Olaparib Tablet: A Review in Ovarian Cancer Maintenance Therapy

Investigation of Stabilized Amorphous Solid Dispersions to Improve Oral Olaparib Absorption

In this study, we investigated the formulation of stable solid dispersions to enhance the bioavailability of olaparib (OLA), a therapeutic agent for ovarian cancer and breast cancer characterized as a BCS class IV drug with low solubility and low permeability. Various polymers were screened based on solubility tests, and OLA-loaded solid dispersions were prepared using spray drying. The physicochemical properties of these dispersions were investigated via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier Transform Infrared Spectroscopy (FT-IR). Subsequent dissolution tests, along with assessments of morphological and crystallinity changes in aqueous solutions, led to the selection of a hypromellose (HPMC)-based OLA solid dispersion as the optimal formulation. HPMC was effective at maintaining the supersaturation of OLA in aqueous solutions and exhibited a stable amorphous state without recrystallization. In an in vivo study, this HPMC-based OLA solid dispersion significantly enhanced bioavailability, increasing AUC0-24 by 4.19-fold and Cmax by more than 10.68-fold compared to OLA drug powder (crystalline OLA). Our results highlight the effectiveness of HPMC-based solid dispersions in enhancing the oral bioavailability of OLA and suggest that they could be an effective tool for the development of oral drug formulations.

New hopes and promises in the treatment of ovarian cancer focusing on targeted treatment-a narrative review

Unfortunately, ovarian cancer is still diagnosed most often only in an advanced stage and is also the most lethal gynecological cancer. Another problem is the fact that treated patients have a high risk of disease recurrence. Moreover, ovarian cancer is very diverse in terms of molecular, histological features and mutations. Many patients may also develop platinum resistance, resulting in poor response to subsequent lines of treatment. To improve the prognosis of patients with ovarian cancer, it is expected to make better existing and implement new, promising treatment methods. Targeted therapies seem very promising. Currently, bevacizumab - a VEGF inhibitor and therapy with olaparib - a polyADP-ribose polymerase inhibitor are approved. Other methods worth considering in the future include: folate receptor α, immune checkpoints or other immunotherapy methods. To improve the treatment of ovarian cancer, it is also important to ameliorate the determination of molecular features to describe and understand which group of patients will benefit most from a given treatment method. This is important because a larger group of patients treated for ovarian cancer can have a greater chance of surviving longer without recurrence.

Secondary cytoreductive surgery followed by olaparib tablets as maintenance therapy in patients with BRCA mutated recurrent ovarian cancer: A multi-center retrospective study

OBJECTIVE

To evaluate the effect of secondary cytoreductive surgery (SeCRS) followed by platinum-based chemotherapy (PBC) and olaparib tablets as maintenance therapy in patients with BRCA mutated recurrent epithelial ovarian cancer.

METHODS

This was a retrospective study of a prospective database. We collected information on 623 patients diagnosed with BRCA mutated recurrent epithelial ovarian cancer, all of whom underwent SeCRS followed by PBC in combination with or without olaparib. Overall survival and progression-free survival were measured to evaluate treatment effectiveness.

RESULTS

Of the 623 patients recruited, 240 underwent SeCRS plus hyperthermic intraperitoneal chemotherapy followed by PBC and olaparib maintenance therapy (Group A), 248 underwent SeCRS followed by PBC and olaparib maintenance therapy (Group B), and 135 underwent SeCRS followed by PBC only upon recurrence (Group C). The median progression-free survival for Group A was significantly longer than that for Group B (32.5 vs. 24.2 months, P<0.001), and Group B was significantly longer than Group C (24.2 vs. 15.1 months, P<0.001). The median overall survival for Groups A was significantly longer than that for Group B (71.4 vs. 63.5 months, P<0.001), and Group B was significantly longer than Group C (63.5 vs. 47.5 months, P<0.001).

CONCLUSIONS

This study suggested that SeCRS followed by PBC and olaparib maintenance therapy resulted in longer overall survival and progression-free survival than SeCRS followed by PBC only in patients with BRCA mutated recurrent ovarian cancer, especially in patients treated with SeCRS plus hyperthermic intraperitoneal chemotherapy.

DNA replication: Mechanisms and therapeutic interventions for diseases

Accurate and integral cellular DNA replication is modulated by multiple replication-associated proteins, which is fundamental to preserve genome stability. Furthermore, replication proteins cooperate with multiple DNA damage factors to deal with replication stress through mechanisms beyond their role in replication. Cancer cells with chronic replication stress exhibit aberrant DNA replication and DNA damage response, providing an exploitable therapeutic target in tumors. Numerous evidence has indicated that posttranslational modifications (PTMs) of replication proteins present distinct functions in DNA replication and respond to replication stress. In addition, abundant replication proteins are involved in tumorigenesis and development, which act as diagnostic and prognostic biomarkers in some tumors, implying these proteins act as therapeutic targets in clinical. Replication-target cancer therapy emerges as the times require. In this context, we outline the current investigation of the DNA replication mechanism, and simultaneously enumerate the aberrant expression of replication proteins as hallmark for various diseases, revealing their therapeutic potential for target therapy. Meanwhile, we also discuss current observations that the novel PTM of replication proteins in response to replication stress, which seems to be a promising strategy to eliminate diseases.

The Current State of the Art in PARP Inhibitor-Based Delivery Nanosystems

Poly (adenosine diphosphate [ADP]–ribose) polymerases inhibitors (PARPi), the first clinically approved drug that exhibits synthetic lethality, are moving to the forefront of cancer treatments. Currently, the oral bioavailability of PARPi is quite low; thus, it is a major challenge to effectively and safely deliver PARPi during clinical cancer therapy. Nanotechnology has greatly advanced the development of drug delivery. Based on the basic characteristics and various forms of nanoparticles, drug delivery systems can prolong the time that drugs circulate, realize the controlled release of drugs, provide drugs with an active targeting ability, and spatiotemporally present combination treatment. Furthermore, nanosystems may not only enhance drug efficiency but also reduce adverse side effects. This review focuses on strategies involving nanoparticle-based delivery for PARPi, including single administration and codelivery with other agents. We believe that nanosystems have great potential in advancing PARPi efficacy for cancer therapy.

PARP Inhibition Activates STAT3 in Both Tumor and Immune Cells Underlying Therapy Resistance and Immunosuppression In Ovarian Cancer

Despite the promising activity of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) in many cancer types with defects in the DNA damage response the majority of the treated patients acquire PARPi resistance and succumb to their diseases. Consequently, there is an urgent need to identify the mechanisms of PARPi resistance. Here, we show that PARPi treatment promotes STAT3 activation in ovarian cancer cells, tumor-associated immune cells and fibroblasts, resulting in PARPi resistance and immunosuppression. Comparison of ovarian cancer patient-matched tumor biopsies before and after PARPi therapy revealed that STAT3 activity was significantly higher in tumor cells and tumor-associated immune cells and fibroblasts post PARPi treatment. Moreover, one-time PARPi treatment activated STAT3 both in tumor cells as well as diverse immune subsets and fibroblasts. PARPi-treated immune cells exhibited decreased expression of immunostimulatory interferon (IFN)-γ and Granzyme B while increasing immunosuppressive cytokine IL-10. Finally, we demonstrate that the acquisition of PARPi resistance in ovarian cancer cells was accompanied by increased STAT3 activity. Ablating STAT3 inhibited PARPi-resistant ovarian tumor cell growth and/or restored PARPi sensitivity. Therefore, our study has identified a critical mechanism intrinsic to PARPi that promotes resistance to PARPi and induces immunosuppression during PARPi treatment by activating STAT3 in tumor cells and tumor-associated immune cells/fibroblasts.

Olaparib: A Review as First-Line Maintenance Therapy in Advanced Ovarian Cancer

Olaparib (Lynparza^®) is a poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor approved for first-line maintenance treatment in adults with advanced ovarian cancer who are in complete or partial response to first-line, platinum-based chemotherapy. Originally approved as monotherapy, olaparib is also approved to be administered in combination with bevacizumab in patients whose cancer is associated with homologous recombination deficiency (HRD), defined by either a BRCA1/2 mutation and/or genomic instability. In phase III trials, olaparib monotherapy significantly improved progression-free survival (PFS) relative to placebo (SOLO-1), as did olaparib plus bevacizumab relative to placebo plus bevacizumab (PAOLA-1), in patients with advanced ovarian cancer who had responded to platinum-based chemotherapy. In PAOLA-1, improvements in PFS with olaparib plus bevacizumab were not seen in patients with HRD-negative tumours relative to placebo plus bevacizumab. Both olaparib monotherapy and olaparib in combination with bevacizumab had generally manageable tolerability profiles. Olaparib, alone or in combination with bevacizumab, is a useful option for the first-line maintenance treatment of adults with HRD-positive, advanced epithelial ovarian, fallopian tube or primary peritoneal cancer who are in complete or partial response to first-line, platinum-based chemotherapy.

Characteristics of BRCA1/2 pathogenic germline mutations in chinese NSCLC patients and a comparison with HBOC

Background and purposes

The pathogenic BRCA1/2 germline mutations contributed to Hereditary Breast and Ovarian Cancer (HBOC) susceptibility. The features of BRCA1/2 germline mutations in non-small cell lung cancer (NSCLC) have not been systematically studied. Here we performed the first study investigating the characteristics of pathogenic BRCA1/2 germline mutations in Chinese NSCLC patients and compared them with those from Chinese HBOC.

Methods

Information on BRCA1/2 germline mutations from 9010 Chinese NSCLC patients were collected from available studies and analyzed, and compared with the BRCA1/2 germline mutations from Chinese HBOC BRCA1/2 database (LOVD database, 20,523 patients).

Results

19 (20 carriers, 0.22 %) pathogenic BRCA1 and 60 (66 carriers, 0.73 %) pathogenic BRCA2 germline mutations from NSCLC were identified. The carrier frequency of BRCA1/2 in Chinese NSCLC patients (86/9010 = 0.95 %) was significantly lower than that in Chinese breast and ovary cancer patients (1481/20,523 = 7.2 %) (P < 0.001). We found that frameshift and nonsense mutations were the predominant types of BRCA1/2 mutation in NSCLC, with no obvious hot spot mutations. No significant difference in the ratio of frameshift and nonsense mutations was found between BRCA1 and BRCA2 in NSCLC. 5 out of 19 mutations in BRCA1 and 23 out of 60 mutations in BRCA2 were novel mutations found in NSCLC that have never been reported in Chinese HBOC. A trend of higher percentage of BRCA1 nonsense mutations in the carriers was revealed in NSCLC compared with HBOC, while no such difference was found in BRCA2 in all types of mutations.

Conclusions

BRCA1/2 germline mutations from NSCLC exhibited distinct characteristics compared with those from HBOC in Chinese population, including lower carrier frequency than HBOC, higher ratio of nonsense mutations and carriers than HBOC, and novel BRCA1/2 germline mutations never found in HBOC.

A new targeted treatment for patients with a germline BRCA mutation: olaparib in pancreatic cancer

Pancreatic cancer has a poor prognosis. Focused efforts in the development of novel treatments of this disease have led to the approval of new combinations. Improvements in knowledge of the biology of these tumors have been made, and it is now widely accepted that a proportion of patients have potentially targetable altered genes. One such gene is BRCA, which confers sensibility to PARP inhibitors. Olaparib, an oral PARP inhibitor, initially demonstrated activity in Phase II clinical trials including germline BRCA-mutated patients. This was confirmed in a Phase III clinical trial in pancreatic cancer patients with a germline BRCA mutation. After the results of this study, new scenarios have been evoked. We review the development of olaparib in pancreatic cancer.

Adverse events in women switching from olaparib capsules to tablets: retrospective observational study of US claims data

Aim: Describe rates of prespecified adverse events in patients who switched from olaparib capsules to tablets. Patients & methods: Retrospective, observational cohort analysis using self-controlled, pre-post design. Data on patients with ovarian cancer who switched from olaparib capsules to tablets between January 2015 and February 2019 were obtained from a US claims database. Results: Among all patients (n = 48), proportion with any prespecified adverse event was 45.8% (95% confidence interval: 31.4-60.8) during initial 90 days' capsule use and 35.4% (22.2-50.5) during initial 90 days' tablets use; difference -10.4% (-28.8-9.0). Conclusion: Switching from olaparib capsules to tablets was manageable with no evidence of increased toxicity. This real-world study supports the manageable tolerability of olaparib in women with ovarian cancer.

Molecular Mechanisms of PARP-1 Inhibitor 7-Methylguanine

7-Methylguanine (7-MG), a natural compound that inhibits DNA repair enzyme poly(ADP-ribose) polymerase 1 (PARP-1), can be considered as a potential anticancer drug candidate. Here we describe a study of 7-MG inhibition mechanism using molecular dynamics, fluorescence anisotropy and single-particle Förster resonance energy transfer (spFRET) microscopy approaches to elucidate intermolecular interactions between 7-MG, PARP-1 and nucleosomal DNA. It is shown that 7-MG competes with substrate NAD⁺ and its binding in the PARP-1 active site is mediated by hydrogen bonds and nonpolar interactions with the Gly863, Ala898, Ser904, and Tyr907 residues. 7-MG promotes formation of the PARP-1–nucleosome complexes and suppresses DNA-dependent PARP-1 automodification. This results in nonproductive trapping of PARP-1 on nucleosomes and likely prevents the removal of genotoxic DNA lesions.

Pharmacological issues concerning olaparib capsule and tablet formulations in treating ovarian cancer: Are they really the same drug?

Olaparib is a first-in-class PARP inhibitor that has demonstrated efficacy as maintenance therapy in patients with ovarian cancer. It has been approved as a capsule formulation and after the publication of data from SOLO2 study became available also as tablet formulation. Due to different pharmacokinetic properties, these different formulations cannot be considered bioequivalent nor interchangeable. The tablet formulation has improved bioavailability, reducing pill burden and offering a more convenient dosage regimen. Furthermore, olaparib tablet formulation had a manageable tolerability profile if compared to capsule one, with most of adverse events of mild or moderate severity. Under this light, olaparib tablet formulation is a useful maintenance strategy for recurrent, platinum-sensitive ovarian cancer, providing a more convenient dosing option than the capsule formulation.