Low WBC, Neutrophils Low BEFORE Chemo?

My husband is 60, has stage 4 metastatic, hormone sensitive PC (spread to bones), Gleason 10, PSA 500. Three weeks ago his PSA was 159, but a low WBC. With respect to treatment, he's had one treatment of radiation (shoulders), received a shot of Eligard and started Nubeqa 10 days ago. We don't have a recent PSA count, but his WBC continue to slowly fall, and his Neutrophils are 1.13. We need to be in a better range for chemo. Is this something for us to be concerned about? Had anyone experienced this? I'd appreciate any and all advice, thank you!