FDA Approves Apalutamide for Metastatic Castration-Sensitive Prostate Cancer

The FDA has approved a supplemental New Drug Application (sNDA) for apalutamide (Erleada) for the treatment of patients with metastatic castration-sensitive prostate cancer (mCSPC).¹

The sNDA was processed through the Real-Time Oncology Review Program after the application received a priority review designation when it was submitted in April 2019. Results of the phase III TITAN trial, which were presented at the 2019 ASCO Annual Meeting, were the basis for the sNDA.

"Prostate cancer is more difficult to treat once it spreads, and for patients with castration-sensitive disease, it is clear that androgen deprivation therapy [ADT] alone, is often not enough," Kim Chi, MD, a medical oncologist at BC Cancer - Vancouver and principal investigator of the TITAN study, said in a statement. "Results from the TITAN study showed that, regardless of the extent of disease, patients with metastatic castration-sensitive prostate cancer have the potential to benefit from treatment with apalutamide in addition to ADT."

The FDA has noted that the recommended dose for apalutamide is 240 mg or 4 tablets of 60 mg each, given orally once daily with or without food. Additionally, the agency recommends that patients also receive a gonadotropin-releasing hormone analog concurrently with apalutamide or should have received a bilateral orchiectomy.²

The international, randomized, double-blind phase III TITAN trial included 1052 patients with metastatic castration-sensitive prostate cancer across 260 sites, regardless of prior localized therapy, docetaxel treatment, or the extent of their disease. Patients were randomized 1:1 to receive either 240 mg oral apalutamide once daily plus ADT (n = 525) or placebo plus ADT (n = 527). Treatment was given until disease progression, unacceptable toxicity, or the end of treatment was reached.

Patients had a median age of 68 years and 62.7% had high-volume disease whereas the other 37.3% had low-volume disease. A total of 16.4% of patients had undergone a prostatectomy or had received radiotherapy for localized therapy. Previosu docetaxel therapy was noted in 10.7% of patients.

The coprimary endpoints of the trial were radiographic progression-free survival (rPFS) and overall survival (OS).

Apalutamide with ADT demonstrated an improvement in OS compared with ADT alone, resulting in a 33% reduction in the risk of death (HR, 0.67; 95% CI, 0.51-0.89;P= .0053). The combination also demonstrated a 52% reduction in the risk of radiographic progression or death (HR, 0.48; 95% CI, 0.39-0.60;P<.0001).¹

According to findings presented at the 2019 ASCO Annual Meeting and subsequently published in theNew England Journal of Medicine,at 2 years, the rate of OS was 82.4% with apalutamide and ADT compared with 73.5% in the ADT and placebo group (HR, 0.67; 95% CI, 0.51-0.89;P= .005). The 2-year rate of rPFS was 68.2% with the combination versus 47.5% with ADT alone.^3,4

Both the median times to prostate-specific antigen (PSA) progression (HR, 0.26; 95% CI, 0.21-0.32) and cytotoxic chemotherapy (HR, 0.39; 95% CI, 0.27-0.56;P<.001) were improved with the addition of apalutamide. In the combination arm, 68.4% of patients demonstrated significant PSA declines to undetectable levels compared with 28.7% in the ADT and placebo group.

Treatment with apalutamide and ADT also resulted in a 34% risk reduction in the median time to second PFS (HR, 0.66; 95% CI, 0.50-0.87).

Grade 3/4 adverse events (AEs) occurred in 42.2% of patients in the apalutamide arm compared with 40.8% in the control arm. Serious AEs occurred in 19.8% of patients versus 20.3% in the 2 arms, respectively. Discontinuations due to AEs occurred in 8% of the apalutamide arm compared with 5.3% in the group receiving ADT alone. There were 10 AE-related deaths in the apalutamide arm versus 16 in the placebo arm.

Grade &ge;3 AEs of special interest included rash (6.3% in the apalutamide arm vs 0.6% in the ADT-alone arm), fatigue (1.5% vs 1.1%, respectively), fall (0.8% in each arm), fracture (1.3% vs 0.8%), and seizure (0.2% vs 0).

"Erleada has the potential to change how patients with prostate cancer are treated, regardless of the extent of the disease or prior docetaxel treatment history, by delaying disease progression and prolonging survival," Margaret Yu, MD, vice president, prostate cancer disease area leader, Janssen Research & Development, LLC, said in a statement. "This milestone highlights Janssen's commitment to improve the standard of care for patients with prostate cancer as we continue to develop innovative treatments across the disease continuum."

Apalutamide previously received FDA approval in February 2018 for the treatment of patients with nonmetastatic castration-resistant prostate cancer.

References

1. U.S. FDA Approves Supplemental New Drug Application (sNDA) for ERLEADA (apalutamide) for the Treatment of Patients with Metastatic Castration-Sensitive Prostate Cancer (mCSPC) [press release]. Horsham, PA: Janssen Pharmaceutical Companies of Johnson & Johnson; September 17, 2019. https://prn.to/2kRwT6m. Accessed September 18, 2019.
2. FDA approves apalutamide for metastatic castration-sensitive prostate cancer. FDA website. Posted September 18, 2019. https://bit.ly/2lVOeve. Accessed September 18, 2019.
3. Chi KN, Agarwal N, Bjartell A, et al. First results from TITAN: A phase III double-blind, randomized study of apalutamide (APA) versus placebo (PBO) in patients (pts) with metastatic castration-sensitive prostate cancer (mCSPC) receiving androgen deprivation therapy (ADT).J Clin Oncol.2019;37(suppl; abstr 5006). doi: 10.1200/JCO.2019.37.15_suppl.5006.
4. Chi KN, Agarwal N, Bjartell A, et al; TITAN Investigators. Apalutamide for metastatic, castration-sensitive prostate cancer.N Engl J Med.2019;381(1):13-24. doi: 10.1056/NEJMoa1903307.