Scholz M, et al. – Keeping the objective in mind, researchers demonstrated that the addition of ipilimumab (IPI) to sipuleucel–T (SIP–T) was well tolerated. The data indicated that IPI increased immunoglobulins specific for the PA2024 protein and PAP above the level achieved with SIP–T alone.

Methods

• They prospectively treated 9 men with progressive metastatic castrate–resistant prostate cancer (mCRPC) with SIP–T followed immediately by IPI with one of the following doses of IPI: 1 mg/kg at 1 week after SIP–T; 1 mg/kg at 1 and 4 weeks after SIP–T; or 1 mg/kg at 1, 4, and 7 weeks after SIP–T.
• They analyzed 3 patients at each level.
• Thereafter, cancer–specific immunoglobulins directed at granulocyte–macrophage–colony–stimulating factor/prostatic acid phosphatase (PAP) fusion protein (PA2024) and PAP were assessed prior to SIP–T, after SIP–T, 1 week after IPI, every other month for 5 months, then every 3 months for an additional 12 months.

Results

• It was showed that adverse events of SIP–T were consistent with previous reports.
• This study showed that IPI only caused a transient grade 1 rash in one patient.
• The evidence indicated that median age, Gleason score, and number of previous hormonal interventions were 77 years, 8, and 3, respectively.
• Eight men had bone metastases and one had lymph node metastasis.
• Statistically significant increases in serum immunoglobulin G (IgG) and IgG–IgM specific for PA2024 and PAP occurred after SIP–T.
• An additional statistically significant increase in the aforementioned immunoglobulins – above the levels achieved by SIP–T – occurred after IPI.
• They demonstrated that median clinical follow–up was 36 months (range: 26–40).
• They found that 3 patients died from progressive disease after 9, 18, and 20 months.
• Moreover, out of the remaining six patients, five of them needed further treatment that included abiraterone acetate, enzalutamide, radium–223 dichloride, and spot radiation.
• They detected that 1 patient had an undetectable PSA, who did not receive any other treatment except spot radiation.
• The evidence suggested that median PSA at last follow–up for the surviving patients was 3.8 (range: 0.6–7.47).