Biotech Strategy Blog

Commentary on Science, Innovation & New Products with a focus on Oncology, Hematology & Cancer Immunotherapy

Posts tagged ‘Alpharadin’

Radium-223 Delays time to first SRE

At the 2012 American Society of Clinical Oncology (ASCO) annual meeting, data was presented by Dr Oliver Sartor (ASCO 2012 Abstract 4551) that showed radium-223 (Alpharadin) significantly delayed time to first skeletal-related event (SRE) in patients with castratation-resistant prostate cancer (CRPC) and bone metastases.

The SRE data for radium-223 from the ALSYMPCA phase III trial was first presented at ASCO GU earlier this year.

ASCO 2012 radium-223 data discrepancies

Algeta in a communication I received today, however, have advised that the data contained in the ASCO 2012 abstracts has “discrepancies.”  In the absence of more precise information, the discrepancies may or may not be significant.

As with good practice, the sponsors have conducted further verification of the ALSYMPCA SRE data in preparation for the US FDA NDA regulatory submission. This has resulted in changes in the numbers previously reported for SRE data in the ASCO 2012 abstracts (Abstract #4551, LBA #4512). Though discrepancies were noted, the overall interpretation of the results has not changed. The SRE data will be disclosed once all additional data verification and analyses activities are completed.

Mike Booth, Algeta Communications & Corporate Affairs, June 15, 2012 email communication.

While the message that radium-223 significantly delays time to first SRE may not have changed, data accuracy is important and should not be taken lightly.

In his ASCO 2012 prostate cancer poster discussion, Evan Yu, Associate Professor at the University of Washington, made no mention of any “discrepancy.” Instead he used the data in Sartor’s poster that showed the time to first SRE with radium-223 to be 13.6 months versus 8.4 months with placebo, a delay of 5.1 months.

Dr Parker presented updated ALSYMPCA trial data at ASCO 2012 that showed a 5.5 month delay in time to first SRE with radium-223 (12.2 versus 6.7 months). Dr Sartor’s poster was based on 541 patients on radium-223, while Dr Parker’s data was for 614 patients. This suggests that the two presentations represent data at different time points.

Were Bayer and Algeta aware of the issues at the time of ASCO and chose not to say anything?  Obviously, if the discrepancies are small or insignificant then it would not make much difference, but a large difference would be more of a concern.

What is the accurate SRE data for radium-223 from the ALSYMPCA trial?

I look forward to a future press release from Algeta/Bayer clarifying this, and hope that they will advise ASCO if corrections need to be made to the data previously presented and published.

The abstracts for the forthcoming American Society of Clinical Oncology 2012 Genitourinary Cancers Symposium (ASCO GU) have been released and offer insight into some of the new data that will be presented at the meeting.

radium-223 Alpharadin Prostate CancerThe results of the phase III ALSYMPCA trial for radium-223 (Alpharadin) in prostate cancer were presented at ECCO/ESMO last September by Dr Chris Parker.

As expected, there is no change to data presented in Stockholm that showed radium-223 (Alpharadin) improves both Overall Survival and Skeletal Related Events:

radium-223 Overall Survival Benefit
median 14.0 vs 11.2 months; P value = 0.00185; HR = 0.695

radium-223 time to first SRE 
median 13.6 vs 8.4 months; P value = 0.00046; HR = 0.610

However, the meeting abstract published today shows that radium-223 in bone-metastatic castration resistant prostate cancer patients (CRPC), not only significantly prolonged time to first skeletal related event (SRE), but significantly prolonged 3 out of the 4 SRE components:

  • time to spinal cord compression,
  • time to pathological bone fracture
  • time to external beam radiation

No significant improvement in the SRE component of time to surgical intervention was seen with radium-223.

Subscribers to Premium Content can login to read commentary by Dr Oliver Sartor on the clinical significance of this data:

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The recent AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics international conference in San Francisco was an informative meeting.

What I particularly liked was the strategic overview that took place in many of the plenary sessions.

As an example, Johann de Bono, Professor of Experimental Cancer Medicine at The Institute of Cancer Research/The Royal Marsden in London highlighted the potential drug development targets based on prostate cancer biology:

  • Androgen Receptor (AR)
  • Heat Shock Proteins (Hsp)
  • Signaling: HER3, MET, IGF-1R, CCL2, IL-6, Src
  • PI3K/AKT/TOR signaling
  • PARP and BRCAness
  • Estrogen receptor (ER)
  • c-MYC & CHK1

His presentation discussed the possible therapeutic approaches, and complexity involved in developing novel targeted therapies for prostate cancer.

This is something that I expect we will hear more of at the AACR special conference on Advances in Prostate Cancer Research early next year.

In particular, de Bono discussed drug development strategies to target androgen receptor signaling, and some of the future challenges including:

  • Proving to the regulatory authorities that circulating tumor cell (CTC) count falls are a robust immediate endpoint of overall survival
  • Developing improved imaging for bone metastases

As a side note, there were several posters for cabozantinib (XL184) at the meeting (available on the Exelixis website), including preliminary research on computer-aided quantitative bone scan assessment.

However, as de Bono mentioned in his presentation, “diffusion weighted MRI shows hot spots not detected by bone scans.”

2010 and 2011 were good years for prostate cancer drugs, and with new approvals for MDV3100 and radium-223 (Alpharadin) expected, 2012 is set to be another “grand cru” year, to paraphase Bertrand Tombal.

If you were not able to make it to San Francisco for the Molecular Targets and Cancer Therapeutics conference, webcasts of many sessions will be available on the AACR site.


Times-Square-NYC-November-11-2011This morning the 8am session at the Chemotherapy Foundation Symposium (The Greenspan Meeting) in NYC featured a review of current developments in Prostate Cancer.

The informative 1.5 hour session covered a lot of ground with the presenters reviewing clinical data for:

  • Radium-223 Chloride: a new option for CRPC (Oliver Sartor)
  • Pomegranite extract for Rising PSA (Michael Carducci)
  • XL184 in mCRPC (David Smith)
  • Optimizing patient selection for sipuleucel-T (Simon Hall)
  • Intermittent androgen suppression for prostate cancer (Laurence Klotz)
  • Lenolidomide/docetaxel in CRPC (Daniel Petrylak)

Oliver-Sartor-MD-presenting-at-NYC-Chemotherapy-Foundation-Symposium-2011The highlight, in my opinion, was Oliver Sartor’s excellent presentation on radium-223 chloride (Alpharadin) in which he cogently outlined its mechanism of action.  He explained that radium-223:

  • targets osteoblastic bone metastases by acting as a calcium mimic
  • is a bone-seeking calcium mimetic that binds to hydroxyapatite
  • has preferential uptake in areas of new bone formation

As mentioned previously on this blog, there are critical differences between an alpha emitter such as radium-223 and other bone-seeking radiopharmaceuticals that are beta emitters.

Sartor presented some excellent slides that showed how alpha emitters require much fewer DNA hits to kill cells, are short range and have a higher initial energy per particle.  In other words they are very effective at short range within the bone microenvironment, something that Chris Parker from The Royal Marsden Hospital mentioned in his interview from ECCO/ESMO in Stockholm.

Sartor concluded his Chemotherapy Foundation Symposium presentation by reflecting on “where do we go from here” in prostate cancer?  Some of his observations were:

  • We are currently in a sequencing paradigm. Drug A then B then C
  • We need to combine active agents to give the best results, that is our next challenge
  • How are we going to afford it all?

Sartor succinctly highlighted where the rubber currently hits the road, and left the audience with plenty to reflect upon. I am sure we can expect further debate on sequencing and combination possibilities at medical and scientific meetings in 2012.

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Prostate cancer is the second leading cause of cancer death in men, so it was good news this morning when Medivation & Astellas issued a press release that showed positive data from the phase 3 AFFIRM trial for MDV3100.

MDV3100 produced a 4.8-month advantage in median overall survival compared to placebo.

The estimated median survival for men treated with MDV3100 was 18.4 months compared with 13.6 months for men treated with placebo.

MDV3100 provided a 37 percent reduction in risk of death compared to placebo (Hazard Ratio=0.631).

To put the 4.8 month survival advantage in context, this compares favorably with 3.9 months for abiraterone (Hazard Ratio =0.646), in the COU-AA-301 trial.

Positive data was expected given the sound scientific rationale behind MDV3100 and the preliminary data (abstract 4501) presented at the ASCO annual meeting this year. J Clin Oncol 29: 2011 (suppl; abstr 4501).

The drug has a high affinity for the androgen receptor (AR) that is highly expressed on prostate cancer cells.  You can read an excellent interview on Pharma Strategy Blog with Charles Sawyers, who was one of the co-inventors.

MDV3011 blocks the androgen receptor (AR) from moving into the nucleus and activating growth genes and is a more complete inhibitor of AR than bicalutamide.

One hot topic of conversation at ASCO was the potential to combine MDV3100 (androgen receptor blocker) with abiraterone acetate (Zytiga) (androgen synthesis inhibitor), thereby shutting down upstream and downstream activity of the driving receptor in advanced prostate cancer.  The scientific rationale for this appears sound, so it is likely that a combination clinical trial may well be done to test this hypothesis at some point in the future.

MDV3100 has a significant advantage over abiraterone acetate (Zytiga) in that concomitant steroids are not required. Daily steroids have their side effects.  Urologists in particular will be attracted to MDV3100 and its ease of use.

Clinical trials in prostate cancer are ongoing with a multitude of new emerging therapies including TAK-700, Cabozantinib (XL184), radium-223 chloride (Alpharadin), BPX-101, Prostvac-VF, ipilumumab, Custirsen (OGX-011), dasatinib (Sprycel), lenalidomide (Revlimid) and ARN-509 to name but a few.

It is a therapeutic area with a lot going on after very little activity for a decade. The positive interim data for MDV3100 announced today is good news for prostate cancer patients, and we await presentation of the data next year.

Medivation and Astellas plan to hold a pre-NDA meeting with the U.S. Food and Drug Administration (FDA) in early 2012, so US approval could be possible later next year.

The Oncologist Journal of the Society for Translational Oncology (STO) has published a video recording on prostate cancer that is well worth watching for those with an interest in this area.

At their Sept 8, 2011 CME symposium held in Belfast, a roundtable was held entitled “Prostate Cancer: Progress & Promise.”

Moderated by Bruce A. Chabner (Mass General/Harvard), the panelists were Joe O’Sullivan (Queen’s University, Belfast), Johann De Bono (The Institute for Cancer Research) and David Waugh (Queen’s University, Belfast).

Professor de Bono in the video comments that”

“with regards to our dream of eventually treating men with prostate cancer without castrating them, which must be our ultimate goal and curing them of cancer. I think we will have to focus on for example drugs targeting ERG or ERG signaling.”

Chabner then asks the good question of whether ERG is a druggable target?

To which De Bono replies that you can drug ERG by inhibiting PARP and references a paper by the Chinnaiyan group published in the May 2011 issue of Cancer Cell.

PARP inhibition represents an interesting area of prostate cancer research.

If you would like to know more, Sally Church, PhD has written about this on Pharma Strategy Blog.  See posts on “TMPRSS2: ERG may be a more useful marker than PSA in prostate cancer” and “Personalized Therapy for Prostate Cancer – is it possible?

In the STO video, De Bono discusses why he would like to replace bone scans in prostate cancer with another imaging modality that more accurately reflects the activity of the disease. Future possibilities include use of diffusion weighted magnetic resonance imaging and novel PET tracers.

There’s also a good discussion about Alpharadin for those interested in some anecdotal commentary on experiences with it.

Another notable comment by De Bono is his belief that “taxanes work in prostate cancer primarily by targeting androgen receptor signaling.” Taxanes have typically been thought to target mitosis.

De Bono goes on to say that clinical trial data being submitted for publication shows that patients who are refractory to abiraterone, are also refractory to docetaxel when they progress on it.  The suggestion is that there may be cross resistance between abiraterone and taxanes with a subgroup of patients who just don’t do well on androgen receptor (AR) targeting drugs.  The reason for this isn’t yet clear.

A new phase 2 clinical trial is starting soon that will look at the sequencing of abiraterone and cabazitaxel.  One group will receive abiraterone followed by cabazitaxel, the other cabazitaxel followed by abiraterone.

The Belfast STO symposium was the second in a three part series. The next one will be held during ASCO GU in San Francisco next year.

Another potentially useful meeting in this area is the February 2012 AACR workshop on “Advances in Prostate Cancer Research” chaired by Arul Chinnaiyan & Charles Sawyers.

Prostate cancer remains an exciting therapeutic area to watch with tremendous progress and promise of late.

Biotech Strategy Blog is 1 today!  I can’t believe that a year has gone by so quickly!  Before moving on to year 2, I thought a brief review might be interesting.

What have been the top posts on Biotech Strategy Blog this past year?

In terms of total visitors per post:

  1. Results from NEJM Lucentis v Avastin AMD CATT clinical trial
  2. AUA Results from PIVOT study show no benefit from radical prostatectomy in low risk early stage patients
  3. ASCO 2011 Cabozantinib (XL184) may be an exciting new prostate cancer drug
  4. Merck’s capthepsin-K inhibitor odanacatib in osteoporosis
  5. Update from AACR on new prostate cancer drugs to watch

For those who like metrics:

  • Highest number of reads per month was in May (19,927)
  • Year to date there have been 79,179 visitors
  • Most visited day was September 22, 2011 (2136 reads)

What have been some of the other posts that I enjoyed writing about?

My top 5 (not in rank order) would be:

  1. Alpharadin will be new treatment option for prostate cancer
  2. Patient advocacy session at European Hematology Assocation EHA Congress shows impact of drug adherence on outcome
  3. How nanotechnology may revolutionize the detection of traumatic brain injury using a sensor that changes color
  4. Innovation in Nanotechnology will lead to improved drug delivery, diagnostics & imaging
  5. Insights of the decade

Finally, I have produced 4 videos that you can watch on the biotechstrategy channel on YouTube.

It’s been a busy but enjoyable year. Biotech Strategy Blog is still a work in progress.  If you have enjoyed a particular series of posts or would like me explore a topic or theme in the future, do email me or post a comment.

Radium-223 (Alpharadin) is a novel bone targeted treatment for advanced prostate cancer.

At the recent European Multidisciplinary Cancer Congress in Stockholm (EMCC 2011), Dr Chris Parker from The Royal Marsden Hospital presented results of the phase 3 ALSYMPCA trial that showed both delayed time to first skeletal-related event (SRE) AND an overall survival (OS) benefit for those men with advanced prostate cancer taking radium-223.  This is the first time a product in the bone category has shown such a survival benefit – neither denosumab or zoledronic acid can claim that distinction.

Unlike the recent regulatory approvals for cabazitaxel (Jevtana) and abiraterone acetate (Zytiga), which focused on the post-docetaxel setting, the ALSYMPCA trial included not only those who had already received cytotoxic therapy, but also pre-docetaxel patients, who were unable to take chemotherapy.

As Dr Parker mentions in the interview that he kindly gave in Stockholm (the first video interview on Biotech Strategy Blog), radium-223, assuming it gains regulatory approval, will provide a new treatment option for the considerable population of men with bone metastases who may be too weak, too old or otherwise unable to take chemotherapy such as docetaxel.

Radium-223 is, therefore, potentially good news for this “neglected” population of prostate cancer patients.

In the video interview, Dr Parker talks about why he believes combining radium-223 with abiraterone acetate (Zytiga) makes sense.

He also talks about some of the challenges that radium-223 still faces, such as how to monitor treatment and work out the optimal dose.  It is hard to believe that Algeta/Bayer would undertake a phase 3 registration study of a novel bone targeted agent without any bone imaging in the protocol!

As Cora Sternberg mentioned in the educational session at EMCC 2011, in advanced prostate cancer, “80% of the disease is in the bone.radium-223 is an exciting radiopharmaceutical that is likely to be “practice changing” once approved.

That’s not to say there are not going to be challenges and issues with its commercialization.  Algeta/Bayer have a lot of work to do now that it is clearly on fast track for FDA approval next year.

Dr Parker also mentions in his interview that radium-223 is a weak alpha emitter and the radiation can be blocked by paper or glass. It therefore requires no special facilities, such as lead lined rooms, for its administration, unlike beta emitters.  The latter have been challenging commercially in the past for this reason.

However, it does require a radiopharmaceutical license, which means that community based oncologists and urologists in the United States will most likely have to refer patients to receive their injection at an approved facility where there is a nuclear medicine/radiology department or equivalent expertise.  In Europe, this is less of an issue given most cancer patients are treated in outpatient clinics associated with hospitals, whereas in the US, the majority of patients are seen in the community setting.

Despite that, it is hard to believe that radium-223 (Alpharadin) will not have a major impact on the advanced prostate cancer market if it can be commercially supplied without difficulty and the details are worked out on how to use it optimally and monitor progress. I am sure we will hear more on these issues at cancer conferences next year.

Looking at the other indications for bone targeted agents such as denosumab and zoledronic acid, radium-223 or a similar radiopharmaceutical could offer potential benefits in other tumor types such as breast cancer, were there are also skeletal related events (SRE’s) associated with treatment.

The video interview I did with Dr Chris Parker is well worth watching, and I am grateful to him for taking the time out of his busy schedule at the recent Cancer Congress in Stockholm. Since this is a first for Biotech Strategy Blog, do let me know if this is something you’d like to see more of moving forwards.

Challenges & opportunities for radium-223 (Alpharadin) in advanced prostate cancer – an interview with Dr Chris Parker 

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