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Catalyst Pharmaceuticals Inc (NASDAQ:CPRX)Q1 2019 Earnings CallMay. 13, 2019, 8:30 a.m. ETContents: Prepared Remarks Questions and Answers Call Participants Prepared Remarks:
Greetings. Welcome to Catalyst Pharmaceuticals First Quarter 2019 Financial Results Conference Call. At this time, all participants are in a listen-only mode. A question-and-answer session will follow the formal presentation. (Operator Instructions) Please note this conference is being recorded.
I will now turn the conference over to Alicia Grande, Chief Financial Officer. Thank you. You may begin.
Alicia Grande -- Vice President, Chief Financial Officer and Treasurer
Good morning, everyone, and thanks for joining today's conference call. On today's call, we have Pat McEnany, Chairman and Chief Executive Officer; Dr. Steve Miller, Chief Operating Officer and Chief Scientific Officer; Dr. Gary Ingenito, Chief Medical Officer and Head of Regulatory Affairs; and Dan Brennan, Chief Commercial Officer.
Before we begin, I would like to remind you that in the following comments and in the Q&A session, we will make statements about expected future results, which may be forward-looking statements for purposes of the federal securities laws. These statements relate to our current expectations, estimates and projections and are not guarantees of future performance. They involve risks, uncertainties and assumptions that are difficult to predict and which may prove not to be accurate. Actual results may vary. These forward-looking statements should be considered only in conjunction with the detailed information contained in our SEC filings, including the risk factors in our Annual Report on Form 10-K.
At this time, I will turn the call over to Pat.
Patrick J. McEnany -- Co-Founder, Chairman, President and Chief Executive Officer
Thank you, Ali. Good morning everyone and thank you for joining us on our first quarter 2019 results conference call. First quarter of 2019 was a very important one for us, beginning with the mid-January launch of Firdapse for adult patients with Lambert-Eaton Myasthenic Syndrome or LEMS. With the launch of Firdapse, we are now starting to deliver on our mission to make a positive and meaningful impact in the lives of patients suffering with rare neuromuscular diseases like LEMS, as well as driving value for Catalyst shareholders.
We have heard from doctors and patients alike that have -- since the availability of Firdapse has helped many to access treatment for the first time. Before Firdapse's approval, many patients were poorly served with very limited access. Under a diagnosis by physicians was the norm. We've taken a full approach on generating awareness, educating the patient population, and equipping all docs nationwide with what they need to provide this life altering medicine to LEMS patients.
We'll spend most in today's call discussing our first quarter results and metrics that we believe support that our launch of Firdapse has been a success by any measure. However, it is important that I first discussed the news from last Monday of the FDA's decision to approve in NDA from Jacobus Pharmaceuticals for an amifampridine product to treat pediatric LEMS patients, 6 to less than 17 years of age. One of the press reports regarding the approval stated that there are less than 15 pediatric LEMS patients in the United States. We believe that this action by the FDA may affect whether pharmaceutical companies will invest in the development of other therapies to treat patients suffering from ultra-rare orphan designated diseases. Our management and legal teams along with our regulatory advisors are actively assessing the impact of the decision on our Company. The legality of the FDA's actions and our options going forward. We will have more to say about this subject in the very near future.
Turning back to our business activities. We're continuing to run our last business according to our plans as designed for 2019. I'd like to remind everyone on this call today about the three strategic priorities that we have previously highlighted: the successful execution of our Firdapse launch plan; the continued execution of our clinical pipeline evaluating Firdapse for other rare-neuromuscular diseases; and our development plan for a longer acting, potentially more convenient and patient prudently formulation of Firdapse.
First, we are pleased with the success that we have had with the initial launch of Firdapse for LEMS, particularly in our initial phase of transitioning patients on investigational drug to commercial Firdapse. We are encouraged by the strong momentum that we've experienced in the first few months of the launch, including the breadth of prescribers and the number of patients initiating therapy with commercial Firdapse. We are probably most gratified by the number of LEMS patients that have come into our program who were previously naive to any form of amifampridine. Having said that, we are still in the early stages of our launch in learning more every day about our patients needs and the patients journey to a definitive diagnosis, and as a result, we'll have a great deal of work in front of us to achieve our longer-term goals.
As we have reported, we recorded $12.4 (ph) million in net revenue for the first quarter and an operating loss of $645,000. As we have previously stated, we expect by the end of the second quarter to have most of all of the estimated 300 LEMS patients, they were participating in both early access programs to be transitioned to commercial Firdapse.
As we progress into the second half of this year, we expect a steady, slower pace of patient enrollments from this very meaningful base that is being established. Previously I've stated that we expected to be in a position to provide you with revenue guidance for the full year 2019 on today's call. In light of the FDA's decision last week with the approval of a different formulation of amifampridine for pediatric use, we will need to fully assess the impact of this approval before we can give you guidance for the full year.
But I can tell you today, as we go as we are about halfway through the second quarter that we expect to substantially increase revenue in this quarter over the quarter ending March 31, 2019. Ali will be providing more information on the financial results for the first quarter shortly.
I'll now take a minute to provide you with some of the launch key performance indicators that we monitor on a daily basis to track our analytics. As of last Thursday, May 9th, we had 409 LEMS patients that had been prescribed Firdapse by their physician. 380 LEMS patients are now active on Firdapse, 214 unique prescribers that have written at least one prescription. What is most gratifying again to me is the fact that there are now 81 unique patients that have been prescribed Firdapse during the past three months that previously did not have access to any form of the amifampridine. Dan will provide more details on our commercial launch activities shortly.
An important part of the successful uptake of the co