Tag Archives: drug development

Olaparib for resistant prostate cancer


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In what is the first (and hopefully one of many) example of using modern genomic methods to match treatments to the molecular defects in prostate cancer, the FDA has just granted “breakthrough designation” to olaparib, a drug made by AstraZeneca. This followed a publication in the NEJM with nearly as many authors as patients, illustrating the power of team science and international collaboration.

Cancer cells develop numerous mutations that provide them with the ability to divide, metastasize, escape immune surveillance and so forth. One of the drivers of this mutation cascade is genetic instability, in part due to the accumulation of mutations that keep the cells from correcting DNA alterations. These mutations in DNA-repair enzymes can leave the cancer susceptible to additional inhibitors of DNA repair, one of which is PARP, an enzyme found in the nucleus that detects DNA strand breaks and initiates repair. When olaparib interferes with this enzyme, cells can become so genetically unstable they die.

In the TOPARP-A trial, 50 patients who had castrate resistant prostate cancer and had progressed on second generation anti-androgen treatment and docetaxel were given olaparib. 16 of 49 evaluable patients responded, however the exciting finding was that because these patients participated in the clinical trial and allowed the investigators to biopsy their tumors, it was possible to relate response to the presence of defects in the DNA repair genes. For this subgroup, 14 of 16 responded, indicating that using the repair defects as a biomarker you could predict high response rates, while at the same time, patients without such genetic defects had a much lower response rate (2/33). There is an excellent video that illustrates the results accompanying the publication that you can find by clicking here.

Although this is terrific news for prostate cancer patients, it brings a number of challenges. Testing for genetic mutations is a growing (and somewhat expensive) process. When compared to giving patients a drug that predictably won’t work, however, it can be very cost effective. Second, when you biopsy a tumor, the results can vary depending on where you biopsy as I discussed in this previous blog. “Liquid biopsies” of circulating DNA or tumor cells may provide some help in meeting this challenge.  Third, responses to targeted therapies such as olaparib tend to be rather short-lived, as the cancer cells continue to mutate to find ways around the new agent. The hope would be that combining a targeted treatment like olaparib with an immune approach might bring more prolonged responses. Finally, we must find a way to deal with the extraordinary costs of the new oncology drugs. The actual cost of olaparib is $13,440/month according to this article in the ASCO post. I have previously opined on this issue and invite you to join the discussion by clicking here.

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Prostate Drug Costs


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Most readers will have seen something in the popular press over the last 6 months regarding the increasing awareness of oncology drug costs. For example, there have been very nice commentaries in the New England Journal of Medicine like this one, that deals with the cost of nivolumab, a PD-1 pathway inhibitor that is approved for treating melanoma and may show promise in a number of other cancers like kidney cancer. The final paragraph is telling:

Hand clapping for science is now inextricably linked to hand wringing over affordability. Drug prices are increasing more rapidly than their benefits, and the growth in spending on drugs has started to outstrip growth in other areas of health care. Addressing this problem requires realizing that cost-effectiveness assessment — a step that we are not even ready for in the United States — has limitations when one considers the price of the comparator and the impact on overall budgets.

I have opined elsewhere in this blog site on the excitement over the new immune-stimulating drugs that show promise. Indeed, some may be able to improve the response to prostate vaccine approaches. The question is whether we can afford all of these drugs, who decides, how they decide, and what methods they use. In the past, a QALY (quality adjusted life year) has been used to benchmark some of the things we do in medicine. In a nice NEJM perspective article, the classic “$50,000/QALY” benchmark was reviewed, but the authors suggested that given medical progress and inflation, a more realistic number might be as high as $100,000 or $150,000. The costs of the newer prostate cancer drugs such as abiraterone, enzalutamide, sipuleucel-T, cabazitaxel etc. have not escaped attention. Medscape had an article on this over 2 years ago. I am no expert on Markov models, differing ways to evaluate cost-effectiveness, and the economics of medicine. But as a simple way of explaining the challenge, how much is cisplatin, a cornerstone of curative treatment for testis cancer, the number one cancer of young men in their 20’s worth? If you can answer that, then how much would it be worth if you were using the same drug as a third line to treat prostate cancer, where responses are rare except in the case of the small cell variant, but no one is cured? In the case of the young testis cancer patient, many years (or QALY’s) are achieved while in the case of even the “sensitive” form of prostate cancer, the benefit would be in months at best. Should testis cancer patients have to pay huge sums because it works so well for them and prostate cancer patients less? And how do we figure in the drug development costs in a fair way that retains a financial incentive for the pharmaceutical companies and researchers to keep working for new discoveries?

Added to this is my own experience when I have described using a highly expensive (sometimes toxic) drug to a patient with well-known, very limited (but measurable, approved, and “covered” by Medicare or insurance) benefit. Often when I am honest and say, “this may help for a while, but is not a cure,” to a patient who may have very few symptoms at all but is progressing based on a rising PSA, the reply will be “what choice do I have”? That is a great question. If someone else is paying for some very expensive drug, why not try it? Although I know that the ethicists feel “my wishful answer” is unethical, I would like to be able to say something like this: “Well Mr. Smitherton, Medicare has decided that if you would rather take the money and apply it to your grandchild’s college fund, they will be willing to divert the costs (or some proportion of them) to that cause because ‘we’ [society] feel that should be your choice, rather than having us pay for a relatively ineffective, expensive drug if you don’t think it is worth it, or if you value his/her education over a few months of additional life span.” If wishes were horses, beggars would ride. And if I was qualified in ethics, I would probably not be writing this. That’s my 2¢ – or maybe it should be my $20,000??

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Support the petition for reasonable drug prices.


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I hereby confess that when it comes to healthcare, I am somewhat of a socialist. I feel healthcare should be a right, not a privilege. However, I would draw some sort of line for certain conditions, even including cancer. For example, there is little evidence that 3rd or 4th line therapies for many cancers have any significant impact on survival, yet we often prescribe them for patients who are healthy enough to try them with the rationale that “even a 5% chance” is worth taking. Weighing that 5% chance against a 25% chance of causing further toxicity and NOT improving someone’s quality of life requires sensitive counseling and is part of the “art” of practicing medical oncology. We already don’t pay for cosmetic surgery when it comes to face-lifts, but breast cancer patients enjoy coverage for breast reconstruction, while men with erectile dysfunction following surgery or radiation don’t have coverage in most instances for ED drugs or other treatments. Thus, there is a lot of room for improvement in our health care system. The ACA is not the best answer, but it may provide at least a start through inclusion of coverage for end-of-life counseling and funding of the Patient-Centered Outcomes Research Institute. We should not tolerate having the most expensive health care system on the planet that delivers care that ranks dead last in the developed world.

One of the most disturbing trends in our broken health care system has been the introduction of numerous new cancer drugs that have (in some cases) remarkable activity but are priced beyond any reasonable value consideration. Trying to decide about “value” itself is an extremely challenging undertaking. Numerous articles like this one have proposed guidelines through which value might be better quantified. Now a group of oncology physicians have published a position statement regarding cancer drug costs that deserves your attention. They propose a number of solutions that could help the cancer community move toward the kind of progress made by the AIDS community when they were faced with similar challenges of highly expensive drugs. You should read the whole article to see the context, but their enumerated suggestions are as follows:

If you agree that these actions should become a part of our national discussion, please join me in signing the petition these thoughtful oncology leaders have started. You can click on this link to sign up, and please invite your friends to join you.

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Prostate cancer advances – The Oscars are in…


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I have been attending the ASCO led GU oncology symposium for the last 48 hours. As usual, it is somewhat of a “firehose to take a drink” scenario with great presentations, more posters than you can possibly absorb, and lots of progress on many fronts. I remember when there were only about 50 “GU oncologists” 30 years ago, and about 300 attended this meeting when it first started. The attendance is 2900 from around the world. As one of my patients likes to put on his blog, “help is on the way”, which is really encouraging. There is more to report than I can possibly do in a blog, so I will just poach from existing internet info and highlight some of the existing posts.

Chemotherapy for newly diagnosed patients with many metastases is now the “standard of care” following the CHAARTED trial that I previously discussed. The French completed a smaller study that did NOT show an advantage for using docetaxel “up front”. There are a number of possible explanations that you can read about here. Not mentioned in that discussion is a moderately complex explanation that came up in the discussion period after the presentation. It turns out that ADT leads to changes in the way docetaxel is metabolized. Thus, the approval of the use of docetaxel in the setting of castrate resistant pca (which has been the usual situation) is different from using docetaxel when a patient hasn’t been on ADT for very long. The French study had more toxicity, and potentially more delays in treatment but the relationship of when the ADT started may have been different from the CHAARTED trial and could explain differences. Nevertheless, CHAARTED was larger and I think the trial still sets a new standard.

The optimal duration of ADT when given to enhance radiation was covered extensively by Anthony D’amico. The details are pretty complex, and if you want to wade into these weeds, you can start with his JCO article. Basically, the issue is this: ADT helps radiation therapy be more effective. But it is clearly “toxic” in terms of quality of life, and possibly increases cardiac events in men with a history of heart disease. Both of these factors make it questionable to use at all in men with “low intermediate risk” disease, and we would certainly like to use for as little time as necessary to get the benefit so that quality of life is preserved. In the higher risk patients there is no doubt that it should be used, but the duration is still up for discussion, with the existing “definitive” study showing 36 months is better than 6 months. Generally in such patients, I go over this, and then say, “let’s see how well you tolerate ADT before we reach any final decision on how long to continue”. Certainly a minimum of 4 months is required, and possibly the longer the better, but I suspect 36 months is too long. And really no one has taken into account the factor that a single 3 month leuprolide injection can result in quite variable overall duration of testosterone suppression with older men generally not recovering as quickly as the younger guys.

On the vaccine front, data were presented on Prostvac in combination with the immune checkpoint inhibitor, ipilumimab. The exciting findings in using checkpoint inhibitors (including the PD1 and PDL1 drugs in other diseases has lagged somewhat in prostate cancer because it isn’t clear that the ongoing immune response is very good. (For example ipi alone in prostate cancer didn’t work) However, given the promising data on using Prostvac in the phase II trials, the phase III trial has now accrued all of its patients and we await the result. Meanwhile, investigators have begun to look at whether adding a checkpoint inhibitor to a vaccine can make further headway. An abstract presented at the meeting reported on the early results of this approach. Dr. Singh from the NCI GU oncology team stated “In a Phase 1 combination study of 30 mCRPC patients with similar baseline characteristics (predicted median OS of 18.5 months), patients were treated with PROSTVAC plus escalating doses of ipilimumab. The observed median OS was 31.3 months for all dose cohorts and 37.2 months for patients treated at 10 mg/kg based on updated overall survival data. Furthermore, there appears to be a tail on the curve with approximately 20% of patients at 10 mg/kg alive at 80 months.” This certainly means that if the Phase III trial of Prostvac leads to approval by the FDA, there will quickly be more studies of how to make this vaccine even more effective.

Many of us have been talking at this meeting and other recent meetings about a “kitchen sink” approach combining all of the newer drugs to get a biochemical complete response in metastatic patients and then using a vaccine to “clean up” the microscopic disease that is clearly left behind. I’m looking forward to these trials which are probably a year or two away, but optimism abounds. Example: A new man with metastatic disease who had prostate radiation or surgery 5 years ago is found because of a rising PSA. We do fancy scans with C-11 acetate or choline, radiate the known disease, treat with second generation ADT plus docetaxel x 6, then use the vaccine with a checkpoint inhibitor. (read that link by the way – terrific) Given that prostate cancer is generally a “slow cancer”, there are many men alive today with lurking metastases that will only become apparent 5 or 10 years from now. These guys will almost certainly be able to take advantage of such an approach – never fast enough, but never more promising prospects, either.

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The challenge of new drugs


Long long ago, I had just finished my fellowship in medical oncology and moved from Boston to Denver. In the lab, I was working on an obscure enzyme that seemed to differentiate leukemia from normal cells, cystathionase. In the clinic, we had very few clinical trials, so I wrote a cold call letter to 10 different pharma companies. Only TAP Pharmaceuticals wrote back. They had developed a new drug that ultimately became Lupron, and we had the opportunity to participate in all of the trials that led to its approval. The biggest shock I had in that experience was the cost that TAP charged, although by today’s drug standards, I guess it was a bargain.

A few years later, we were asked to participate in the trials that led to approval of goserelin, or Zoladex™. My anticipation was that if approved, the costs of both drugs would drop as the companies competed for market share. It didn’t happen. There are of course many reasons, the greatest being that physicians generally didn’t worry too much about how much a drug cost….insurance or Medicare picked up the cost. Instead, the two companies competed with favors to physicians. Many urology practices made huge profits from the mark-ups in drug, and ultimately TAP paid one of the largest fines in history for unethical practices.

With the new drugs, notably abiraterone and enzalutamide, there have yet to emerge competitors that are approved. The drugs both work on the androgen stimulation axis, but via different mechanisms I have covered elsewhere. Each is incredibly expensive, around $6000/month. But beyond the above “no compete” story, I am concerned that competitors may never even reach the “podium” to provide competition (whether financial or in marketing). The reason is that prostate cancer is inherently slow and that the FDA requires survival as an endpoint. Add to this, that if a patient is on a new drug with some modest improvement in survival, this can be overwhelmed by patients going onto one of the other actives after they progress (rising psa or new lesions on scans) that will make it difficult to see the contribution to survival by “new drug”. The placebo patients will benefit equally from the new approved drugs. This may well be what happened to orteronel, (TAK 700) that was reported to have missed its survival endpoint needed for approval at last weeks ASCO GU meeting. Although I would  like to think that approval would result in lower prices for all of the new drugs, the experience described above makes me skeptical. So how about a new approval process? If a drug is clearly (and I’m not judging whether orteronel is or isn’t the equal of abiraterone here) a comparable, approve it IF the company will provide its “me too” drug to patients at a substantially reduced price. There would still be an advantage for companies to race to be “first to market” and they would enjoy the high profits of being the winner with a new category of drug. On the other hand, competitors could still expect to enter the arena and do well, perhaps competing for first place by price rather than some minor difference in side effects or similar. HOWEVER…this assumes that Medicare, physicians, and insurers would prescribe based on cost savings, something currently forbidden by Medicare but allowed in the VA administration.  And then there would be the fancy TV ads trying to convince patients one drug is better than another based on sitting in bath tubs and looking at sunsets….

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