Everolimus: an mTOR inhibitor for the treatment of tuberous sclerosis

Tuberous sclerosis complex (TSC) is a devastating disease affecting virtually all organ systems of the body and is characterized by multiple hamartomas and neurodevelopmental disorders. The majority of patients with TSC have mutations in TSC1 or TSC2, resulting in constitutive activation of mTOR. Because the pathogenesis of the disease is mTOR hyperactivity, mTOR inhibitors have the potential to treat the underlying cause in TSC patients. Everolimus is the first mTOR inhibitor approved in the USA for the treatment of patients with subependymal giant-cell astrocytomas (SEGAs) associated with TSC. Evidence supports and ongoing studies are evaluating the role of mTOR inhibitors in the treatment of a wide spectrum of disease manifestations, including reduction in tumor volume (SEGAs, renal angiomyolipoma) and improvement in epilepsy, lung function and skin manifestations, including facial angiofibromas. In time, the use of mTOR inhibitors in patients with TSC will likely be very well established.     

Comparative effectiveness of everolimus and axitinib as second targeted therapies for metastatic renal cell carcinoma in the US: a retrospective chart review

Background Second targeted therapies for metastatic renal cell carcinoma (mRCC) include mammalian target of rapamycin inhibitors (mTORis) and tyrosine kinase inhibitors (TKIs). This observational study compares overall survival (OS) and progression-free survival (PFS) of patients treated with everolimus (an mTORi) and axitinib (a TKI) following first TKI, and assesses the impact of type and duration of first TKI on the relative effectiveness of these second targeted therapies.

Methods Retrospective reviews of medical records were conducted by medical oncologists or hematologists/oncologists recruited from a nationwide panel. Included patients with mRCC were required to have discontinued a first TKI (sunitinib, sorafenib, or pazopanib) for medical reasons, and to have initiated everolimus or axitinib as second targeted therapy between February 2012 and January 2013. OS and PFS were compared between patients treated with everolimus vs. axitinib using multivariable Cox proportional hazards regression models. Comparative results were also stratified by type and duration of first TKI.

Results Included patients (n?=?325 for everolimus and n?=?127 for axitinib) had a mean age of 61 years and 31% were female. Sunitinib was the most commonly used first TKI (73%). After adjusting for patient characteristics, no statistically significant differences were observed in OS or PFS between everolimus and axitinib. When stratifying by type and duration of first TKI, there was no statistically significant difference in OS between everolimus and axitinib in all subgroups except for patients with?<6 months on sunitinib or sorafenib as first TKI. No significant difference in PFS was observed in any subgroup.

Limitations Important limitations include potential missing or inaccurate data in medical charts, and confounding due to unobserved factors.

Conclusions In this retrospective chart review, no significant differences were detected in OS or PFS between axitinib and everolimus as second targeted therapy. Longer duration of first TKI was not associated with increased effectiveness of subsequent axitinib compared to everolimus.     

Everolimus compliance and persistence among tuberous sclerosis complex patients with renal angiomyolipoma or subependymal giant cell astrocytoma

Objective: Everolimus is the only FDA approved drug to treat renal angiomyolipoma or subependymal giant-cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC). Potential differences exist between patients with commercial and Medicaid insurance on everolimus use; however, there is limited information from the real world. This study compared compliance and persistence of everolimus between commercial and Medicaid patients using US claims data.

Methods: Patients with ≥1 claim of TSC with renal angiomyolipoma or SEGA were selected from the MarketScan commercial (1 January 2009–31 August 2016) and Medicaid (1 January 2009–30 June 2015) databases. Patients were followed from index date (the earliest date of TSC, renal angiomyolipoma or SEGA diagnosis) to death or end of data. Non-persistence, defined as ≥60?day gap without everolimus, and medication possession ratio (MPR) were assessed among the subset of patients with ≥1 year of follow-up from the first everolimus claim.

Results: A total of 1497 TSC patients met the study criteria (896 renal angiomyolipoma only, 411 SEGA only and 190 both). Compared to Medicaid patients (N?=?513), commercial patients (N?=?984) had the same ages (22 years) but a shorter length of follow-up (38 vs. 48 months, p?<?.001). Medicaid and commercial patients had similar rates of being treated with everolimus (14.4% vs. 13.6%, p?=?.668), but it took Medicaid patients a longer time to start everolimus (871 vs. 704 days, p?<?.001). Although the non-persistence rate was not significantly different between commercial and Medicaid patients (42.5% vs. 35.1%, p?=?.561), the number of days from everolimus initiation to non-persistence was significantly lower for commercial patients (945 vs. 1132, p?<?.001). During the 1 year post everolimus initiation, commercial patients had a significantly higher MPR (0.81 vs. 0.74, p?<?.001) and higher percentage of patients with MPR ≥0.80 (67.8% vs. 58.1%, p?<?.001).

Conclusions: Among TSC patients with renal angiomyolipoma or SEGA and treated with everolimus, everolimus MPR was between 0.74 and 0.81. Medicaid patients had lower MPR than commercial patients but better persistence.     

Everolimus-induced osteonecrosis of the jaw in the absence of bisphosphonates: a case report

Osteonecrosis of the jaw (ONJ) is a rare, but severe, condition that has traditionally been associated with the use of bisphosphonates. We report what is, to our knowledge, the first case of ONJ secondary to the use of everolimus, in the absence of treatment with bisphosphonates in a 65-year-old man who was given it for immunosuppression after a renal transplant. After 18 months of treatment, he was diagnosed with severe ONJ and underwent radical debridement of the palate and complete dental clearance of the maxilla.     

Therapeutic Drug Monitoring for Everolimus in Heart Transplant Recipients Based on Exposure–Effect Modeling

Everolimus, a proliferation signal inhibitor, is an immunosuppressant that targets the primary causes of progressive allograft dysfunction, thus improving the long-term outcome after heart transplantation. The present study investigated whether therapeutic drug monitoring (TDM) of everolimus would benefit heart transplant patients. Data from a twelve-month phase III trial comparing everolimus (1.5 or 3 mg daily) with azathioprine were used to evaluate everolimus pharmacokinetics, exposure-efficacy/safety and TDM prognostic simulations. Everolimus trough levels were stable in the first year post-transplant and averaged 5.2 +/- 3.8 and 9.4 +/- 6.3 ng/mL in patients treated with 1.5 and 3 mg/day, respectively. Cyclosporine trough levels were similar in all treatment groups. Biopsy-proven acute rejection (BPAR) was reduced with everolimus trough levels > or =3 ng/mL. Intravascular ultrasound (IVUS) analysis showed evidence of reduced vasculopathy at 12 months with increasing everolimus exposure. Unlike cyclosporine, increasing everolimus exposure was not related to a higher rate of renal dysfunction. The TDM simulation, which was based on two everolimus dose adjustments and an initial starting dose of 1.5 mg/day, showed that the simulated BPAR rate (with TDM) was 21% versus 26% in the group with fixed dosing. Therefore, TDM in heart transplantation could optimize immunosuppressive efficacy and reduce treatment-related toxicity.     

Everolimus with Optimized Cyclosporine Dosing in Renal Transplant Recipients: 6-Month Safety and Efficacy Results of Two Randomized Studies

Two prospective, randomized studies evaluated everolimus 1.5 vs. 3 mg/day with steroids and low-exposure cyclosporine (CsA) (C2 monitoring) in de novo renal transplant patients. Everolimus dosing was adjusted to maintain a minimum trough level of 3 ng/mL. Study 1 (A2306; n=237) had no induction therapy; in Study 2 (A2307; n=256) basiliximab was administered (Days 0 and 4). The primary endpoint was renal function at 6 months. CsA C2 target levels, initially 1200 ng/mL in Study 1 and 600 ng/mL in Study 2, were tapered over time post-transplant. Median creatinine levels in Study 1 were 133 and 132 micromol/L at 6 months in the 1.5 and 3 mg/day groups, respectively, and 130 micromol/L in both groups in Study 2. Biopsy-proven acute rejection (BPAR) occurred in 25.0% and 15.2% of patients in the 1.5 and 3 mg/day groups in Study 1, and 13.7% and 15.1% in Study 2. Incidence of BPAR was significantly higher in patients with an everolimus trough <3 ng/mL. There were no significant between-group differences in the composite endpoint of BPAR, graft loss or death, nor any significant between-group differences in adverse events in either study. Concentration-controlled everolimus with low-exposure CsA provided effective protection against rejection with good renal function.     

Lenvatinib for the treatment of kidney cancer

Introduction: Sequential administration of single targeted agents has evolved as the dominant paradigm in advanced RCC treatment. Lenvatinib plus everolimus is the first combination therapy in advanced RCC to show improvement in efficacy compared to monotherapy in advanced RCC while maintaining manageable toxicity profile.

Areas covered: This review gives a brief overview of the contemporary clinical data on lenvatinib including its mechanism of action, pharmacokinetics, efficacy and safety profile in combination with everolimus. The clinical applications of lenvatinib in combination with everolimus are addressed within the context of the current competitive therapeutic landscape of RCC.

Expert commentary: Lenvatinib is a new VEGF receptor-targeted tyrosine kinase inhibitor approved in combination with everolimus for second-line therapy in patients with advanced renal cell carcinoma progressing on a first-line VEGF receptor-targeted tyrosine kinase inhibitor. The combination of lenvatinib with everolimus significantly improved progression-free survival compared with everolimus with a hazard ratio of 0.40 and increased objective response to 43%. Optimal sequence of therapy targeting the tumor and the immune system remains a challenge and further investigation is warranted.     

Conversion from calcineurin inhibitors to mTOR inhibitors as primary immunosuppressive drugs in pediatric heart transplantation

There are only a few reports of successful use of mammalian target of rapamycin (mTORI) as primary immunosuppression in pediatric heart transplantation. Compared to calcineurin inhibitors, mTORI have less side effects, especially nephrotoxicity, infections, and malignancies. A retrospective study was conducted at our institution of all 170 heart transplants from 1995 to 2015. Nineteen patients were switched from tacrolimus (n=15) or cyclosporin (n=4) to everolimus (n=4) or sirolimus (n=15) due to nephrotoxicity (n=5), malignancy (n=8), EBV viremia/reactive plasmacytic changes (n=5), and immune hemolytic anemia (n=1). We monitored for rejection, infection, BUN, creatinine, hyperlipidemia, EBV and CMV copies, CBC, cardiac allograft vasculopathy (CAV), and death. Target trough levels of sirolimus and everolimus were 4‐10. Four treatment failures included debilitating rash, bone marrow suppression, recurrent rejection, and renal transplantation. There were no deaths. One patient had recurrent rejection episodes, and tacrolimus was reinitiated. One patient with preexisting CAV underwent heart retransplantation. One patient, who was treated for PTLD, transformed to CD30+ Hodgkins disease, and was treated with brentuximab. There were three acute rejection episodes. Median creatinine preswitch was higher 0.82 than postswitch 0.78 (P=.016). Median eGFR was lower preswitch, 75.6, than postswitch, 91.2 (P=.0004). These results indicate that conversion to mTORI as primary immunosuppression may be safely accomplished in some pediatric heart transplant patients.