Addition of Metformin after Progression on Abiraterone.

[pjoshea13]

New Swiss Phase 2 Pilot study below [1].

"Twenty-five men with metastatic castration-resistant prostate cancer and prostate-specific antigen (PSA) progression while receiving treatment with abiraterone from 3 Swiss centers were included in this single-arm phase 2 trial between November 2013 and September 2016. Metformin was added to abiraterone continuously at 1000 mg twice daily in uninterrupted 4-week cycles. The primary end point was the absence of disease progression at 12 weeks"

"The primary end point PFS12 was 12% (3 of 25 patients)"

"A higher-than-expected gastrointestinal toxicity attributed to metformin was observed."

Conclusion: "no meaningful clinical benefit".

Some of the team were on the Swiss study that impressed Dr. Myers [2]. That study was "Metformin in chemotherapy-naive castration-resistant prostate cancer". It reported: "Thirty-six percent of patients were progression-free at 12 wk". Seems that after Abi failure, PCa is less responsive to Metformin. Also, perhaps Abi treatment makes the stomach less able to tolerate Metformin.

-Patrick

[1] ncbi.nlm.nih.gov/pubmed/306...

[2] ncbi.nlm.nih.gov/pubmed/244...

[cujoe]

Patrick,

What is you opinion on berberine being an "or/equal" (or possibly even better for various cancers) substitute for metformin. I'm guessing you are probably at least somewhat familiar with the multitude of research on each?

Thanks in advance for any pjoshea13 insight you provide. Be Well - cujoe

[pjoshea13 in reply to cujoe]

Cujoe,

I have an old post [1]: "Foods/Supplements-Vitamins: Berberine"

LEF introduced an AMPK activator [2] when men reported that their doctors would not give them Metformin [2].

When I was on a lower dose of Metformin, I also used berberine, & later the AMPK activator. But when I was able to get 2,000 mg Metformin daily, I stopped the others.

I stick with Metformin, but I would use berberine if that was all that was available - & I wouldn't lose any sleep.

-Patrick

[1] healthunlocked.com/advanced...

[2] swansonvitamins.com/life-ex...

[cujoe in reply to pjoshea13]

Thanks, Patrick. I am currently off treatment, have never tried for a metformin prescription, but have been proactively taking berberine for several years. So far, so good.

[snoraste]

Toxicity from metformin? that's in sharp contrast with the other study. I understand that there are a couple of clinical trials involving Metformin. Hopefully will not be long.

[dorke in reply to snoraste]

There is an arm of STAMPEDE checking this.

stampedetrial.org/media/203...

One sentence that caught my eye:

Metformin does not interact with any of the other treatments for prostate cancer and should be

continued during all further treatments given for disease progression.

[gusgold]

That sure sucks....I am tempted to drop Xtandi before it drops me and switch to DES

[podsart]

Abi?

[pjoshea13 in reply to podsart]

Lazy man's "Abiraterone".

The experts on the panel discussions I have posted seem to like the abbreviation. But that's no excuse.

-Patrick

[podsart in reply to pjoshea13]

Thanks

[tarhoosier]

My onc said, in response to my complaint of intestinal trouble from metformin, that metformin concentration in serum varied five times the value in differing individuals and this was independent of weight or BMI. He suggested taking what I could accept which is 500-750 mg/day. I sympathize with those on the trial who suffered "A higher-than-expected gastrointestinal toxicity attributed to metformin was observed." Higher than expected means truly suffering.

[jdm3]

My oncologist does not prescribe Metformin. Interestingly, he does not prescribe Duasteride with Zytiga even though one of his colleagues at DFCI helped write the research paper discussed recently.

But back to Metformin... my family physician has developed a keen interest in Metformin and its potential benefits for a variety of conditions and patients and asked if I could provide more infomation. I gave him a summary of PubMed and other references, but am wondering if anybody has recommendations for another doctor or researcher that he could call in order to discuss. One that comes to mind is Dr. Sartor. Other recommendations for peer-to-peer Metformin talks??

Thanks.