Former US President Joe Biden has become significantly weaker while undergoing treatment for an aggressive form of metastatic prostate cancer. However, the therapy is having a positive effect, according to The Washington Post, citing sources close to the politician, as reported by infohub.kz.

According to The Washington Post, the 83-year-old Biden's life is now largely centered around medical procedures. The former White House occupant spends time with family, close friends, and longtime aides, rarely appearing at public events.

Sources told the newspaper that the treatment appears to be working, but the disease itself and the side effects of therapy have significantly affected the former president's physical condition.

The Washington Post also reports that health issues have complicated several of Biden's plans. Specifically, fundraising for the construction of his presidential library in Delaware has become more difficult, and a tour to promote his memoirs, scheduled for release on November 17, remains in question.

Biden's diagnosis became known last May. At that time, his press office announced that the former president had been diagnosed with an aggressive form of prostate cancer that had metastasized to bone tissue.

Biden later said he began treatment under the care of one of the country's leading specialists and received a favorable prognosis from doctors. In addition, he underwent surgery last month to remove skin cancer cells.

As The Washington Post notes, metastatic prostate cancer is considered incurable, but modern therapies can slow its progression and improve patients' quality of life.