Improving olaparib exposure to optimize adverse effects management

Background

Olaparib is an inhibitor of the human poly-(ADP-ribose)-polymerase enzymes (PARP1/2) needed to repair single-strand DNA breaks. It is used in breast, ovarian, prostate and pancreatic cancer.

Objectives

This work aimed to describe the pharmacokinetics/pharmacodynamics (PK/PD) relationship between olaparib plasma concentrations and common adverse effects (i.e. anaemia and hypercreatininaemia), in a real-life setting, to propose a target concentration for therapeutic drug monitoring.

Methods

Two PK/PD models describing the evolution of haemoglobinaemia and creatininaemia as a function of time were developed, based on data from, respectively, 38 and 37 patients receiving olaparib. The final model estimates were used to calculate the incidence of anaemia and creatinine increase according to plasma trough concentrations for 1000 virtual subjects to define target exposure.

Results

The final models correctly described the temporal evolution of haemoglobinaemia and creatininaemia for all patients. The haemoglobinaemia PK/PD model is inspired by Friberg's model, and the creatininaemia PK/PD model is an indirect response model. Model parameters were in agreement with physiological values and close to literature values for similar models. The mean (population) plasma haemoglobin concentration at treatment initiation, as estimated by the model, was 11.62 g/dL, while creatinine concentration was 71.91 µmol/L. Using simulations, we have identified a target trough concentration of 3500-4000 ng/mL, above which more than 20% of patients would report grade ≥3 anaemia.

Conclusion

Based on real-world data, we were able to properly describe the time course of haemoglobinaemia and plasma creatininaemia during olaparib treatment.

Pazopanib pharmacokinetically guided dose optimization in three cancer patients with gastrointestinal resection

PURPOSE

Pazopanib is approved in advanced renal cell carcinoma (RCC) and soft-tissue sarcoma at a flat-fixed dose despite a large pharmacokinetics interindividual variability and a narrow therapeutic index. To our knowledge, pazopanib exposure in patients with gastrointestinal resections (GIR) has not been described. This report focuses on feasibility of pharmacokinetics-guided dose escalation in these patients and clinical implications for their management.

METHOD

A retrospective data collection was performed for three patients with GIR treated with pazopanib, including pazopanib plasma concentrations (high-performance liquid chromatography with UV detection) and treatment adherence (Girerd score).

CASE PRESENTATION

First patient (55-year-old man, RCC, gastric bypass surgery) pazopanib Cmin,ss at day 39 was 4.1 mg/L. Dose escalation to 1800 mg/day fractionated allowed to reach Cmin,ss of 18.5 mg/L (target threshold in RCC patients: 20.5 mg/L). Patient 2 (50-year-old woman, metastatic myxofibrosarcoma, gastric band) showed Cmin,ss of 4.0 mg/L at day 13. In patient 3 (49-year-old man, gastric malignant peripheral nerve sheath tumor, gastrectomy), Cmin,ss at day 13 was 2.7 mg/L. For these two patients, intake with food and dose fractioning only slightly increased pazopanib Cmin,ss to 12.0 mg/L and 6.5 mg/L, respectively (therapeutic threshold in sarcoma patients: 27 mg/L). Treatment adherence was good in all patients.

CONCLUSION

Optimal pazopanib exposure cannot be achieved in patients with GIR, and thus, other therapeutic strategies should be encouraged. Pretherapeutic assessment seems crucial to evaluate factors as bariatric surgery that may impact pazopanib concentrations. Therapeutic drug monitoring could be helpful to optimize pazopanib response in these patients.

Biology and Management of High-Grade Chondrosarcoma: An Update on Targets and Treatment Options

This review provides an overview of histopathology, clinical presentation, molecular pathways, and potential new systemic treatments of high-grade chondrosarcomas (CS), including grade 2−3 conventional, dedifferentiated, and mesenchymal CS. The diagnosis of CS combines radiological and histological data in conjunction with patient clinical presentations. Conventional CS is the most frequent subtype of CS (85%) and represents about 25% of primary bone tumors in adults; they can be categorized according to their bone location into central, peripheral, and periosteal chondrosarcomas. Central and peripheral CS differ at the molecular level with either IDH1/2 mutations or EXT1/2 mutations, respectively. CDKN2A/B deletions are also frequent in conventional CS, as well as COL2A1 mutations. Dedifferentiated CS develops when low-grade conventional CS transforms into a high-grade sarcoma and most frequently exhibits features of osteosarcoma, fibrosarcoma, or undifferentiated pleomorphic sarcoma. Their molecular characteristics are similar to conventional CS. Mesenchymal CS is a totally different pathological entity exhibiting recurrent translocations. Their clinical presentation and management are different too. The standard treatment of CSs is wide en-bloc resection. CS are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in an attempt to achieve local control in unresectable tumors. Chemotherapy is possibly effective in mesenchymal chondrosarcoma and is of uncertain value in dedifferentiated chondrosarcoma. Due to resistance to standard anticancer agents, the prognosis is poor in patients with metastatic or unresectable chondrosarcomas. Recently, the refined characterization of the molecular profile, as well as the development of new treatments, allow new therapeutic options for these rare tumors. The efficiency of IDH1 inhibitors in other malignancies suggests that these inhibitors will be part of IDH1/2 mutated conventional CS management soon. Other treatment approaches, such as PIK3-AKT-mTOR inhibitors, cell cycle inhibitors, and epigenetic or immune modulators based on improving our understanding of CS molecular biology, are emerging.

Development and validation of a host-dependent, PDL1-independent, biomarker to predict 6-month progression-free survival in metastatic non-small cell lung cancer (mNSCLC) patients treated with anti-PD1 immune checkpoint inhibitors (ICI) in the CERTIM Cohort: The ELY study

Background

Immune checkpoint inhibitors (ICI) are dramatically active in a minority of non-small cell lung cancer (NSCLC) patients. We studied here the relationship between patients's metabolism and outcome under ICI.

Methods

Metastatic NSCLC patients underwent a nutritional assessment prior to initiating immunotherapy. Resting energy expenditure (REE) was measured (mREE) using ambulatory indirect calorimetry and compared with the theoretical value (tREE) provided by the Harris and Benedict formula. The primary endpoint was 6-month progression-free survival (PFS). Secondary endpoints included objective response rate (ORR) and disease control rate (DCR) based on investigator review per RECIST v1.1. and overall survival (OS). The association of patient's metabolism with 6-month PFS was first explored in a single-center training cohort to estimate the effect size. The relationship between patient's metabolism and 6-month PFS was then tested in an independent non interventional observational prospective cohort (ELY) of 100 patients recruited in two tertiary university centers.

Findings

In the entire cohort, the ORR was 14% for the hypermetabolic group (n = 10/74) vs 38% for the normometabolic group (n = 26/68), respectively (estimated difference 25%, 95CI 9–40%, p = 0.001). The DCR was 28% for the hypermetabolic group (n = 21/74) vs 53% for the normometabolic group (n = 36/68), respectively (estimated difference 25%, 95CI 7–42%, p = 0.005). In the validation cohort (100 patients, 2 centers), normometabolic patients (defined as mREE/tREE < 110%) had increased 6-month PFS (57% versus 22%; odds ratio: 4.76; IC95 [1.87 – 12.89]; p<0.001) and improved overall survival (HR 2.20; IC95: 1.41–3.44; p<0.001). The positive and negative predictive values of normometabolism to identify non-progressive patients at 6 months, were 57% and 78% respectively, sensitivity was 72% and specificity was 66%. In multivariate analysis including PD-L1 tumor status, basal metabolism was an independent predictive factor for 6-month PFS.

Interpretation

Normometabolism is a new independent parameter to identify mNSCLC patients who will benefit from ICI, with both improved tumor response, 6-month PFS, and survival.

Funding

This work was supported by Baxter (04012016).

Impact of the COVID-19 pandemic on the management of cancer patients: the experience of the cancer outpatients department of a university hospital in Paris

Cancer patients are a highly vulnerable group in the COVID-19 pandemic and it has been necessary for oncology units to adapt to this unexpected situation. We present our management of outpatients with cancer during the pandemic. We applied two major adaptations: extending the intervals between injections for maintenance therapy and protocol adaptation for patients with comorbidities. Between 17 March and 30 April 2020, 406 patients were treated in our outpatients department. Protocols were adapted for 94 (23.1%) patients. Among them, 49% had an extended interval between treatment administrations, 22.3% had modified protocols to reduce toxicity, 20.2% had therapeutic interruptions and 5.3% did not receive their treatment because of a COVID-19 infection. Overall, protocol adaptations concerned more than 20% of the patients. This pandemic was an opportunity for oncologists to re-examine the risk versus benefit balance of administering immunosuppressive treatment and highlighted that oncology daily routine should not be applied automatically.

Determinants of the access to remote specialised services provided by national sarcoma reference centres

Background

Spatial inequalities in cancer management have been evidenced by studies reporting lower quality of care or/and lower survival for patients living in remote or socially deprived areas. NETSARC+ is a national reference network implemented to improve the outcome of sarcoma patients in France since 2010, providing remote access to specialized diagnosis and Multidisciplinary Tumour Board (MTB). The IGéAS research program aims to assess the potential of this innovative organization, with remote management of cancers including rare tumours, to go through geographical barriers usually impeding the optimal management of cancer patients.

Methods

Using the nationwide NETSARC+ databases, the individual, clinical and geographical determinants of the access to sarcoma-specialized diagnosis and MTB were analysed. The IGéAS cohort (n = 20,590) includes all patients living in France with first sarcoma diagnosis between 2011 and 2014. Early access was defined as specialised review performed before 30 days of sampling and as first sarcoma MTB discussion performed before the first surgery.

Results

Some clinical populations are at highest risk of initial management without access to sarcoma specialized services, such as patients with non-GIST visceral sarcoma for diagnosis [OR 1.96, 95% CI 1.78 to 2.15] and MTB discussion [OR 3.56, 95% CI 3.16 to 4.01]. Social deprivation of the municipality is not associated with early access on NETSARC+ remote services. The quintile of patients furthest away from reference centres have lower chances of early access to specialized diagnosis [OR 1.18, 95% CI 1.06 to 1.31] and MTB discussion [OR 1.24, 95% CI 1.10 to 1.40] but this influence of the distance is slight in comparison with clinical factors and previous studies on the access to cancer-specialized facilities.

Conclusions

In the context of national organization driven by reference network, distance to reference centres slightly alters the early access to sarcoma specialized services and social deprivation has no impact on it. The reference networks’ organization, designed to improve the access to specialized services and the quality of cancer management, can be considered as an interesting device to reduce social and spatial inequalities in cancer management. The potential of this organization must be confirmed by further studies, including survival analysis.

Abstract 3721: Relationship between insulin resistance and chemosensitivity of high grade bone sarcoma

Background: Neoadjuvant chemotherapy with intercalated surgery is the standard of care for resectable high-grade bone sarcoma (BS) but identification of biomarkers for chemosensitivity prediction is still needed. Insulin-like Growth Factor (IGF) pathway was first linked with sarcoma biology approximately 30 years ago (El-Brady OM, 1990).

Methods: We recruited 138 pts with newly diagnosed primary localized or metastatic BS. We measured fasting blood glucose and insulin, body mass index (BMI). The HOMA-IR (Homeostasis Model Assessment) score ((Glucose (mmol/l) x Insulin) / 22.5), which has been proven to reliably detect insulin resistance IR was calculated, and patients with HOMA-IR &gt; 2.6 were considered as IR. We collected characteristics usually associated with insulin resistance: age, obesity, diabetes, dyslipidemia and hypertension.

Results: Out of 138 pts, 50 (36%) were insulin resistant: HOMA-IR &gt;2.6. Thirty-two IR patients (64%) had no cardiovascular risk factor. In univariate analysis, IR was associated with obesity (BMI &gt; 30 kg/m2)(22% vs 3%, p=0.0015), but not with age (median 36,8 vs 41 years, p=0.19). IR was more prevalent in Ewing sarcoma (14/29; 48%) and chondrosarcoma (7/16; 44%) followed by osteosarcoma (25/67; 37%) and other rare bone sarcomas (4/26; 15.3%), but not significantly (p=0.097). After neoadjuvant chemotherapy and surgery of Ewing tumor and osteosarcoma, pathologic tumor necrosis was higher in IR pts (88.9 vs 75%, p= 0.028).

Conclusion: Our results suggest that metabolic profile may help to discriminate best candidates for neoadjuvant chemotherapy in high-grade bone sarcomas. Further studies are needed to confirm and explain these results.

Citation Format: Pascaline Boudou-Rouquette, Ithar Gataa, Sixtine De Percin, Camille Tlemsani, David Biau, Valerie Dumaine, Virginie Audard, Frédérique Larousserie, Philippe Anract, Anne Jouinot, François Goldwasser. Relationship between insulin resistance and chemosensitivity of high grade bone sarcoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3721.

Metabolic profile and neoadjuvant chemotherapy sensitivity in high-grade bone sarcoma

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Background: Neoadjuvant chemotherapy with intercalated surgery is the standard of care for resectable high-grade bone sarcoma (BS) but identification of biomarkers for chemosensitivity prediction is still needed. Methods: We recruited 121 pts with new primary localized or metastatic BS, measured fasting blood glucose and insulin, body mass index (BMI). The HOMA-IR (Homeostasis Model Assessment) score ((Glucose (mmol/l) x Insulin) / 22.5), which has been proven to reliably detect insulin resistance was calculated, and patients with HOMA-IR > 2.6 were considered as insulin resistant (IR). We collected characteristics usually associated with insulin resistance (IR): age, obesity, diabetes, dyslipidemia and hypertension. Results: Out of 121 pts, 48 (40%) were IR: HOMA-IR > 2.6. Thirty IR patients (62%) had no cardiovascular risk factor. In univariate analysis, IR was associated with obesity (BMI > 30 kg/m2)(23% vs 3%, p = 0.0013), but not with age (median 38.4 vs 43.3 years, p = 0.15). IR was more prevalent in Ewing sarcoma (12/21; 57%) and chondrosarcoma (7/13; 54%) followed by osteosarcoma (25/61; 41%) and other rare bone sarcomas (4/26; 15.3%)(p = 0.037). After preoperative chemotherapy and surgery of Ewing tumor and osteosarcoma, pathologic tumor necrosis was higher in IR pts (85.8 vs 69.3%, p = 0.012). Using multivariate linear regression models, IR was independently associated with pathologic tumor necrosis (p = 0.042) but not with obesity (p = 0.55). Conclusions: Our results suggest that tumor-induced metabolic profile may help to discriminate best candidates for preoperative chemotherapy in high-grade bone sarcomas. Further studies are needed to confirm and explain these results.