GCIG CA125 response rate [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]
  • Incidence of grade 3 or 4 serious adverse events, graded according to the National Cancer Institute CTCAE version 4.0 [ Time Frame: Up to 1 year ] [ Designated as safety issue: Yes ]
  • Objective response by RECIST version 1.1 [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]
  • Overall survival [ Time Frame: Up to 1 year ] [ Designated as safety issue: No ]

Survival estimates will be computed using the Kaplan-Meier method.

  • p53 protein expression in archival tumor tissue by immunohistochemistry (IHC) [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  • TP53 mutations (presence and type of mutation) by Sanger sequencing [ Time Frame: Baseline ] [ Designated as safety issue: No ]

 

These Trials Are Not Investigating TP53 Status of Patient Cohorts

A Phase I Study of Single-agent MK-1775, a Wee1 Inhibitor, in Patients With Advanced Refractory Solid Tumors

 

This study is currently recruiting participants. (see Contacts and Locations)

ClinicalTrials.gov Identifier:NCT01748825

 

PRIMARY OBJECTIVE:

  • To establish the safety and tolerability of single-agent MK-1775 in patients with refractory solid tumors
  • To determine the pharmacokinetics of MK-1775 in patients with refractory solid tumors

SECONDARY OBJECTIVES:

  • To determine the effect of MK-1775 on markers of DNA damage and apoptosis in tumor tissue and circulating tumor cells
  • To evaluate the antitumor activity of MK-1775 in patients with refractory solid tumors

Note: A further expansion cohort of 6 additional patients with documented tumors harboring BRCA-1 or -2 mutations will lso be enrolled at the MTD to further explore the safety of the agent and obtain preliminary evidence of activity in this patient population

A Phase 1/2 Study of AZD1775 (MK-1775) in Combination With Oral Irinotecan in Children, Adolescents, and Young Adults With Relapsed or Refractory Solid Tumors

PRIMARY OBJECTIVES:

  1. To estimate the maximum tolerated dose (MTD) and/or recommended Phase 2 dose of MK-1775 (WEE1 inhibitor MK-1775) administered on days 1 through 5 every 21 days, in combination with oral irinotecan (irinotecan hydrochloride), to children with recurrent or refractory solid tumors.
  2. To define and describe the toxicities of MK-1775 in combination with oral irinotecan administered on this schedule.

III. To characterize the pharmacokinetics of MK-1775 in children with refractory cancer.

SECONDARY OBJECTIVES:

  1. To preliminarily define the antitumor activity of MK-1775 and irinotecan within the confines of a Phase 1 study.
  2. To obtain initial Phase 2 efficacy data on the anti-tumor activity of MK-1775 in combination with irinotecan administered to children with relapsed or refractory neuroblastoma and in children with relapsed or refractory medulloblastoma/CNS PNET (central nervous system primitive neuroectodermal tumor).

III. To investigate checkpoint over-ride by MK-1775 via the mechanism-based pharmacodynamic (PD) biomarker of decreased cyclin-dependent kinase 1 (CDK1) phosphorylation in correlative and exploratory studies.

  1. To evaluate potential predictive biomarkers of MK-1775 sensitivity, including v-myc avian myelocytomatosis viral oncogene homolog (MYC), v-myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog (MYCN), phosphorylated-WEE1 G2 checkpoint kinase (p-Wee1), enhancer of zeste homolog 2 (Drosophila) (EZH2) and gamma-H2A histone family, member X (H2AX) in tumor tissues in correlative and exploratory studies.

 

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Targeted immunotherapy

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Fighting cancer with targeted drugs “Cancer” is a collective term that describes numerous different and malignant new tissue formations. Malignant tumors emerge from changes in DNA fragments when the body can no longer counteract these mutations, which is often associated with increased age. Yet the risk of developing cancer also depends on genetic factors, lifestyle habits and different environmental influences. Chemotherapy – an optimized base The classic triad of medical treatment, radiation therapy and surgery is a proven procedure.

While radiation therapy uses ionizing radiation to completely inactivate or at least push back the tumor, cytostatic drugs are applied in chemotherapy to inhibit cell growth. The treatment planning depends on specific tumor characteristics, the patient’s overall health condition, as well as the stage of the disease. New, individual therapeutic approaches promise more effective cancer treatment.

Chemotherapy is almost always applied – mainly by infusion, while certain cytostatic drugs are also suited for oral administration. Since researchers have tested and re-combined proven active ingredients in different doses, as well as introduced new substances, good results are now often achieved at higher tolerance. While emerging countries focus on chemotherapy, the standard treatment in the industrial world is more and more often combined with new, targeted therapeutic approaches.

Revolution in cancer treatment The cell division of healthy people is strictly regulated. A cell is only reproduced when it receives an according signal. If this procedure is thrown out of balance, the result is uncontrolled cell growth. Unlike cytostatic drugs, which act as cellular toxin, modern therapies draw on the molecular bases of tumor development. A type of enzymes known as kinases plays an important role in transmitting the signals. Kinase inhibitors act as low-molecular agents and block their function. For instance, the treatment of chronic myeloid leukemia with the active ingredient Imatinib1 has proven successful and spurred research. Most kinase inhibitors are administered orally and are partly based on highly complex formulations. Angiogenesis inhibitors are another example of targeted therapeutics. They block the development of blood vessels, which are indispensable for the growth of tumor cells. Immunotherapy against cancer In immunotherapy, the patient’s own immune system is stimulated to take independent action against tumor cells. This way, monoclonal antibodies can be developed, which attach themselves to the characteristic structures of the tumor surface. They inhibit cell proliferation (uncontrolled cell growth) or induce cell death. The targeted effect of monoclonal antibodies can also be combined with cell poison such as cytostatic agents or toxins.

Like in a Trojan Optimal operator protection at the highest product quality – sterile filling lines combined with barrier systems 1

Vasella, Daniel (2003): Magic Cancer Bullet: How a Tiny Orange Pill May Rewrite Medical History 6

 

Checkpoint inhibitors block the control points and are thus able to direct the immune system against the cancer. Since antibodies are complex protein structures that are “digested” by the gastrointestinal tract, this therapy is administered via infusion.

Therapeutic differentiation The trend is toward individually tailored therapies. Companion diagnostics are consequently becoming the focus of active ingredient development to verify the effectiveness for each patient before treatment initiation. Conversely, this implies an even closer cooperation between pharmaceutical companies and manufacturers of laboratory diagnostics as well as medical devices. Ever more specific therapies reduce the number of patients available for clinical studies, increasingly blurring the line between drug development and treatment. This medicine, which is described as “translational”, offers great opportunities to fight tumors formerly known as difficult to treat. More targeted tumor therapies will hence change the image of cancer – from death sentence to a severe, yet manageable chronic condition.

For further information, please contact: Dr Johannes Rauschnabel Phone: +49 7951 402 452 E-mail: johannes.rauschnabel@bosch.com

So-called antibody-drug conjugates transport the cell poison directly into the cancer cells. In the context of “checkpoint inhibition”, particular attention has recently been paid to monoclonal antibodies. The immune system is equipped with control points that protect the organism against autoimmune reactions. Tumors use these mechanisms to thwart a counter-reaction of the immune system.

Fighting cancer with Bosch technologies

The portfolio from Bosch Packaging Technology is suited for nearly all forms of oncological drug development, production and filling. For instance, sterile filling lines can be combined with barrier systems to protect operators from highly potent active agents such as cytostatic drugs, while ensuring the highest possible quality. Oral cytostatic drugs such as the active ingredient Imatinib can be processed on capsule filling machines and tablet presses from Bosch, which in conjunction with containment systems protect the operators from product dust. Bosch also offers machines for all laboratory process steps for both liquid and solid pharmaceuticals. Devices for the biopharmaceutical production of monoclonal antibodies and antibody-drug conjugates are among the core process competencies of the Bosch subsidiary Pharmatec. The production of antibodies requires a multi-stage process. First, the cells are cultivated in increasing scaling steps and harvested (upstream process). The active ingredients are then separated and purified using different technologies, followed by the formulation of the final injection solution (downstream process).

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