Dr. Andrew Merron, Executive Director, DRG Oncology
A true milestone event in oncology occurred this September 2018 when the FDA approved a novel PD-1 inhibitor – Sanofi and Regeneron’s Libtayo.
Dr. Andrew Merron discusses:
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Hello, and welcome back to DRG oncology video series. As everybody knows there's never a dull moment in the landscape of immuno-oncology, but a really revolutionary and milestone event occurred at the end of September. On the 28th of September, the FDA approved a novel PD-1 inhibitor, Libtayo. Sanofi and Regeneron's cemiplimab or Libtayo is the first and only the approved therapy for the treatment of cutaneous squamous cell carcinoma.
Specifically, Libtayo is approved for metastatic patients and also locally advanced patients who are not eligible to receive curative treatment through radiotherapy or surgery. Libtayo is the third approved PD-1 inhibitor by the FDA. It is the sixth FDA approved PD-1 or PD-L1 inhibitor. And overall it's the seventh approved immune checkpoint inhibitor.
Now, as this table shows, immune checkpoint inhibitors are a proof of many oncology indications now. Immune checkpoint inhibitors were approved for 14 oncology indications and multiple patient sub-populations within that group. So, the significant development and investment in this class is certainly starting to pay off. Libtayo was approved on the basis of two non-randomized clinical trials. These trials enrolled 108 patients. The objective response rate was 47.2%, and the complete response was relatively low, just 3.7%.
But if we're thinking about the efficacy of immune checkpoint inhibitors it's the duration of response which is really important. And similar to other immune checkpoint inhibitors, the duration of response for Libtayo was good. The majority of patients who did achieve a response had a duration of response of at least six months. The uptake is probably going to be quite rapid in cutaneous squamous cell carcinoma patients, but bear in mind that the treatable pool is relatively small because metastatic cutaneous squamous cell carcinoma is comparatively rare. But there is an opportunity for Libtayo in multiple other oncology indications.
When we're thinking about competition in the immune checkpoint inhibitor marketplace, I tend to think about this in three different ways. The first is, among currently approved drugs in currently approved indications. The second way I think about it is for current drugs when they're looking for label expansions and new indications. And the third way is looking at novel emerging immune checkpoint inhibitors. So, if we're thinking about current drugs in already approved indications, I think non-small cell lung cancer is a great example to dwell on a little bit more because of the significant competition in this market and because of the high commercial opportunity.
So, data from DRG oncology shows that the early lead from Opdivo has faltered recently over the last year and a half or so. And this is really down to the significant uptake of Keytruda. Now, Keytruda is in fact the dominant immune checkpoint inhibitor in non-small cell lung cancer. And this is down to the good clinical trial design, the excellent efficacy, the good commercialization, and the successive label expansions that Keytruda has achieved in non-small cell lung cancer. And we're tracking this throughout real-world data on a monthly basis. And we can see how Keytruda is performing and is doing very well.
Now, this data from DRG oncology's clinical trial monitor, highlights the range of indications for which currently approved checkpoint inhibitors are undergoing clinical development. And it's significant because there is many indications for which these drugs are being evaluated. This really highlights the broad applicability for new checkpoint inhibitors. Also, you can see the significant development activity in non-small cell lung cancer in particular, but I want to really highlight the range of indications here.
Now, cutaneous squamous cell carcinoma, the indication for which Libtayo has just approved, isn't on here because I've just plotted the top 40 indications, but indeed there are ongoing trials that we're monitoring for currently approved immune checkpoint inhibitors in cutaneous squamous cell carcinoma. And we're updating our data on a weekly basis to understand the competitive dynamics in this field.
Thank you for joining today's session, I hope you found it interesting and insightful. For more insights on the immune checkpoint inhibitor landscape and other data in oncology, be sure to check out drgoncology.com and sign up to receive regular updates. Take care, until next time.