Agitation in Alzheimer's Disease - An Unmet Need Pt 2

We previously wrote about this unmet medical need back in 2016 here Agitation in Alzheimer's Disease - An Unmet Need. Since then, the field has narrowed with some of those companies no longer pursuing this indication for different reasons, but most likely their drug was not successful for this indication in clinical trials. With a safe and effective therapy for these patients experiencing agitation, the likelihood for them remaining in their homes becomes more favorable, as it would be easier on their caregivers, thus reducing the necessity for nursing home care. The companies still pursuing this important indication are as follows.

Axsome Therapeutics - AXS-05 completed first pivotal phase 2/3 

John Hopkins - Escitalopram first phase 3 ongoing

Otsuka - AVP-786 has not successfully completed a pivotal phase 3

Otsuka / Lundbeck - Brexpiprazole completed two phase 3's, with one showing efficacy

The path to FDA approval is especially important, due to becoming a first mover in that space and establishing your product within the medical community. The projected clinical readouts of the current clinical trials are listed in order, as follows. Brexpiprazole 4/2022, AVP-786 6/2022, , Escitalopram 8/2022, AXS-05 9/2022.

AVP-786 has completed one phase 3 clinical trial using the (SPCD) Sequential Parallel Comparison Design. The SPCD is designed to reduce the placebo effect. Avanir disclosed that one of the two doses showed significant efficacy, but the company did not go into detail whether the higher or lower dose achieved the significant efficacy. In the second clinical trial using a Parallel Group Placebo Controlled design, patients did not experience a significant improvement in agitation compared to patients treated with placebo, per Avanir press release. Thus, putting the entire Agitation in Alzheimer's Disease program in question.

Just a bit of history. The non-deuterated version of AVP-786 is known as AVP-923, which is a combination of dextromethorphan and quinidine. In a phase 2 clinical trial run by Avanir for patients with Alzheimer's disease experiencing agitation in 2014, AVP-923 was highly successful utilizing the (SPCD) clinical trial design. That clinical trial success, led to a $3.5 billion buyout of Avanir from giant Otsuka.

Understanding how AVP-786 ended up in Otsuka's hands, you have to go back several years when Concert Pharmaceuticals obtained a patent for the deuterated version of AVP-923, and licensed that version known as AVP-786 to Avanir, who later was acquired by Otsuka. The successful AVP-923 combo of 20mg dextromethorphan, and 10mg quinidine had a potential safety drawback known as QTc prolongation which may have become worrisome to the FDA for this elderly patient population. One of the goals of the deuterated version was to lower the quinidine inhibitor dose down from 10 mg to 4.9 mg as shown in a comparison of exclusion's between AVP-923, and AVP-786 clinical trial design here AVP-923 and AVP-786. 

There is one other issue to consider regarding AVP-786. When Concert Pharmaceutical's provided deuteration to AVP-923 and achieved patent, did the composition of AVP-786 get modified from the original in any way? We could only find one research article that may answer that question, here Deuterated (d6) - dextromethorphan elicits antidepressant effects in mice. This research suggests that AMPA, and Sigma 1, receptor targets of deuterated DM may differ from DM in their small animal study as quoted The data suggests d6-DM has anti-depressant like effects, though it may be recruiting different molecular targets and/or acting through a different mix or ratio of metabolites from regular DM. Perhaps that could be the performance difference between AVP-923 performing so well in the phase 2 clinical trial, and later AVP-786 not highly successful so far in clinical trials with a similar patient population. With limited research, we take that as speculation.

What's important to keep in mind, is that Axsome's AXS-05 is the only drug which the FDA has granted, Breakthrough Therapy Designation (BTD) for this indication. We'll continue to monitor these clinical trials to see if the companies projected completion dates remain the same or change. Axsome Therapeutics AXS-05 is well positioned to become the first safe and effective therapy for this patient population as we await the phase 3 results with their second pivotal clinical trial. Next we will write about Brexpiprazole's path forward. Thank you for reading. 

AVP-786 for Alzheimer's Agitation

Otsuka  Pharmaceutical announced results from the first phase 3 clinical trial TRIAD 1 & 2, for the treatment of Alzheimer's Agitation. The Otsuka press release from 3-25-19 is here AVP-786.  The results from that phase 3 were deemed to be significant for one of the two doses using the Cohen-Mansfield Agitation Inventory with the SPCD design. The other phase three clinical trials will utilize the more standard parallel group, placebo controlled design. The safety profile was similar to other clinical trials which included falls, urinary tract infection, headache and diarrhea. There will be a peered-reviewed journal with a more complete look of the results to follow.
The reported significant results become a positive for Concert Pharmaceuticals who could benefit from  a royalty agreement, should the drug achieve FDA approval. The patent for AVP-786 runs to 2030 in the U.S. Thank you for reading.

AVP-786 for Neurobehaviorial Disinhibition

A new clinical trial AVP-786 was recently posted on the clinicaltrials.gov website. Avanir Pharmaceuticals (the company Concert Pharmaceuticals licensed AVP-786 to) will be initiating AVP-786 for patients who experienced a traumatic brain injury (TBI), and suffer from neurobehavioral disinhibition, including aggression, agitation, and irritability. The phase 2 clinical trial is planning on enrolling 150 patients at 17 U.S. locations. The completion date is estimated to finish in December of 2019. More importantly, this is further validation that Otsuka is committed to furthering AVP-786 for neurological indications. Concert could achieve royalties in the mid single digits to low double digits based on AVP-786 future sales. Thank you for reading.

Otsuka's Commitment to AVP-786

Otsuka a focused CNS company, and the producer of Abilify, purchased drug AVP-786 for $3.5 billion through their acquisition with Avanir on November 13, 2014.  To get a sense of just how committed the company is to AVP-786, we have to look at the clinical trials that have started since the acquisition, and compare that to the number of clinical trials the company has started with another Otsuka drug Brexpiprazole, deemed the second generation drug of Abilify, that would compete in the indications similar to AVP-786.

Clinical Trials Started Since Acquisition
(3)  Alzheimer's Agitation - U.S.        phase 3
(1)  Residual Schizophrenia                phase 2
(1)  Disinhibition                                   phase 2
(1)  Alzheimer's Agitation - Japan     phase 3

Ongoing Trials With AVP-786
(1)  Treatment Resistant Major Depression Disorder  phase 2

New Otsuka Clinical Trials with Brexpiprazole
(0)
The company was previously in clinical trials prior to the acquisition of AVP-786, for Alzheimer's Agitation, MDD, and Schizophrenia as co- partner with Lundbeck.  But has not initiated anything new since agreeing to acquire AVP-786 from Avanir late 2014.  

Bottom Line:  Some significance into the timing of initiating clinical trials, may help us identify a companies priority in their clinical pipeline.  Thank you for reading.
 

Avanir Initiates (TRIAD) for Alzheimer's Agitation

Today it was announced that Avanir Pharmaceuticals (Otsuka) has initiated what they call their TRIAD clinical programs.  The clinical trials will utilize AVP-786 for the treatment of agitation in patients with Alzheimer's disease.  There will be two parts to the initial TRIAD program, Triad-1 which has been initiated, and Triad-2, which will be initiated in 2015 also. The clinicial trial should last around two years.  
  
TRIAD-1  NCT02442765
Dosing will be (DM/Q)  18/4.9 mg, or 28/4.9 mg over 12 weeks, and enroll 380 patients.
TRIAD-2   NCT02442778
Dosing will be (DM/Q)  28/4.9 mg, over 12 weeks, and enroll 325 patients.

Avanir also announced that the company has received "Fast Track" for this indication, and that AVP-786 used for their phase 2 clinical trial as adjunct for major depression disorder, will complete enrollment by the end of 2015.  

Bottom Line:  
The TRIAD program that has been announced today, is a big commitment to drug AVP-786, not only for agitation in Alzheimer's, but also adjunct for major depression disorder, residual schizophrenia, and disinhibition syndrome.  Thank you for reading.  
 

AVP-786 for Treatment of Disinhibition

The number of clinical trials utilizing Avanir / Otsuka NMDA modulator drug AVP-786 is increasing with each quarter. The number now stands at six with the addition of the latest posting at Clinical Trials.gov that pertains to Disinhibition Syndrome here Treatment of Disinhibition. There is not a drug specifically approved for this indication, or Frontal Temporal Dementia (FTD) that I can find. The main inclusion into the trial is as follows.

• Documented diagnosis of a Neurodegenerative Disorder including frontotemporal dementia, Alzheimer's disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), dementia with Lewy bodies (DBL), vascular cognitive disorders, or Huntington's disease, at least 3 months prior to Baseline.

This is a very broad inclusion into this phase 2 clinical trial, with only 12 patients aged 50-90 being recruited.  In general the patient must have some sort of Neurodegenerative Disorder.

Bottom Line:  It's easy to see why Otsuka bought Avanir Pharmaceuticals for $3.5 billion in 2014. They see the potential for NMDA drug AVP-786, and it's use for many indications. Thank you for reading.  
 

Rexulti & AVP-923 Safety Profile Comparison

There is not an FDA approved drug for the treatment of agitation in patients with dementia of the Alzheimer's type.  Otsuka Pharmaceuticals has a total of five phase 3 clinical trials that have been in progress, or about to start.  The two drugs that are addressing this indication are Rexulti (Brexpiprazole), and AVP-923 (AVP-786). Rexulti is a joint 50% ownership between Lundbeck and Otsuka.  AVP-923 (AVP-786) is 100% owned by Otsuka, with a milestone and royalty licensing agreement with Concert Pharmaceuticals.  The side effect comparison between Rexulti and AVP-923 is below.

Rexulti (Brexpiprazole)
In clinical trials here phase 3 Schizophrenia, the 2 mg group of Rexulti exhibited the following side effect profile.
Insomnia 13.4%
Headache 9.3%
Agitation 8.6%
In clinical trials here phase 3 Adjunctive Major Depression, the 2 mg group of Rexulti exhibited the following side effect profile.
Weight Increase 8.0%
Akathisia 7.4%

AVP-923 (AVP-786)
In a phase 2 clinical trial for patients with agitation of the Alzheimer's type, the following side effect profile was exhibited.
Falls 8.6%
Diarrhea 5.9%
Urinary Tract Infection 5.3%

Falls had a baseline skew, that had more patients in the treatment group (17.2% to 12.6%) and 25% more patient-day exposure to AVP-923 than placebo, noted here JAMA DM/Q Phase 2 Alz. Agitation.  In addition from that phase 2 clinical trial, there were no new cardiovascular safety signals and no clinically significant changes in QTc observed in the study.  These results above are consistent with several other clinical trials that Avanir has run with AVP-923, for traumatic brain injury, or stroke here Prism II, with diarrhea being the most commonly reported adverse event.

Bottom Line:  Otsuka has advanced the deutered version of AVP-923, (known as AVP-786) into three phase 3 clinical trials for the treatment of agitation in patients with dementia of the Alzheimer's type, to begin soon.  The company also has two ongoing clinical trials in progress with Rexulti for the same patients, that started in 2013. The patent for Rexulti runs until 2027 US and until 2025 EU, the patent for AVP-786 runs until 2030 in the US, and 2028 in the EU. Thank you for reading.
              

FDA Approves Rexulti (Brexpiprazole)

Late Friday the FDA approved Otsuka and Lundbeck's atypical antipsychotic drug Rexulti (Brexpiprazole), as mono therapy for Acute Schizophrenia, and as adjunct therapy for Major Depressive Disorder. We previously wrote about Brexpiprazole here Lundbeck Clinical Trials Update .  Otsuka, the maker of Abilify has been under pressure to replace lost sales of the world's number one selling drug Abilify (Top Selling Drugs) in 2014, due to patent expiration in 2015. Rexulti (Brexpiprazole) has been the drug to replace Abilify for several similar CNS indications. Under the marketing agreement Lundbeck (co-developer and co-commercialization) will get 45% of Brexpiprazole U.S. net sales, and 50% net sales in Europe.  The patent for Rexulti runs until 2027 US, and 2025 in the EU. The label for Rexulti is below.

INDICATIONS and IMPORTANT SAFETY INFORMATION for REXULTI ^®(brexpiprazole)
INDICATIONS
REXULTI is indicated for:

• Use as an adjunctive therapy to antidepressants in adults with major depressive disorder
• Treatment of schizophrenia in adults

IMPORTANT SAFETY INFORMATION

Increased Mortality in Elderly Patients with Dementia-Related Psychosis

Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk (1.6 to 1.7 times) of death compared to placebo (4.5% vs 2.6%, respectively). Although the causes of death were varied, most of the deaths appeared to be cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. REXULTI is not approved for the treatment of patients with dementia-related psychosis.

Rexulti (Brexpiprazole) deemed the second generation Abilify, is getting a similar safety label as Abilify, even though the side effect profile between the two drugs varies, with Rexulti showing improvement in some areas such as akathisia.  It will be interesting to see what kind of label AVP-786 gets for the Treatment of Agitation in Patients with Dementia of the Alzheimer's Type.  AVP-786 is about to enter phase 3 clinical trials in September. Thank you for reading.