Penfluridol induces endoplasmic reticulum stress leading to autophagy in pancreatic cancer.

Pancreatic cancer is one of the most aggressive and difficult to treat cancers. Experimental and clinical evidence suggests that high basal state autophagy in pancreatic tumors could induce resistance to chemotherapy. Recently, we have demonstrated that penfluridol suppresses pancreatic tumor growth by autophagy-mediated apoptosis both in vitro and in vivo; however, the mechanism of autophagy induction by penfluridol was not clear. Several studies have established that endoplasmic reticulum stress could lead to autophagy and inhibit tumor progression. In this study, we demonstrated that penfluridol induced endoplasmic reticulum stress in BxPC-3, AsPC-1, and Panc-1 pancreatic cancer cell lines as indicated by upregulation of endoplasmic reticulum stress markers such as binding protein (BIP), C/EBP homologous protein (CHOP) and inositol requiring 1α (IRE1α) after treatment with penfluridol in a concentration-dependent manner. Inhibiting endoplasmic reticulum stress by pretreatment with pharmacological inhibitors such as sodium phenylbutyrate and mithramycin or by silencing CHOP using CHOP small interfering RNA, blocked penfluridol-induced autophagy. These results clearly indicate that penfluridol-induced endoplasmic reticulum stress lead to autophagy in our model. Western blot analysis of subcutaneously implanted AsPC-1 and BxPC-3 tumors as well as orthotopically implanted Panc-1 tumors demonstrated upregulation of BIP, CHOP, and IRE1α expression in the tumor lysates from penfluridol-treated mice as compared to tumors from control mice. Altogether, our study establishes that penfluridol-induced endoplasmic reticulum stress leads to autophagy resulting in reduced pancreatic tumor growth. Our study opens a new therapeutic target for advanced chemotherapies against pancreatic cancer.

Evaluation of the effectiveness and acceptability of the long-acting oral antipsychotic penfluridol: Illustrative case series.

AIM: In this study, we sought to determine clinical outcomes at 1 year for patients prescribed penfluridol in an inner London National Health Service Trust. Using noninterventional data, we describe the use, effectiveness and safety of this treatment modality. RESULTS: We retrospectively followed up 17 patients prescribed penfluridol as part of routine clinical practice. All patients took penfluridol once weekly. Of these patients, 12 (70.6%) were considered treatment resistant. The average duration of illness for this cohort was 10 years (SD = 6.7). At 1 year, nine (53%) patients remained on treatment. Median survival time was not reached at 1-year follow-up; mean time on penfluridol was 251 days (95% confidence interval (CI), 184-318). The mean number of admissions to hospital in the year following penfluridol initiation was 0.6 compared with 0.8, 1 year before initiation (p = 0.465). The median number of bed days 1 year before penfluridol initiation was 24, whereas in the year following penfluridol initiation, it was 0 (p = 0.514). CLINICAL IMPLICATIONS: Although penfluridol is unlicensed in the United Kingdom, limited data suggest that this long-acting oral therapy has the potential to be used safely and effectively for the treatment of psychotic disorders. However, more data are required to establish the place of penfluridol and other potential long-acting oral antipsychotic formulations in the treatment of psychotic disorders.

The Impact of Antipsychotic Formulations on Time to Medication Discontinuation in Patients with Schizophrenia: A Dutch Registry-Based Retrospective Cohort Study.

BACKGROUND: Many patients with schizophrenia discontinue antipsychotic medication, frequently with adverse outcomes. Although different antipsychotic formulations are associated with different times to discontinuation, not much is known about discontinuation rates with oral-weekly formulations. Such a formulation of penfluridol is available in both the Netherlands and several other countries. OBJECTIVES: We aimed to investigate the impact of antipsychotic formulations on time to discontinuation, especially the oral-weekly formulation. METHODS: In a large, registry-based, retrospective cohort study from 1 January 2013 to 31 December 2016, we determined the time to medication discontinuation during the follow-up period with antipsychotic formulations, including oral-daily, oral-weekly, depot, or a combination of these. Patients with schizophrenia aged between 18 and 69 years were included and stratified according to the duration of recent antipsychotic use (taking the same formulation for ≤ 60 days or > 60 days before follow-up: short-term or long-term recent antipsychotic use). Medication discontinuation was defined as discontinuation of current antipsychotic formulation. RESULTS: Overall, 8257 patients were included for analyses, with 80% of patients discontinuing antipsychotic medication. Time to discontinuation was longer in those with long-term recent antipsychotic use before the follow-up period and longest for oral-daily formulations. Patterns for discontinuation of oral-weekly and depot formulations were similar, regardless of the duration of recent antipsychotic use before follow-up. More prior discontinuations were associated with shorter time to discontinuation. CONCLUSIONS: Time to discontinuation differed considerably between formulations. The duration of recent antipsychotic use was a strong predictor of time to discontinuation. While oral-daily formulations had the longest time to discontinuation in the long-term recent antipsychotic use group, discontinuation trends were similar for oral-weekly and depot formulations. An oral-weekly formulation, whose administration route is noninvasive, might therefore be considered an alternative to depot formulations.

Penfluridol overcomes paclitaxel resistance in metastatic breast cancer.

Paclitaxel is a first line chemotherapeutic agent for the patients with metastatic breast cancer. But inherited or acquired resistance to paclitaxel leads to poor response rates in a majority of these patients. To identify mechanisms of paclitaxel resistance, we developed paclitaxel resistant breast cancer cell lines, MCF-7 and 4T1 by continuous exposure to paclitaxel for several months. Western blot analysis showed increased expression of HER2 and ß-catenin pathway in resistant cell lines as compared to parent cells. Hence, we hypothesized that HER2/ß-catenin mediates paclitaxel resistance in breast cancer and suppression of HER2/ß-catenin signaling could overcome paclitaxel resistance. Our data showed that penfluridol (PFL) treatment significantly reduced the survival of paclitaxel-resistant cells. Western blot analysis revealed that PFL treatment suppressed HER2, as well as, ß-catenin pathway. In vivo data confirmed that PFL significantly potentiated tumor growth suppressive effects of paclitaxel in an orthotropic breast cancer model. In addition, tumors from paclitaxel and PFL-treated mice showed reduced HER2 and ß-catenin expression, along with increased apoptosis. Taken together our results demonstrate a novel role of HER2/ß-catenin in paclitaxel resistance and open up new avenues for application of PFL as a therapeutic option for overcoming paclitaxel resistance.

Penfluridol suppresses glioblastoma tumor growth by Akt-mediated inhibition of GLI1.

Glioblastoma (GBM) is the most common brain tumor with poor survival rate. Our results show that penfluridol, an antipsychotic drug significantly reduced the survival of ten adult and pediatric glioblastoma cell lines with IC50 ranging 2-5 µM after 72 hours of treatment and induced apoptosis. Penfluridol treatment suppressed the phosphorylation of Akt at Ser473 and reduced the expression of GLI1, OCT4, Nanog and Sox2 in several glioblastoma cell lines in a concentration-dependent manner. Inhibiting Akt with LY294002 and siRNA, or inhibiting GLI1 using GANT61, cyclopamine, siRNA and CRISPR/Cas9 resulted in enhanced cell growth suppressive effects of penfluridol. On the other hand, overexpression of GLI1 significantly attenuated the effects of penfluridol. Our results further demonstrated that penfluridol treatment inhibited the growth of U87MG tumors by 65% and 72% in subcutaneous and intracranial in vivo glioblastoma tumor models respectively. Immunohistochemical and western blot analysis of tumors revealed reduced pAkt (Ser 473), GLI1, OCT4 and increase in caspase-3 cleavage and TUNEL staining, confirming in vitro findings. Taken together, our results indicate that overall glioblastoma tumor growth suppression by penfluridol was associated with Akt-mediated inhibition of GLI1.

Penfluridol: An Antipsychotic Agent Suppresses Metastatic Tumor Growth in Triple-Negative Breast Cancer by Inhibiting Integrin Signaling Axis.

Metastasis of breast cancer, especially to the brain, is the major cause of mortality. The inability of anticancer agents to cross the blood-brain-barrier represents a critical challenge for successful treatment. In the current study, we investigated the antimetastatic potential of penfluridol, an antipsychotic drug frequently prescribed for schizophrenia with anticancer activity. We show that penfluridol induced apoptosis and reduced the survival of several metastatic triple-negative breast cancer (TNBC) cell lines. In addition, penfluridol treatment significantly reduced the expression of integrin α6, integrin ß4, Fak, paxillin, Rac1/2/3, and ROCK1 in vitro. We further evaluated the efficacy of penfluridol in three different in vivo tumor models. We demonstrate that penfluridol administration to an orthotopic model of breast cancer suppressed tumor growth by 49%. On the other hand, penfluridol treatment inhibited the growth of metastatic brain tumors introduced by intracardiac or intracranial injection of breast cancer cells by 90% and 72%, respectively. Penfluridol-treated tumors from all three models exhibited reduced integrin ß4 and increased apoptosis. Moreover, chronic administration of penfluridol failed to elicit significant toxic or behavioral side effects in mice. Taken together, our results indicate that penfluridol effectively reduces the growth of primary TNBC tumors and especially metastatic growth in the brain by inhibiting integrin signaling, and prompt further preclinical investigation into repurposing penfluridol for the treatment of metastatic TNBC.

Penfluridol suppresses pancreatic tumor growth by autophagy-mediated apoptosis.

Pancreatic tumors exhibit enhanced autophagy as compared to any other cancer, making it resistant to chemotherapy. We evaluated the effect of penfluridol against pancreatic cancer. Penfluridol treatment induced apoptosis and inhibited the growth of Panc-1, BxPC-3 and AsPC-1, pancreatic cancer cells with IC50 ranging between 6-7 µM after 24 h of treatment. Significant autophagy was induced by penfluridol treatment in pancreatic cancer cells. Punctate LC3B and autophagosomes staining confirmed autophagy. Inhibiting autophagy by chloroquine, bafilomycin, 3-methyladenine or LC3BsiRNA, significantly blocked penfluridol-induced apoptosis, suggesting that autophagy lead to apoptosis in our model. Penfluridol treatment suppressed the growth of BxPC-3 tumor xenografts by 48% as compared to 17% when treated in combination with chloroquine. Similarly, penfluridol suppressed the growth of AsPC-1 tumors by 40% versus 16% when given in combination with chloroquine. TUNEL staining and caspase-3 cleavage revealed less apoptosis in the tumors from mice treated with penfluridol and chloroquine as compared to penfluridol alone. Penfluridol treatment also suppressed the growth of orthotopically implanted Panc-1 tumors by 80% by inducing autophagy-mediated apoptosis in the tumors. These studies established that penfluridol inhibits pancreatic tumor growth by autophagy-mediated apoptosis. Since penfluridol is already in clinic, positive findings from our study will accelerate its clinical development.

Penfluridol steady-state kinetics in psychiatric patients.

Twenty-two hospitalized schizophrenic patients, participating in a large-scale phase II double-blind dose-effect study (30, 60, and 120 mg weekly) of penfluridol, a new diphenylbutylpiperidine neuroleptic, were maintained on a regular dosage regimen for 13 wk. Several blood samples were taken during the last dosage interval. Results show that the peak concentration develops within 12 hr after the last dose. A rapid decline, probably due to tissue re-equilibration, then occurs and is followed by a much slower falloff. Detectable concentrations 168 hr after administration are consistent with the long duration of action of penfluridol. Statistically significant differences between doses were found in the analysis of variance of plasma concentrations at all sampling times and in mean steady-state plasm concentrations. Wide differences in plasma concentrations were noted in patients receiving the same absolute dose, but a good relationship was defined between mean steady-state concentration and the dose expressed as mg per either kg of body weight or square meter of body surface area.

A long term comparative trial of penfluridol and fluphenazine decanoate in schizophrenic outpatients.

Penfluridol, a diphenylbutylpiperidene derivative, is a new long acting neuroleptic, administered orally, once weekly. It is marketed in several European countries and has been used successfully in the treatment of various acute psychoses, for severely ill chronic schizophrenic patients, and as maintenance therapy for chronic schizophrenic patients. The present study was designed to compare, in a double-blind fashion, the efficacy of penfluridol and fluphenazine decanoate in the maintenance therapy of schizophrenic outpatients.

Penfluridol: an open phase III study in acute newly admitted hospitalized schizophrenic patients.

An open study was carried out in 17 acutely ill, newly admitted, floridly psychotic schizophrenic patients to a city hospital in New York. Penfluridol was given on a daily basis up to doses of 120 mg and patients were rated objectively by means of different psychometric evaluations; vital signs were monitored daily as were side effects. The drug was found to be a rapid acting, well-tolerated, and highly effective antipsychotic agent within the population of patients explored and within the dose range used. It was particularly effective in acutely agitated floridly paranoid schizophrenics; a statistically significant impact was achieved by 7 days and usually within 72 h after initiating treatment. The drug appears unique in that (1) its effects are realized without the untoward and usually troublesome effects of nonspecific sedation attendant upon the use of many other 'neuroleptic' medications, and (2) even within the relatively high doses used it produced no hypotensive effects. It is concluded that this appears to be a unique antipsychotic agent and a potentially important addition to the treatment armamentarium of both acute and chronic schizophrenic individuals.

Penfluridol in the maintenance treatment of schizophrenic patients newly discharged from a brief therapy unit.

Penfluridol, a long-acting neuroleptic that can be administered orally once a week, was compared with chlorpromazine in the maintenance treatment of 29 schizophrenic patients newly discharged from a brief therapy unit. The results indicate that penfluridol was of a similar efficacy to chlorpromazine in the treatment of these patients. Penfluridol-treated patients experienced less drowsiness but more extrapyramidal symptoms than those treated with chlorpromazine.

Study of penfluridol and chlorpromazine in the treatment of chronic schizophrenia.

This study presents data on the use of penfluridol, a once-a-week orally administered, antipsychotic agent, in the treatment of chronic schizophrenic patients. Fifty-nine patients participated in the initial dose titration segment during which doses of penfluridol were adjusted weekly until the patients' condition became stabilized. The starting dose did not exceed 60 mg per week, and the maximum weekly dose did not exceed 140 mg. Forty-one of these patients continued on to participate in a double-blind comparison of penfluridol with chlorpromazine. Maximum doses did not exceed 140 mg per dose per week for penfluridol and 7350 mg per week for chlorpromazine in the double-blind segment. Patients were abruptly switched from their previous neuroleptic medication to penfluridol without loss of control. Side effects, mainly extrapyramidal in nature, were readily alleviated with benztropine mesylate. Penfluridol, administered orally once a week, appeared to be well tolerated; it was comparable to daily chlorpromazine in treating and maintaining schizophrenic patients.

Penfluridol, a peroral long-acting neuroleptic, for the maintenance treatment of schizophrenic patients who relapse.

In a multicenter collaborative study, 28 newly readmitted schizophrenic patients, stabilized for one week on short-acting neuroleptic drugs, had their medication abruptly changed to penfluridol given once a week on an outpatient basis. The average dose required for maintenance was approximately 40 mg weekly. Analysis of BPRS evaluations carried out during the 16-week trial revealed a significant linear trend toward further improvement. Social functioning, as measured by the KAS questionnaire in the outpatient period of the trial, also revealed a significant linear trend toward improvement. Significant worsening was not found with any psychometric evaluation. Side effects, when observed, were neither frequent nor severe. Three laboratory and vital sign values showed significant changes: increase in BUN concentrations, decrease in pulse rate, and increase in body weight. The changes in weight and pulse appeared to be within relatively normal ranges, and the increase in BUN concentrations did not appear to be clinically significant. During the first part of a long-term study, penfluridol received a high degree of patient acceptability and is a welcome addition to the maintenance treatment of schizophrenia.

Comparative short-term evaluation of penfluridol and trifluoperazine in chronic schizophrenia.

A double blind comparative study was conducted to evaluate the efficacy and safety of penfluridol and trifluoperazine in patients of chronic schizophrenia. Penfluridol was administered once weekly while trifluoperazine was administered twice daily by preparing identical capsules. The data revealed that both the compounds were similarly effective in maintaining control of symptoms of chronic schizophrenia. However, penfluridol has a definite advantage over trifluoperazine since it is administered once a week instead of twice a day.