Why would anyone even want to take Zytiga now that Yonsa has been FDA approved?!
"The Yonsa formulation of Yonsa is developed to have a smaller overall particle size. In prior studies, the fine particle size was found to increase dissolution rates and oral bioavailability while decreasing the effects of food on treatment efficacy. In the phase 2 study, the 500-mg dose of Yonsa had similar absorption as the 1000-mg dose of Zytiga."
"Yonsa was administered with methylprednisolone at 4 mg and Zytiga was given with prednisone at 5 mg."
"Four patients had a serious AE in the Yonsa group compared with 7 in the Zytiga arm, two of which led to death (prostate cancer progression and myocardial infarction)."
curetoday.com/articles/fda-...
FDA Approves Combination Treatment for Metastatic Prostate Cancer
The Food and Drug Administration (FDA) approved a new formulation of Yonsa (abiraterone acetate) in combination with methylprednisolone as a treatment for men with metastatic castration-resistant prostate cancer (mCRPC), according to Sun Pharma, the company commercializing the treatment.
BY Silas Inman
PUBLISHED May 24, 2018
The Food and Drug Administration (FDA) approved a new formulation of Yonsa (abiraterone acetate) in combination with methylprednisolone as a treatment for men with metastatic castration-resistant prostate cancer (mCRPC), according to Sun Pharma, the company commercializing the treatment.
The approval was based on findings from a phase 2 study comparing the Yonsa formulation of Yonsa to the original, Zytiga, which was approved in 2011. In the trial, which was known as STAAR, Yonsa demonstrated therapeutic equivalence to Zytiga, based on serum testosterone levels, and both agents showed similar declines in PSA of 50 percent or higher (PSA-50).
“We are pleased to add Yonsa to our growing oncology portfolio and continue to deliver on Sun Pharma’s commitment for enhanced patient access to innovative cancer therapies,” Abhay Gandhi, CEO - North America, Sun Pharma, said in a statement announcing the approval.
The Yonsa formulation of Yonsa is developed to have a smaller overall particle size. In prior studies, the fine particle size was found to increase dissolution rates and oral bioavailability while decreasing the effects of food on treatment efficacy. In the phase 2 study, the 500-mg dose of Yonsa had similar absorption as the 1000-mg dose of Zytiga.
The STAAR trial included 53 patients with mCRPC who had not received prior Yonsa, enzalutamide, radium-223, or chemotherapy (unless it was docetaxel one or more year prior to study entry). Patients were randomized in a 1 to 1 ratio to receive Yonsa at 500 mg (four tablets at 125 mg each) or Zytiga at 1000 mg (four tablets at 250 mg each). Yonsa was administered with methylprednisolone at 4 mg and Zytiga was given with prednisone at 5 mg.
Across both arms, approximately half of patients (54.7 percent) had Gleason higher than 7 disease. There were more Caucasians in the Yonsa arm (83.3 percent) than in the Zytiga group (69 percent). The mean time since diagnosis of mCRPC was 2.1 years in both groups and baseline testosterone levels were 7.28 in the Yonsa group and 7.95 in the Zytiga arm (8.4 percent relative difference).
The mean testosterone level at day 9 and 10 was 0.32 (±0.45) in the Yonsa group and 0.29 (±0.29) in the Zytiga arm. The median level at day 9 and 10 was 0.15 with Yonsa and 0.19 with Zytiga. At day 28, patients in both arms had a mean testosterone level of 0.10 and the mean was 0.22 (±0.26) and 0.25 (±0.30) in the Yonsa and Zytiga groups, respectively. At day 84, the median was 0.10 with Yonsa and 0.15 with Zytiga.
PSA-50 was observed in more than 65 percent of patients in both arms of the study. The least square mean difference in serum PSA level between Yonsa and Zytiga at day 28 was -15.13. At day 84, the difference was -18.80.
Overall, fewer patients experienced treatment-emergent adverse events (AEs) in the Yonsa arm compared with Zytiga (75 percent vs 82.8 percent, respectively). Grade 3 or higher AEs were experienced by 16.7 percent of patients in the Yonsa arm and for 17.2 percent in the Zytiga group. Four patients had a serious AE in the Yonsa group compared with 7 in the Zytiga arm, two of which led to death (prostate cancer progression and myocardial infarction).
Yonsa (Zytiga) was initially approved as a treatment for men with mCRPC following chemotherapy. It subsequently gained approval for use prior to chemotherapy. In February 2018, Zytiga was approved in combination with prednisone for patients with metastatic high-risk castration-sensitive prostate cancer.
) - My apology for not responding earlier. I've been more than overwhelmed lately. My mother passed away in March from ovarian cancer, leaving behind my 92 yr old dad who she was taking 100% care of, and he's not able to be on his own, and they were living hundreds of miles from us. (Mom was diagnosed stage 4 ovarian, a couple weeks after my husband was diagnosed st 4 prostate cancer - early winter 2017 - both were a surprise/shock). During this time my husband went through a very 'scary' period where his blood test results disqualified him from any more treatments of the combo chemo he needed (he only had 1 infusion of carboplatin/jevtana). His bone pain was gettting worse, so while he was waiting for the benefits of the 10 radiation treatments to kick in (lower spine, L1-L4) he had to keep upping the opoid pain meds, which made him basically comatose,in bed all day - same position, and vomiting every once in a while. That was horrible!! Dr. started him on Lynparza at the beginning of March (he has the BRCA gene - somatic). Once on Lynparza, his pain quickly lessened (probably a combo of the Lynparza and the radaiation treatments kicking in) and at the same time his blood tests showed his liver numbers were back within normal range (yay!!). Once his pain lessened, he immediately went off all the opoids and other meds he was taking for the side effects of the Lupron and opoids, and the side effects from those 'side effect' drugs!! That caused difficult withdrawal side effects for about 1-1/2 weeks. Almost immediately after stopping the opoids, my husband came back!! So at that point, he only needed the Lynparza - a miracle drug! A couple weeks ago he had a bone scan and CT scan which gave mixed results, but our MO felt overal positive. The Lynparza has been working in soft tissue, but his PSA was up, and bone scans were showing activity. So our MO just added Zytiga to his Lynparza. He will have a blood test next week to see how this is going. Most importantly, he's been much happier - up and about - walking the dog in the morning (carefully! and not too far) and just feeling overall better - almost 'normal'. He's still anemic (a side effect of the Lynparza - almost needed a transfusion a couple times), so he gets a bit out of breath when being more active, but this, too, has been slowly improving. 
Zytiga vs xtandi 
Syncromune Granted FDA Fast-Track Designation for SYNC-T SV-102 for the Treatment of Metastatic Castrate-Resistant Prostate Cancer (mCRPC)
'Substandard' Control Arms in Clinical Trials– Practice found common in prostate cancer studies
Zytiga vs Docetaxel in mCRPC 
