A Phase 2 interventional study of ATTO-1310 and Placebo in Chronic Pruritus of Unknown Origin, sponsored by Attovia Therapeutics Inc. Not yet recruiting. Open to participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-09-22.
Sponsored by Attovia Therapeutics Inc · Phase 2, Interventional, and Treatment
The goal of this clinical trial is to assess the efficacy and safety of ATTO-1310 in patients with chronic pruritus/itch of unknown origin.
The main questions it aims to answer are:
Does ATTO-1310 treatment alleviate symptoms of itch in participants with chronic pruritus/itch? What medical problems do participants have when taking ATTO-1310 for 24 weeks? Researchers will compare ATTO-1310 to a placebo (a look-alike substance that contains no drug). Participants will be dosed with ATTO-1310 or a placebo, visit the clinic for checkups and tests, and keep a diary of their symptoms.
This is a Phase 2, multicenter, randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the efficacy and safety of ATTO-1310 in adults with chronic pruritus/itch of unknown origin (CPUO). Participants with CPUO will receive one of three induction treatments (low dose ATTO-1310, high dose ATTO-1310, or placebo) for 12 weeks. Following induction, participants will be assessed for response to treatment. Response to the 12 week induction treatment will determine their treatment progression for the maintenance period. Responders will be re-randomized to one of 4 ATTO-1310 active treatment regimens (high or low dose combined with frequent or infrequent dosing). Non-responders and participants who received placebo during the induction period will be assigned to receive a high dose high frequency ATTO-1310 regimen for the maintenance period through 28 weeks. Participants will be followed for safety through week 36.
490 studies on the registry are indexed under Pruritus; 93 are open to participants now.
This study's planned enrollment of 300 is above the median of 60 across 422 interventional studies indexed under Pruritus.
Browse Pruritus studies →Attovia Therapeutics Inc is the lead sponsor of 4 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ATTO-1310 high dose induction
Drug: ATTO-1310
ATTO-1310 low dose induction
Drug: ATTO-1310
Placebo induction
Drug: Placebo
ATTO-1310 high dose high frequency maintenance
Drug: ATTO-1310
ATTO-1310 high dose low frequency maintenance
Drug: ATTO-1310
ATTO-1310 low dose high frequency maintenance
Drug: ATTO-1310
ATTO-1310 low dose low frequency maintenance
Drug: ATTO-1310
ATTO-1310
Placebo preparation to match ATTO-1310 dose
≥4-point improvement from baseline in Worst Itch Numerical Rating Scale (WI-NRS) at Week 12 (WI-NRS4 response)
Participants achieved a response if their WI-NRS improved 4 or more points from baseline on a scale ranging from zero (no itch) to 10 (worst possible itch). The baseline is calculated as the average in the final week prior to Day 1. The WI-NRS4 response endpoint at Week 12 is calculated as the average of the daily WI-NRS during Week 12 visit relative to the baseline average WI-NRS.
Time frame: Baseline and Week 12
WI-NRS4 response at Week 4
Participants achieved a response if they had an improvement of at least 4 points on a scale ranging from 0 (no itch) to 10 (worst possible itch).
Time frame: Baseline and Week 4
≥5-point improvement from baseline in WI-NRS (WI-NRS5 response) at Week 4
Participants achieved a response if they scored a 5 or more point improvement from baseline on a scale ranging from 0 (no itch) to 10 (worst possible itch).
Time frame: Baseline and Week 4
≥5-point improvement from baseline in WI-NRS (WI-NRS5 response) at Week 12
Participants achieved a response if they scored a 5 or more point improvement from baseline on a scale ranging from 0 (no itch) to 10 (worst possible itch).
Time frame: Baseline and Week 12
WI-NRS <2 (WI-NRS<2 response) at Week 4
Participants achieved a response if their WI-NRS score was less than 2 at Week 4
Time frame: Week 4
WI-NRS <2 (WI-NRS<2 response) at Week 12
Participants achieved a response if their WI-NRS score was less than 2 at Week 4
Time frame: Week 12
Patient Global Impression of Severity (PGI-S) of pruritus of "none" or "mild" at Week 4
Participant's impression of severity of itching over the past 7 days on a 4-point Likert scale with the options of: none, mild, moderate, or severe.
Time frame: Week 4
Patient Global Impression of Severity (PGI-S) of pruritus of "none" or "mild" at Week 12
Participant's impression of severity of itching over the past 7 days on a 4-point Likert scale with the options of: none, mild, moderate, or severe.
Time frame: Week 12
Absolute change from baseline in weekly average WI-NRS at Week 4
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive change from baseline will indicate worsening of itch. Negative change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 4
Absolute change from baseline in weekly average WI-NRS at Week 12
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive change from baseline will indicate worsening of itch. Negative change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 12
Percent change from baseline in weekly average WI-NRS at Week 4
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive percent change from baseline will indicate worsening of itch. Negative Percent change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 4
Percent change from baseline in weekly average WI-NRS at Week 12
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive percent change from baseline will indicate worsening of itch. Negative Percent change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week1 12
Absolute change from baseline in weekly average itch-related sleep disruption NRS (iSD-NRS) at Week 4
iSD-NRS score of 0 is equivalent to "itching did not disrupt my sleep" and 10 indicates "complete disruption, I was unable to sleep because of itching." Positive change from baseline will indicate worsening of sleep disruption due to itch. Negative change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 4
Absolute change from baseline in weekly average itch-related sleep disruption NRS (iSD-NRS) at Week 12
iSD-NRS score of 0 is equivalent to "itching did not disrupt my sleep" and 10 indicates "complete disruption, I was unable to sleep because of itching." Positive change from baseline will indicate worsening of sleep disruption due to itch. Negative change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 12
Percent change from baseline in weekly average iSD-NRS at Week 4
iSD-NRS score of 0 is equivalent to "itching did not disrupt my sleep" and 10 indicates "complete disruption, I was unable to sleep because of itching." Positive percent change from baseline will indicate worsening of itch. Negative percent change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 4
Percent change from baseline in weekly average iSD-NRS at Week 12
iSD-NRS score of 0 is equivalent to "itching did not disrupt my sleep" and 10 indicates "complete disruption, I was unable to sleep because of itching." Positive percent change from baseline will indicate worsening of itch. Negative percent change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline, Week 12
WI-NRS4 response through Week 28
Participants achieved a response if they had a 4 or more point improvement in WI-NRS on a scale where zero is "no itch" and 10 is equivalent to "worst possible itch".
Time frame: Weekly through Week 28
Absolute change from baseline in weekly average WI-NRS through Week 28
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive change from baseline will indicate worsening of itch. Negative change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline and weekly through week 28
Percent change from baseline in weekly average WI-NRS through Week 28
WI-NRS score of zero is equivalent to "no itch" and 10 is equivalent to "worst possible itch". Positive percent change from baseline will indicate worsening of itch. Negative Percent change from baseline will indicate improvement. No change from baseline will indicate no improvement.
Time frame: Baseline and weekly through Week 28
Incidence and severity of treatment-emergent adverse events (TEAEs) or serious adverse events (SAEs) from baseline through end of study (EOS)
The analysis will describe the incidence of AEs and laboratory abnormalities from baseline through end of study. AEs will be coded according to system organ class and preferred term using the Medical Dictionary for Regulatory Activities (MedDRA). Their severity will be graded using the NCI CTCAE V6.0 or current version.
Time frame: Baseline through Day 253 (EOS)
No study locations are listed for this record.
Plan to share: Undecided
No publications or documents are linked to this record.
Start is estimated for Dec 2026; primary completion for Aug 2028, 20 months later.
Of 37 industry-sponsored phase 2 interventional studies under Pruritus, half reached primary completion within 14 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 21. This study's planned 20 months is above that.
Counting every sponsor, half of 52 studies reached it within 16 months; a quarter within 10 and three quarters within 31.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Attovia Therapeutics Inc