Pfizer Receives FDA Rejection on Trastuzumab, Next up Is Amgen/Allergan

When Pfizer announced that it received a complete response letter from the Food and Drug Administration (FDA), the wait for an available biosimilar to Herceptin® just got longer. According to the manufacturer, the FDA specified that the reasons for the rejection of PF-05280014 were not related to clinical questions. The rejection was not associated with manufacturing plant problems, which have tripped up biosimilar manufacturers, including Pfizer, in the past. Instead, the FDA cited the need for additional data related to “technical issues.”

The next potential team up at bat for a trastuzumab biosimilar approval is Amgen and Allergan. A decision on their biosimilar should be rendered before the end of the second quarter. To date, only Mylan/Biocon have obtained approval on this oncologic product (Ogivri™). However, the launch has been delayed by their signing an agreement with Roche, the maker of the reference product. Teva/Celltrion had received a rejection from FDA relating to manufacturing issues in early April, setting back their own marketing timetable.

Even if Pfizer did receive approval at this time, Roche had sued the company in November 2017 for patent infringement. Pfizer had elected to launch at risk with Inflectra®, despite looming legal battles with Janssen over Remicade®, so an immediate launch of their trastuzumab biosimilar could not be ruled out.

Like the situation with pegfilgrastim, gaining competition for trastuzumab is proving frustrating for payers. Obviously, it will occur, but the latest news does not alleviate payers concerns over price increases in the oncology area.

Teva and Celltrion Receive Rejections on Trastuzumab and Rituximab Biosimilars

Celltrion and its partner Teva were dealt a significant blow today, as the Korean manufacturer announced that the latest two biosimilar candidates were rejected by the Food and Drug Administration (FDA).

Celltrion logo1As first reported by Dan Stanton in the Biopharma Reporter, the FDA issued complete response letters as a result of inspection problems uncovered at Celltrion’s manufacturing facility in Incheon, Korea. Celltrion initially receive the negative inspection report in January of this year, which highlighted deficiencies in aseptic practices and processing, and failure to investigate variations in batches.Teva

Under the partners’ pact, signed in 2016, Teva would commercialize the two biosimilars. Teva has a separate concern, however, in that the same Celltrion plant cited by the FDA has been tabbed to produce its CGRP-inhibitor fremanezumab for migraine prevention. This migraine prevention antibody, which also has the potential to reach sales of $1 billion, has a PDUFA date of mid-June.

In a statement published by Mr. Stanton, a Celltrion spokesperson said, “Celltrion is making progress addressing the concerns raised by the FDA in a Warning Letter issued in January and is committed to working with the agency to fully resolve all outstanding issues with the highest priority and urgency.”

The issuance of the CRLs may be extremely poor timing for the partners. Although Mylan signed an agreement with Roche to delay the launch of its approved biosimilar version of Herceptin® until at least 2019, the other competitors have not. Amgen/Allergan expect word on their 351(k) submission within the month, and Samsung Bioepis should hear in the fourth quarter. On the rituximab front, Sandoz should receive word early in the third quarter.

Teva’s Syprine Generic Priced 14% Below Jacked Up Valeant Product Price

In an announcement that surprised few, Teva Pharmaceuticals announced that its generic version of trientine hydrochloride (Syprine®) for the treatment of Wilson’s disease will be sold for a very nongeneric price. Also unsurprising, Teva executives did not address the fact that the price of Syprine had been jacked up astronomically by Valeant Pharmaceuticals only recently, to $21,267 in 2015 froTeva Pharmaceuticals, maker of the new generic for Syprinem a mere $652 in 2010. Also, Syprine had been available since 1969.

An outrage? Yes of course, but not surprising for a number of reasons. Wilson’s disease is an extremely rare disease, on the order of 5,000 patients. At a price of $652 per person, the resulting revenue might be a paltry $3.2 million.

In preparation for launch, Teva evidently looked at its options for discounts based on the current list price, not the pricing from several years ago. This is also unsurprising. However, the discount offered is not great—$18,375 for a bottle of 100 pills.

Wilson’s disease is the result of a genetic disorder of the liver that causes hepatic cells to accumulate and store excess copper. The disease impairs the liver’s ability to excrete copper into the bile and then into the gastrointestinal tract. The copper build-up is toxic to the liver, and can cause cirrhosis and death. Ordinarily treated with d-pencillamine, patients can be intolerant to it and require additional therapy, such as trientine.

As most payers know, generic pricing today is unlike generic pricing of the past. Even relatively simple compounds, available for decades, are subject to competitive forces like number of mBiosimilars news, reviews, and reportsanufacturers and supply. However, demand seems to be the one market force that is not in play. With so few potential patients, overall demand would seem low, particularly with pencillamine already available to treat patients.

Teva’s pricing could have reflected the reality of 2010 or the reality of 2018. The company chose the latter, which so many others would also do today. If an additional generic was introduced into the market dynamic (though unlikely due to the demand), pricing (or at least net costs) could be strongly affected.

Payers hope to see this dynamic play out in the biosimilars arena as well. With a single biosimilar agent competing against the reference product, the retail cost discounts have been small. But with the introduction of additional competition, net costs (if not wholesale average costs) will fall rapidly.

Pfizer US Biosimilar Revenues Growing Slowly, Better News Internationally

According to an article posted on the Market Realist website, Pfizer’s US and global biosimilars revenues are growing, but its sales of Inflectra® remainPfizer Headquarters stunted.

In the fourth-quarter of 2017, the New York–based company posted US biosimilar revenues of $44 million—all attributable to its infliximab biosimilar. The product was launched in Q4 2016 (and gained only $4 million in revenues), but the revenue was reported to be somewhat higher than in Q3 2017. Total 2017 Inflectra revenue was $118 million.

Internationally, where Pfizer not only markets Inflectra, but its Retacrit® form of epoetin alpha and its Nivestim® brand of filgrastim, biosimilars contributed $531 million to the bottom line in 2017, an increase of 37% compared to the previous year.

There is little doubt that Pfizer’s US Inflectra revenues will continue to increase, but competition from Samsung/Merck’s Renflexis® and Janssen Biotech’s continuing heavy rebates on Remicade® should prove challenging to Pfizer. Merck has not yet reported its Q3 or Q4 sales of Renflexis, which was only launched in July 2017.

Pfizer’s second US biosimilar approval was also for an infliximab biosimilar (a legacy product from its Hospira acquisition). This agent, infliximab-qbtx, dubbed Ixifi™, was approved in December 2017 and will apparently not be launched in the US.

 

Its next big splash into the US biosimilars market may not occur in 2018. Its rituximab biosimilar (PF-05280586) met its primary outcomes measures in a phase 3 trial, as announced in January, but no target date has been yet reported for its 351(k) application to the Food and Drug Administration (FDA). However, this product may face stiff competition from Celltrion and Sandoz for their rituximab biosimilars currently being reviewed by the FDA. Celltrion is partnered with Mylan (not Pfizer) in the commercialization of its rituximab biosimilar.

Two New Trastuzumab Biosimilars Submitted for FDA Approval

The team of Mylan and Biocon may have some company in the biosimilar competition for Herceptin® (trastuzumab). Two additional partnerships announced the filing of their 351(k) applications for trastuzumab biosimilars.

Amgen and Allergan are hoping ABP 980 will have smooth sailing through the approval system. The phase 3 study in patients with early-stage HER2-positive breast cancer was completed in January 2017, with study results reported in July 2016. This study enrolled 725 patients, and yielded positive results in terms of safety, efficacy, and similarity to the originator product.

Celltrion submitted their product application for CT-P6 (Herzuma™) to the FDA on July 30 as well. Its partner Teva will distribute and market the product in the US, upon approval. The phase 3 study for this product is ongoing, but the results of the primary outcome data from 549 patients were published in June 2017. The outcomes were found to be similar to those of Herceptin.

Mylan and Biocon had submitted their biosimilar version on November 1, 2016. The FDA Advisory Committee reviewing their product gave it their unanimous support on July 13, and the final FDA decision is expected by September 3, 2017. If approved, Mylan will have at least a 9-month time advantage to get their foot in the door of a $2.6 billion trastuzumab marketplace.

This sets up a very interesting pricing dynamic. I had originally thought that this scenario might occur first with adalimumab after the patent litigation was resolved, but it is very possible that multiple biosimilars for trastuzumab may be launched first and in a very short timeframe.

Assuming Mylan gets the nod from FDA first, they have a couple of obvious paths they can travel: (1) launch with a substantial discount in an attempt to capture as much marketshare as possible before the other market entrants arrive or (2) launch with a modest (but attractive) discount in an effort to maximize their revenue while their product remains the sole biosimilar available. It will then be a guessing game as to how Amgen/Allergan and Celltrion/Teva play their turns in this poker game. With sudden market competition, such as their launches could potentially pose, payers may play a bit of a waiting game themselves, to see where the chips fall.

Biosimilar Rituximab Under FDA Review

Celltrion announced June 30, 2017 that it has submitted its 351(k) application to the Food and Drug Administration for approval of its biosimilar version of rituximab. This represents the first biosimilar application for rituximab, a monoclonal antibody to CD20.

The product, known during investigations as CT-P10, was approved in the European Union in February, and has been launched there as Truxima in late April. Clinical data have been presented on this biosimilar’s efficacy and safety in treating rheumatoid arthritis and advanced follicular lymphoma, a form of non-Hodgkin lymphoma

If approved, Celltrion will market this product with Teva in North America, which signed a partnership agreement with Celltrion in October 2016 for this biosimilar agent to treat cancer and for CT-P6 (trastuzumab). The FDA application for trastuzumab is expected to be filed this summer. It is currently partnered with Pfizer to market its product Inflectra® (infliximab-dyyb) in the US and Canada.

Also in June, Sandoz received approval from the European Medicines Agency to market its own version of rituximab, called Rixathon™.

In other biosimilar news…Coherus Biosciences, which took hits from the FDA and its investors in the rejection of its pegfilgrastim biosimilar in June, laid off 51 workers (about 30% of its workforce) in an effort to cut costs. Coherus is working towards addressing the issues outlined in FDA’s Complete Response Letter on pegfilgrastim. In its letter, FDA did not require additional clinical studies. In the meantime, Coherus still is seeking to file its biosimilar etanercept for approval in Europe later this year, and its version of adalimumab in the US in early 2018. However, John Carroll reported that Coherus’ clinical development partner on etanercept in Japan, Daiichi Sankyo, has decided to pull out because of concerns that Coherus will not be able to manufacture the product.

Are 2 Biosimilars to the Same Originator Product Biosimilar to Each Other?

In Europe, several manufacturers are marketing approved biosimilars to the same originator product. In fact, 7 manufacturers compete for the biosimilar filgrastim market, 5 biosimilar versions of epoetin are sold, and 3 biosimilars of infliximab seek marketshare from Remicade®. In the US, this situation is not a reality yet. It will be one day, however, and it raises a couple of important questions.

We know that the biosimilars are not exactly the same structurally as the originator products, but how similar may they be to each other? In other words, at some point, payers will prefer one biosimilar version of filgrastim over another one, as some do currently with Zarxio® versus Neupogen®. We can assume that with 3 filgrastim biosimilars sold in the US, payers will seek to leverage 1 against the others and make it their preferred or only available form of filgrastim available. However, is another manufacturer’s version of filgrastim biosimilar to Zarxio? We can also assume that the new manufacturer’s product has received US Food and Drug Administration approval through testing for comparability only with the originator product—not against Zarxio. How about compared with Teva’s product tbo-filgrastim (a follow-on biologic, not a biosimilar according to the regulatory and statutory rules)?

What does this mean for switching products, much less interchangeability? Is one biosimilar interchangeable with another? Based on what we know about the FDA, the answer is likely no, as the agency seems to be having difficulty devising interchangeability guidelines for a biosimilar and its originator product.

Why is this important? Consider the patient with Crohn’s disease in 2019 who changes health plans. The patient was receiving biosimilar A, and the new plan covers only biosimilar B. Maybe he or she needs to enroll in a new plan in 2020, and the reverse is true. Regardless of whether we like it, that patient may be unintentionally providing real-world evidence of interchangeability.