If approved by the FDA in the next few months, ibalizumab for patients with multidrug resistant HIV has the potential to be a game changer for Theratechnologies (TSX:TH).
The FDA accepted ibalizumab for priority review in the summer, with a PDUFA decision date by Jan. 3, 2018.
“This approval would make us a leader in niche products for HIV patients, a market segment that is often overlooked,” Luc Tanguay, president and CEO, says in an interview with BioTuesdays. “Our sales force is ready to begin selling ibalizumab immediately after approval.”
Adds Philippe Dubuc, SVP and CFO, “Ibalizumab represents the first new anti-retroviral class of drugs for HIV in 10 years, the first non-daily treatment for HIV and the first monoclonal antibody for HIV.”
In addition, he points out that there is no drug-drug interaction and no cross-resistance with ibalizumab, which is critical among HIV patients with multidrug resistance. “Ibalizumab works by blocking entry of the virus into healthy cells, preventing the virus from replicating.”
Unlike other antiretroviral agents, ibalizumab would be administered intravenously once every two weeks.
Mr. Dubuc explains that ibalizumab binds primarily to the second extracellular domain of the CD4+ T-cell receptor, away from major histocompatibility complex 2 molecule binding sites. It potentially prevents HIV from infecting CD4+ immune T-cells while preserving normal immunological function.
According to Theratechnologies’ estimates, the U.S. HIV-infected population stands at 1.2 million individuals, of which 450,000-to-650,000 people are being treated. The European population is estimated to be of a similar size.
Mr. Dubuc says the company figures there are 20,000-to-25,000 multidrug resistant HIV patients in the U.S., of which the annual population requiring new treatment is 10,000-to-12,000 a year. “This would be our focus with ibalizumab,” he adds.
“We have already guided that, if approved, ibalizumab would sell at a premium to other HIV drugs on the market, so our target patient population would represent a $500-million total market opportunity.”
If approved by the FDA, ibalizumab would have 12 years of regulatory exclusivity in the U.S.
CIBC World Markets analyst, Prakash Gowd, rates Theratechnologies at “outperform” with a price target of $10.30. “Given its breakthrough status, as well as a clear unmet medical need addressing multidrug resistant HIV, ibalizumab may be approved in advance of the Jan. 3 PDUFA date.” The stock closed at $7.84 on Friday.
“We expect Theratechnologies stock to outperform as it runs into a possible year-end approval,” Mr. Gowd said in a September research report.
Theratechnologies, which acquired the commercial rights for ibalizumab from TaiMed Biologics of Taiwan in March 2016, already has a presence is the niche HIV products segment with its FDA-approved EGRIFTA for the treatment of HIV-associated lipodystrophy, a common side effect of antiretrovirals that causes body fat to be abnormally redistributed.
Earlier this year, the companies expanded their partnership to cover sales of ibalizumab in Europe, which Mr. Dubuc figures could start in 2020, following an application for regulatory approval. TaiMed currently is working on an intra-muscular formulation of ibalizumab, as well as a once monthly formulation.
EGRIFTA is the only FDA-approved drug shown to reduce excess abdominal fat in people living with HIV and affected by lipodystrophy. There are 15,000 severe cases of HIV-associated lipodystrophy in the U.S.
The drug, which is also approved in Canada and Mexico, has been on the market for seven years and Theratechnologies is guiding to sales of $42-million to $44-million in 2017, up from $37-million in 2016.
“EGRIFTA’s sustained cash flow has helped us acquire the commercial rights for ibalizumab and build our sales team in preparation for the launch of ibalizumab,” Mr. Tanguay contends.
Theratechnologies has expanded its sales team to 41 people to promote EGRIFTA and ibalizumab, when approved, up from 12 people in 2016. The reimbursement and medical science liaison teams also are expected to grow to 11 from four.
“Our expanded team should reach 95% of the 5,000 most important physicians in the U.S. treating HIV and key opinion leaders, up from around 1,000 physicians last year,” Mr. Tanguay suggests. EGRIFTA also would benefit from the expanded commercialization team in the U.S.
“We are also working on expanding our product portfolio through either product acquisitions or in-licensing deals,” he adds. “We would like to add one or two additional products to gain operating efficiencies from our expanded sales force.”
In a pivotal trial with ibalizumab, 82.5% of patients achieved the primary endpoint, with an average viral load reduction of 1.1 log 10 after seven days and no treatment-related severe adverse events. “The outcome was beyond our expectations,” Mr. Dubuc admits.
At the end of the 24-week trial, the mean reduction in viral load was 1.6 log 10 and 43% of patients achieved undetectable viral load, with a mean reduction of 3.1 log 10. “These results give us a very high confidence in FDA approval,” he adds.
Earlier this month, Theratechnologies presented additional positive safety and efficacy results for ibalizumab in patients who completed the 24-week Phase 3 study and continued treatment in an expanded access program.
“This long-term data reinforces the critical role ibalizumab could have for patients struggling with multidrug resistant HIV,” Mr. Dubuc points out.