Phase I Study of Entinostat in Combination with Enzalutamide for Treatment of Patients with Metastatic Castration-Resistant Prostate Cancer

LESSONS LEARNED

Entinostat at the selected dose levels in combination with a standard dose of enzalutamide showed a promising safety profile in this small phase I study BACKGROUND: Entinostat inhibits prostate cancer (PCa) growth and suppresses Treg cell function in vitro and in vivo.

METHODS

This was a phase I study to explore the safety and preliminary efficacy of entinostat (3 and 5 mg orally per week) in combination with enzalutamide in castration resistant PCa (CRPC). The study was carried out in an open-label two-cohort design. Patients who had developed disease progression on or were eligible for enzalutamide were enrolled in the study. The safety profile of the combination therapy, Prostate specific antigen (PSA) levels, the pharmacokinetics of enzalutamide after entinostat administration, peripheral T-cell subtype (including Treg quantitation), and mononuclear cell (PBMC) histone H3 acetylation were analyzed.

RESULTS

Six patients with metastatic CRPC were enrolled. There was no noticeable increment of fatigue related to entinostat. Toxicities possibly or probably related to entinostat or the combination therapy included grade 3 anemia 1/6 (17%), grade 2 white blood cell (WBC) decrease 1/6 (17%), and other self-limiting grade 1 adverse events (AEs). Median duration of treatment with entinostat was 18 weeks. Entinostat did not affect the steady plasma concentration of enzalutamide. Increased PBMC histone H3 acetylation was observed in blood samples. No evident T-cell subtype changes were detected, including in Treg quantitation.

CONCLUSION

Entinostat 5 mg weekly in combination with enzalutamide showed an acceptable safety profile in this small phase I study. A planned phase II part of the trial was terminated because of sponsor withdrawal.

Phase I study of entinostat in combination with enzalutamide for treatment of patients with castration-resistant prostate cancer

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Background: Entinostat (SNDX-275, MS-275) is an oral histone deacetylase (HDAC) inhibitor with selectivity towards class I and IV HDACs. Entinostat inhibits prostate cancer (PCa) growth and suppresses Treg cell function in vitro and in vivo. The primary objective of this study was to determine the safe dose of Entinostat in combination with Enzalutamide in prostate cancer patients (PCa). Methods: Phase I, 2 cohorts "3+3", dose-escalation study to explore the safety and preliminary efficacy of Entinostat in combination with Enzalutamide in castration-resistant PCa (CRPC). The planned dose level of Entinostat was 3 and 5 mg orally per week. CRPC Patients progressed on Enzalutamide or eligible for Enzalutamide, able to tolerate 160 mg daily dose (in the initial run-in phase if Enzalutamide naïve), ECOG 0-1, and acceptable organ functions were enrolled in the study. The safety profile of the combination therapy, PSA, pharmacokinetics of Enzalutamide post-Entinostat administration, and peripheral T cell subtype (including Treg), mononuclear cell (PBMC) histone 3 acetylation were analyzed. Results: Total 6 mCRPC patients were enrolled. There was no dose limiting toxicity related to Entinostat in these patients. No obvious increased fatigue related to Entinostat. Toxicities possibly or probably related to Entinostat or the combination therapy included G3 anemia 1/6 (17%), G2 WBC decrease 1/6 (17%), All other toxicities were grade 1 only (Nausea 2/6, anorexia 1/6, emesis 1/6, constipation 1/6, headache 1/6, platelet count decrease 1/6, hypokalemia 1/6, hypoalbuminemia 1/6, hypermagnesemia 1/6). The median duration of treatment with Entinostat was 18 weeks. For patients already progressed on Enzalutamide there was no PSA response after Entinostat was added. Entinostat did not affect the steady plasma concentration of Enzalutamide. Increased PBMC H3 acetylation was observed (up to 3.6 fold from baseline) in the tested samples. No evident T cell subtype, including Treg, changes from these sample analysis. Phase II part of the trial was terminated because of sponsor withdrawal. Conclusions: Entinostat at the selected dose levels in combination with standard dose of enzalutamide showed promising safety profile in this small phase I study. Clinical trial information: NCT03829930.

Surveillance biologique après chirurgie orthopédique. Quel apport au diagnostic des complications infectieuses et thromboemboliques ?

OBJECTIVES

To evaluate the usefulness of monitoring C-reactive protein (CRP) level and leukocyte count for early diagnosis of infection following orthopedic surgery.

METHOD

A cohort of 179 patients was followed: group 1 comprised 128 patients undergoing lower limb arthroplasty, group 2 comprised 29 patients undergoing lower limb surgery without implant, and group 3 comprised 22 patients undergoing spinal or upper limb surgery. CRP level and leukocyte count were systematically measured on admission and then once a week for 4 weeks. Wound infections, other infections, wound disconnection without infection and hematoma were noted. CRP level and leukocyte count were monitored postoperatively in patients with and without complications.

RESULTS

CRP level was 4- to 8-fold above the normal range at the first postoperative measurement but normalized within the next 3 weeks (reaching normal levels by the 30th postoperative day, on average). In the 7 cases of wound infection (WI), the CRP level rose to 28-fold above normal and was significantly different from that in without infection or with intercurrent infection (P<0.01). A receiver operating characteristic (ROC) curve was established for CRP level, and for a value of 60 (12-fold above the normal range) the sensitivity was 100%, the specificity 83.6% and the negative predictive value 100%. The variation in leukocyte count was minor, with a significant difference noted between only patients not infected or those with WI (P<0.05).

DISCUSSION AND CONCLUSIONS

Measurement of CRP level can be used for early diagnosis of wound infection. In the case of strong clinical suspicion or in the presence of high risk factors, when the level is at 12-fold or more above the normal range, the diagnosis of infection is highly probable.

Surveillance biologique après chirurgie orthopédique. Quel apport au diagnostic des complications infectieuses et thromboemboliques ?

OBJECTIVES

To determine the modification in postoperative D-dimer level as a function of the surgical act and to assess the relevance of this measure for diagnosing thromboembolism.

METHOD

A cohort of 179 patients was followed: group 1 comprised 128 patients undergoing lower limb arthroplasty, group 2 comprised 29 patients undergoing lower limb surgery without implant, and group 3 comprised 22 patients undergoing spinal or upper limb surgery. D-dimer level was systematically measured on admission and then once a week for 4 weeks. Doppler ultrasonography was performed on clinical suspicion of deep vein thrombosis. D-dimer levels were compared between patients with and without deep vein thrombosis.

RESULTS

D-dimer levels were constantly elevated postsurgery (2- to 6-fold above normal) and returned to normal by week 4 in groups 2 and 3 but remained elevated in group 1 (3-fold above normal). Deep vein thrombosis was suspected in 45 cases and confirmed by Doppler ultrasonography in 10 cases. D-dimer level was not significantly different between patients with deep vein thrombosis and those without.

DISCUSSION AND CONCLUSIONS

In the postoperative period, measurement of D-dimer level does not aid in diagnosing thromboembolism since its constant high level obviates any negative predictive value.