Efficacy of combined androgen blockade therapy in patients with metastatic hormone‐sensitive prostate cancer stratified by tumor burden

Organ-Specific Tumor Response to Enfortumab Vedotin for Metastatic Urothelial Carcinoma: A Multicenter Retrospective Study

INTRODUCTION

To evaluate the organ-specific therapeutic effect of enfortumab vedotin (EV) after chemotherapy and immunotherapy failed for advanced urothelial carcinoma.

MATERIALS METHODS

At 6 institutions between December 2021 and July 2023, we retrospectively analyzed patients with metastatic upper and lower urinary tract cancer who received EV monotherapy after platinum-based chemotherapy and immune checkpoint blockade therapy. Objective response rate (ORR) and organ-specific response rate (OSRR) were evaluated according to the Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

This study analyzed 58 patients with 210 tumor lesions, of which 24% were females and 48% had upper urinary tract cancer. The ORR and disease control rate were 53.5% and 74.1%. Moreover, we found 15 target lesions in the primary site, 7 in local recurrence, 93 in the lymph nodes, 46 in the lung, 29 in the liver, and 20 in the bone, with OSRRs of 40%, 71.4%, 61.1%, 70.6%, 90.9%, and 18.2%, respectively. Over time from baseline, the reduction rate (median) in tumor burden was 50% or more in the lymph node, lung, and liver metastases.

CONCLUSION

The organ-specific tumor response to EV in patients with metastatic urothelial carcinoma was almost favorable. The antitumor activity of EV monotherapy may be less in bone metastasis than in other organ sites. Conversely, EV showed remarkably high efficacy against liver metastasis.

Effects of apalutamide dose reduction on skin-related adverse events in patients with advanced prostate cancer: A multicenter retrospective study

BACKGROUND

We aimed to evaluate the effects of apalutamide dose reduction on skin-related adverse events (AEs) and castration-resistant prostate cancer (CRPC)-free survival in patients with advanced prostate cancer (PC).

METHODS

We retrospectively evaluated 35 patients with nonmetastatic CRPC and 72 patients with treatment-naïve metastatic castration-sensitive PC (mCSPC) who were treated with apalutamide. The primary outcome was the effect of apalutamide dose reduction on skin-related AEs. The secondary outcomes were the effect of apalutamide dose reduction on skin-related AEs in patients with small body size, postskin AE apalutamide discontinuation rate, and CRPC-free survival in patients with mCSPC treated with upfront apalutamide plus androgen deprivation therapy.

RESULTS

Of the 107 patients, 65 (60.7%) and 42 (39.3%) were treated with full and reduced doses of apalutamide, respectively. The skin-related AE rate was not significantly different between the groups (55% vs. 43%, p = 0.761). In the group receiving reduced apalutamide dose, the incidence of skin-related AEs was significantly lower in patients with small body sizes (body weight <67 kg and body mass index <24 kg/m² ) than in those with other body sizes. The postskin AE apalutamide discontinuation rate was significantly differed between patients receiving the full (50%) and reduced (16.7%) doses. In the 72 patients with mCSPC, CRPC-free survival was not significantly different between the full and reduced dose groups.

CONCLUSION

Apalutamide dose reduction was not significantly associated with the incidence of skin-related AEs. However, dose reduction in patients with small body sizes may alleviate skin-related AEs without sacrificing oncological outcomes.

Comparison of efficacy and medical costs between upfront docetaxel and abiraterone treatments of metastatic hormone-sensitive prostate cancer patients in real-world practice: a multicenter retrospective study

PURPOSE

We compared the real-world efficacy and medical costs for treatment with upfront docetaxel (DOC) and abiraterone acetate (ABI) up to progression-free survival 2 (PFS2) in patients with metastatic hormone-sensitive prostate cancer (mHSPC).

METHODS

This multicenter retrospective study included 340 patients with mHSPC treated with either upfront DOC or upfront ABI between October 2015 and December 2021. We compared PFS2 and medical costs between the two treatment groups. PFS2 was defined as the time from first-line therapy to progression on second-line therapy. Medical costs were estimated using the National Health Insurance drug prices in 2022 in Japan.

RESULTS

The upfront DOC and ABI groups included 107 and 233 patients, respectively. The incidence of metastatic castration-resistant PC progression was significantly higher in the upfront DOC group compared with the incidence in the upfront ABI group. However, no significant differences in PFS2 were observed between the two treatment groups. Monthly medical costs per patient were significantly higher in the upfront ABI group ($3453) compared with the costs in the upfront DOC group ($1239, P < 0.001). The cost differences were significantly influenced by differences in the length of androgen deprivation therapy monotherapy (DOC group, 13.4 months vs. ABI group, 0.0 months).

CONCLUSIONS

We observed a significant cost benefit in the upfront DOC group in Japanese real-world practice, while the PFS2 rates were similar between the groups. Upfront DOC was a more cost-effective option for men with mHSPC who were eligible for toxic chemotherapy.

Humoral response after SARS-CoV-2 mRNA vaccination in patients with prostate cancer using steroids

OBJECTIVES

The effect of concomitant steroid use on the antibody response to a SARS-CoV-2 vaccine in patients with prostate cancer (PC) remains unknown. We aimed to evaluate the rates of antispike immunoglobulin G (IgG) antibody response to the BNT162b2 mRNA vaccine in patients with PC using steroids.

METHODS

This cross-sectional study conducted from June 21, 2021 to January 5, 2022 included 215 patients with PC who received the second dose of the BNT162b2 mRNA vaccine at least 7 days before the measurement of titers of IgG antibodies against the receptor-binding domain of SARS-CoV-2 spike (S) protein. We compared the rate of anti-SARS-CoV-2 S IgG ≥15 U/mL between patients with or without concomitant steroid use.

RESULTS

Of 215, we identified 33 patients who had concomitant steroid use. Of these, 12 and 21 patients were metastatic castration-sensitive PC and castration-resistant PC (CRPC), respectively. Patients with concomitant steroid use had a significantly lower rate of antibody titer ≥15 U/mL than those without steroid use (82% vs. 95%, P = 0.021). Patients with CRPC with concomitant steroid use (n =21) also had a lower rate of antibody titer ≥15 U/mL (71%) than those without steroid use (93%, P = 0.051), although this was not statistically different. Increased number of systemic treatments administered after diagnosis of CRPC (3 lines or more) were significantly associated with antibody titers <15 U/mL (97% vs. 77%, P <0.001).

CONCLUSION

The humoral response to the BNT162b2 mRNA vaccine was significantly lower in patients with concomitant steroid use. Anti-SARS-CoV-2 S antibody titers were affected by CRPC status, the accumulation of post-CRPC treatments, and steroid use.

Effect of upfront intensive therapy on oncological outcomes in older patients with high tumor burden metastatic castration-sensitive prostate cancer: A multicenter retrospective study

BACKGROUND

The effect of upfront intensive therapy on the prognosis of older patients with metastatic castration-sensitive prostate cancer (mCSPC) remains unclear. Thus, we assessed the impact of older age (≥75 years) on oncological outcomes in mCSPC patients with a high tumor burden.

METHODS

This multicenter retrospective study included 252 patients aged ≥75 years treated with either upfront or conventional therapy between 2014 and 2021. We compared castration-resistant prostate cancer (CRPC)-free survival (FS) and overall survival (OS) between patients with androgen deprivation therapy (ADT) plus upfront intensive therapy (docetaxel [DTX] or abiraterone acetate [ABI] plus prednisolone) and conventional therapy (ADT monotherapy or ADT combined with bicalutamide). We evaluated the effect of upfront intensive therapy on prognosis by multivariable Cox regression analysis.

RESULTS

The 231 patients enrolled in our study were classified in the conventional group (n = 148) or the upfront group (n = 104; DTX = 27 and ABI = 77). The upfront group had significantly prolonged CRPC-FS and OS compared with the conventional group, and this was also the case in the background-adjusted multivariable Cox regression analysis.

CONCLUSION

Patients aged ≥75 years who received upfront intensive therapy had significantly longer CRPC-FS and OS compared with similar age patients treated with conventional therapy in real-world practice. The oncological benefit may not diminish in this older population.